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analysis</title> <meta name="description" content="Search results for: modal analysis"> <meta name="keywords" content="modal analysis"> <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 navbar-toggler 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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="modal analysis"> <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> 27957</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: modal analysis</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">27957</span> Experimental Modal Analysis of Reinforced Concrete Square Slabs </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20S.%20Ahmed">M. S. Ahmed</a>, <a href="https://publications.waset.org/abstracts/search?q=F.%20A.%20Mohammad"> F. A. Mohammad</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The aim of this paper is to perform experimental modal analysis (EMA) of reinforced concrete (RC) square slabs. EMA is the process of determining the modal parameters (Natural Frequencies, damping factors, modal vectors) of a structure from a set of frequency response functions FRFs (curve fitting). Although experimental modal analysis (or modal testing) has grown steadily in popularity since the advent of the digital FFT spectrum analyzer in the early 1970’s, studying all members and materials using such method have not yet been well documented. Therefore, in this work, experimental tests were conducted on RC square specimens (0.6m x 0.6m with 40 mm). Experimental analysis is based on freely supported boundary condition. Moreover, impact testing as a fast and economical means of finding the modes of vibration of a structure was used during the experiments. In addition, Pico Scope 6 device and MATLAB software were used to acquire data, analyze and plot Frequency Response Function (FRF). The experimental natural frequencies which were extracted from measurements exhibit good agreement with analytical predictions. It is showed that EMA method can be usefully employed to perform the dynamic behavior of RC slabs. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=natural%20frequencies" title="natural frequencies">natural frequencies</a>, <a href="https://publications.waset.org/abstracts/search?q=mode%20shapes" title=" mode shapes"> mode shapes</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=RC%20slabs" title=" RC slabs"> RC slabs</a> </p> <a href="https://publications.waset.org/abstracts/16946/experimental-modal-analysis-of-reinforced-concrete-square-slabs" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/16946.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">408</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">27956</span> The Complete Modal Derivatives</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sebastian%20Andersen">Sebastian Andersen</a>, <a href="https://publications.waset.org/abstracts/search?q=Peter%20N.%20Poulsen"> Peter N. Poulsen</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The use of basis projection in the structural dynamic analysis is frequently applied. The purpose of the method is to improve the computational efficiency, while maintaining a high solution accuracy, by projection the governing equations onto a small set of carefully selected basis vectors. The present work considers basis projection in kinematic nonlinear systems with a focus on two widely used basis vectors; the system mode shapes and their modal derivatives. Particularly the latter basis vectors are given special attention since only approximate modal derivatives have been used until now. In the present work the complete modal derivatives, derived from perturbation methods, are presented and compared to the previously applied approximate modal derivatives. The correctness of the complete modal derivatives is illustrated by use of an example of a harmonically loaded kinematic nonlinear structure modeled by beam elements. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=basis%20projection" title="basis projection">basis projection</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20method" title=" finite element method"> finite element method</a>, <a href="https://publications.waset.org/abstracts/search?q=kinematic%20nonlinearities" title=" kinematic nonlinearities"> kinematic nonlinearities</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20derivatives" title=" modal derivatives"> modal derivatives</a> </p> <a href="https://publications.waset.org/abstracts/92260/the-complete-modal-derivatives" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/92260.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">237</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">27955</span> Numerical Modal Analysis of a Multi-Material 3D-Printed Composite Bushing and Its Application</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Pawe%C5%82%20%C5%BBur">Paweł Żur</a>, <a href="https://publications.waset.org/abstracts/search?q=Alicja%20%C5%BBur"> Alicja Żur</a>, <a href="https://publications.waset.org/abstracts/search?q=Andrzej%20Baier"> Andrzej Baier</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Modal analysis is a crucial tool in the field of engineering for understanding the dynamic behavior of structures. In this study, numerical modal analysis was conducted on a multi-material 3D-printed composite bushing, which comprised a polylactic acid (PLA) outer shell and a thermoplastic polyurethane (TPU) flexible filling. The objective was to investigate the modal characteristics of the bushing and assess its potential for practical applications. The analysis involved the development of a finite element model of the bushing, which was subsequently subjected to modal analysis techniques. Natural frequencies, mode shapes, and damping ratios were determined to identify the dominant vibration modes and their corresponding responses. The numerical modal analysis provided valuable insights into the dynamic behavior of the bushing, enabling a comprehensive understanding of its structural integrity and performance. Furthermore, the study expanded its scope by investigating the entire shaft mounting of a small electric car, incorporating the 3D-printed composite bushing. The shaft mounting system was subjected to numerical modal analysis to evaluate its dynamic characteristics and potential vibrational issues. The results of the modal analysis highlighted the effectiveness of the 3D-printed composite bushing in minimizing vibrations and optimizing the performance of the shaft mounting system. The findings contribute to the broader field of composite material applications in automotive engineering and provide valuable insights for the design and optimization of similar components. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=3D%20printing" title="3D printing">3D printing</a>, <a href="https://publications.waset.org/abstracts/search?q=composite%20bushing" title=" composite bushing"> composite bushing</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-material" title=" multi-material"> multi-material</a> </p> <a href="https://publications.waset.org/abstracts/168441/numerical-modal-analysis-of-a-multi-material-3d-printed-composite-bushing-and-its-application" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/168441.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">109</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">27954</span> A Semantic Analysis of Modal Verbs in Barak Obama’s 2012 Presidential Campaign Speech</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kais%20A.%20Kadhim">Kais A. Kadhim</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper is a semantic analysis of the English modals in Obama’s speech. The main objective of this study is to analyze selected modal auxiliaries identified in selected speeches of Obama’s campaign based on Coates’ (1983) semantic clusters. A total of fifteen speeches of Obama’s campaign were selected as the primary data and the modal auxiliaries selected for analysis include will, would, can, could, should, must, ought, shall, may and might. All the modal auxiliaries taken from the speeches of Barack Obama were analyzed based on the framework of Coates’ semantic clusters. Such analytical framework was carried out to examine how modal auxiliaries are used in the context of persuading people in Obama’s campaign speeches. The findings reveal that modals of intention, prediction, futurity and modals of possibility, ability, permission are mostly used in Obama’s campaign speeches. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=modals" title="modals">modals</a>, <a href="https://publications.waset.org/abstracts/search?q=meaning" title=" meaning"> meaning</a>, <a href="https://publications.waset.org/abstracts/search?q=persuasion" title=" persuasion"> persuasion</a>, <a href="https://publications.waset.org/abstracts/search?q=speech" title=" speech"> speech</a> </p> <a href="https://publications.waset.org/abstracts/13912/a-semantic-analysis-of-modal-verbs-in-barak-obamas-2012-presidential-campaign-speech" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/13912.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">405</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">27953</span> Application of Modal Analysis for Commissioning of a Ball Screw System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=T.%20D.%20Tran">T. D. Tran</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Schlegel"> H. Schlegel</a>, <a href="https://publications.waset.org/abstracts/search?q=R.%20Neugebauer"> R. Neugebauer</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Ball screws are an important component in machine tools. In mechatronic systems and machine tools, a ball screw has to work usually at a high speed. Otherwise the axial compliance of the ball screw, in combination with the inertia of the slide, the motor, the coupling and the screw, will cause an oscillation resonance, which limits the systems bandwidth and consequently influences performance of the motion controller. In this paper, the modal analysis method by measuring and analysing the vibrating parameters of the ball screw system to determine the dynamic characteristic of existing structures is used. On the one hand, the results of this study were obtained by the theoretical analysis and the modal testing of a ball screw system test station with the help of an impact hammer, respectively using excitation by motor. The experimental study showed oscillating forms of the ball screw for each frequency and obtained eigenfrequencies of the ball screw system. On the other hand, in this research a simulation with the help of the numerical modal analysis in order to analyse the oscillation and to find the eigenfrequencies of the ball screw system is used. Furthermore, the model order reduction by modal reduction and also according to Guyan is carried out. On the basis of these results a secure and also rapid commissioning of the control loops with regard to operating in their optimal function is targeted. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title="modal analysis">modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=ball%20screw" title=" ball screw"> ball screw</a>, <a href="https://publications.waset.org/abstracts/search?q=controller%20system" title=" controller system"> controller system</a>, <a href="https://publications.waset.org/abstracts/search?q=machine%20tools" title=" machine tools"> machine tools</a> </p> <a href="https://publications.waset.org/abstracts/22744/application-of-modal-analysis-for-commissioning-of-a-ball-screw-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/22744.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">460</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">27952</span> Cancellation of Transducer Effects from Frequency Response Functions: Experimental Case Study on the Steel Plate</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=P.%20Zamani">P. Zamani</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Taleshi%20Anbouhi"> A. Taleshi Anbouhi</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20R.%20Ashory"> M. R. Ashory</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20Mohajerzadeh"> S. Mohajerzadeh</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20M.%20Khatibi"> M. M. Khatibi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Modal analysis is a developing science in the experimental evaluation of dynamic properties of the structures. Mechanical devices such as accelerometers are one of the sources of lack of quality in measuring modal testing parameters. In this paper, eliminating the accelerometer’s mass effect of the frequency response of the structure is studied. So, a strategy is used for eliminating the mass effect by using sensitivity analysis. In this method, the amount of mass change and the place to measure the structure’s response with least error in frequency correction is chosen. Experimental modal testing is carried out on a steel plate and the effect of accelerometer’s mass is omitted using this strategy. Finally, a good agreement is achieved between numerical and experimental results. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=accelerometer%20mass" title="accelerometer mass">accelerometer mass</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency%20response%20function" title=" frequency response function"> frequency response function</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=sensitivity%20analysis" title=" sensitivity analysis"> sensitivity analysis</a> </p> <a href="https://publications.waset.org/abstracts/29375/cancellation-of-transducer-effects-from-frequency-response-functions-experimental-case-study-on-the-steel-plate" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/29375.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">446</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">27951</span> Theoretical Modal Analysis of Freely and Simply Supported RC Slabs</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20S.%20Ahmed">M. S. Ahmed</a>, <a href="https://publications.waset.org/abstracts/search?q=F.%20A.%20Mohammad"> F. A. Mohammad</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper focuses on the dynamic behavior of reinforced concrete (RC) slabs. Therefore, the theoretical modal analysis was performed using two different types of boundary conditions. Modal analysis method is the most important dynamic analyses. The analysis would be modal case when there is no external force on the structure. By using this method in this paper, the effects of freely and simply supported boundary conditions on the frequencies and mode shapes of RC square slabs are studied. ANSYS software was employed to derive the finite element model to determine the natural frequencies and mode shapes of the slabs. Then, the obtained results through numerical analysis (finite element analysis) would be compared with an exact solution. The main goal of the research study is to predict how the boundary conditions change the behavior of the slab structures prior to performing experimental modal analysis. Based on the results, it is concluded that simply support boundary condition has obvious influence to increase the natural frequencies and change the shape of mode when it is compared with freely supported boundary condition of slabs. This means that such support conditions have direct influence on the dynamic behavior of the slabs. Thus, it is suggested to use free-free boundary condition in experimental modal analysis to precisely reflect the properties of the structure. By using free-free boundary conditions, the influence of poorly defined supports is interrupted. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=natural%20frequencies" title="natural frequencies">natural frequencies</a>, <a href="https://publications.waset.org/abstracts/search?q=mode%20shapes" title=" mode shapes"> mode shapes</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=ANSYS%20software" title=" ANSYS software"> ANSYS software</a>, <a href="https://publications.waset.org/abstracts/search?q=RC%20slabs" title=" RC slabs"> RC slabs</a> </p> <a href="https://publications.waset.org/abstracts/17461/theoretical-modal-analysis-of-freely-and-simply-supported-rc-slabs" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/17461.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">457</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">27950</span> Modal Analysis of Power System with a Microgrid </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Burak%20Yildirim">Burak Yildirim</a>, <a href="https://publications.waset.org/abstracts/search?q=Muhsin%20Tunay%20Gen%C3%A7o%C4%9Flu"> Muhsin Tunay Gençoğlu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A microgrid (MG) is a small power grid composed of localized medium or low level power generation, storage systems, and loads. In this paper, the effects of a MG on power systems voltage stability are shown. The MG model, designed to demonstrate the effects of the MG, was applied to the IEEE 14 bus power system which is widely used in power system stability studies. Eigenvalue and modal analysis methods were used in simulation studies. In the study results, it is seen that MGs affect system voltage stability positively by increasing system voltage instability limit value for buses of a power system in which MG are placed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=eigenvalue%20analysis" title="eigenvalue analysis">eigenvalue analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=microgrid" title=" microgrid"> microgrid</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=voltage%20stability" title=" voltage stability"> voltage stability</a> </p> <a href="https://publications.waset.org/abstracts/76026/modal-analysis-of-power-system-with-a-microgrid" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/76026.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">372</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">27949</span> Experimental Modal Analysis of Kursuncular Minaret</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yunus%20Dere">Yunus Dere</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Minarets are tower like structures where the call to prayer of Muslims is performed. They have a symbolic meaning and sacred place among Muslims. Being tall and slender, they are prone to damage under earthquakes and strong winds. Kursuncular stone minaret was built around thirty years ago in Konya/TURKEY. Its core and helical stairs are made of reinforced concrete. Its stone spire was damaged during a light earthquake. Its spire is later replaced with a light material covered with lead sheets. In this study, the natural frequencies and mode shapes of Kursuncular minaret is obtained experimentally and analytically. First an ambient vibration test is carried out using a data acquisition system with accelerometers located at four locations along the height of the minaret. The collected vibration data is evaluated by operational modal analysis techniques. For the analytical part of the study, the dimensions of the minaret are accurately measured and a detailed 3D solid finite element model of the minaret is generated. The moduli of elasticity of the stone and concrete are approximated using the compressive strengths obtained by Windsor Pin tests. Finite element modal analysis of the minaret is carried out to get the modal parameters. Experimental and analytical results are then compared and found in good agreement. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=experimental%20modal%20analysis" title="experimental modal analysis">experimental modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=stone%20minaret" title=" stone minaret"> stone minaret</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20modal%20analysis" title=" finite element modal analysis"> finite element modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=minarets" title=" minarets"> minarets</a> </p> <a href="https://publications.waset.org/abstracts/30455/experimental-modal-analysis-of-kursuncular-minaret" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/30455.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">326</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">27948</span> Modal Analysis of Small Frames using High Order Timoshenko Beams</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Chadi%20Azoury">Chadi Azoury</a>, <a href="https://publications.waset.org/abstracts/search?q=Assad%20Kallassy"> Assad Kallassy</a>, <a href="https://publications.waset.org/abstracts/search?q=Pierre%20Rahme"> Pierre Rahme</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, we consider the modal analysis of small frames. Firstly, we construct the 3D model using H8 elements and find the natural frequencies of the frame focusing our attention on the modes in the XY plane. Secondly, we construct the 2D model (plane stress model) using Q4 elements. We concluded that the results of both models are very close to each other’s. Then we formulate the stiffness matrix and the mass matrix of the 3-noded Timoshenko beam that is well suited for thick and short beams like in our case. Finally, we model the corners where the horizontal and vertical bar meet with a special matrix. The results of our new model (3-noded Timoshenko beam for the horizontal and vertical bars and a special element for the corners based on the Q4 elements) are very satisfying when performing the modal analysis. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=corner%20element" title="corner element">corner element</a>, <a href="https://publications.waset.org/abstracts/search?q=high-order%20Timoshenko%20beam" title=" high-order Timoshenko beam"> high-order Timoshenko beam</a>, <a href="https://publications.waset.org/abstracts/search?q=Guyan%20reduction" title=" Guyan reduction"> Guyan reduction</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis%20of%20frames" title=" modal analysis of frames"> modal analysis of frames</a>, <a href="https://publications.waset.org/abstracts/search?q=rigid%20link" title="rigid link">rigid link</a>, <a href="https://publications.waset.org/abstracts/search?q=shear%20locking" title=" shear locking"> shear locking</a>, <a href="https://publications.waset.org/abstracts/search?q=and%20short%20beams" title=" and short beams"> and short beams</a> </p> <a href="https://publications.waset.org/abstracts/24752/modal-analysis-of-small-frames-using-high-order-timoshenko-beams" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/24752.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">318</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">27947</span> Variations of the Modal Characteristics of the Feeding Stage with Different Preloaded Linear Guide</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jui-Pui%20Hung">Jui-Pui Hung</a>, <a href="https://publications.waset.org/abstracts/search?q=Yong-Run%20Chen"> Yong-Run Chen</a>, <a href="https://publications.waset.org/abstracts/search?q=Wei-Cheng%20Shih"> Wei-Cheng Shih</a>, <a href="https://publications.waset.org/abstracts/search?q=Chun-Wei%20Lin"> Chun-Wei Lin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study was aimed to assess the variations of the modal characteristics of the feeding stage with different linear guide modulus. The dynamic characteristics of the feeding stage were characterized in terms of the modal stiffness, modal frequency and modal damping, which are assessed from the vibration tests. According to the experimental measurements, the actual preload of the linear guide modulus was found to deviate from the rated values as setting in factory. This may be due to the assemblage errors of guide modules. For the stage with linear guides, the dynamic stiffness was affected to change by the preload set on the rolling balls. The variation of the dynamic stiffness at first and second modes is 20.8 and 10.5%, respectively when the linear guide preload is adjusted from medium and high amount. But the modal damping ratio is reduced by 8.97 and 9.65%, respectively. For high-frequency mode, the modal stiffness increases by 171.2% and the damping ratio reduced by 34.4%. Current results demonstrate the importance in the determining the preloaded amount of linear guide modulus in practical application. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=contact%20stiffness" title="contact stiffness">contact stiffness</a>, <a href="https://publications.waset.org/abstracts/search?q=feeding%20stage" title=" feeding stage"> feeding stage</a>, <a href="https://publications.waset.org/abstracts/search?q=linear%20guides" title=" linear guides"> linear guides</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20characteristics" title=" modal characteristics"> modal characteristics</a>, <a href="https://publications.waset.org/abstracts/search?q=pre-load" title=" pre-load"> pre-load</a> </p> <a href="https://publications.waset.org/abstracts/51628/variations-of-the-modal-characteristics-of-the-feeding-stage-with-different-preloaded-linear-guide" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/51628.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">430</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">27946</span> Structural Damage Detection Using Sensors Optimally Located</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Carlos%20Alberto%20Riveros">Carlos Alberto Riveros</a>, <a href="https://publications.waset.org/abstracts/search?q=Edwin%20Fabi%C3%A1n%20Garc%C3%ADa"> Edwin Fabián García</a>, <a href="https://publications.waset.org/abstracts/search?q=Javier%20Enrique%20Rivero"> Javier Enrique Rivero</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The measured data obtained from sensors in continuous monitoring of civil structures are mainly used for modal identification and damage detection. Therefore when modal identification analysis is carried out the quality in the identification of the modes will highly influence the damage detection results. It is also widely recognized that the usefulness of the measured data used for modal identification and damage detection is significantly influenced by the number and locations of sensors. The objective of this study is the numerical implementation of two widely known optimum sensor placement methods in beam-like structures <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=optimum%20sensor%20placement" title="optimum sensor placement">optimum sensor placement</a>, <a href="https://publications.waset.org/abstracts/search?q=structural%20damage%20detection" title=" structural damage detection"> structural damage detection</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20identification" title=" modal identification"> modal identification</a>, <a href="https://publications.waset.org/abstracts/search?q=beam-like%20structures." title=" beam-like structures. "> beam-like structures. </a> </p> <a href="https://publications.waset.org/abstracts/15240/structural-damage-detection-using-sensors-optimally-located" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/15240.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">431</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">27945</span> Modal Density Influence on Modal Complexity Quantification in Dynamic Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Fabrizio%20Iezzi">Fabrizio Iezzi</a>, <a href="https://publications.waset.org/abstracts/search?q=Claudio%20Valente"> Claudio Valente</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The viscous damping in dynamic systems can be proportional or non-proportional. In the first case, the mode shapes are real whereas in the second case they are complex. From an engineering point of view, the complexity of the mode shapes is important in order to quantify the non-proportional damping. Different indices exist to provide estimates of the modal complexity. These indices are or not zero, depending whether the mode shapes are not or are complex. The modal density problem arises in the experimental identification when the dynamic systems have close modal frequencies. Depending on the entity of this closeness, the mode shapes can hold fictitious imaginary quantities that affect the values of the modal complexity indices. The results are the failing in the identification of the real or complex mode shapes and then of the proportional or non-proportional damping. The paper aims to show the influence of the modal density on the values of these indices in case of both proportional and non-proportional damping. Theoretical and pseudo-experimental solutions are compared to analyze the problem according to an appropriate mechanical system. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=complex%20mode%20shapes" title="complex mode shapes">complex mode shapes</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20systems%20identification" title=" dynamic systems identification"> dynamic systems identification</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20density" title=" modal density"> modal density</a>, <a href="https://publications.waset.org/abstracts/search?q=non-proportional%20damping" title=" non-proportional damping"> non-proportional damping</a> </p> <a href="https://publications.waset.org/abstracts/52803/modal-density-influence-on-modal-complexity-quantification-in-dynamic-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/52803.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">387</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">27944</span> Experimental Analysis of Structure Borne Noise in an Enclosure</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Waziralilah%20N.%20Fathiah">Waziralilah N. Fathiah</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Aminudin"> A. Aminudin</a>, <a href="https://publications.waset.org/abstracts/search?q=U.%20Alyaa%20Hashim"> U. Alyaa Hashim</a>, <a href="https://publications.waset.org/abstracts/search?q=T.%20Vikneshvaran%20D.%20Shakirah%20Shukor"> T. Vikneshvaran D. Shakirah Shukor</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the experimental analysis conducted on a structure borne noise in a rectangular enclosure prototype made by joining of sheet aluminum metal and plywood. The study is significant as many did not realized the annoyance caused by structural borne-noise. In this study, modal analysis is carried out to seek the structure’s behaviour in order to identify the characteristics of enclosure in frequency domain ranging from 0 Hz to 200 Hz. Here, numbers of modes are identified and the characteristic of mode shape is categorized. Modal experiment is used to diagnose the structural behaviour while microphone is used to diagnose the sound. Spectral testing is performed on the enclosure. It is acoustically excited using shaker and as it vibrates, the vibrational and noise responses sensed by tri-axis accelerometer and microphone sensors are recorded respectively. Experimental works is performed on each node lies on the gridded surface of the enclosure. Both experimental measurement is carried out simultaneously. The modal experimental results of the modal modes are validated by simulation performed using MSC Nastran software. In pursuance of reducing the structure borne-noise, mitigation method is used whereby the stiffener plates are perpendicularly placed on the sheet aluminum metal. By using this method, reduction in structure borne-noise is successfully made at the end of the study. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=enclosure" title="enclosure">enclosure</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=sound%20analysis" title=" sound analysis"> sound analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=structure%20borne-noise" title=" structure borne-noise"> structure borne-noise</a> </p> <a href="https://publications.waset.org/abstracts/63244/experimental-analysis-of-structure-borne-noise-in-an-enclosure" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/63244.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">435</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">27943</span> Damage Identification Using Experimental Modal Analysis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Niladri%20Sekhar%20Barma">Niladri Sekhar Barma</a>, <a href="https://publications.waset.org/abstracts/search?q=Satish%20Dhandole"> Satish Dhandole</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Damage identification in the context of safety, nowadays, has become a fundamental research interest area in the field of mechanical, civil, and aerospace engineering structures. The following research is aimed to identify damage in a mechanical beam structure and quantify the severity or extent of damage in terms of loss of stiffness, and obtain an updated analytical Finite Element (FE) model. An FE model is used for analysis, and the location of damage for single and multiple damage cases is identified numerically using the modal strain energy method and mode shape curvature method. Experimental data has been acquired with the help of an accelerometer. Fast Fourier Transform (FFT) algorithm is applied to the measured signal, and subsequently, post-processing is done in MEscopeVes software. The two sets of data, the numerical FE model and experimental results, are compared to locate the damage accurately. The extent of the damage is identified via modal frequencies using a mixed numerical-experimental technique. Mode shape comparison is performed by Modal Assurance Criteria (MAC). The analytical FE model is adjusted by the direct method of model updating. The same study has been extended to some real-life structures such as plate and GARTEUR structures. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=damage%20identification" title="damage identification">damage identification</a>, <a href="https://publications.waset.org/abstracts/search?q=damage%20quantification" title=" damage quantification"> damage quantification</a>, <a href="https://publications.waset.org/abstracts/search?q=damage%20detection%20using%20modal%20analysis" title=" damage detection using modal analysis"> damage detection using modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=structural%20damage%20identification" title=" structural damage identification"> structural damage identification</a> </p> <a href="https://publications.waset.org/abstracts/150078/damage-identification-using-experimental-modal-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/150078.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">116</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">27942</span> Pseudo Modal Operating Deflection Shape Based Estimation Technique of Mode Shape Using Time History Modal Assurance Criterion</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Doyoung%20Kim">Doyoung Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=Hyo%20Seon%20Park"> Hyo Seon Park</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Studies of System Identification(SI) based on Structural Health Monitoring(SHM) have actively conducted for structural safety. Recently SI techniques have been rapidly developed with output-only SI paradigm for estimating modal parameters. The features of these output-only SI methods consist of Frequency Domain Decomposition(FDD) and Stochastic Subspace Identification(SSI) are using the algorithms based on orthogonal decomposition such as singular value decomposition(SVD). But the SVD leads to high level of computational complexity to estimate modal parameters. This paper proposes the technique to estimate mode shape with lower computational cost. This technique shows pseudo modal Operating Deflections Shape(ODS) through bandpass filter and suggests time history Modal Assurance Criterion(MAC). Finally, mode shape could be estimated from pseudo modal ODS and time history MAC. Analytical simulations of vibration measurement were performed and the results with mode shape and computation time between representative SI method and proposed method were compared. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=modal%20assurance%20criterion" title="modal assurance criterion">modal assurance criterion</a>, <a href="https://publications.waset.org/abstracts/search?q=mode%20shape" title=" mode shape"> mode shape</a>, <a href="https://publications.waset.org/abstracts/search?q=operating%20deflection%20shape" title=" operating deflection shape"> operating deflection shape</a>, <a href="https://publications.waset.org/abstracts/search?q=system%20identification" title=" system identification"> system identification</a> </p> <a href="https://publications.waset.org/abstracts/52251/pseudo-modal-operating-deflection-shape-based-estimation-technique-of-mode-shape-using-time-history-modal-assurance-criterion" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/52251.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">410</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">27941</span> Power Flow and Modal Analysis of a Power System Including Unified Power Flow Controller</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Djilani%20Kobibi%20Youcef%20Islam">Djilani Kobibi Youcef Islam</a>, <a href="https://publications.waset.org/abstracts/search?q=Hadjeri%20Samir"> Hadjeri Samir</a>, <a href="https://publications.waset.org/abstracts/search?q=Djehaf%20Mohamed%20Abdeldjalil"> Djehaf Mohamed Abdeldjalil</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The Flexible AC Transmission System (FACTS) technology is a new advanced solution that increases the reliability and provides more flexibility, controllability, and stability of a power system. The Unified Power Flow Controller (UPFC), as the most versatile FACTS device for regulating power flow, is able to control respectively transmission line real power, reactive power, and node voltage. The main purpose of this paper is to analyze the effect of the UPFC on the load flow, the power losses, and the voltage stability using NEPLAN software modules, Newton-Raphson load flow is used for the power flow analysis and the modal analysis is used for the study of the voltage stability. The simulation was carried out on the IEEE 14-bus test system. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=FACTS" title="FACTS">FACTS</a>, <a href="https://publications.waset.org/abstracts/search?q=load%20flow" title=" load flow"> load flow</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=UPFC" title=" UPFC"> UPFC</a>, <a href="https://publications.waset.org/abstracts/search?q=voltage%20stability" title=" voltage stability"> voltage stability</a> </p> <a href="https://publications.waset.org/abstracts/41037/power-flow-and-modal-analysis-of-a-power-system-including-unified-power-flow-controller" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/41037.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">516</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">27940</span> The Cracks Propagation Monitoring of a Cantilever Beam Using Modal Analysis </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Morteza%20Raki">Morteza Raki</a>, <a href="https://publications.waset.org/abstracts/search?q=Abolghasem%20Zabihollah"> Abolghasem Zabihollah</a>, <a href="https://publications.waset.org/abstracts/search?q=Omid%20Askari"> Omid Askari </a> </p> <p class="card-text"><strong>Abstract:</strong></p> Cantilever beam is a simplified sample of a lot of mechanical components used in a wide range of applications, including many industries such as gas turbine blade. Due to the nature of the operating conditions, beams are subject to variety of damages especially crack propagates. Crack propagation may lead to catastrophic failure during operation. Therefore, online detection of crack presence and its propagation is very important and may reduce possible significant cost of the whole system failure. This paper aims to investigate the effect of cracks presence and crack propagation on one end fixed beam`s vibration. A finite element model will be developed for the blade in which the modal response of the structure with and without crack will be studied.  <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=blade" title="blade">blade</a>, <a href="https://publications.waset.org/abstracts/search?q=crack%20propagation" title=" crack propagation"> crack propagation</a>, <a href="https://publications.waset.org/abstracts/search?q=health%20monitoring" title=" health monitoring"> health monitoring</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a> </p> <a href="https://publications.waset.org/abstracts/48812/the-cracks-propagation-monitoring-of-a-cantilever-beam-using-modal-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/48812.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">344</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">27939</span> A Simple Approach to Reliability Assessment of Structures via Anomaly Detection</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Rims%20Janeliukstis">Rims Janeliukstis</a>, <a href="https://publications.waset.org/abstracts/search?q=Deniss%20Mironovs"> Deniss Mironovs</a>, <a href="https://publications.waset.org/abstracts/search?q=Andrejs%20Kovalovs"> Andrejs Kovalovs</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Operational Modal Analysis (OMA) is widely applied as a method for Structural Health Monitoring for structural damage identification and assessment by tracking the changes of the identified modal parameters over time. Unfortunately, modal parameters also depend on such external factors as temperature and loads. Any structural condition assessment using modal parameters should be done taking into consideration those external factors, otherwise there is a high chance of false positives. A method of structural reliability assessment based on anomaly detection technique called Machalanobis Squared Distance (MSD) is proposed. It requires a set of reference conditions to learn healthy state of a structure, which all future parameters are compared to. In this study, structural modal parameters (natural frequency and mode shape), as well as ambient temperature and loads acting on the structure are used as features. Numerical tests were performed on a finite element model of a carbon fibre reinforced polymer composite beam with delamination damage at various locations and of various severities. The advantages of the demonstrated approach include relatively few computational steps, ability to distinguish between healthy and damaged conditions and discriminate between different damage severities. It is anticipated to be promising in reliability assessment of massively produced structural parts. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=operational%20modal%20analysis" title="operational modal analysis">operational modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=reliability%20assessment" title=" reliability assessment"> reliability assessment</a>, <a href="https://publications.waset.org/abstracts/search?q=anomaly%20detection" title=" anomaly detection"> anomaly detection</a>, <a href="https://publications.waset.org/abstracts/search?q=damage" title=" damage"> damage</a>, <a href="https://publications.waset.org/abstracts/search?q=mahalanobis%20squared%20distance" title=" mahalanobis squared distance"> mahalanobis squared distance</a> </p> <a href="https://publications.waset.org/abstracts/148382/a-simple-approach-to-reliability-assessment-of-structures-via-anomaly-detection" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/148382.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">114</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">27938</span> Numerical and Experimental Investigations of Cantilever Rectangular Plate Structure on Subsonic Flutter</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mevl%C3%BCt%20Burak%20Dalm%C4%B1%C5%9F">Mevlüt Burak Dalmış</a>, <a href="https://publications.waset.org/abstracts/search?q=Kemal%20Yaman"> Kemal Yaman</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study, flutter characteristics of cantilever rectangular plate structure under incompressible flow regime are investigated by comparing the results of commercial flutter analysis program ZAERO<sup>©</sup> with wind tunnel tests conducted in Ankara Wind Tunnel (ART). A rectangular polycarbonate (PC) plate, 5x125x1000 mm in dimensions, is used for both numerical and experimental investigations. Analysis and test results are very compatible with each other. A comparison between two different solution methods (<em>g</em> and <em>k-method</em>) of ZAERO<sup>©</sup> is also done. It is seen that, <em>k-method</em> gives closer result than the other one. However, g-method results are on conservative side and it is better to use conservative results namely g-method results. Even if the modal analysis results are used for the flutter analysis for this simple structure, a modal test should be conducted in order to validate the modal analysis results to have accurate flutter analysis results for more complicated structures. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=flutter" title="flutter">flutter</a>, <a href="https://publications.waset.org/abstracts/search?q=plate" title=" plate"> plate</a>, <a href="https://publications.waset.org/abstracts/search?q=subsonic%20flow" title=" subsonic flow"> subsonic flow</a>, <a href="https://publications.waset.org/abstracts/search?q=wind%20tunnel" title=" wind tunnel"> wind tunnel</a> </p> <a href="https://publications.waset.org/abstracts/35131/numerical-and-experimental-investigations-of-cantilever-rectangular-plate-structure-on-subsonic-flutter" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/35131.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">518</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">27937</span> The Use of Corpora in Improving Modal Verb Treatment in English as Foreign Language Textbooks</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Lexi%20Li">Lexi Li</a>, <a href="https://publications.waset.org/abstracts/search?q=Vanessa%20H.%20K.%20Pang"> Vanessa H. K. Pang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study aims to demonstrate how native and learner corpora can be used to enhance modal verb treatment in EFL textbooks in mainland China. It contributes to a corpus-informed and learner-centered design of grammar presentation in EFL textbooks that enhances the authenticity and appropriateness of textbook language for target learners. The linguistic focus is will, would, can, could, may, might, shall, should, must. The native corpus is the spoken component of BNC2014 (hereafter BNCS2014). The spoken part is chosen because pedagogical purpose of the textbooks is communication-oriented. Using the standard query option of CQPweb, 5% of each of the nine modals was sampled from BNCS2014. The learner corpus is the POS-tagged Ten-thousand English Compositions of Chinese Learners (TECCL). All the essays under the 'secondary school' section were selected. A series of five secondary coursebooks comprise the textbook corpus. All the data in both the learner and the textbook corpora are retrieved through the concordance functions of WordSmith Tools (version, 5.0). Data analysis was divided into two parts. The first part compared the patterns of modal verbs in the textbook corpus and BNC2014 with respect to distributional features, semantic functions, and co-occurring constructions to examine whether the textbooks reflect the authentic use of English. Secondly, the learner corpus was analyzed in terms of the use (distributional features, semantic functions, and co-occurring constructions) and the misuse (syntactic errors, e.g., she can sings*.) of the nine modal verbs to uncover potential difficulties that confront learners. The analysis of distribution indicates several discrepancies between the textbook corpus and BNCS2014. The first four most frequent modal verbs in BNCS2014 are can, would, will, could, while can, will, should, could are the top four in the textbooks. Most strikingly, there is an unusually high proportion of can (41.1%) in the textbooks. The results on different meanings shows that will, would and must are the most problematic. For example, for will, the textbooks contain 20% more occurrences of 'volition' and 20% less of 'prediction' than those in BNCS2014. Regarding co-occurring structures, the textbooks over-represented the structure 'modal +do' across the nine modal verbs. Another major finding is that the structure of 'modal +have done' that frequently co-occur with could, would, should, and must is underused in textbooks. Besides, these four modal verbs are the most difficult for learners, as the error analysis shows. This study demonstrates how the synergy of native and learner corpora can be harnessed to improve EFL textbook presentation of modal verbs in a way that textbooks can provide not only authentic language used in natural discourse but also appropriate design tailed for the needs of target learners. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=English%20as%20Foreign%20Language" title="English as Foreign Language">English as Foreign Language</a>, <a href="https://publications.waset.org/abstracts/search?q=EFL%20textbooks" title=" EFL textbooks"> EFL textbooks</a>, <a href="https://publications.waset.org/abstracts/search?q=learner%20corpus" title=" learner corpus"> learner corpus</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20verbs" title=" modal verbs"> modal verbs</a>, <a href="https://publications.waset.org/abstracts/search?q=native%20corpus" title=" native corpus"> native corpus</a> </p> <a href="https://publications.waset.org/abstracts/109495/the-use-of-corpora-in-improving-modal-verb-treatment-in-english-as-foreign-language-textbooks" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/109495.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">142</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">27936</span> Damage Identification in Reinforced Concrete Beams Using Modal Parameters and Their Formulation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ali%20Al-Ghalib">Ali Al-Ghalib</a>, <a href="https://publications.waset.org/abstracts/search?q=Fouad%20Mohammad"> Fouad Mohammad</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The identification of damage in reinforced concrete structures subjected to incremental cracking performance exploiting vibration data is recognized as a challenging topic in the published and heavily cited literature. Therefore, this paper attempts to shine light on the extent of dynamic methods when applied to reinforced concrete beams simulated with various scenarios of defects. For this purpose, three different reinforced concrete beams are tested through the course of the study. The three beams are loaded statically to failure in incremental successive load cycles and later rehabilitated. After each static load stage, the beams are tested under free-free support condition using experimental modal analysis. The beams were all of the same length and cross-sectional area (2.0x0.14x0.09)m, but they were different in concrete compressive strength and the type of damage presented. The experimental modal parameters as damage identification parameters were showed computationally expensive, time consuming and require substantial inputs and considerable expertise. Nonetheless, they were proved plausible for the condition monitoring of the current case study as well as structural changes in the course of progressive loads. It was accentuated that a satisfactory localization and quantification for structural changes (Level 2 and Level 3 of damage identification problem) can only be achieved reasonably through considering frequencies and mode shapes of a system in a proper analytical model. A convenient post analysis process for various datasets of vibration measurements for the three beams is conducted in order to extract, check and correlate the basic modal parameters; namely, natural frequency, modal damping and mode shapes. The results of the extracted modal parameters and their combination are utilized and discussed in this research as quantification parameters. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=experimental%20modal%20analysis" title="experimental modal analysis">experimental modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=damage%20identification" title=" damage identification"> damage identification</a>, <a href="https://publications.waset.org/abstracts/search?q=structural%20health%20monitoring" title=" structural health monitoring"> structural health monitoring</a>, <a href="https://publications.waset.org/abstracts/search?q=reinforced%20concrete%20beam" title=" reinforced concrete beam"> reinforced concrete beam</a> </p> <a href="https://publications.waset.org/abstracts/59519/damage-identification-in-reinforced-concrete-beams-using-modal-parameters-and-their-formulation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/59519.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">263</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">27935</span> On the Accuracy of Basic Modal Displacement Method Considering Various Earthquakes</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seyed%20Sadegh%20Naseralavi">Seyed Sadegh Naseralavi</a>, <a href="https://publications.waset.org/abstracts/search?q=Sadegh%20Balaghi"> Sadegh Balaghi</a>, <a href="https://publications.waset.org/abstracts/search?q=Ehsan%20Khojastehfar"> Ehsan Khojastehfar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Time history seismic analysis is supposed to be the most accurate method to predict the seismic demand of structures. On the other hand, the required computational time of this method toward achieving the result is its main deficiency. While being applied in optimization process, in which the structure must be analyzed thousands of time, reducing the required computational time of seismic analysis of structures makes the optimization algorithms more practical. Apparently, the invented approximate methods produce some amount of errors in comparison with exact time history analysis but the recently proposed method namely, Complete Quadratic Combination (CQC) and Sum Root of the Sum of Squares (SRSS) drastically reduces the computational time by combination of peak responses in each mode. In the present research, the Basic Modal Displacement (BMD) method is introduced and applied towards estimation of seismic demand of main structure. Seismic demand of sampled structure is estimated by calculation of modal displacement of basic structure (in which the modal displacement has been calculated). Shear steel sampled structures are selected as case studies. The error applying the introduced method is calculated by comparison of the estimated seismic demands with exact time history dynamic analysis. The efficiency of the proposed method is demonstrated by application of three types of earthquakes (in view of time of peak ground acceleration). <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=time%20history%20dynamic%20analysis" title="time history dynamic analysis">time history dynamic analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=basic%20modal%20displacement" title=" basic modal displacement"> basic modal displacement</a>, <a href="https://publications.waset.org/abstracts/search?q=earthquake-induced%20demands" title=" earthquake-induced demands"> earthquake-induced demands</a>, <a href="https://publications.waset.org/abstracts/search?q=shear%20steel%20structures" title=" shear steel structures"> shear steel structures</a> </p> <a href="https://publications.waset.org/abstracts/51518/on-the-accuracy-of-basic-modal-displacement-method-considering-various-earthquakes" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/51518.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">355</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">27934</span> Vibrations of Springboards: Mode Shape and Time Domain Analysis </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Stefano%20Frassinelli">Stefano Frassinelli</a>, <a href="https://publications.waset.org/abstracts/search?q=Alessandro%20Niccolai"> Alessandro Niccolai</a>, <a href="https://publications.waset.org/abstracts/search?q=Riccardo%20E.%20Zich"> Riccardo E. Zich</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Diving is an important Olympic sport. In this sport, the effective performance of the athlete is related to his capability to interact correctly with the springboard. In fact, the elevation of the jump and the correctness of the dive are influenced by the vibrations of the board. In this paper, the vibrations of the springboard will be analyzed by means of typical tools for vibration analysis: Firstly, a modal analysis will be done on two different models of the springboard, then, these two model and another one will be analyzed with a time analysis, done integrating the equations of motion od deformable bodies. All these analyses will be compared with experimental data measured on a real springboard by means of a 6-axis accelerometer; these measurements are aimed to assess the models proposed. The acquired data will be analyzed both in frequency domain and in time domain. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=springboard%20analysis" title="springboard analysis">springboard analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=time%20domain%20analysis" title=" time domain analysis"> time domain analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=vibrations" title=" vibrations"> vibrations</a> </p> <a href="https://publications.waset.org/abstracts/61559/vibrations-of-springboards-mode-shape-and-time-domain-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/61559.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">460</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">27933</span> Excitation of Guided Waves in Finite Width Plates Using a Numerical Approach</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Wenbo%20Duan">Wenbo Duan</a>, <a href="https://publications.waset.org/abstracts/search?q=Hossein%20Habibi"> Hossein Habibi</a>, <a href="https://publications.waset.org/abstracts/search?q=Vassilios%20Kappatos"> Vassilios Kappatos</a>, <a href="https://publications.waset.org/abstracts/search?q=Cem%20Selcuk"> Cem Selcuk</a>, <a href="https://publications.waset.org/abstracts/search?q=Tat-Hean%20Gan"> Tat-Hean Gan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Ultrasonic guided waves are often used to remove ice or fouling in different structures, such as ship hulls, wind turbine blades and so on. To achieve maximum sound power output, it is important that multiple transducers are arranged in a particular way so that a desired mode can be excited. The objective of this paper is thus to provide a theoretical basis for generating a particular mode in a finite width rectangular plate which can be used for removing potential ice or fouling on the plate. The number of transducers and their locations with respect to a particular mode will be investigated, and the link between dispersion curves and practical applications will be explored. To achieve this, a semi-analytical finite element (SAFE) method is used to study the dispersion characteristics of all the modes in the ultrasonic frequency range. The detailed modal shapes will be revealed, and from the modal analysis, the particular mode with the strongest yet continuous transverse and axial displacements on the surfaces of the plate will be chosen for the purpose of removing potential ice or fouling on the plate. The modal analysis is followed by providing information on the number, location and amplitude of transducers needed to excite this particular mode. Modal excitation is then implemented in a standard finite element commercial package, namely COMSOL Multiphysics. Wave motion is visualized in COMSOL, and the mode shapes generated in SAFE is found to be consistent with the mode shapes generated in COMSOL. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dispersion%20analysis" title="dispersion analysis">dispersion analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20width%20plate" title=" finite width plate"> finite width plate</a>, <a href="https://publications.waset.org/abstracts/search?q=guided%20wave" title=" guided wave"> guided wave</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20excitation" title=" modal excitation"> modal excitation</a> </p> <a href="https://publications.waset.org/abstracts/40120/excitation-of-guided-waves-in-finite-width-plates-using-a-numerical-approach" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/40120.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">473</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">27932</span> Model Updating Based on Modal Parameters Using Hybrid Pattern Search Technique</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=N.%20Guo">N. Guo</a>, <a href="https://publications.waset.org/abstracts/search?q=C.%20Xu"> C. Xu</a>, <a href="https://publications.waset.org/abstracts/search?q=Z.%20C.%20Yang"> Z. C. Yang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In order to ensure the high reliability of an aircraft, the accurate structural dynamics analysis has become an indispensable part in the design of an aircraft structure. Therefore, the structural finite element model which can be used to accurately calculate the structural dynamics and their transfer relations is the prerequisite in structural dynamic design. A dynamic finite element model updating method is presented to correct the uncertain parameters of the finite element model of a structure using measured modal parameters. The coordinate modal assurance criterion is used to evaluate the correlation level at each coordinate over the experimental and the analytical mode shapes. Then, the weighted summation of the natural frequency residual and the coordinate modal assurance criterion residual is used as the objective function. Moreover, the hybrid pattern search (HPS) optimization technique, which synthesizes the advantages of pattern search (PS) optimization technique and genetic algorithm (GA), is introduced to solve the dynamic FE model updating problem. A numerical simulation and a model updating experiment for GARTEUR aircraft model are performed to validate the feasibility and effectiveness of the present dynamic model updating method, respectively. The updated results show that the proposed method can be successfully used to modify the incorrect parameters with good robustness. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=model%20updating" title="model updating">model updating</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20parameter" title=" modal parameter"> modal parameter</a>, <a href="https://publications.waset.org/abstracts/search?q=coordinate%20modal%20assurance%20criterion" title=" coordinate modal assurance criterion"> coordinate modal assurance criterion</a>, <a href="https://publications.waset.org/abstracts/search?q=hybrid%20genetic%2Fpattern%20search" title=" hybrid genetic/pattern search"> hybrid genetic/pattern search</a> </p> <a href="https://publications.waset.org/abstracts/98650/model-updating-based-on-modal-parameters-using-hybrid-pattern-search-technique" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/98650.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">161</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">27931</span> Modal Analysis for Study of Minor Historical Architecture</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Milorad%20Pavlovic">Milorad Pavlovic</a>, <a href="https://publications.waset.org/abstracts/search?q=Anna%20Manzato"> Anna Manzato</a>, <a href="https://publications.waset.org/abstracts/search?q=Antonella%20Cecchi"> Antonella Cecchi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Cultural heritage conservation is a challenge for contemporary society. In recent decades, significant resources have been allocated for the conservation and restoration of architectural heritage. Historical buildings were restored, protected and reinforced with the intent to limit the risks of degradation or loss, due to phenomena of structural damage and to external factors such as differential settlements, earthquake effects, etc. The wide diffusion of historic masonry constructions in Italy, Europe and the Mediterranean area requires reliable tools for the evaluation of their structural safety. In this paper is presented a free modal analysis performed on a minor historical architecture located in the village of Bagno Grande, near the city of L’Aquila in Italy. The location is characterized by a complex urban context, seriously damaged by the earthquake of 2009. The aim of this work is to check the structural behavior of a masonry building characterized by several boundary conditions imposed by adjacent buildings and infrastructural facilities. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=FEM" title="FEM">FEM</a>, <a href="https://publications.waset.org/abstracts/search?q=masonry" title=" masonry"> masonry</a>, <a href="https://publications.waset.org/abstracts/search?q=minor%20historical%20architecture" title=" minor historical architecture"> minor historical architecture</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a> </p> <a href="https://publications.waset.org/abstracts/53970/modal-analysis-for-study-of-minor-historical-architecture" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/53970.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">317</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">27930</span> Comparison between Pushover Analysis Techniques and Validation of the Simplified Modal Pushover Analysis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=N.%20F.%20Hanna">N. F. Hanna</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20M.%20Haridy"> A. M. Haridy </a> </p> <p class="card-text"><strong>Abstract:</strong></p> One of the main drawbacks of the Modal Pushover Analysis (MPA) is the need to perform nonlinear time-history analysis, which complicates the analysis method and time. A simplified version of the MPA has been proposed based on the concept of the inelastic deformation ratio. Furthermore, the effect of the higher modes of vibration is considered by assuming linearly-elastic responses, which enables the use of standard elastic response spectrum analysis. In this thesis, the simplified MPA (SMPA) method is applied to determine the target global drift and the inter-story drifts of steel frame building. The effect of the higher vibration modes is considered within the framework of the SMPA. A comprehensive survey about the inelastic deformation ratio is presented. After that, a suitable expression from literature is selected for the inelastic deformation ratio and then implemented in the SMPA. The estimated seismic demands using the SMPA, such as target drift, base shear, and the inter-story drifts, are compared with the seismic responses determined by applying the standard MPA. The accuracy of the estimated seismic demands is validated by comparing with the results obtained by the nonlinear time-history analysis using real earthquake records. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title="modal analysis">modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=pushover%20analysis" title=" pushover analysis"> pushover analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=seismic%20performance" title=" seismic performance"> seismic performance</a>, <a href="https://publications.waset.org/abstracts/search?q=target%20displacement" title=" target displacement"> target displacement</a> </p> <a href="https://publications.waset.org/abstracts/69976/comparison-between-pushover-analysis-techniques-and-validation-of-the-simplified-modal-pushover-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/69976.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">361</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">27929</span> Modal Analysis of Functionally Graded Materials Plates Using Finite Element Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20J.%20Shahidzadeh%20Tabatabaei">S. J. Shahidzadeh Tabatabaei</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20M.%20Fattahi"> A. M. Fattahi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Modal analysis of an FGM plate composed of Al2O3 ceramic phase and 304 stainless steel metal phases was performed in this paper by ABAQUS software with the assumption that the behavior of material is elastic and mechanical properties (Young's modulus and density) are variable in the thickness direction of the plate. Therefore, a sub-program was written in FORTRAN programming language and was linked with ABAQUS software. For modal analysis, a finite element analysis was carried out similar to the model of other researchers and the accuracy of results was evaluated after comparing the results. Comparison of natural frequencies and mode shapes reflected the compatibility of results and optimal performance of the program written in FORTRAN as well as high accuracy of finite element model used in this research. After validation of the results, it was evaluated the effect of material (n parameter) on the natural frequency. In this regard, finite element analysis was carried out for different values of n and in simply supported mode. About the effect of n parameter that indicates the effect of material on the natural frequency, it was observed that the natural frequency decreased as n increased; because by increasing n, the share of ceramic phase on FGM plate has decreased and the share of steel phase has increased and this led to reducing stiffness of FGM plate and thereby reduce in the natural frequency. That is because the Young's modulus of Al2O3 ceramic is equal to 380 GPa and Young's modulus of SUS304 steel is 207 GPa. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=FGM%20plates" title="FGM plates">FGM plates</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20frequency" title=" natural frequency"> natural frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20method" title=" finite element method"> finite element method</a> </p> <a href="https://publications.waset.org/abstracts/46792/modal-analysis-of-functionally-graded-materials-plates-using-finite-element-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/46792.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">391</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">27928</span> FEM and Experimental Modal Analysis of Computer Mount</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Vishwajit%20Ghatge">Vishwajit Ghatge</a>, <a href="https://publications.waset.org/abstracts/search?q=David%20Looper"> David Looper</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Over the last few decades, oilfield service rolling equipment has significantly increased in weight, primarily because of emissions regulations, which require larger/heavier engines, larger cooling systems, and emissions after-treatment systems, in some cases, etc. Larger engines cause more vibration and shock loads, leading to failure of electronics and control systems. If the vibrating frequency of the engine matches the system frequency, high resonance is observed on structural parts and mounts. One such existing automated control equipment system comprising wire rope mounts used for mounting computers was designed approximately 12 years ago. This includes the use of an industrial- grade computer to control the system operation. The original computer had a smaller, lighter enclosure. After a few years, a newer computer version was introduced, which was 10 lbm heavier. Some failures of internal computer parts have been documented for cases in which the old mounts were used. Because of the added weight, there is a possibility of having the two brackets impact each other under off-road conditions, which causes a high shock input to the computer parts. This added failure mode requires validating the existing mount design to suit the new heavy-weight computer. This paper discusses the modal finite element method (FEM) analysis and experimental modal analysis conducted to study the effects of vibration on the wire rope mounts and the computer. The existing mount was modelled in ANSYS software, and resultant mode shapes and frequencies were obtained. The experimental modal analysis was conducted, and actual frequency responses were observed and recorded. Results clearly revealed that at resonance frequency, the brackets were colliding and potentially causing damage to computer parts. To solve this issue, spring mounts of different stiffness were modeled in ANSYS software, and the resonant frequency was determined. Increasing the stiffness of the system increased the resonant frequency zone away from the frequency window at which the engine showed heavy vibrations or resonance. After multiple iterations in ANSYS software, the stiffness of the spring mount was finalized, which was again experimentally validated. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=experimental%20modal%20analysis" title="experimental modal analysis">experimental modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=FEM%20Modal%20Analysis" title=" FEM Modal Analysis"> FEM Modal Analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=frequency" title=" frequency"> frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=modal%20analysis" title=" modal analysis"> modal analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=resonance" title=" resonance"> resonance</a>, <a href="https://publications.waset.org/abstracts/search?q=vibration" title=" vibration"> vibration</a> </p> <a 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