The Experts below are selected from a list of 1872 Experts worldwide ranked by ideXlab platform
M. Abdel Wahab - One of the best experts on this subject based on the ideXlab platform.
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Prediction of fretting fatigue crack initiation location and direction using cohesive zone model
Tribology International, 2018Co-Authors: Kyvia De Fatima Resende Pereira, Nadeem Ali Bhatti, M. Abdel WahabAbstract:Abstract Contact Stresses distributions may substantially reduce the fatigue life of components subject to fretting, leading to early unexpected failures. Accurately predicting the components lives is, therefore, an important topic to be addressed, in particular from a design point of view. This topic has received great attention in the past decades and several numerical tools that better estimate these components lives have been proposed. In this paper, the focus is in the crack initiation phase. At this stage, it is important to correctly predict the crack initiation location and orientation, which is often achieved by using critical plane approaches. Instead, the use of cohesive zone model (CZM) as an alternative approach to accurately estimate those parameters is investigated. Cohesive zone model as well as two of its common initiation criteria, namely quadratic traction-separation criterion and Maximum Nominal Stress criterion, are used to study crack initiation location and orientation under fretting conditions. Our results are compared with the traditional critical plane approaches and with experimental data, suggesting that cohesive approaches can accurately be used in crack initiation prediction.
Kyvia De Fatima Resende Pereira - One of the best experts on this subject based on the ideXlab platform.
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Prediction of fretting fatigue crack initiation location and direction using cohesive zone model
Tribology International, 2018Co-Authors: Kyvia De Fatima Resende Pereira, Nadeem Ali Bhatti, M. Abdel WahabAbstract:Abstract Contact Stresses distributions may substantially reduce the fatigue life of components subject to fretting, leading to early unexpected failures. Accurately predicting the components lives is, therefore, an important topic to be addressed, in particular from a design point of view. This topic has received great attention in the past decades and several numerical tools that better estimate these components lives have been proposed. In this paper, the focus is in the crack initiation phase. At this stage, it is important to correctly predict the crack initiation location and orientation, which is often achieved by using critical plane approaches. Instead, the use of cohesive zone model (CZM) as an alternative approach to accurately estimate those parameters is investigated. Cohesive zone model as well as two of its common initiation criteria, namely quadratic traction-separation criterion and Maximum Nominal Stress criterion, are used to study crack initiation location and orientation under fretting conditions. Our results are compared with the traditional critical plane approaches and with experimental data, suggesting that cohesive approaches can accurately be used in crack initiation prediction.
Xu Chen - One of the best experts on this subject based on the ideXlab platform.
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Temperature-Dependent Bending Ratcheting Behavior of a 316LN Stainless Steel
Journal of Materials Engineering and Performance, 2015Co-Authors: Xuyang Yuan, Xu ChenAbstract:Load-controlled cyclic three-point bending tests were conducted on a 316LN austenitic stainless steel at temperatures ranging from 20 to 450 °C. A fair method based on the concept of equivalent Maximum Nominal Stress (MNS) was proposed to quantitatively characterize the temperature-dependent bending ratcheting behavior of the steel. The equivalent MNS was determined by ensuring consistent residual deflections after the first bending cycle at varied temperatures. Two loading paths, namely simple cycling and dwelling-cycling, were employed under the equivalent MNS. Under the simple cycling path, the ratcheting behavior of the steel tends to shakedown as temperature rises. Under the simple cycling path where a dwelling was introduced at the Maximum loading, the ratcheting potential of the steel appears to be exhausted at relatively low temperatures. These facts are presumably attributed to the loss of viscosity induced by the dynamic strain aging effect.
Nadeem Ali Bhatti - One of the best experts on this subject based on the ideXlab platform.
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Prediction of fretting fatigue crack initiation location and direction using cohesive zone model
Tribology International, 2018Co-Authors: Kyvia De Fatima Resende Pereira, Nadeem Ali Bhatti, M. Abdel WahabAbstract:Abstract Contact Stresses distributions may substantially reduce the fatigue life of components subject to fretting, leading to early unexpected failures. Accurately predicting the components lives is, therefore, an important topic to be addressed, in particular from a design point of view. This topic has received great attention in the past decades and several numerical tools that better estimate these components lives have been proposed. In this paper, the focus is in the crack initiation phase. At this stage, it is important to correctly predict the crack initiation location and orientation, which is often achieved by using critical plane approaches. Instead, the use of cohesive zone model (CZM) as an alternative approach to accurately estimate those parameters is investigated. Cohesive zone model as well as two of its common initiation criteria, namely quadratic traction-separation criterion and Maximum Nominal Stress criterion, are used to study crack initiation location and orientation under fretting conditions. Our results are compared with the traditional critical plane approaches and with experimental data, suggesting that cohesive approaches can accurately be used in crack initiation prediction.
Changguo Wang - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature on the rupture behavior of highly stretchable acrylic elastomer
Polymer Testing, 2020Co-Authors: Jingtian Kang, Zeyi Zhang, Changguo WangAbstract:Abstract Dielectric elastomer has been recently explored extensively to make diverse soft actuators and energy harvesting devices. The lack of study on the rupture behavior under the influence of temperature hinders further applications where heat generation and accumulation are unavoidable. In this paper, an experimental study has been carried out to investigate the effect of temperature on the rupture behavior of acrylic dielectric elastomer. By using VHB 4910 films with and without an initial crack, the fracture energy at different temperature and stretch rate is measured by pure shear test. The storage modulus and phase angle have been investigated by dynamic mechanical analysis (DMA). The images of defects and rupture surface are provided by scanning electron microscope (SEM). It is found that the stretch at rupture is insensitive to the temperature for both pristine and precut samples. In addition, the Maximum Nominal Stress and fracture energy linearly decrease with environmental temperature, especially at high stretch rate. Furthermore, we measure the stretch at rupture for rectangular strips with a single edge-notch under uniaxial tension and compare them with the theoretical prediction using nonlinear fracture mechanics based on the measured fracture energy. The results obtained in this paper will give a reference to the engineering design and applications of dielectric elastomer, especially for those working at different temperatures.