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fatigue</title> <meta name="description" content="Search results for: multiaxial fatigue"> <meta name="keywords" content="multiaxial fatigue"> <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="multiaxial fatigue"> <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> 642</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: multiaxial fatigue</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">642</span> Multiaxial Fatigue Analysis of a High Performance Nickel-Based Superalloy</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=P.%20Selva">P. Selva</a>, <a href="https://publications.waset.org/abstracts/search?q=B.%20Lorraina"> B. Lorraina</a>, <a href="https://publications.waset.org/abstracts/search?q=J.%20Alexis"> J. Alexis</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Seror"> A. Seror</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Longuet"> A. Longuet</a>, <a href="https://publications.waset.org/abstracts/search?q=C.%20Mary"> C. Mary</a>, <a href="https://publications.waset.org/abstracts/search?q=F.%20Denard"> F. Denard</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Over the past four decades, the fatigue behavior of nickel-based alloys has been widely studied. However, in recent years, significant advances in the fabrication process leading to grain size reduction have been made in order to improve fatigue properties of aircraft turbine discs. Indeed, a change in particle size affects the initiation mode of fatigue cracks as well as the fatigue life of the material. The present study aims to investigate the fatigue behavior of a newly developed nickel-based superalloy under biaxial-planar loading. Low Cycle Fatigue (LCF) tests are performed at different stress ratios so as to study the influence of the multiaxial stress state on the fatigue life of the material. Full-field displacement and strain measurements as well as crack initiation detection are obtained using Digital Image Correlation (DIC) techniques. The aim of this presentation is first to provide an in-depth description of both the experimental set-up and protocol: the multiaxial testing machine, the specific design of the cruciform specimen and performances of the DIC code are introduced. Second, results for sixteen specimens related to different load ratios are presented. Crack detection, strain amplitude and number of cycles to crack initiation vs. triaxial stress ratio for each loading case are given. Third, from fractographic investigations by scanning electron microscopy it is found that the mechanism of fatigue crack initiation does not depend on the triaxial stress ratio and that most fatigue cracks initiate from subsurface carbides. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cruciform%20specimen" title="cruciform specimen">cruciform specimen</a>, <a href="https://publications.waset.org/abstracts/search?q=multiaxial%20fatigue" title=" multiaxial fatigue"> multiaxial fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=nickel-based%20superalloy" title=" nickel-based superalloy"> nickel-based superalloy</a> </p> <a href="https://publications.waset.org/abstracts/22039/multiaxial-fatigue-analysis-of-a-high-performance-nickel-based-superalloy" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/22039.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">295</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">641</span> Fatigue Life Evaluation of Al6061/Al2O3 and Al6061/SiC Composites under Uniaxial and Multiaxial Loading Conditions</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=C.%20E.%20Sutton">C. E. Sutton</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Varvani-Farahani"> A. Varvani-Farahani</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Fatigue damage and life prediction of particle metal matrix composites (PMMCs) under uniaxial and multiaxial loading conditions were investigated. Three PMM composite materials of Al6061/Al2O3/20p-T6, Al6061/Al2O3/22p-T6 and Al6061/SiC/17w-T6 tested under tensile, torsion, and combined tension-torsion fatigue cycling were evaluated with various fatigue damage models. The fatigue damage models of Smith-Watson-Topper (S. W. T.), Ellyin, Brown-Miller, Fatemi-Socie, and Varvani were compared for their capability to assess the fatigue damage of materials undergoing various loading conditions. Fatigue life predication results were then evaluated by implementing material-dependent coefficients that factored in the effects of the particle reinforcement in the earlier developed Varvani model. The critical plane-energy approach incorporated the critical plane as the plane of crack initiation and early stage of crack growth. The strain energy density was calculated on the critical plane incorporating stress and strain components acting on the plane. This approach successfully evaluated fatigue damage values versus fatigue lives within a narrower band for both uniaxial and multiaxial loading conditions as compared with other damage approaches studied in this paper. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue%20damage" title="fatigue damage">fatigue damage</a>, <a href="https://publications.waset.org/abstracts/search?q=life%20prediction" title=" life prediction"> life prediction</a>, <a href="https://publications.waset.org/abstracts/search?q=critical%20plane%20approach" title=" critical plane approach"> critical plane approach</a>, <a href="https://publications.waset.org/abstracts/search?q=energy%20approach" title=" energy approach"> energy approach</a>, <a href="https://publications.waset.org/abstracts/search?q=PMM%20composites" title=" PMM composites"> PMM composites</a> </p> <a href="https://publications.waset.org/abstracts/18743/fatigue-life-evaluation-of-al6061al2o3-and-al6061sic-composites-under-uniaxial-and-multiaxial-loading-conditions" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/18743.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">403</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">640</span> Investigation of the Multiaxial Pedicle Screw Tulip Design Using Finite Element Analysis</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Daqiqeh%20Rezaei">S. Daqiqeh Rezaei</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.%20R.%20Sharifi"> M. R. Sharifi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Pedicle screws are used to stabilize vertebrae and treat several types of spinal diseases and injuries. Multiaxial pedicle screws are a type of pedicle screw that increase surgical versatility, but they also increase design complexity. Failure of multiaxial pedicle screws caused by static loading, dynamic loading and fatigue can lead to irreparable damage to the patient. Inappropriate deformation of the multiaxial pedicle screw tulip can cause system failure. Investigation of deformation and stress in these tulips can be employed to optimize multiaxial pedicle screw design. The sensitivity of this matter necessitates precise analyzing and modeling of pedicle screws. In this work, three commercial multiaxial pedicle screw tulips and a newly designed tulip are investigated using finite element analysis. Employing video measuring machine (VMM), tulips are modeled. Afterwards, utilizing ANSYS, static analysis is performed on these models. In the end, stresses and displacements of the models are compared. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=pedicle%20screw" title="pedicle screw">pedicle screw</a>, <a href="https://publications.waset.org/abstracts/search?q=multiaxial%20pedicle%20screw" title=" multiaxial pedicle screw"> multiaxial pedicle screw</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=static%20analysis" title=" static analysis"> static analysis</a> </p> <a href="https://publications.waset.org/abstracts/29320/investigation-of-the-multiaxial-pedicle-screw-tulip-design-using-finite-element-analysis" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/29320.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">368</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">639</span> The Multiaxial Load Proportionality Effect on the Fracture Surface Topography of Forged Magnesium Alloys</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Andrew%20Grygu%C4%87">Andrew Gryguć</a>, <a href="https://publications.waset.org/abstracts/search?q=Seyed%20Behzad%20Behravesh"> Seyed Behzad Behravesh</a>, <a href="https://publications.waset.org/abstracts/search?q=Hamid%20Jahed"> Hamid Jahed</a>, <a href="https://publications.waset.org/abstracts/search?q=Mary%20Wells"> Mary Wells</a>, <a href="https://publications.waset.org/abstracts/search?q=Wojciech%20Macek"> Wojciech Macek</a>, <a href="https://publications.waset.org/abstracts/search?q=Bruce%20Williams"> Bruce Williams</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This extended abstract investigates the influence of the multiaxial loading on the fatigue behavior of forged magnesium through quantitative analysis of its fracture surface topography and mesoscopic cracking orientation. Fatigue tests were performed on hollow tubular sample geometries extracted from closed-die forged AZ80 Mg components, with three different multiaxial strain paths (axial/shear), proportional, 45° out of phase, and 90° out of phase. Regardless of the strain path, fatigue cracks are initiated at the outer surface of the specimen where the combined stress state is largest. Depending on the salient mode of deformation, distinctive features in the fracture surface manifested themselves with different topographic amplitudes, surface roughness, and mesoscopic cracking orientation in the vicinity of the initiation site. The dominant crack propagation path was in the circumferential direction of the hollow tubular specimen (i.e., cracking transverse to the sample axis, with little to no branching), which is congruent with previous findings of low to moderate shear strain energy density (SED) multiaxial loading. For proportional loading, the initiation zone surface morphology was largely flat and striated, whereas, at phase angles of 45° and 90°, the initiation surface became more faceted and inclined. Overall, both a qualitative and quantitative link was developed between the fracture surface morphology and the level of non-proportionality in the loading providing useful insight into the fracture mechanics of forged magnesium as a relevant focus for future study. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue" title="fatigue">fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=fracture" title=" fracture"> fracture</a>, <a href="https://publications.waset.org/abstracts/search?q=magnesium" title=" magnesium"> magnesium</a>, <a href="https://publications.waset.org/abstracts/search?q=forging" title=" forging"> forging</a>, <a href="https://publications.waset.org/abstracts/search?q=fractography" title=" fractography"> fractography</a>, <a href="https://publications.waset.org/abstracts/search?q=anisotropy" title=" anisotropy"> anisotropy</a>, <a href="https://publications.waset.org/abstracts/search?q=strain%20energy%20density" title=" strain energy density"> strain energy density</a>, <a href="https://publications.waset.org/abstracts/search?q=asymmetry" title=" asymmetry"> asymmetry</a>, <a href="https://publications.waset.org/abstracts/search?q=multiaxial%20fatigue" title=" multiaxial fatigue"> multiaxial fatigue</a> </p> <a href="https://publications.waset.org/abstracts/162670/the-multiaxial-load-proportionality-effect-on-the-fracture-surface-topography-of-forged-magnesium-alloys" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/162670.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">82</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">638</span> Multiaxial Stress Based High Cycle Fatigue Model for Adhesive Joint Interfaces</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Martin%20Alexander%20Eder">Martin Alexander Eder</a>, <a href="https://publications.waset.org/abstracts/search?q=Sergei%20Semenov"> Sergei Semenov</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Many glass-epoxy composite structures, such as large utility wind turbine rotor blades (WTBs), comprise of adhesive joints with typically thick bond lines used to connect the different components during assembly. Performance optimization of rotor blades to increase power output by simultaneously maintaining high stiffness-to-low-mass ratios entails intricate geometries in conjunction with complex anisotropic material behavior. Consequently, adhesive joints in WTBs are subject to multiaxial stress states with significant stress gradients depending on the local joint geometry. Moreover, the dynamic aero-elastic interaction of the WTB with the airflow generates non-proportional, variable amplitude stress histories in the material. Empiricism shows that a prominent failure type in WTBs is high cycle fatigue failure of adhesive bond line interfaces, which in fact over time developed into a design driver as WTB sizes increase rapidly. Structural optimization employed at an early design stage, therefore, sets high demands on computationally efficient interface fatigue models capable of predicting the critical locations prone for interface failure. The numerical stress-based interface fatigue model presented in this work uses the Drucker-Prager criterion to compute three different damage indices corresponding to the two interface shear tractions and the outward normal traction. The two-parameter Drucker-Prager model was chosen because of its ability to consider shear strength enhancement under compression and shear strength reduction under tension. The governing interface damage index is taken as the maximum of the triple. The damage indices are computed through the well-known linear Palmgren-Miner rule after separate rain flow-counting of the equivalent shear stress history and the equivalent pure normal stress history. The equivalent stress signals are obtained by self-similar scaling of the Drucker-Prager surface whose shape is defined by the uniaxial tensile strength and the shear strength such that it intersects with the stress point at every time step. This approach implicitly assumes that the damage caused by the prevailing multiaxial stress state is the same as the damage caused by an amplified equivalent uniaxial stress state in the three interface directions. The model was implemented as Python plug-in for the commercially available finite element code Abaqus for its use with solid elements. The model was used to predict the interface damage of an adhesively bonded, tapered glass-epoxy composite cantilever I-beam tested by LM Wind Power under constant amplitude compression-compression tip load in the high cycle fatigue regime. Results show that the model was able to predict the location of debonding in the adhesive interface between the webfoot and the cap. Moreover, with a set of two different constant life diagrams namely in shear and tension, it was possible to predict both the fatigue lifetime and the failure mode of the sub-component with reasonable accuracy. It can be concluded that the fidelity, robustness and computational efficiency of the proposed model make it especially suitable for rapid fatigue damage screening of large 3D finite element models subject to complex dynamic load histories. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=adhesive" title="adhesive">adhesive</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue" title=" fatigue"> fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=interface" title=" interface"> interface</a>, <a href="https://publications.waset.org/abstracts/search?q=multiaxial%20stress" title=" multiaxial stress"> multiaxial stress</a> </p> <a href="https://publications.waset.org/abstracts/100342/multiaxial-stress-based-high-cycle-fatigue-model-for-adhesive-joint-interfaces" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/100342.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">169</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">637</span> Multiaxial Fatigue in Thermal Elastohydrodynamic Lubricated Contacts with Asperities and Slip</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Carl-Magnus%20Everitt">Carl-Magnus Everitt</a>, <a href="https://publications.waset.org/abstracts/search?q=Bo%20Alfredsson"> Bo Alfredsson</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Contact mechanics and tribology have been combined with fundamental fatigue and fracture mechanics to form the asperity mechanism which supplies an explanation for the surface-initiated rolling contact fatigue damage, called pitting or spalling. The cracks causing the pits initiates at one surface point and thereafter they slowly grow into the material before chipping of a material piece to form the pit. In the current study, the lubrication aspects on fatigue initiation are simulated by passing a single asperity through a thermal elastohydrodynamic lubricated, TEHL, contact. The physics of the lubricant was described with Reynolds equation and the lubricants pressure-viscosity relation was modeled by Roelands equation, formulated to include temperature dependence. A pressure dependent shear limit was incorporated. To capture the full phenomena of the sliding contact the temperature field was resolved through the incorporation of the energy flow. The heat was mainly generated due to shearing of the lubricant and from dry friction where metal contact occurred. The heat was then transported, and conducted, away by the solids and the lubricant. The fatigue damage caused by the asperities was evaluated through Findley’s fatigue criterion. The results show that asperities, in the size of surface roughness found in applications, may cause surface initiated fatigue damage and crack initiation. The simulations also show that the asperities broke through the lubricant in the inlet, causing metal to metal contact with high friction. When the asperities thereafter moved through the contact, the sliding provided the asperities with lubricant releasing the metal contact. The release of metal contact was possible due to the high viscosity the lubricant obtained from the high pressure. The metal contact in the inlet caused higher friction which increased the risk of fatigue damage. Since the metal contact occurred in the inlet it increased the fatigue risk more for asperities subjected to negative slip than positive slip. Therefore the fatigue evaluations showed that the asperities subjected to negative slip yielded higher fatigue stresses than the asperities subjected to positive slip of equal magnitude. This is one explanation for why pitting is more common in the dedendum than the addendum on pinion gear teeth. The simulations produced further validation for the asperity mechanism by showing that asperities cause surface initiated fatigue and crack initiation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue" title="fatigue">fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=rolling" title=" rolling"> rolling</a>, <a href="https://publications.waset.org/abstracts/search?q=sliding" title=" sliding"> sliding</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20elastohydrodynamic" title=" thermal elastohydrodynamic"> thermal elastohydrodynamic</a> </p> <a href="https://publications.waset.org/abstracts/101169/multiaxial-fatigue-in-thermal-elastohydrodynamic-lubricated-contacts-with-asperities-and-slip" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/101169.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">121</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">636</span> Influence of Maximum Fatigue Load on Probabilistic Aspect of Fatigue Crack Propagation Life at Specified Grown Crack in Magnesium Alloys</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seon%20Soon%20Choi">Seon Soon Choi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The principal purpose of this paper is to find the influence of maximum fatigue load on the probabilistic aspect of fatigue crack propagation life at a specified grown crack in magnesium alloys. The experiments of fatigue crack propagation are carried out in laboratory air under different conditions of the maximum fatigue loads to obtain the fatigue crack propagation data for the statistical analysis. In order to analyze the probabilistic aspect of fatigue crack propagation life, the goodness-of fit test for probability distribution of the fatigue crack propagation life at a specified grown crack is implemented through Anderson-Darling test. The good probability distribution of the fatigue crack propagation life is also verified under the conditions of the maximum fatigue loads. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue%20crack%20propagation%20life" title="fatigue crack propagation life">fatigue crack propagation life</a>, <a href="https://publications.waset.org/abstracts/search?q=magnesium%20alloys" title=" magnesium alloys"> magnesium alloys</a>, <a href="https://publications.waset.org/abstracts/search?q=maximum%20fatigue%20load" title=" maximum fatigue load"> maximum fatigue load</a>, <a href="https://publications.waset.org/abstracts/search?q=probability" title=" probability"> probability</a> </p> <a href="https://publications.waset.org/abstracts/66629/influence-of-maximum-fatigue-load-on-probabilistic-aspect-of-fatigue-crack-propagation-life-at-specified-grown-crack-in-magnesium-alloys" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/66629.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">389</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">635</span> Development of a New Device for Bending Fatigue Testing</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=B.%20Mokhtarnia">B. Mokhtarnia</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Layeghi"> M. Layeghi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This work presented an original bending fatigue-testing setup for fatigue characterization of composite materials. A three-point quasi-static setup was introduced that was capable of applying stress control load in different loading waveforms, frequencies, and stress ratios. This setup was equipped with computerized measuring instruments to evaluate fatigue damage mechanisms. A detailed description of its different parts and working features was given, and dynamic analysis was done to verify the functional accuracy of the device. Feasibility was validated successfully by conducting experimental fatigue tests. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=bending%20fatigue" title="bending fatigue">bending fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=quasi-static%20testing%20setup" title=" quasi-static testing setup"> quasi-static testing setup</a>, <a href="https://publications.waset.org/abstracts/search?q=experimental%20fatigue%20testing" title=" experimental fatigue testing"> experimental fatigue testing</a>, <a href="https://publications.waset.org/abstracts/search?q=composites" title=" composites"> composites</a> </p> <a href="https://publications.waset.org/abstracts/165432/development-of-a-new-device-for-bending-fatigue-testing" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/165432.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">132</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">634</span> Perfectly Matched Layer Boundary Stabilized Using Multiaxial Stretching Functions</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Adriano%20Trono">Adriano Trono</a>, <a href="https://publications.waset.org/abstracts/search?q=Federico%20Pinto"> Federico Pinto</a>, <a href="https://publications.waset.org/abstracts/search?q=Diego%20Turello"> Diego Turello</a>, <a href="https://publications.waset.org/abstracts/search?q=Marcelo%20A.%20Ceballos"> Marcelo A. Ceballos</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Numerical modeling of dynamic soil-structure interaction problems requires an adequate representation of the unbounded characteristics of the ground, material non-linearity of soils, and geometrical non-linearities such as large displacements due to rocking of the structure. In order to account for these effects simultaneously, it is often required that the equations of motion are solved in the time domain. However, boundary conditions in conventional finite element codes generally present shortcomings in fully absorbing the energy of outgoing waves. In this sense, the Perfectly Matched Layers (PML) technique allows a satisfactory absorption of inclined body waves, as well as surface waves. However, the PML domain is inherently unstable, meaning that it its instability does not depend upon the discretization considered. One way to stabilize the PML domain is to use multiaxial stretching functions. This development is questionable because some Jacobian terms of the coordinate transformation are not accounted for. For this reason, the resulting absorbing layer element is often referred to as "uncorrected M-PML” in the literature. In this work, the strong formulation of the "corrected M-PML” absorbing layer is proposed using multiaxial stretching functions that incorporate all terms of the coordinate transformation. The results of the stable model are compared with reference solutions obtained from extended domain models. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=mixed%20finite%20elements" title="mixed finite elements">mixed finite elements</a>, <a href="https://publications.waset.org/abstracts/search?q=multiaxial%20stretching%20functions" title=" multiaxial stretching functions"> multiaxial stretching functions</a>, <a href="https://publications.waset.org/abstracts/search?q=perfectly%20matched%20layer" title=" perfectly matched layer"> perfectly matched layer</a>, <a href="https://publications.waset.org/abstracts/search?q=soil-structure%20interaction" title=" soil-structure interaction"> soil-structure interaction</a> </p> <a href="https://publications.waset.org/abstracts/174073/perfectly-matched-layer-boundary-stabilized-using-multiaxial-stretching-functions" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/174073.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">70</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">633</span> Effect of Load Ratio on Probability Distribution of Fatigue Crack Propagation Life in Magnesium Alloys</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seon%20Soon%20Choi">Seon Soon Choi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> It is necessary to predict a fatigue crack propagation life for estimation of structural integrity. Because of an uncertainty and a randomness of a structural behavior, it is also required to analyze stochastic characteristics of the fatigue crack propagation life at a specified fatigue crack size. The essential purpose of this study is to present the good probability distribution fit for the fatigue crack propagation life at a specified fatigue crack size in magnesium alloys under various fatigue load ratio conditions. To investigate a stochastic crack growth behavior, fatigue crack propagation experiments are performed in laboratory air under several conditions of fatigue load ratio using AZ31. By Anderson-Darling test, a goodness-of-fit test for probability distribution of the fatigue crack propagation life is performed and the good probability distribution fit for the fatigue crack propagation life is presented. The effect of load ratio on variability of fatigue crack propagation life is also investigated. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue%20crack%20propagation%20life" title="fatigue crack propagation life">fatigue crack propagation life</a>, <a href="https://publications.waset.org/abstracts/search?q=load%20ratio" title=" load ratio"> load ratio</a>, <a href="https://publications.waset.org/abstracts/search?q=magnesium%20alloys" title=" magnesium alloys"> magnesium alloys</a>, <a href="https://publications.waset.org/abstracts/search?q=probability%20distribution" title=" probability distribution"> probability distribution</a> </p> <a href="https://publications.waset.org/abstracts/34718/effect-of-load-ratio-on-probability-distribution-of-fatigue-crack-propagation-life-in-magnesium-alloys" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/34718.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">649</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">632</span> Flexural Fatigue Performance of Self-Compacting Fibre Reinforced Concrete</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Surinder%20Pal%20Singh">Surinder Pal Singh</a>, <a href="https://publications.waset.org/abstracts/search?q=Sanjay%20Goel"> Sanjay Goel</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The paper presents results of an investigation conducted to study the flexural fatigue characteristics of Self Compacting Concrete (SCC) and Self Compacting Fibre Reinforced Concrete (SCFRC). In total 360 flexural fatigue tests and 270 static flexural strength tests were conducted on SCC and SCFRC specimens to obtain the fatigue test data. The variability in the distribution of fatigue life of SCC and SCFRC have been analyzed and compared with that of NVC and NVFRC containing steel fibres of comparable size and shape. The experimental coefficients of fatigue equations have been estimated to represent relationship between stress level (S) and fatigue life (N) for SCC and SCFRC containing different fibre volume fractions. The probability of failure (Pf) has been incorporated in S-N relationships to obtain families of S-N-Pf relationships. A good agreement between the predicted curves and those obtained from the test data has been observed. The fatigue performance of SCC and SCFRC has been evaluated in terms of two-million cycles fatigue strength/endurance limit. The theoretic fatigue lives were also estimated using single-log fatigue equation for 10% probability of failure to estimate the enhanced extent of theoretic fatigue lives of SCFRC with reference to SCC and NVC. The reduction in variability in the fatigue life, increased endurance limit and increased theoretiac fatigue lives demonstrates an overall better fatigue performance for SCC and SCFRC. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue%20life" title="fatigue life">fatigue life</a>, <a href="https://publications.waset.org/abstracts/search?q=fibre" title=" fibre"> fibre</a>, <a href="https://publications.waset.org/abstracts/search?q=probability%20of%20failure" title=" probability of failure"> probability of failure</a>, <a href="https://publications.waset.org/abstracts/search?q=self-compacting%20concrete" title=" self-compacting concrete"> self-compacting concrete</a> </p> <a href="https://publications.waset.org/abstracts/6843/flexural-fatigue-performance-of-self-compacting-fibre-reinforced-concrete" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/6843.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">358</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">631</span> Improvement of Fatigue and Fatigue Corrosion Resistances of Turbine Blades Using Laser Cladding</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sami%20I.%20Jafar">Sami I. Jafar</a>, <a href="https://publications.waset.org/abstracts/search?q=Sami%20A.%20Ajeel"> Sami A. Ajeel</a>, <a href="https://publications.waset.org/abstracts/search?q=Zaman%20A.%20Abdulwahab"> Zaman A. Abdulwahab</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The turbine blades used in electric power plants are made of low alloy steel type 52. These blades will be subjected to fatigue and also at other times to fatigue corrosion with aging time. Due to their continuous exposure to cyclic rotational stresses in corrosive steam environments, The current research aims to deal with this problem using the laser cladding method for low alloy steel type 52, which works to re-compose the metallurgical structure and improve the mechanical properties by strengthening the resulting structure, which leads to an increase in fatigue and wears resistance, therefore, an increase in the life of these blades is observed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue" title="fatigue">fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue%20corrosion" title=" fatigue corrosion"> fatigue corrosion</a>, <a href="https://publications.waset.org/abstracts/search?q=turbine%20blades" title=" turbine blades"> turbine blades</a>, <a href="https://publications.waset.org/abstracts/search?q=laser%20cladding" title=" laser cladding"> laser cladding</a> </p> <a href="https://publications.waset.org/abstracts/143461/improvement-of-fatigue-and-fatigue-corrosion-resistances-of-turbine-blades-using-laser-cladding" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/143461.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">199</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">630</span> Characteristics of Cumulative Distribution Function of Grown Crack Size at Specified Fatigue Crack Propagation Life under Different Maximum Fatigue Loads in AZ31</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seon%20Soon%20Choi">Seon Soon Choi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Magnesium alloy has been widely used in structure such as an automobile. It is necessary to consider probabilistic characteristics of a structural material because a fatigue behavior of a structure has a randomness and uncertainty. The purpose of this study is to find the characteristics of the cumulative distribution function (CDF) of the grown crack size at a specified fatigue crack propagation life and to investigate a statistical crack propagation in magnesium alloys. The statistical fatigue data of the grown crack size are obtained through the fatigue crack propagation (FCP) tests under different maximum fatigue load conditions conducted on the replicated specimens of magnesium alloys. The 3-parameter Weibull distribution is used to find the CDF of grown crack size. The CDF of grown crack size in case of larger maximum fatigue load has longer tail in below 10 percent and above 90 percent. The fatigue failure occurs easily as the tail of CDF of grown crack size becomes long. The fatigue behavior under the larger maximum fatigue load condition shows more rapid propagation and failure mode. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cumulative%20distribution%20function" title="cumulative distribution function">cumulative distribution function</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue%20crack%20propagation" title=" fatigue crack propagation"> fatigue crack propagation</a>, <a href="https://publications.waset.org/abstracts/search?q=grown%20crack%20size" title=" grown crack size"> grown crack size</a>, <a href="https://publications.waset.org/abstracts/search?q=magnesium%20alloys" title=" magnesium alloys"> magnesium alloys</a>, <a href="https://publications.waset.org/abstracts/search?q=maximum%20fatigue%20load" title=" maximum fatigue load"> maximum fatigue load</a> </p> <a href="https://publications.waset.org/abstracts/76512/characteristics-of-cumulative-distribution-function-of-grown-crack-size-at-specified-fatigue-crack-propagation-life-under-different-maximum-fatigue-loads-in-az31" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/76512.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">288</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">629</span> Serum Levels of Carnitine in Multiple Sclerosis Patients in Comparison with Healthy People and its Association with Fatigue Severity</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Hossein%20Harirchian">Mohammad Hossein Harirchian</a>, <a href="https://publications.waset.org/abstracts/search?q=Siavash%20Babaie"> Siavash Babaie</a>, <a href="https://publications.waset.org/abstracts/search?q=Nika%20keshtkaran"> Nika keshtkaran</a>, <a href="https://publications.waset.org/abstracts/search?q=Sama%20Bitarafan"> Sama Bitarafan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Background: Fatigue is a common complaint of multiple sclerosis (MS) patients, adversely affecting their quality of life. There is a lot of evidence showing that Carnitine deficiency is linked to fatigue development and severity in some conditions. This study aimed to compare the levels of Free L-Carnitine (FLC) between MS patients and healthy people and evaluate its association with the severity of fatigue. Methods: This case-control study included 30 patients with relapsing-remitting MS (RRMS) in 2 sex-matched equal-number groups according to the presence or absence of fatigue and 30 sex-matched healthy people in the control group. In addition, between two patient groups, we compared Serum level of FLC between the patient and healthy group. Fatigue was scored using two valid questionnaires of fatigue Severity Scale (FSS) and Modified Fatigue Impact Scale (MFIS). In addition, association between Serum level of FLC and fatigue severity was evaluated in MS patients. Results: There was no significant difference in serum levels of FLC between MS patients and healthy people. The patients with fatigue had a significantly lower FLC (mg/dl) value than patients without fatigue (22.53 ± 15.84 vs. 75.36 ± 51.98, P < 0.001). The mean value of FSS and MFIS in patients with fatigue were 48.80±8.55 and 62.87 ± 13.63, respectively, which was nearly two-fold higher than group without fatigue (P < 0.001). There was a negative correlation between the serum level of FLC and fatigue severity scales (Spearman rank correlation= 0.76, P < 0.001). Conclusion: We showed healthy people and MS patients were not different in levels of FLC. In addition, patients with lower serum levels of FLC might experience more severe fatigue. Therefore, this could clarify that supplementation with L-Carnitine might be considered as a complementary treatment for MS-related fatigue. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue" title="fatigue">fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=multiple%20sclerosis" title=" multiple sclerosis"> multiple sclerosis</a>, <a href="https://publications.waset.org/abstracts/search?q=L-carnitine" title=" L-carnitine"> L-carnitine</a>, <a href="https://publications.waset.org/abstracts/search?q=modified%20fatigue%20impact%20scale" title=" modified fatigue impact scale"> modified fatigue impact scale</a> </p> <a href="https://publications.waset.org/abstracts/147672/serum-levels-of-carnitine-in-multiple-sclerosis-patients-in-comparison-with-healthy-people-and-its-association-with-fatigue-severity" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/147672.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">139</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">628</span> Correlation Test of Psychomotor Vigilance Test Fatigue Scores on Sleep Quality at Home in Oil and Gas Tanker Driver: A Diagnostic Study</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Pandega%20Gama%20Mahardika">Pandega Gama Mahardika</a>, <a href="https://publications.waset.org/abstracts/search?q=Muhammad%20Rifki%20Al%20Iksan"> Muhammad Rifki Al Iksan</a>, <a href="https://publications.waset.org/abstracts/search?q=Datuk%20Fachrul%20Razy"> Datuk Fachrul Razy</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Oil And Gas Tanker Driver is a high-risk jobdesc. drivers drive with sleep circadian rhythm disturbances. Therefore, FAMOUS (Fatigue Management Online Ultimate System) conducted a diagnostic test on the effectiveness and accuracy of the Psychomotor vigilance test (PVT) in the field to capture the fatigue level of Oil And Gas Tanker Driver. Fatigue examination with the PVP method for 3 minutes using the Pertamina FAMOUS system (Fatigue Management Online Ultimate System). The research sample was Oil And Gas Tanker Driver Elnusa petrofin drivers as many as 2205 people. PVT is categorical data that states a driver has a low or high fatigue level. The quality of sleep at home was recorded by filling in a score of 1 = not well, 2 = not well, 3 = well, per person. A total of 1852 (84%) driver had a low fatigue level, while 353 (16%) driver had a high fatigue level. Poor sleep quality was experienced by 68 (79%) driver who had a high fatigue level. Oil And Gas Tanker Driver who slept soundly at home as many as 1804 (87%) had a low fatigue level. The correlation coefficient of sleep quality home and fatigue level is significant because it shows a probability value of 0.00 (p <5%). Fatigue level can be diagnosed through examining sleep quality, using FAMOUS Program for occupational medicine, particularly in the oil and gas sector. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=psychomotor%20vigilance%20test" title="psychomotor vigilance test">psychomotor vigilance test</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue" title=" fatigue"> fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep" title=" sleep"> sleep</a>, <a href="https://publications.waset.org/abstracts/search?q=oil%20and%20gas%20tanker%20driver%20drivers" title=" oil and gas tanker driver drivers"> oil and gas tanker driver drivers</a>, <a href="https://publications.waset.org/abstracts/search?q=pertamina%20FAMOUS" title=" pertamina FAMOUS"> pertamina FAMOUS</a> </p> <a href="https://publications.waset.org/abstracts/170592/correlation-test-of-psychomotor-vigilance-test-fatigue-scores-on-sleep-quality-at-home-in-oil-and-gas-tanker-driver-a-diagnostic-study" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/170592.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">90</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">627</span> Effect of Inclusions in the Ultrasonic Fatigue Endurance of Maraging 300 Steel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=G.%20M.%20Dominguez%20Almaraz">G. M. Dominguez Almaraz</a>, <a href="https://publications.waset.org/abstracts/search?q=J.%20A.%20Ruiz%20Vilchez"> J. A. Ruiz Vilchez</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20A.%20Sanchez%20Miranda"> M. A. Sanchez Miranda</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Ultrasonic fatigue tests have been carried out in the maraging 300 steel. Experimental results show that fatigue endurance under this modality of testing is closely related to the nature and geometrical properties of inclusions present in this alloy. A model was proposed to correlate the ultrasonic fatigue endurance with the nature and geometrical properties of the crack initiation inclusion. Scanning Electron Microscopy analyses were obtained on the fracture surfaces, in order to assess the crack initiation inclusion and to introduce these parameters in the proposed model, with good agreement for the fatigue life prediction. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=inclusions" title="inclusions">inclusions</a>, <a href="https://publications.waset.org/abstracts/search?q=ultrasonic%20fatigue" title=" ultrasonic fatigue"> ultrasonic fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=maraging%20300%20steel" title=" maraging 300 steel"> maraging 300 steel</a>, <a href="https://publications.waset.org/abstracts/search?q=crack%20initiation" title=" crack initiation"> crack initiation</a> </p> <a href="https://publications.waset.org/abstracts/141323/effect-of-inclusions-in-the-ultrasonic-fatigue-endurance-of-maraging-300-steel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/141323.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">214</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">626</span> Thermal Fatigue Behavior of 400 Series Ferritic Stainless Steels</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seok%20Hong%20Min">Seok Hong Min</a>, <a href="https://publications.waset.org/abstracts/search?q=Tae%20Kwon%20Ha"> Tae Kwon Ha</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study, thermal fatigue properties of 400 series ferritic stainless steels have been evaluated in the temperature ranges of 200-800oC and 200-900oC. Systematic methods for control of temperatures within the predetermined range and measurement of load applied to specimens as a function of temperature during thermal cycles have been established. Thermal fatigue tests were conducted under fully constrained condition, where both ends of specimens were completely fixed. It has been revealed that load relaxation behavior at the temperatures of thermal cycle was closely related with the thermal fatigue property. Thermal fatigue resistance of 430J1L stainless steel is found to be superior to the other steels. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ferritic%20stainless%20steel" title="ferritic stainless steel">ferritic stainless steel</a>, <a href="https://publications.waset.org/abstracts/search?q=automotive%20exhaust" title=" automotive exhaust"> automotive exhaust</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20fatigue" title=" thermal fatigue"> thermal fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=microstructure" title=" microstructure"> microstructure</a>, <a href="https://publications.waset.org/abstracts/search?q=load%20relaxation" title=" load relaxation"> load relaxation</a> </p> <a href="https://publications.waset.org/abstracts/44161/thermal-fatigue-behavior-of-400-series-ferritic-stainless-steels" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/44161.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">345</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">625</span> Experimental Characterization of Fatigue Crack Initiation of AA320 Alloy under Combined Thermal Cycling (CTC) and Mechanical Loading (ML) during Four Point Rotating and Bending Fatigue Testing Machine</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Rana%20Atta%20Ur%20Rahman">Rana Atta Ur Rahman</a>, <a href="https://publications.waset.org/abstracts/search?q=Daniel%20Juhre"> Daniel Juhre</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Initiation of crack during fatigue of casting alloys are noticed mainly on the basis of experimental results. Crack initiation and strength of fatigue of AA320 are summarized here. Load sequence effect is applied to notify initiation phase life. Crack initiation at notch root and fatigue life is calculated under single & two-step mechanical loading (ML) with and without combined thermal cycling (CTC). An Experimental setup is proposed to create the working temperature as per alloy applications. S-N curves are plotted, and a comparison is made between crack initiation leading to failure under different ML with & without thermal loading (TL). <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue" title="fatigue">fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=initiation" title=" initiation"> initiation</a>, <a href="https://publications.waset.org/abstracts/search?q=SN%20curve" title=" SN curve"> SN curve</a>, <a href="https://publications.waset.org/abstracts/search?q=alloy" title=" alloy"> alloy</a> </p> <a href="https://publications.waset.org/abstracts/63983/experimental-characterization-of-fatigue-crack-initiation-of-aa320-alloy-under-combined-thermal-cycling-ctc-and-mechanical-loading-ml-during-four-point-rotating-and-bending-fatigue-testing-machine" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/63983.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">624</span> Contribution in Fatigue Life Prediction of Composite Material </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mostefa%20Bendouba">Mostefa Bendouba</a>, <a href="https://publications.waset.org/abstracts/search?q=Djebli%20Abdelkader"> Djebli Abdelkader</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdelkrim%20Aid"> Abdelkrim Aid</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Benguediab"> Mohamed Benguediab </a> </p> <p class="card-text"><strong>Abstract:</strong></p> The damage evolution mechanism is one of the important focuses of fatigue behaviour investigation of composite materials and also is the foundation to predict fatigue life of composite structures for engineering application. This paper is dedicated to a damage investigation under two block loading cycle fatigue conditions submitted to composite material. The loading sequence effect and the influence of the cycle ratio of the first stage on the cumulative fatigue life were studied herein. Two loading sequences, i.e., high-to-low and low-to-high cases are considered in this paper. The proposed damage indicator is connected cycle by cycle to the S-N curve and the experimental results are in agreement with model expectations. Some experimental researches are used to validate this proposition. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue" title="fatigue">fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=damage%20acumulation" title=" damage acumulation"> damage acumulation</a>, <a href="https://publications.waset.org/abstracts/search?q=composite" title=" composite"> composite</a>, <a href="https://publications.waset.org/abstracts/search?q=evolution" title=" evolution"> evolution</a> </p> <a href="https://publications.waset.org/abstracts/17290/contribution-in-fatigue-life-prediction-of-composite-material" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/17290.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">501</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">623</span> Structure-Phase States of Al-Si Alloy After Electron-Beam Treatment and Multicycle Fatigue</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Krestina%20V.%20Alsaraeva">Krestina V. Alsaraeva</a>, <a href="https://publications.waset.org/abstracts/search?q=Victor%20E.%20Gromov"> Victor E. Gromov</a>, <a href="https://publications.waset.org/abstracts/search?q=Sergey%20V.%20Konovalov"> Sergey V. Konovalov</a>, <a href="https://publications.waset.org/abstracts/search?q=Anna%20A.%20Atroshkina"> Anna A. Atroshkina</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Processing of Al-19.4Si alloy by high intensive electron beam has been carried out and multiple increase in fatigue life of the material has been revealed. Investigations of structure and surface modified layer destruction of Al-19.4Si alloy subjected to multicycle fatigue tests to fracture have been carried out by methods of scanning electron microscopy. The factors responsible for the increase of fatigue life of Al-19.4Si alloy have been revealed and analyzed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Al-19.4Si%20alloy" title="Al-19.4Si alloy">Al-19.4Si alloy</a>, <a href="https://publications.waset.org/abstracts/search?q=high%20intensive%20electron%20beam" title=" high intensive electron beam"> high intensive electron beam</a>, <a href="https://publications.waset.org/abstracts/search?q=multicycle%20fatigue" title=" multicycle fatigue"> multicycle fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=structure" title=" structure"> structure</a> </p> <a href="https://publications.waset.org/abstracts/18754/structure-phase-states-of-al-si-alloy-after-electron-beam-treatment-and-multicycle-fatigue" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/18754.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">554</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">622</span> The Effect of Mental Workload Towards Mental Fatigue on Customer Care Agent Using Electroencephalogram</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Maya%20Arlini%20Puspasari">Maya Arlini Puspasari</a>, <a href="https://publications.waset.org/abstracts/search?q=Shafira%20Karamina%20Alifah"> Shafira Karamina Alifah</a>, <a href="https://publications.waset.org/abstracts/search?q=Hardianto%20Iridiastadi"> Hardianto Iridiastadi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> High mental workload can lead to fatigue and further result in decreased concentration and work performance. This study is conducted to see the effects of mental workload towards mental fatigue. Mental fatigue measurement was conducted at the first and the last 10 minutes of the working time using electroencephalogram, while mental workload measurement was conducted after the work is completed using the NASA-TLX questionnaire. The result shows that there is an increase in alpha band which indicates an increase in mental fatigue. This study also shows absolute alpha is more sensitive compared to the relative alpha. This study proves that there is a relationship between mental workload and mental fatigue although not relatively strong. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=mental%20workload" title="mental workload">mental workload</a>, <a href="https://publications.waset.org/abstracts/search?q=electroencephalogram" title=" electroencephalogram"> electroencephalogram</a>, <a href="https://publications.waset.org/abstracts/search?q=customer%20care%20agents" title=" customer care agents"> customer care agents</a>, <a href="https://publications.waset.org/abstracts/search?q=NASA-TLX" title=" NASA-TLX"> NASA-TLX</a> </p> <a href="https://publications.waset.org/abstracts/55448/the-effect-of-mental-workload-towards-mental-fatigue-on-customer-care-agent-using-electroencephalogram" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/55448.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">222</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">621</span> Fatigue Crack Initiation of Al-Alloys: Effect of Heat Treatment Condition</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20Benachour">M. Benachour</a>, <a href="https://publications.waset.org/abstracts/search?q=N.%20Benachour"> N. Benachour</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Benguediab"> M. Benguediab</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this investigation an empirical study was made on fatigue crack initiation on 7075 T6 and 7075 T71 al-alloys under constant amplitude loading. At initiation stage, local strain approach at the notch was applied. Single Edge Notch Tensile specimen with semi circular notch is used. Based on experimental results, effect of mean stress, is highlights on fatigue initiation life. Results show that fatigue life initiation is affected by notch geometry and mean stress. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue%20crack%20initiation" title="fatigue crack initiation">fatigue crack initiation</a>, <a href="https://publications.waset.org/abstracts/search?q=al-alloy" title=" al-alloy"> al-alloy</a>, <a href="https://publications.waset.org/abstracts/search?q=mean%20stress" title=" mean stress"> mean stress</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20treatment%20state" title=" heat treatment state"> heat treatment state</a> </p> <a href="https://publications.waset.org/abstracts/1777/fatigue-crack-initiation-of-al-alloys-effect-of-heat-treatment-condition" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/1777.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">233</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">620</span> Fatigue of Multiscale Nanoreinforced Composites: 3D Modelling</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Leon%20Mishnaevsky%20Jr.">Leon Mishnaevsky Jr.</a>, <a href="https://publications.waset.org/abstracts/search?q=Gaoming%20Dai"> Gaoming Dai</a> </p> <p class="card-text"><strong>Abstract:</strong></p> 3D numerical simulations of fatigue damage of multiscale fiber reinforced polymer composites with secondary nanoclay reinforcement are carried out. Macro-micro FE models of the multiscale composites are generated automatically using Python based software. The effect of the nanoclay reinforcement (localized in the fiber/matrix interface (fiber sizing) and distributed throughout the matrix) on the crack path, damage mechanisms and fatigue behavior is investigated in numerical experiments. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=computational%20mechanics" title="computational mechanics">computational mechanics</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue" title=" fatigue"> fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=nanocomposites" title=" nanocomposites"> nanocomposites</a>, <a href="https://publications.waset.org/abstracts/search?q=composites" title=" composites"> composites</a> </p> <a href="https://publications.waset.org/abstracts/16741/fatigue-of-multiscale-nanoreinforced-composites-3d-modelling" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/16741.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">607</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">619</span> Investigation of Different Stimulation Patterns to Reduce Muscle Fatigue during Functional Electrical Stimulation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=R.%20Ruslee">R. Ruslee</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Gollee"> H. Gollee</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Functional electrical stimulation (FES) is a commonly used technique in rehabilitation and often associated with rapid muscle fatigue which becomes the limiting factor in its applications. The objective of this study is to investigate the effects on the onset of fatigue of conventional synchronous stimulation, as well as asynchronous stimulation that mimic voluntary muscle activation targeting different motor units which are activated sequentially or randomly via multiple pairs of stimulation electrodes. We investigate three different approaches with various electrode configurations, as well as different patterns of stimulation applied to the gastrocnemius muscle: Conventional Synchronous Stimulation (CSS), Asynchronous Sequential Stimulation (ASS) and Asynchronous Random Stimulation (ARS). Stimulation was applied repeatedly for 300 ms followed by 700 ms of no-stimulation with 40 Hz effective frequency for all protocols. Ten able-bodied volunteers (28±3 years old) participated in this study. As fatigue indicators, we focused on the analysis of Normalized Fatigue Index (NFI), Fatigue Time Interval (FTI) and pre-post Twitch-Tetanus Ratio (ΔTTR). The results demonstrated that ASS and ARS give higher NFI and longer FTI confirming less fatigue for asynchronous stimulation. In addition, ASS and ARS resulted in higher ΔTTR than conventional CSS. In this study, we proposed a randomly distributed stimulation method for the application of FES and investigated its suitability for reducing muscle fatigue compared to previously applied methods. The results validated that asynchronous stimulation reduces fatigue, and indicates that random stimulation may improve fatigue resistance in some conditions. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=asynchronous%20stimulation" title="asynchronous stimulation">asynchronous stimulation</a>, <a href="https://publications.waset.org/abstracts/search?q=electrode%20configuration" title=" electrode configuration"> electrode configuration</a>, <a href="https://publications.waset.org/abstracts/search?q=functional%20electrical%20stimulation%20%28FES%29" title=" functional electrical stimulation (FES)"> functional electrical stimulation (FES)</a>, <a href="https://publications.waset.org/abstracts/search?q=muscle%20fatigue" title=" muscle fatigue"> muscle fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=pattern%20stimulation" title=" pattern stimulation"> pattern stimulation</a>, <a href="https://publications.waset.org/abstracts/search?q=random%20stimulation" title=" random stimulation"> random stimulation</a>, <a href="https://publications.waset.org/abstracts/search?q=sequential%20stimulation" title=" sequential stimulation"> sequential stimulation</a>, <a href="https://publications.waset.org/abstracts/search?q=synchronous%20stimulation" title=" synchronous stimulation"> synchronous stimulation</a> </p> <a href="https://publications.waset.org/abstracts/50118/investigation-of-different-stimulation-patterns-to-reduce-muscle-fatigue-during-functional-electrical-stimulation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/50118.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">306</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">618</span> Substantial Fatigue Similarity of a New Small-Scale Test Rig to Actual Wheel-Rail System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Meysam%20Naeimi">Meysam Naeimi</a>, <a href="https://publications.waset.org/abstracts/search?q=Zili%20Li"> Zili Li</a>, <a href="https://publications.waset.org/abstracts/search?q=Roumen%20Petrov"> Roumen Petrov</a>, <a href="https://publications.waset.org/abstracts/search?q=Rolf%20Dollevoet"> Rolf Dollevoet</a>, <a href="https://publications.waset.org/abstracts/search?q=Jilt%20Sietsma"> Jilt Sietsma</a>, <a href="https://publications.waset.org/abstracts/search?q=Jun%20Wu"> Jun Wu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The substantial similarity of fatigue mechanism in a new test rig for rolling contact fatigue (RCF) has been investigated. A new reduced-scale test rig is designed to perform controlled RCF tests in wheel-rail materials. The fatigue mechanism of the rig is evaluated in this study using a combined finite element-fatigue prediction approach. The influences of loading conditions on fatigue crack initiation have been studied. Furthermore, the effects of some artificial defects (squat-shape) on fatigue lives are examined. To simulate the vehicle-track interaction by means of the test rig, a three-dimensional finite element (FE) model is built up. The nonlinear material behaviour of the rail steel is modelled in the contact interface. The results of FE simulations are combined with the critical plane concept to determine the material points with the greatest possibility of fatigue failure. Based on the stress-strain responses, by employing of previously postulated criteria for fatigue crack initiation (plastic shakedown and ratchetting), fatigue life analysis is carried out. The results are reported for various loading conditions and different defect sizes. Afterward, the cyclic mechanism of the test rig is evaluated from the operational viewpoint. The results of fatigue life predictions are compared with the expected number of cycles of the test rig by its cyclic nature. Finally, the estimative duration of the experiments until fatigue crack initiation is roughly determined. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue" title="fatigue">fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=test%20rig" title=" test rig"> test rig</a>, <a href="https://publications.waset.org/abstracts/search?q=crack%20initiation" title=" crack initiation"> crack initiation</a>, <a href="https://publications.waset.org/abstracts/search?q=life" title=" life"> life</a>, <a href="https://publications.waset.org/abstracts/search?q=rail" title=" rail"> rail</a>, <a href="https://publications.waset.org/abstracts/search?q=squats" title=" squats"> squats</a> </p> <a href="https://publications.waset.org/abstracts/18986/substantial-fatigue-similarity-of-a-new-small-scale-test-rig-to-actual-wheel-rail-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/18986.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">515</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">617</span> Bi-Directional Evolutionary Topology Optimization Based on Critical Fatigue Constraint </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Khodamorad%20Nabaki">Khodamorad Nabaki</a>, <a href="https://publications.waset.org/abstracts/search?q=Jianhu%20Shen"> Jianhu Shen</a>, <a href="https://publications.waset.org/abstracts/search?q=Xiaodong%20Huang"> Xiaodong Huang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper develops a method for considering the critical fatigue stress as a constraint in the Bi-directional Evolutionary Structural Optimization (BESO) method. Our aim is to reach an optimal design in which high cycle fatigue failure does not occur for a specific life time. The critical fatigue stress is calculated based on modified Goodman criteria and used as a stress constraint in our topology optimization problem. Since fatigue generally does not occur for compressive stresses, we use the p-norm approach of the stress measurement that considers the highest tensile principal stress in each point as stress measure to calculate the sensitivity numbers. The BESO method has been extended to minimize volume an object subjected to the critical fatigue stress constraint. The optimization results are compared with the results from the compliance minimization problem which shows clearly the merits of our newly developed approach. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=topology%20optimization" title="topology optimization">topology optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=BESO%20method" title=" BESO method"> BESO method</a>, <a href="https://publications.waset.org/abstracts/search?q=p-norm" title=" p-norm"> p-norm</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue%20constraint" title=" fatigue constraint"> fatigue constraint</a> </p> <a href="https://publications.waset.org/abstracts/78086/bi-directional-evolutionary-topology-optimization-based-on-critical-fatigue-constraint" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/78086.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">295</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">616</span> Thermal Fatigue Behavior of Austenitic Stainless Steels</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jung-Ho%20Moon">Jung-Ho Moon</a>, <a href="https://publications.waset.org/abstracts/search?q=Tae%20Kwon%20Ha"> Tae Kwon Ha</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Continually increasing working temperature and growing need for greater efficiency and reliability of automotive exhaust require systematic investigation into the thermal fatigue properties especially of high temperature stainless steels. In this study, thermal fatigue properties of 300 series austenitic stainless steels have been evaluated in the temperature ranges of 200-800°C and 200-900°C. Systematic methods for control of temperatures within the predetermined range and measurement of load applied to specimens as a function of temperature during thermal cycles have been established. Thermal fatigue tests were conducted under fully constrained condition, where both ends of specimens were completely fixed. Load relaxation behavior at the temperatures of thermal cycle was closely related with the thermal fatigue property. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=austenitic%20stainless%20steel" title="austenitic stainless steel">austenitic stainless steel</a>, <a href="https://publications.waset.org/abstracts/search?q=automotive%20exhaust" title=" automotive exhaust"> automotive exhaust</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20fatigue" title=" thermal fatigue"> thermal fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=microstructure" title=" microstructure"> microstructure</a>, <a href="https://publications.waset.org/abstracts/search?q=load%20relaxation" title=" load relaxation"> load relaxation</a> </p> <a href="https://publications.waset.org/abstracts/9692/thermal-fatigue-behavior-of-austenitic-stainless-steels" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/9692.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">377</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">615</span> The Effect of Surface Roughness on the Fatigue Life of SCM440 Steel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=C.%20Han">C. Han</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Kim"> H. Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20Park"> S. Park</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The purpose of the present study is to analyze the effect of surface roughness on fatigue life of SCM440 steel. Two groups of specimens were made from SCM440 steel with and without surface polished after forging process and resulted in different values of surface roughness. The difference of the surface roughness between two groups was clearly distinguished even to the naked eye. Surface roughness of both groups of the specimens was quantitatively measured by a roughness measuring device, Talysurf series2 (Taylor-Hobson Co., USA). Average roughness (Ra) and maximum roughness depth (Rmax) values were obtained by scanning 45 mm with a speed of 0.25 mm/s. Fatigue tests were conducted using a three-point bending method with a cyclic sinusoidal profile of 5 Hz, stress ratio of R = 0.1 and reference life for fatigue limit of 1 × 106 cycles. Ra and Rmax without surface polished were 10.497 ± 1.721 μm and 87.936 ± 16.210 μm, respectively while those values with surface polished were much smaller (ongoing measurements). Fatigue lives of the surface-polished specimens achieved approximately 1 × 106 cycles under the maximum stress of 900 MPa, which was 10 times longer than those of the surface-untreated specimens with an average roughness of 10.082 μm. The results showed that an increase in surface roughness values led to a decrease in fatigue lives. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=surface%20roughness" title="surface roughness">surface roughness</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue%20test" title=" fatigue test"> fatigue test</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue%20life" title=" fatigue life"> fatigue life</a>, <a href="https://publications.waset.org/abstracts/search?q=SCM440%20steel" title=" SCM440 steel"> SCM440 steel</a> </p> <a href="https://publications.waset.org/abstracts/60431/the-effect-of-surface-roughness-on-the-fatigue-life-of-scm440-steel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/60431.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">354</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">614</span> Fatigue Strength of S275 Mild Steel under Cyclic Loading</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=T.%20Aldeeb">T. Aldeeb</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Abduelmula"> M. Abduelmula</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study examines the fatigue life of S275 mild steel at room temperature. Mechanical components can fail under cyclic loading during period of time, known as the fatigue phenomenon. In order to prevent fatigue induced failures, material behavior should be investigated to determine the endurance limit of the material for safe design and infinite life, thus leading to reducing the economic cost and loss in human lives. The fatigue behavior of S275 mild steel was studied and investigated. Specimens were prepared in accordance with ASTM E3-11, and fatigue tests of the specimen were conducted in accordance with ASTM E466-07 on a smooth plate, with a continuous radius between ends (hourglass-shaped plate). The method of fatigue testing was applied with constant load amplitude and constant frequency of 4 Hz with load ratio (Fully Reversal R= -1). Surface fractures of specimens were investigated using Scanning Electron Microscope (SEM). The experimental results were compared with the results of a Finite Element Analysis (FEA), using simulation software. The experiment results indicated that the endurance fatigue limit of S275 mild steel was 195.47 MPa. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fatigue%20strength" title="fatigue strength">fatigue strength</a>, <a href="https://publications.waset.org/abstracts/search?q=fatigue%20life" title=" fatigue life"> fatigue life</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20analysis%28FEA%29" title=" finite element analysis(FEA)"> finite element analysis(FEA)</a>, <a href="https://publications.waset.org/abstracts/search?q=S275%20mild%20steel" title=" S275 mild steel"> S275 mild steel</a>, <a href="https://publications.waset.org/abstracts/search?q=scanning%20electron%20microscope%20%28SEM%29" title=" scanning electron microscope (SEM)"> scanning electron microscope (SEM)</a> </p> <a href="https://publications.waset.org/abstracts/93422/fatigue-strength-of-s275-mild-steel-under-cyclic-loading" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/93422.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">160</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">613</span> Environmental Fatigue Analysis for Control Rod Drive Mechanisms Seal House</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Xuejiao%20Shao">Xuejiao Shao</a>, <a href="https://publications.waset.org/abstracts/search?q=Jianguo%20Chen"> Jianguo Chen</a>, <a href="https://publications.waset.org/abstracts/search?q=Xiaolong%20Fu"> Xiaolong Fu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, the elastoplastic strain correction factor computed by software of ANSYS was modified, and the fatigue usage factor in air was also corrected considering in water under reactor operating condition. The fatigue of key parts on control rod drive mechanisms was analyzed considering the influence of environmental fatigue caused by the coolant in the react pressure vessel. The elastoplastic strain correction factor was modified by analyzing thermal and mechanical loads separately referring the rules of RCC-M 2002. The new elastoplastic strain correction factor Ke(mix) is computed to replace the original Ke computed by the software of ANSYS when evaluating the fatigue produced by thermal and mechanical loads together. Based on the Ke(mix) and the usage cycle and fatigue design curves, the new range of primary plus secondary stresses was evaluated to obtain the final fatigue usage factor. The results show that the precision of fatigue usage factor can be elevated by using modified Ke when the amplify of the primary and secondary stress is large to some extent. One approach has been proposed for incorporating the environmental effects considering the effects of reactor coolant environments on fatigue life in terms of an environmental correction factor Fen, which is the ratio of fatigue life in air at room. To incorporate environmental effects into the RCCM Code fatigue evaluations, the fatigue usage factor based on the current Code design curves is multiplied by the correction factor. The contribution of environmental effects to results is discussed. Fatigue life decreases logarithmically with decreasing strain rate below 10%/s, which is insensitive to strain rate when temperatures below 100°C. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=environmental%20fatigue" title="environmental fatigue">environmental fatigue</a>, <a href="https://publications.waset.org/abstracts/search?q=usage%20factor" title=" usage factor"> usage factor</a>, <a href="https://publications.waset.org/abstracts/search?q=elastoplastic%20strain%20correction%20factor" title=" elastoplastic strain correction factor"> elastoplastic strain correction factor</a>, <a href="https://publications.waset.org/abstracts/search?q=environmental%20correction" title=" environmental correction"> environmental correction</a> </p> <a href="https://publications.waset.org/abstracts/59209/environmental-fatigue-analysis-for-control-rod-drive-mechanisms-seal-house" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/59209.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">324</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=multiaxial%20fatigue&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=multiaxial%20fatigue&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=multiaxial%20fatigue&page=4">4</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=multiaxial%20fatigue&page=5">5</a></li> <li class="page-item"><a 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