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constant</title> <meta name="description" content="Search results for: damping constant"> <meta name="keywords" content="damping constant"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button class="d-block d-lg-none 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action="https://publications.waset.org/abstracts/search"> <div id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="damping constant"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 2389</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: damping constant</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2389</span> Vibration Analysis of Pendulum in a Viscous Fluid by Analytical Methods</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Arash%20Jafari">Arash Jafari</a>, <a href="https://publications.waset.org/abstracts/search?q=Mehdi%20Taghaddosi"> Mehdi Taghaddosi</a>, <a href="https://publications.waset.org/abstracts/search?q=Azin%20Parvin"> Azin Parvin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study, a vibrational differential equation governing on swinging single-degree-of-freedom pendulum in a viscous fluid has been investigated. The damping process is characterized according to two different regimes: at first, damping in stationary viscous fluid, in the second, damping in flowing viscous fluid with constant velocity. Our purpose is to enhance the ability of solving the mentioned nonlinear differential equation with a simple and innovative approach. Comparisons are made between new method and Numerical Method (rkf45). The results show that this method is very effective and simple and can be applied for other nonlinear problems. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=oscillating%20systems" title="oscillating systems">oscillating systems</a>, <a href="https://publications.waset.org/abstracts/search?q=angular%20frequency%20and%20damping%20ratio" title=" angular frequency and damping ratio"> angular frequency and damping ratio</a>, <a href="https://publications.waset.org/abstracts/search?q=pendulum%20at%20fluid" title=" pendulum at fluid"> pendulum at fluid</a>, <a href="https://publications.waset.org/abstracts/search?q=locus%20of%20maximum" title=" locus of maximum"> locus of maximum</a> </p> <a href="https://publications.waset.org/abstracts/58354/vibration-analysis-of-pendulum-in-a-viscous-fluid-by-analytical-methods" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/58354.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">337</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2388</span> Selection of Rayleigh Damping Coefficients for Seismic Response Analysis of Soil Layers</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Huai-Feng%20Wang">Huai-Feng Wang</a>, <a href="https://publications.waset.org/abstracts/search?q=Meng-Lin%20Lou"> Meng-Lin Lou</a>, <a href="https://publications.waset.org/abstracts/search?q=Ru-Lin%20Zhang"> Ru-Lin Zhang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> One good analysis method in seismic response analysis is direct time integration, which widely adopts Rayleigh damping. An approach is presented for selection of Rayleigh damping coefficients to be used in seismic analyses to produce a response that is consistent with Modal damping response. In the presented approach, the expression of the error of peak response, acquired through complete quadratic combination method, and Rayleigh damping coefficients was set up and then the coefficients were produced by minimizing the error. Two finite element modes of soil layers, excited by 28 seismic waves, were used to demonstrate the feasibility and validity. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Rayleigh%20damping" title="Rayleigh damping">Rayleigh damping</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20damping" title=" modal damping"> modal damping</a>, <a href="https://publications.waset.org/abstracts/search?q=damping%20coefficients" title=" damping coefficients"> damping coefficients</a>, <a href="https://publications.waset.org/abstracts/search?q=seismic%20response%20analysis" title=" seismic response analysis"> seismic response analysis</a> </p> <a href="https://publications.waset.org/abstracts/57421/selection-of-rayleigh-damping-coefficients-for-seismic-response-analysis-of-soil-layers" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/57421.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">438</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2387</span> Estimation of the Effect of Initial Damping Model and Hysteretic Model on Dynamic Characteristics of Structure</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Shinji%20Ukita">Shinji Ukita</a>, <a href="https://publications.waset.org/abstracts/search?q=Naohiro%20Nakamura"> Naohiro Nakamura</a>, <a href="https://publications.waset.org/abstracts/search?q=Yuji%20Miyazu"> Yuji Miyazu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In considering the dynamic characteristics of structure, natural frequency and damping ratio are useful indicator. When performing dynamic design, it's necessary to select an appropriate initial damping model and hysteretic model. In the linear region, the setting of initial damping model influences the response, and in the nonlinear region, the combination of initial damping model and hysteretic model influences the response. However, the dynamic characteristics of structure in the nonlinear region remain unclear. In this paper, we studied the effect of setting of initial damping model and hysteretic model on the dynamic characteristics of structure. On initial damping model setting, Initial stiffness proportional, Tangent stiffness proportional, and Rayleigh-type were used. On hysteretic model setting, TAKEDA model and Normal-trilinear model were used. As a study method, dynamic analysis was performed using a lumped mass model of base-fixed. During analysis, the maximum acceleration of input earthquake motion was gradually increased from 1 to 600 gal. The dynamic characteristics were calculated using the ARX model. Then, the characteristics of 1st and 2nd natural frequency and 1st damping ratio were evaluated. Input earthquake motion was simulated wave that the Building Center of Japan has published. On the building model, an RC building with 30×30m planes on each floor was assumed. The story height was 3m and the maximum height was 18m. Unit weight for each floor was 1.0t/m2. The building natural period was set to 0.36sec, and the initial stiffness of each floor was calculated by assuming the 1st mode to be an inverted triangle. First, we investigated the difference of the dynamic characteristics depending on the difference of initial damping model setting. With the increase in the maximum acceleration of the input earthquake motions, the 1st and 2nd natural frequency decreased, and the 1st damping ratio increased. Then, in the natural frequency, the difference due to initial damping model setting was small, but in the damping ratio, a significant difference was observed (Initial stiffness proportional≒Rayleigh type>Tangent stiffness proportional). The acceleration and the displacement of the earthquake response were largest in the tangent stiffness proportional. In the range where the acceleration response increased, the damping ratio was constant. In the range where the acceleration response was constant, the damping ratio increased. Next, we investigated the difference of the dynamic characteristics depending on the difference of hysteretic model setting. With the increase in the maximum acceleration of the input earthquake motions, the natural frequency decreased in TAKEDA model, but in Normal-trilinear model, the natural frequency didn’t change. The damping ratio in TAKEDA model was higher than that in Normal-trilinear model, although, both in TAKEDA model and Normal-trilinear model, the damping ratio increased. In conclusion, in initial damping model setting, the tangent stiffness proportional was evaluated the most. In the hysteretic model setting, TAKEDA model was more appreciated than the Normal-trilinear model in the nonlinear region. Our results would provide useful indicator on dynamic design. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=initial%20damping%20model" title="initial damping model">initial damping model</a>, <a href="https://publications.waset.org/abstracts/search?q=damping%20ratio" title=" damping ratio"> damping ratio</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20analysis" title=" dynamic analysis"> dynamic analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=hysteretic%20model" title=" hysteretic model"> hysteretic model</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20frequency" title=" natural frequency"> natural frequency</a> </p> <a href="https://publications.waset.org/abstracts/84895/estimation-of-the-effect-of-initial-damping-model-and-hysteretic-model-on-dynamic-characteristics-of-structure" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/84895.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">178</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2386</span> Mean Square Responses of a Cantilever Beam with Various Damping Mechanisms</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yaping%20Zhao">Yaping Zhao</a>, <a href="https://publications.waset.org/abstracts/search?q=Yimin%20Zhang"> Yimin Zhang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In the present paper, the stationary random vibration of a uniform cantilever beam is investigated. Two types of damping mechanism, i.e. the external and internal viscous dampings, are taken into account simultaneously. The excitation form is the support motion, and it is ideal white. Because two type of damping mechanism are considered concurrently, the product of the modal damping ratio and the natural frequency is not a constant anymore. As a result, the infinite definite integral encountered in the process of computing the mean square response is more complex than that in the existing literature. One signal progress of this work is to have calculated these definite integrals accurately. The precise solution of the mean square response is thus obtained in the infinite series form finally. Numerical examples are supplied and the numerical outcomes acquired confirm the validity of the theoretical analyses. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=random%20vibration" title="random vibration">random vibration</a>, <a href="https://publications.waset.org/abstracts/search?q=cantilever%20beam" title=" cantilever beam"> cantilever beam</a>, <a href="https://publications.waset.org/abstracts/search?q=mean%20square%20response" title=" mean square response"> mean square response</a>, <a href="https://publications.waset.org/abstracts/search?q=white%20noise" title=" white noise"> white noise</a> </p> <a href="https://publications.waset.org/abstracts/13060/mean-square-responses-of-a-cantilever-beam-with-various-damping-mechanisms" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/13060.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">384</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2385</span> Shock Isolation Performance of a Pre-Compressed Large Deformation Shock Isolator with Quasi-Zero-Stiffness Characteristic</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ji%20Chen">Ji Chen</a>, <a href="https://publications.waset.org/abstracts/search?q=Chunhui%20Zhang"> Chunhui Zhang</a>, <a href="https://publications.waset.org/abstracts/search?q=Fanming%20Zeng"> Fanming Zeng</a>, <a href="https://publications.waset.org/abstracts/search?q=Lei%20Zhang"> Lei Zhang</a>, <a href="https://publications.waset.org/abstracts/search?q=Ying%20Li"> Ying Li</a>, <a href="https://publications.waset.org/abstracts/search?q=Wei%20Zhang"> Wei Zhang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Based on the synthetic principle of force, a pre-compressed nonlinear isolator with quasi-zero-stiffness (QZS) is developed for shock isolation of ship equipment. The proposed isolator consists of a vertical spring with positive stiffness and several lateral springs with negative stiffness. An analytical expression of vertical stiffness of the nonlinear isolator is derived and numerical simulation on the effect of the geometric design parameters is carried out. Besides, a pre-compressed QZS shock isolation system model is established. The stiffness characteristic of the system is studied and the effects of excitation amplitude and friction damping on shock isolation performance are discussed respectively. The research results show that in comparison with linear shock isolation system, the pre-compressed QZS shock isolation system could realize constant-force or approximately constant-force function and perform better anti-impact performance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=quasi-zero-stiffness" title="quasi-zero-stiffness">quasi-zero-stiffness</a>, <a href="https://publications.waset.org/abstracts/search?q=constant-force" title=" constant-force"> constant-force</a>, <a href="https://publications.waset.org/abstracts/search?q=pre-compressed" title=" pre-compressed"> pre-compressed</a>, <a href="https://publications.waset.org/abstracts/search?q=large%20deformation" title=" large deformation"> large deformation</a>, <a href="https://publications.waset.org/abstracts/search?q=shock%20isolation" title=" shock isolation"> shock isolation</a>, <a href="https://publications.waset.org/abstracts/search?q=friction%20damping" title=" friction damping"> friction damping</a> </p> <a href="https://publications.waset.org/abstracts/39796/shock-isolation-performance-of-a-pre-compressed-large-deformation-shock-isolator-with-quasi-zero-stiffness-characteristic" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/39796.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">697</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2384</span> Evaluation of High Damping Rubber Considering Initial History through Dynamic Loading Test and Program Analysis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kyeong%20Hoon%20Park">Kyeong Hoon Park</a>, <a href="https://publications.waset.org/abstracts/search?q=Taiji%20Mazuda"> Taiji Mazuda</a> </p> <p class="card-text"><strong>Abstract:</strong></p> High damping rubber (HDR) bearings are dissipating devices mainly used in seismic isolation systems and have a great damping performance. Although many studies have been conducted on the dynamic model of HDR bearings, few models can reflect phenomena such as dependency of experienced shear strain on initial history. In order to develop a model that can represent the dependency of experienced shear strain of HDR by Mullins effect, dynamic loading test was conducted using HDR specimen. The reaction of HDR was measured by applying a horizontal vibration using a hybrid actuator under a constant vertical load. Dynamic program analysis was also performed after dynamic loading test. The dynamic model applied in program analysis is a bilinear type double-target model. This model is modified from typical bilinear model. This model can express the nonlinear characteristics related to the initial history of HDR bearings. Based on the dynamic loading test and program analysis results, equivalent stiffness and equivalent damping ratio were calculated to evaluate the mechanical properties of HDR and the feasibility of the bilinear type double-target model was examined. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=base-isolation" title="base-isolation">base-isolation</a>, <a href="https://publications.waset.org/abstracts/search?q=bilinear%20model" title=" bilinear model"> bilinear model</a>, <a href="https://publications.waset.org/abstracts/search?q=high%20damping%20rubber" title=" high damping rubber"> high damping rubber</a>, <a href="https://publications.waset.org/abstracts/search?q=loading%20test" title=" loading test"> loading test</a> </p> <a href="https://publications.waset.org/abstracts/127258/evaluation-of-high-damping-rubber-considering-initial-history-through-dynamic-loading-test-and-program-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/127258.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">123</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2383</span> Experimental Damping Performance of Composite Materials with Different Fibre Orientations</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ferhat%20Kadioglu">Ferhat Kadioglu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A clamped-free vibrating beam technique was used to evaluate dynamic properties of glass fiber reinforced polymer matrix composite. In the experiment, an electromagnetic shaker and a non-contact laser head were used to vibrate and to take the response of the specimens, respectively. Test results showed that damping and elastic modulus of the material, as dynamic properties, could be obtained successfully using this technique. It was found that the balanced and symmetric specimens with 45 degrees are the best for damping performance. It is believed that such results could be used for the modal design of aerospace structures. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=composite%20materials" title="composite materials">composite materials</a>, <a href="https://publications.waset.org/abstracts/search?q=damping%20values" title=" damping values"> damping values</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20properties" title=" dynamic properties"> dynamic properties</a>, <a href="https://publications.waset.org/abstracts/search?q=non-contact%20measurements" title=" non-contact measurements"> non-contact measurements</a> </p> <a href="https://publications.waset.org/abstracts/62566/experimental-damping-performance-of-composite-materials-with-different-fibre-orientations" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/62566.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">348</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2382</span> Second Order Statistics of Dynamic Response of Structures Using Gamma Distributed Damping Parameters</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Badreddine%20Chemali">Badreddine Chemali</a>, <a href="https://publications.waset.org/abstracts/search?q=Boualem%20Tiliouine"> Boualem Tiliouine</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This article presents the main results of a numerical investigation on the uncertainty of dynamic response of structures with statistically correlated random damping Gamma distributed. A computational method based on a Linear Statistical Model (LSM) is implemented to predict second order statistics for the response of a typical industrial building structure. The significance of random damping with correlated parameters and its implications on the sensitivity of structural peak response in the neighborhood of a resonant frequency are discussed in light of considerable ranges of damping uncertainties and correlation coefficients. The results are compared to those generated using Monte Carlo simulation techniques. The numerical results obtained show the importance of damping uncertainty and statistical correlation of damping coefficients when obtaining accurate probabilistic estimates of dynamic response of structures. Furthermore, the effectiveness of the LSM model to efficiently predict uncertainty propagation for structural dynamic problems with correlated damping parameters is demonstrated. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=correlated%20random%20damping" title="correlated random damping">correlated random damping</a>, <a href="https://publications.waset.org/abstracts/search?q=linear%20statistical%20model" title=" linear statistical model"> linear statistical model</a>, <a href="https://publications.waset.org/abstracts/search?q=Monte%20Carlo%20simulation" title=" Monte Carlo simulation"> Monte Carlo simulation</a>, <a href="https://publications.waset.org/abstracts/search?q=uncertainty%20of%20dynamic%20response" title=" uncertainty of dynamic response"> uncertainty of dynamic response</a> </p> <a href="https://publications.waset.org/abstracts/37599/second-order-statistics-of-dynamic-response-of-structures-using-gamma-distributed-damping-parameters" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/37599.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">280</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2381</span> Damping Optimal Design of Sandwich Beams Partially Covered with Damping Patches</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Guerich%20Mohamed">Guerich Mohamed</a>, <a href="https://publications.waset.org/abstracts/search?q=Assaf%20Samir"> Assaf Samir</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The application of viscoelastic materials in the form of constrained layers in mechanical structures is an efficient and cost-effective technique for solving noise and vibration problems. This technique requires a design tool to select the best location, type, and thickness of the damping treatment. This paper presents a finite element model for the vibration of beams partially or fully covered with a constrained viscoelastic damping material. The model is based on Bernoulli-Euler theory for the faces and Timoshenko beam theory for the core. It uses four variables: the through-thickness constant deflection, the axial displacements of the faces, and the bending rotation of the beam. The sandwich beam finite element is compatible with the conventional C1 finite element for homogenous beams. To validate the proposed model, several free vibration analyses of fully or partially covered beams, with different locations of the damping patches and different percent coverage, are studied. The results show that the proposed approach can be used as an effective tool to study the influence of the location and treatment size on the natural frequencies and the associated modal loss factors. Then, a parametric study regarding the variation in the damping characteristics of partially covered beams has been conducted. In these studies, the effect of core shear modulus value, the effect of patch size variation, the thickness of constraining layer, and the core and the locations of the patches are considered. In partial coverage, the spatial distribution of additive damping by using viscoelastic material is as important as the thickness and material properties of the viscoelastic layer and the constraining layer. Indeed, to limit added mass and to attain maximum damping, the damping patches should be placed at optimum locations. These locations are often selected using the modal strain energy indicator. Following this approach, the damping patches are applied over regions of the base structure with the highest modal strain energy to target specific modes of vibration. In the present study, a more efficient indicator is proposed, which consists of placing the damping patches over regions of high energy dissipation through the viscoelastic layer of the fully covered sandwich beam. The presented approach is used in an optimization method to select the best location for the damping patches as well as the material thicknesses and material properties of the layers that will yield optimal damping with the minimum area of coverage. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20model" title="finite element model">finite element model</a>, <a href="https://publications.waset.org/abstracts/search?q=damping%20treatment" title=" damping treatment"> damping treatment</a>, <a href="https://publications.waset.org/abstracts/search?q=viscoelastic%20materials" title=" viscoelastic materials"> viscoelastic materials</a>, <a href="https://publications.waset.org/abstracts/search?q=sandwich%20beam" title=" sandwich beam"> sandwich beam</a> </p> <a href="https://publications.waset.org/abstracts/134289/damping-optimal-design-of-sandwich-beams-partially-covered-with-damping-patches" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/134289.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">147</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2380</span> Chaotic Motion of Single-Walled Carbon Nanotube Subject to Damping Effect</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tai-Ping%20Chang">Tai-Ping Chang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In the present study, the effects on chaotic motion of single-walled carbon nanotube (SWCNT) due to the linear and nonlinear damping are investigated. By using the Hamilton’s principle, the nonlinear governing equation of the single-walled carbon nanotube embedded in a matrix is derived. The Galerkin’s method is adopted to simplify the integro-partial differential equation into a nonlinear dimensionless governing equation for the SWCNT, which turns out to be a forced Duffing equation. The variations of the Lyapunov exponents of the SWCNT with damping and harmonic forcing amplitudes are investigated. Based on the computations of the top Lyapunov exponent, it is concluded that the chaotic motion of the SWCNT occurs when the amplitude of the periodic excitation exceeds certain value, besides, the chaotic motion of the SWCNT occurs with small linear damping and tiny nonlinear damping. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=chaotic%20motion" title="chaotic motion">chaotic motion</a>, <a href="https://publications.waset.org/abstracts/search?q=damping" title=" damping"> damping</a>, <a href="https://publications.waset.org/abstracts/search?q=Lyapunov%20exponents" title=" Lyapunov exponents"> Lyapunov exponents</a>, <a href="https://publications.waset.org/abstracts/search?q=single-walled%20carbon%20nanotube" title=" single-walled carbon nanotube"> single-walled carbon nanotube</a> </p> <a href="https://publications.waset.org/abstracts/43091/chaotic-motion-of-single-walled-carbon-nanotube-subject-to-damping-effect" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/43091.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">320</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2379</span> Simplified Analysis on Steel Frame Infill with FRP Composite Panel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=HyunSu%20Seo">HyunSu Seo</a>, <a href="https://publications.waset.org/abstracts/search?q=HoYoung%20Son"> HoYoung Son</a>, <a href="https://publications.waset.org/abstracts/search?q=Sungjin%20Kim"> Sungjin Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=WooYoung%20Jung"> WooYoung Jung</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In order to understand the seismic behavior of steel frame structure with infill FRP composite panel, simple models for simulation on the steel frame with the panel systems were developed in this study. To achieve the simple design method of the steel framed structure with the damping panel system, 2-D finite element analysis with the springs and dashpots models was conducted in ABAQUS. Under various applied spring stiffness and dashpot coefficient, the expected hysteretic energy responses of the steel frame with damping panel systems we re investigated. Using the proposed simple design method which decides the stiffness and the damping, it is possible to decide the FRP and damping materials on a steel frame system. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=numerical%20analysis" title="numerical analysis">numerical analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=FEM" title=" FEM"> FEM</a>, <a href="https://publications.waset.org/abstracts/search?q=infill" title=" infill"> infill</a>, <a href="https://publications.waset.org/abstracts/search?q=GFRP" title=" GFRP"> GFRP</a>, <a href="https://publications.waset.org/abstracts/search?q=damping" title=" damping"> damping</a> </p> <a href="https://publications.waset.org/abstracts/47889/simplified-analysis-on-steel-frame-infill-with-frp-composite-panel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/47889.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">424</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2378</span> Characteristics Influencing Response of a Base Isolated Building</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ounis%20Hadj%20Mohamed">Ounis Hadj Mohamed</a>, <a href="https://publications.waset.org/abstracts/search?q=Ounis%20Abdelhafid"> Ounis Abdelhafid</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In order to illustrate the effect of damping on the response of a base-isolated building, a parametric study is led, taking into account the progressive variation of the damping ratio (10% to 30%) under different types of seismic excitations (near and far field). A time history analysis is used to determine the response of the structure in terms of relative displacement and understory drift at various levels of the building. Thus, the results show that the efficiency of the isolator increases with the assumed damping ratio, provided that this latter is less or equal to 20%. Beyond this value, the isolator becomes less convenient. Furthermore, a strong deviation of energy capacity by the LRB (Lead Rubber Bearing) system is recorded. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=damping" title="damping">damping</a>, <a href="https://publications.waset.org/abstracts/search?q=base%20isolation" title=" base isolation"> base isolation</a>, <a href="https://publications.waset.org/abstracts/search?q=LRB" title=" LRB"> LRB</a>, <a href="https://publications.waset.org/abstracts/search?q=seismic%20excitation" title=" seismic excitation"> seismic excitation</a>, <a href="https://publications.waset.org/abstracts/search?q=hysteresis" title=" hysteresis"> hysteresis</a> </p> <a href="https://publications.waset.org/abstracts/14885/characteristics-influencing-response-of-a-base-isolated-building" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/14885.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">416</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2377</span> Improving Seat Comfort by Semi-Active Control of Magnetorheological Damper</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Karel%20%C5%A0ebesta">Karel Šebesta</a>, <a href="https://publications.waset.org/abstracts/search?q=Ji%C5%99%C3%AD%20%C5%BD%C3%A1%C4%8Dek"> Jiří Žáček</a>, <a href="https://publications.waset.org/abstracts/search?q=Matu%C5%A1%20Salva"> Matuš Salva</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Housam"> Mohammad Housam</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Drivers of agricultural vehicles are exposed to continuous vibration caused by driving over rough terrain. The long-term effects of these vibrations could start with a decreased level of vigilance at work and could reach the level of several health problems. Therefore, eliminating the vibration to maximize the comfort of the driver is essential for better/longer performance. One of the modern damping systems, which can deal with this problem is the Semi-active (S/A) suspension system featuring a Magnetorheological (MR) damper. With this damper, the damping level can be adjusted using varying currents through the coil. Adjustments of the damping force can be carried out continuously based on the evaluated data (position and acceleration of seat) by the control algorithm. The advantage of this system is the wide dynamic range and the high speed of force response time. Compared to other S/A or active systems, the MR damper does not need as much electrical power, and the system is much simpler. This paper aims to prove the effectiveness of this damping system used in the tractor seat. The vibration testing stand was designed and manufactured specifically for this type of research, which is used to simulate vibrations with constant amplitude at variable frequency. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=magnetorheological%20damper" title="magnetorheological damper">magnetorheological damper</a>, <a href="https://publications.waset.org/abstracts/search?q=semi-active%20suspension" title=" semi-active suspension"> semi-active suspension</a>, <a href="https://publications.waset.org/abstracts/search?q=seat%20scissor%20mechanism" title=" seat scissor mechanism"> seat scissor mechanism</a>, <a href="https://publications.waset.org/abstracts/search?q=sky-hook" title=" sky-hook"> sky-hook</a> </p> <a href="https://publications.waset.org/abstracts/155257/improving-seat-comfort-by-semi-active-control-of-magnetorheological-damper" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/155257.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">96</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2376</span> Vibration Control of Two Adjacent Structures Using a Non-Linear Damping System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Soltani%20Amir">Soltani Amir</a>, <a href="https://publications.waset.org/abstracts/search?q=Wang%20Xuan"> Wang Xuan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The advantage of using non-linear passive damping system in vibration control of two adjacent structures is investigated under their base excitation. The base excitation is El Centro earthquake record acceleration. The damping system is considered as an optimum and effective non-linear viscous damper that is connected between two adjacent structures. A Matlab program is developed to produce the stiffness and damping matrices and to determine a time history analysis of the dynamic motion of the system. One structure is assumed to be flexible while the other has a rule as laterally supporting structure with rigid frames. The response of the structure has been calculated and the non-linear damping coefficient is determined using optimum LQR algorithm in an optimum vibration control system. The non-linear parameter of damping system is estimated and it has shown a significant advantage of application of this system device for vibration control of two adjacent tall building. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=active%20control" title="active control">active control</a>, <a href="https://publications.waset.org/abstracts/search?q=passive%20control" title=" passive control"> passive control</a>, <a href="https://publications.waset.org/abstracts/search?q=viscous%20dampers" title=" viscous dampers"> viscous dampers</a>, <a href="https://publications.waset.org/abstracts/search?q=structural%20control" title=" structural control"> structural control</a>, <a href="https://publications.waset.org/abstracts/search?q=vibration%20control" title=" vibration control"> vibration control</a>, <a href="https://publications.waset.org/abstracts/search?q=tall%20building" title=" tall building"> tall building</a> </p> <a href="https://publications.waset.org/abstracts/5867/vibration-control-of-two-adjacent-structures-using-a-non-linear-damping-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/5867.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">514</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2375</span> Supplemental VisCo-friction Damping for Dynamical Structural Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sharad%20Singh">Sharad Singh</a>, <a href="https://publications.waset.org/abstracts/search?q=Ajay%20Kumar%20Sinha"> Ajay Kumar Sinha</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Coupled dampers like viscoelastic-frictional dampers for supplemental damping are a newer technique. In this paper, innovative Visco-frictional damping models have been presented and investigated. This paper attempts to couple frictional and fluid viscous dampers into a single unit of supplemental dampers. Visco-frictional damping model is developed by series and parallel coupling of frictional and fluid viscous dampers using Maxwell and Kelvin-Voigat models. The time analysis has been performed using numerical simulation on an SDOF system with varying fundamental periods, subject to a set of 12 ground motions. The simulation was performed using the direct time integration method. MATLAB programming tool was used to carry out the numerical simulation. The response behavior has been analyzed for the varying time period and added damping. This paper compares the response reduction behavior of the two modes of coupling. This paper highlights the performance efficiency of the suggested damping models. It also presents a mathematical modeling approach to visco-frictional dampers and simultaneously suggests the suitable mode of coupling between the two sub-units. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=hysteretic%20damping" title="hysteretic damping">hysteretic damping</a>, <a href="https://publications.waset.org/abstracts/search?q=Kelvin%20model" title=" Kelvin model"> Kelvin model</a>, <a href="https://publications.waset.org/abstracts/search?q=Maxwell%20model" title=" Maxwell model"> Maxwell model</a>, <a href="https://publications.waset.org/abstracts/search?q=parallel%20coupling" title=" parallel coupling"> parallel coupling</a>, <a href="https://publications.waset.org/abstracts/search?q=series%20coupling" title=" series coupling"> series coupling</a>, <a href="https://publications.waset.org/abstracts/search?q=viscous%20damping" title=" viscous damping"> viscous damping</a> </p> <a href="https://publications.waset.org/abstracts/142635/supplemental-visco-friction-damping-for-dynamical-structural-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/142635.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">158</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2374</span> Optimization of Passive Vibration Damping of Space Structures </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Emad%20Askar">Emad Askar</a>, <a href="https://publications.waset.org/abstracts/search?q=Eldesoky%20Elsoaly"> Eldesoky Elsoaly</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Kamel"> Mohamed Kamel</a>, <a href="https://publications.waset.org/abstracts/search?q=Hisham%20Kamel"> Hisham Kamel</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The objective of this article is to improve the passive vibration damping of solar array (SA) used in space structures, by the effective application of numerical optimization. A case study of a SA is used for demonstration. A finite element (FE) model was created and verified by experimental testing. Optimization was then conducted by implementing the FE model with the genetic algorithm, to find the optimal placement of aluminum circular patches, to suppress the first two bending mode shapes. The results were verified using experimental testing. Finally, a parametric study was conducted using the FE model where patch locations, material type, and shape were varied one at a time, and the results were compared with the optimal ones. The results clearly show that through the proper application of FE modeling and numerical optimization, passive vibration damping of space structures has been successfully achieved. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=damping%20optimization" title="damping optimization">damping optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=genetic%20algorithm%20optimization" title=" genetic algorithm optimization"> genetic algorithm optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=passive%20vibration%20damping" title=" passive vibration damping"> passive vibration damping</a>, <a href="https://publications.waset.org/abstracts/search?q=solar%20array%20vibration%20damping" title=" solar array vibration damping"> solar array vibration damping</a> </p> <a href="https://publications.waset.org/abstracts/61696/optimization-of-passive-vibration-damping-of-space-structures" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/61696.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">450</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2373</span> Nonlinear Impact Responses for a Damped Frame Supported by Nonlinear Springs with Hysteresis Using Fast FEA</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=T.%20Yamaguchi">T. Yamaguchi</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Watanabe"> M. Watanabe</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Sasajima"> M. Sasajima</a>, <a href="https://publications.waset.org/abstracts/search?q=C.%20Yuan"> C. Yuan</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20Maruyama"> S. Maruyama</a>, <a href="https://publications.waset.org/abstracts/search?q=T.%20B.%20Ibrahim"> T. B. Ibrahim</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Tomita"> H. Tomita</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper deals with nonlinear vibration analysis using finite element method for frame structures consisting of elastic and viscoelastic damping layers supported by multiple nonlinear concentrated springs with hysteresis damping. The frame is supported by four nonlinear concentrated springs near the four corners. The restoring forces of the springs have cubic non-linearity and linear component of the nonlinear springs has complex quantity to represent linear hysteresis damping. The damping layer of the frame structures has complex modulus of elasticity. Further, the discretized equations in physical coordinate are transformed into the nonlinear ordinary coupled differential equations using normal coordinate corresponding to linear natural modes. Comparing shares of strain energy of the elastic frame, the damping layer and the springs, we evaluate the influences of the damping couplings on the linear and nonlinear impact responses. We also investigate influences of damping changed by stiffness of the elastic frame on the nonlinear coupling in the damped impact responses. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dynamic%20response" title="dynamic response">dynamic response</a>, <a href="https://publications.waset.org/abstracts/search?q=nonlinear%20impact%20response" title=" nonlinear impact response"> nonlinear impact response</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20analysis" title=" finite element analysis"> finite element analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20analysis" title=" numerical analysis"> numerical analysis</a> </p> <a href="https://publications.waset.org/abstracts/15947/nonlinear-impact-responses-for-a-damped-frame-supported-by-nonlinear-springs-with-hysteresis-using-fast-fea" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/15947.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">434</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2372</span> Numerical Tools for Designing Multilayer Viscoelastic Damping Devices</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mohammed%20Saleh%20Rezk">Mohammed Saleh Rezk</a>, <a href="https://publications.waset.org/abstracts/search?q=Reza%20Kashani"> Reza Kashani</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Auxiliary damping has gained popularity in recent years, especially in structures such as mid- and high-rise buildings. Distributed damping systems (typically viscous and viscoelastic) or reactive damping systems (such as tuned mass dampers) are the two types of damping choices for such structures. Distributed VE dampers are normally configured as braces or damping panels, which are engaged through relatively small movements between the structural members when the structure sways under wind or earthquake loading. In addition to being used as stand-alone dampers in distributed damping applications, VE dampers can also be incorporated into the suspension element of tuned mass dampers (TMDs). In this study, analytical and numerical tools for modeling and design of multilayer viscoelastic damping devices to be used in dampening the vibration of large structures are developed. Considering the limitations of analytical models for the synthesis and analysis of realistic, large, multilayer VE dampers, the emphasis of the study has been on numerical modeling using the finite element method. To verify the finite element models, a two-layer VE damper using ½ inch synthetic viscoelastic urethane polymer was built, tested, and the measured parameters were compared with the numerically predicted ones. The numerical model prediction and experimentally evaluated damping and stiffness of the test VE damper were in very good agreement. The effectiveness of VE dampers in adding auxiliary damping to larger structures is numerically demonstrated by chevron bracing one such damper numerically into the model of a massive frame subject to an abrupt lateral load. A comparison of the responses of the frame to the aforementioned load, without and with the VE damper, clearly shows the efficacy of the damper in lowering the extent of frame vibration. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=viscoelastic" title="viscoelastic">viscoelastic</a>, <a href="https://publications.waset.org/abstracts/search?q=damper" title=" damper"> damper</a>, <a href="https://publications.waset.org/abstracts/search?q=distributed%20damping" title=" distributed damping"> distributed damping</a>, <a href="https://publications.waset.org/abstracts/search?q=tuned%20mass%20damper" title=" tuned mass damper"> tuned mass damper</a> </p> <a href="https://publications.waset.org/abstracts/158763/numerical-tools-for-designing-multilayer-viscoelastic-damping-devices" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/158763.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">107</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2371</span> Simulation of Particle Damping in Boring Tool Using Combined Particles</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Chockalingam">S. Chockalingam</a>, <a href="https://publications.waset.org/abstracts/search?q=U.%20Natarajan"> U. Natarajan</a>, <a href="https://publications.waset.org/abstracts/search?q=D.%20M.%20Santhoshsarang"> D. M. Santhoshsarang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Particle damping is a promising vibration attenuating technique in boring tool than other type of damping with minimal effect on the strength, rigidity and stiffness ratio of the machine tool structure. Due to the cantilever nature of boring tool holder in operations, it suffers chatter when the slenderness ratio of the tool gets increased. In this study, Copper-Stainless steel (SS) particles were packed inside the boring tool which acts as a damper. Damper suppresses chatter generated during machining and also improves the machining efficiency of the tool with better slenderness ratio. In the first approach of particle damping, combined Cu-SS particles were packed inside the vibrating tool, whereas Copper and Stainless steel particles were selected separately and packed inside another tool and their effectiveness was analysed in this simulation. This study reveals that the efficiency of finite element simulation of the boring tools when equipped with particles such as copper, stainless steel and a combination of both. In this study, the newly modified boring tool holder with particle damping was simulated using ANSYS12.0 with and without particles. The aim of this study is to enhance the structural rigidity through particle damping thus avoiding the occurrence of resonance in the boring tool during machining. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=boring%20bar" title="boring bar">boring bar</a>, <a href="https://publications.waset.org/abstracts/search?q=copper-stainless%20steel" title=" copper-stainless steel"> copper-stainless steel</a>, <a href="https://publications.waset.org/abstracts/search?q=chatter" title=" chatter"> chatter</a>, <a href="https://publications.waset.org/abstracts/search?q=particle%20damping" title=" particle damping"> particle damping</a> </p> <a href="https://publications.waset.org/abstracts/28966/simulation-of-particle-damping-in-boring-tool-using-combined-particles" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/28966.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">461</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2370</span> Studies on Organic and Inorganic Micro/Nano Particle Reinforced Epoxy Composites</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Daniel%20Karthik">Daniel Karthik</a>, <a href="https://publications.waset.org/abstracts/search?q=Vijay%20Baheti"> Vijay Baheti</a>, <a href="https://publications.waset.org/abstracts/search?q=Jiri%20Militky"> Jiri Militky</a>, <a href="https://publications.waset.org/abstracts/search?q=Sundaramurthy%20Palanisamy"> Sundaramurthy Palanisamy</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Fibre based nano particles are presently considered as one of the potential filler materials for the improvement of mechanical and physical properties of polymer composites. Due to high matrix-filler interfacial area there will be uniform and homogeneous dispersion of nanoparticles. In micro/nano filler reinforced composites, resin material is usually tailored by organic or inorganic nanoparticles to have improved matrix properties. The objective of this study was to compare the potential of reinforcement of different organic and inorganic micro/nano fillers in epoxy composites. Industrial and agricultural waste of fibres like Agave Americana, cornhusk, jute, basalt, carbon, glass and fly ash was utilized to prepare micro/nano particles. Micro/nano particles were obtained using high energy planetary ball milling process in dry condition. Milling time and ball size were kept constant throughout the ball milling process. Composites were fabricated by hand lay method. Particle loading was kept constant to 3% wt. for all composites. In present study, loading of fillers was selected as 3 wt. % for all composites. Dynamic mechanical properties of the nanocomposite films were performed in three-point bending mode with gauge length and sample width of 50 mm and 10 mm respectively. The samples were subjected to an oscillating frequency of 1 Hz, 5 Hz and 10 Hz and 100 % oscillating amplitude in the temperature ranges of 30°C to 150°C at the heating rate of 3°C/min. Damping was found to be higher with the jute composites. Amongst organic fillers lowest damping factor was observed with Agave Americana particles, this means that Agave americana fibre particles have betters interface adhesion with epoxy resin. Basalt, fly ash and glass particles have almost similar damping factors confirming better interface adhesion with epoxy. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ball%20milling" title="ball milling">ball milling</a>, <a href="https://publications.waset.org/abstracts/search?q=damping%20factor" title=" damping factor"> damping factor</a>, <a href="https://publications.waset.org/abstracts/search?q=matrix-filler%20interface" title=" matrix-filler interface"> matrix-filler interface</a>, <a href="https://publications.waset.org/abstracts/search?q=particle%20reinforcements" title=" particle reinforcements"> particle reinforcements</a> </p> <a href="https://publications.waset.org/abstracts/91243/studies-on-organic-and-inorganic-micronano-particle-reinforced-epoxy-composites" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/91243.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">264</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2369</span> Clarifications on the Damping Mechanism Related to the Hunting Motion of the Wheel Axle of a High-Speed Railway Vehicle</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Barenten%20Suciu">Barenten Suciu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In order to explain the damping mechanism, related to the hunting motion of the wheel axle of a high-speed railway vehicle, a generalized dynamic model is proposed. Based on such model, analytic expressions for the damping coefficient and damped natural frequency are derived, without imposing restrictions on the ratio between the lateral and vertical creep coefficients. Influence of the travelling speed, wheel conicity, dimensionless mass of the wheel axle, ratio of the creep coefficients, ratio of the track span to the yawing diameter, etc. on the damping coefficient and damped natural frequency, is clarified. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=high-speed%20railway%20vehicle" title="high-speed railway vehicle">high-speed railway vehicle</a>, <a href="https://publications.waset.org/abstracts/search?q=hunting%20motion" title=" hunting motion"> hunting motion</a>, <a href="https://publications.waset.org/abstracts/search?q=wheel%20axle" title=" wheel axle"> wheel axle</a>, <a href="https://publications.waset.org/abstracts/search?q=damping" title=" damping"> damping</a>, <a href="https://publications.waset.org/abstracts/search?q=creep" title=" creep"> creep</a>, <a href="https://publications.waset.org/abstracts/search?q=vibration%20model" title=" vibration model"> vibration model</a>, <a href="https://publications.waset.org/abstracts/search?q=analysis." title=" analysis."> analysis.</a> </p> <a href="https://publications.waset.org/abstracts/78472/clarifications-on-the-damping-mechanism-related-to-the-hunting-motion-of-the-wheel-axle-of-a-high-speed-railway-vehicle" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/78472.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">290</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2368</span> Drastic Increase of Wave Dissipation within Metastructures Having Negative Stiffness Inclusions </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=D.%20Chronopoulos">D. Chronopoulos</a>, <a href="https://publications.waset.org/abstracts/search?q=I.%20Antoniadis"> I. Antoniadis</a>, <a href="https://publications.waset.org/abstracts/search?q=V.%20Spitas"> V. Spitas</a>, <a href="https://publications.waset.org/abstracts/search?q=D.%20Koulocheris"> D. Koulocheris</a>, <a href="https://publications.waset.org/abstracts/search?q=V.%20Polenta"> V. Polenta</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A concept of a simple linear oscillator, incorporating a negative stiffness element is demonstrated to exhibit extraordinary damping properties. This oscillator shares the same overall (static) stiffness, the same mass and the same damping element with a reference classical linear SDOF oscillator. However, it differs from the original SDOF oscillator by appropriately redistributing the component spring stiffness elements and by re-allocating the damping element. Despite the fact that the proposed oscillator incorporates a negative stiffness element, it is designed to be both statically and dynamically stable. Once such an oscillator is optimally designed, it is shown to exhibit an extraordinary apparent damping ratio, which is even several orders of magnitude higher than that of the original SDOF system, especially in cases where the original damping of the SDOF system is low. This damping behavior is not a result of a novel additional extraordinary energy dissipation mechanism, but a result of the phase difference between the positive and the negative stiffness elastic forces, which is in turn a consequence of the proper re-distribution of the stiffness and the damper elements. This fact ensures that an adequate level of elastic forces exists throughout the entire frequency range, able to counteract the inertial and the excitation forces. Next, Acoustic or Phononic Meta-materials are considered, in which one atom is replaced by the concept of the above simple linear oscillator. The results indicate that not only the damping of the meta-material verifies and exceeds the one expected from the so-called "meta-damping" behavior, but also that the band gap of the meta-material can be significantly increased. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=wave%20propagation" title="wave propagation">wave propagation</a>, <a href="https://publications.waset.org/abstracts/search?q=periodic%20structures" title=" periodic structures"> periodic structures</a>, <a href="https://publications.waset.org/abstracts/search?q=wave%20damping" title=" wave damping"> wave damping</a>, <a href="https://publications.waset.org/abstracts/search?q=mechanical%20engineering" title=" mechanical engineering"> mechanical engineering</a> </p> <a href="https://publications.waset.org/abstracts/12429/drastic-increase-of-wave-dissipation-within-metastructures-having-negative-stiffness-inclusions" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/12429.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">357</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2367</span> The Effect of Damping Treatment for Noise Control on Offshore Platforms Using Statistical Energy Analysis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ji%20Xi">Ji Xi</a>, <a href="https://publications.waset.org/abstracts/search?q=Cheng%20Song%20Chin"> Cheng Song Chin</a>, <a href="https://publications.waset.org/abstracts/search?q=Ehsan%20Mesbahi"> Ehsan Mesbahi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Structure-borne noise is an important aspect of offshore platform sound field. It can be generated either directly by vibrating machineries induced mechanical force, indirectly by the excitation of structure or excitation by incident airborne noise. Therefore, limiting of the transmission of vibration energy throughout the offshore platform is the key to control the structure-borne noise. This is usually done by introducing damping treatment to the steel structures. Two types of damping treatment using on-board are presented. By conducting a statistical energy analysis (SEA) simulation on a jack-up rig, the noise level in the source room, the neighboring rooms, and remote living quarter cabins are compared before and after the damping treatments been applied. The results demonstrated that, in the source neighboring room and living quarter area, there is a significant noise reduction with the damping treatment applied, whereas in the source room where air-borne sound predominates that of structure-borne sound, the impact is not obvious. The subsequent optimization design of damping treatment in the offshore platform can be made which enable acoustic professionals to implement noise control during the design stage for offshore crews’ hearing protection and habitant comfortability. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=statistical%20energy%20analysis" title="statistical energy analysis">statistical energy analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=damping%20treatment" title=" damping treatment"> damping treatment</a>, <a href="https://publications.waset.org/abstracts/search?q=noise%20control" title=" noise control"> noise control</a>, <a href="https://publications.waset.org/abstracts/search?q=offshore%20platform" title=" offshore platform"> offshore platform</a> </p> <a href="https://publications.waset.org/abstracts/33178/the-effect-of-damping-treatment-for-noise-control-on-offshore-platforms-using-statistical-energy-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/33178.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">555</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2366</span> Response of Vibration and Damping System of UV Irradiated Renewable Biopolymer </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Anika%20Zafiah%20M.%20Rus">Anika Zafiah M. Rus</a>, <a href="https://publications.waset.org/abstracts/search?q=Nik%20Normunira%20Mat%20Hassan"> Nik Normunira Mat Hassan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Biopolymer made from renewable material are one of the most important group of polymer because of their versatility and they can be manufactured in a wide range of densities and stiffness. In this project, biopolymer based on waste vegetable oil were synthesized and crosslink with commercial polymethane polyphenyl isocyanate (known as BF).The BF was compressed by using hot compression moulding technique at 90 oC based on the evaporation of volatile matter and known as compress biopolymer (CB). The density, vibration and damping characteristic of CB were determined after UV irradiation. Treatment with titanium dioxide (TiO2) was found to affect the physical property of compress biopolymer composite (CBC). The density of CBC samples was steadily increased with an increase of UV irradiation time and TiO2 loading. The highest density of CBC samples is at 10 % of TiO2 loading of 1.1088 g/cm3 due to the amount of filler loading. The vibration and damping characteristic of CBC samples was generated at displacements of 1 mm and 1.5 mm and acceleration of 0.1 G and 0.15 G base excitation according to ASTM D3580-9. It was revealed that, the vibration and damping characteristic of CBC samples is significantly increased with the increasing of UV irradiation time, lowest thickness and percentages of TiO2 loading at the frequency range of 15 - 25 Hz. Therefore, this study indicated that the damping property of CBC could be improved upon prolonged exposure to UV irradiation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=biopolymer%20flexible%20foam" title="biopolymer flexible foam">biopolymer flexible foam</a>, <a href="https://publications.waset.org/abstracts/search?q=TGA" title=" TGA"> TGA</a>, <a href="https://publications.waset.org/abstracts/search?q=UV%20irradiation" title=" UV irradiation"> UV irradiation</a>, <a href="https://publications.waset.org/abstracts/search?q=vibration%20and%20damping" title=" vibration and damping"> vibration and damping</a> </p> <a href="https://publications.waset.org/abstracts/16776/response-of-vibration-and-damping-system-of-uv-irradiated-renewable-biopolymer" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/16776.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">466</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2365</span> Optimum Parameter of a Viscous Damper for Seismic and Wind Vibration </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Soltani%20Amir">Soltani Amir</a>, <a href="https://publications.waset.org/abstracts/search?q=Hu%20Jiaxin"> Hu Jiaxin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Determination of optimal parameters of a passive control system device is the primary objective of this study. Expanding upon the use of control devices in wind and earthquake hazard reduction has led to development of various control systems. The advantage of non-linearity characteristics in a passive control device and the optimal control method using LQR algorithm are explained in this study. Finally, this paper introduces a simple approach to determine optimum parameters of a nonlinear viscous damper for vibration control of structures. A MATLAB program is used to produce the dynamic motion of the structure considering the stiffness matrix of the SDOF frame and the non-linear damping effect. This study concluded that the proposed system (variable damping system) has better performance in system response control than a linear damping system. Also, according to the energy dissipation graph, the total energy loss is greater in non-linear damping system than other systems. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=passive%20control%20system" title="passive control system">passive control system</a>, <a href="https://publications.waset.org/abstracts/search?q=damping%20devices" title=" damping devices"> damping devices</a>, <a href="https://publications.waset.org/abstracts/search?q=viscous%20dampers" title=" viscous dampers"> viscous dampers</a>, <a href="https://publications.waset.org/abstracts/search?q=control%20algorithm" title=" control algorithm"> control algorithm</a> </p> <a href="https://publications.waset.org/abstracts/10226/optimum-parameter-of-a-viscous-damper-for-seismic-and-wind-vibration" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/10226.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">470</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2364</span> A Multiobjective Damping Function for Coordinated Control of Power System Stabilizer and Power Oscillation Damping</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jose%20D.%20Herrera">Jose D. Herrera</a>, <a href="https://publications.waset.org/abstracts/search?q=Mario%20A.%20Rios"> Mario A. Rios</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper deals with the coordinated tuning of the Power System Stabilizer (PSS) controller and Power Oscillation Damping (POD) Controller of Flexible AC Transmission System (FACTS) in a multi-machine power systems. The coordinated tuning is based on the critical eigenvalues of the power system and a model reduction technique where the Hankel Singular Value method is applied. Through the linearized system model and the parameter-constrained nonlinear optimization algorithm, it can compute the parameters of both controllers. Moreover, the parameters are optimized simultaneously obtaining the gains of both controllers. Then, the nonlinear simulation to observe the time response of the controller is performed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=electromechanical%20oscillations" title="electromechanical oscillations">electromechanical oscillations</a>, <a href="https://publications.waset.org/abstracts/search?q=power%20system%20stabilizers" title=" power system stabilizers"> power system stabilizers</a>, <a href="https://publications.waset.org/abstracts/search?q=power%20oscillation%20damping" title=" power oscillation damping"> power oscillation damping</a>, <a href="https://publications.waset.org/abstracts/search?q=hankel%20singular%20values" title=" hankel singular values"> hankel singular values</a> </p> <a href="https://publications.waset.org/abstracts/58164/a-multiobjective-damping-function-for-coordinated-control-of-power-system-stabilizer-and-power-oscillation-damping" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/58164.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">592</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2363</span> The Effect of Mathematical Modeling of Damping on the Seismic Energy Demands</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Selamawit%20Dires">Selamawit Dires</a>, <a href="https://publications.waset.org/abstracts/search?q=Solomon%20Tesfamariam"> Solomon Tesfamariam</a>, <a href="https://publications.waset.org/abstracts/search?q=Thomas%20Tannert"> Thomas Tannert</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Modern earthquake engineering and design encompass performance-based design philosophy. The main objective in performance-based design is to achieve a system performing precisely to meet the design objectives so to reduce unintended seismic risks and associated losses. Energy-based earthquake-resistant design is one of the design methodologies that can be implemented in performance-based earthquake engineering. In energy-based design, the seismic demand is usually described as the ratio of the hysteretic to input energy. Once the hysteretic energy is known as a percentage of the input energy, it is distributed among energy-dissipating components of a structure. The hysteretic to input energy ratio is highly dependent on the inherent damping of a structural system. In numerical analysis, damping can be modeled as stiffness-proportional, mass-proportional, or a linear combination of stiffness and mass. In this study, the effect of mathematical modeling of damping on the estimation of seismic energy demands is investigated by considering elastic-perfectly-plastic single-degree-of-freedom systems representing short to long period structures. Furthermore, the seismicity of Vancouver, Canada, is used in the nonlinear time history analysis. According to the preliminary results, the input energy demand is not sensitive to the type of damping models deployed. Hence, consistent results are achieved regardless of the damping models utilized in the numerical analyses. On the other hand, the hysteretic to input energy ratios vary significantly for the different damping models. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=damping" title="damping">damping</a>, <a href="https://publications.waset.org/abstracts/search?q=energy-based%20seismic%20design" title=" energy-based seismic design"> energy-based seismic design</a>, <a href="https://publications.waset.org/abstracts/search?q=hysteretic%20energy" title=" hysteretic energy"> hysteretic energy</a>, <a href="https://publications.waset.org/abstracts/search?q=input%20energy" title=" input energy"> input energy</a> </p> <a href="https://publications.waset.org/abstracts/111458/the-effect-of-mathematical-modeling-of-damping-on-the-seismic-energy-demands" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/111458.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">168</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2362</span> Estimation of Hysteretic Damping in Steel Dual Systems with Buckling Restrained Brace and Moment Resisting Frame</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seyed%20Saeid%20Tabaee">Seyed Saeid Tabaee</a>, <a href="https://publications.waset.org/abstracts/search?q=Omid%20Bahar"> Omid Bahar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Nowadays, using energy dissipation devices has been commonly used in structures. A high rate of energy absorption during earthquakes is the benefit of using such devices, which results in damage reduction of structural elements specifically columns. The hysteretic damping capacity of energy dissipation devices is the key point that it may adversely complicate analysis and design of such structures. This effect may be generally represented by equivalent viscous damping. The equivalent viscous damping may be obtained from the expected hysteretic behavior under the design or maximum considered displacement of a structure. In this paper, the hysteretic damping coefficient of a steel moment resisting frame (MRF), which its performance is enhanced by a buckling restrained brace (BRB) system has been evaluated. Having the foresight of damping fraction between BRB and MRF is inevitable for seismic design procedures like Direct Displacement-Based Design (DDBD) method. This paper presents an approach to calculate the damping fraction for such systems by carrying out the dynamic nonlinear time history analysis (NTHA) under harmonic loading, which is tuned to the natural frequency of the system. Two steel moment frame structures, one equipped with BRB, and the other without BRB are simultaneously studied. The extensive analysis shows that proportion of each system damping fraction may be calculated by its shear story portion. In this way, the contribution of each BRB in the floors and their general contribution in the structural performance may be clearly recognized, in advance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=buckling%20restrained%20brace" title="buckling restrained brace">buckling restrained brace</a>, <a href="https://publications.waset.org/abstracts/search?q=direct%20displacement%20based%20design" title=" direct displacement based design"> direct displacement based design</a>, <a href="https://publications.waset.org/abstracts/search?q=dual%20systems" title=" dual systems"> dual systems</a>, <a href="https://publications.waset.org/abstracts/search?q=hysteretic%20damping" title=" hysteretic damping"> hysteretic damping</a>, <a href="https://publications.waset.org/abstracts/search?q=moment%20resisting%20frames" title=" moment resisting frames"> moment resisting frames</a> </p> <a href="https://publications.waset.org/abstracts/28860/estimation-of-hysteretic-damping-in-steel-dual-systems-with-buckling-restrained-brace-and-moment-resisting-frame" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/28860.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">434</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2361</span> Prediction of Pounding between Two SDOF Systems by Using Link Element Based On Mathematic Relations and Suggestion of New Equation for Impact Damping Ratio</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seyed%20M.%20Khatami">Seyed M. Khatami</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Naderpour"> H. Naderpour</a>, <a href="https://publications.waset.org/abstracts/search?q=R.%20Vahdani"> R. Vahdani</a>, <a href="https://publications.waset.org/abstracts/search?q=R.%20C.%20Barros"> R. C. Barros</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Many previous studies have been carried out to calculate the impact force and the dissipated energy between two neighboring buildings during seismic excitation, when they collide with each other. Numerical studies are an important part of impact, which several researchers have tried to simulate the impact by using different formulas. Estimation of the impact force and the dissipated energy depends significantly on some parameters of impact. Mass of bodies, stiffness of spring, coefficient of restitution, damping ratio of dashpot and impact velocity are some known and unknown parameters to simulate the impact and measure dissipated energy during collision. Collision is usually shown by force-displacement hysteresis curve. The enclosed area of the hysteresis loop explains the dissipated energy during impact. In this paper, the effect of using different types of impact models is investigated in order to calculate the impact force. To increase the accuracy of impact model and to optimize the results of simulations, a new damping equation is assumed and is validated to get the best results of impact force and dissipated energy, which can show the accuracy of suggested equation of motion in comparison with other formulas. This relation is called "n-m". Based on mathematical relation, an initial value is selected for the mentioned coefficients and kinetic energy loss is calculated. After each simulation, kinetic energy loss and energy dissipation are compared with each other. If they are equal, selected parameters are true and, if not, the constant of parameters are modified and a new analysis is performed. Finally, two unknown parameters are suggested to estimate the impact force and calculate the dissipated energy. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=impact%20force" title="impact force">impact force</a>, <a href="https://publications.waset.org/abstracts/search?q=dissipated%20energy" title=" dissipated energy"> dissipated energy</a>, <a href="https://publications.waset.org/abstracts/search?q=kinetic%20energy%20loss" title=" kinetic energy loss"> kinetic energy loss</a>, <a href="https://publications.waset.org/abstracts/search?q=damping%20relation" title=" damping relation "> damping relation </a> </p> <a href="https://publications.waset.org/abstracts/14416/prediction-of-pounding-between-two-sdof-systems-by-using-link-element-based-on-mathematic-relations-and-suggestion-of-new-equation-for-impact-damping-ratio" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/14416.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">552</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2360</span> Assessment Power and Oscillation Damping Using the POD Controller and Proposed FOD Controller</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tohid%20Rahimi">Tohid Rahimi</a>, <a href="https://publications.waset.org/abstracts/search?q=Yahya%20Naderi"> Yahya Naderi</a>, <a href="https://publications.waset.org/abstracts/search?q=Babak%20Yousefi"> Babak Yousefi</a>, <a href="https://publications.waset.org/abstracts/search?q=Seyed%20Hossein%20Hoseini"> Seyed Hossein Hoseini</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Today’s modern interconnected power system is highly complex in nature. In this, one of the most important requirements during the operation of the electric power system is the reliability and security. Power and frequency oscillation damping mechanism improve the reliability. Because of power system stabilizer (PSS) low speed response against of major fault such as three phase short circuit, FACTs devise that can control the network condition in very fast time, are becoming popular. However, FACTs capability can be seen in a major fault present when nonlinear models of FACTs devise and power system equipment are applied. To realize this aim, the model of multi-machine power system with FACTs controller is developed in MATLAB/SIMULINK using Sim Power System (SPS) blockiest. Among the FACTs device, Static synchronous series compensator (SSSC) due to high speed changes its reactance characteristic inductive to capacitive, is effective power flow controller. Tuning process of controller parameter can be performed using different method. However, Genetic Algorithm (GA) ability tends to use it in controller parameter tuning process. In this paper, firstly POD controller is used to power oscillation damping. But in this station, frequency oscillation dos not has proper damping situation. Therefore, FOD controller that is tuned using GA is using that cause to damp out frequency oscillation properly and power oscillation damping has suitable situation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=power%20oscillation%20damping%20%28POD%29" title="power oscillation damping (POD)">power oscillation damping (POD)</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20oscillation%20damping%20%28FOD%29" title=" frequency oscillation damping (FOD)"> frequency oscillation damping (FOD)</a>, <a href="https://publications.waset.org/abstracts/search?q=Static%20synchronous%20series%20compensator%20%28SSSC%29" title=" Static synchronous series compensator (SSSC)"> Static synchronous series compensator (SSSC)</a>, <a href="https://publications.waset.org/abstracts/search?q=Genetic%20Algorithm%20%28GA%29" title=" Genetic Algorithm (GA)"> Genetic Algorithm (GA)</a> </p> <a href="https://publications.waset.org/abstracts/18560/assessment-power-and-oscillation-damping-using-the-pod-controller-and-proposed-fod-controller" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/18560.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">476</span> </span> </div> </div> <ul class="pagination"> <li class="page-item disabled"><span class="page-link">&lsaquo;</span></li> <li class="page-item active"><span class="page-link">1</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=damping%20constant&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=damping%20constant&page=3">3</a></li> <li class="page-item"><a class="page-link" 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