The Experts below are selected from a list of 44580 Experts worldwide ranked by ideXlab platform
Martyn J Pavier - One of the best experts on this subject based on the ideXlab platform.
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three dimensional finite element prediction of crack closure and fatigue crack growth rate for a corner crack
International Journal of Fatigue, 2006Co-Authors: S Simandjuntak, H Alizadeh, David J Smith, Martyn J PavierAbstract:Abstract The effect of plasticity induced crack closure on fatigue crack growth rate has been examined for the case of a 2024 aluminium alloy plate with two lateral corner cracks emanating from a central hole. The plate was subjected to constant amplitude loading and a combination of constant amplitude and single overload loading prior to the measurement of the opening load. The opening load was measured by comparing the strain ahead of the crack tips with the far field strain as the load on the specimen was cycled. Measurements were also made of the growth rate of the crack in fatigue. A three-dimensional finite element Quarter Model was developed of the plate with a central hole and corner cracks. The geometry of the Model forced the crack to assume a constant aspect ratio of bore length to surface length as the crack grew. Two different aspect ratios of 1:1 and 1.5:1 were considered. The load on the Model was cycled and the crack extended by releasing nodes so as to predict the development of a plastic wake behind the advancing crack. The opening load was predicted from the finite element displacement versus load results. These opening load predictions agreed favourably with the experimental measurements. The finite element Model was also used to predict the fatigue crack growth rate. This was achieved by first evaluating the effective stress intensity factor range from the stress distribution ahead of the crack tip. A Paris law fit to high R -ratio test data was then made to allow the corresponding growth rate to be calculated. Encouraging comparisons of the finite element predictions of fatigue crack growth rate with experimental measurement were obtained.
Galal Ali Hassaan - One of the best experts on this subject based on the ideXlab platform.
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car dynamics using Quarter Model and passive suspension part vi sprung mass step response
IOSR Journal of Computer Engineering, 2015Co-Authors: Galal Ali HassaanAbstract:The objective of the paper is to investigate the step response of a 2 DOF Quarter-car Model with passive suspension. The mathematical Models of the sprung-mass displacement and acceleration as response to the step road disturbance are derived. The step response of the system is plotted using MATLAB for a 100 mm step amplitude. The effect of the suspension parameters on the step response of the sprung-mass is investigated in terms of motion displacement and acceleration. The maximum percentage overshoot and settling time of the step response are evaluated as time-based characteristics of the dynamic system for a specific range of the suspension parameters. The maximum acceleration of the sprung-mass due to the step road disturbance did not conform with the ride comfort requirements according to ISO 2631-1 standard .
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Car Dynamics using Quarter Model and Passive Suspension, Part I: Effect of Suspension Damping and Car Speed
2014Co-Authors: Galal Ali HassaanAbstract:Quarter-car Model is in use for years to study the car dynamics. The objection of this paper is to examine the dynamics of a car passing a circular hump for sake maintaining ride comfort for the passengers. Passive suspension elements are considered with suspension damping coefficient in the range 1 to 15 kNs/m. Car speed in the range 5 to 25 km/h is considered when passing the hump. Important phenomenon evolved from the analysis of the car dynamics which is performed using MATLAB. The mathematical Model of the Quarter-car Model is derived in the state form and the dynamics are evaluated in terms of the sprung mass displacement and acceleration. The effect of suspension damping and car speed on the sprung-mass displacement and acceleration is examined. The study shows that for ride comfort the car speed has not to exceed 6.75 km/h when passing a circular hump depending on the suspension damping. .
S Simandjuntak - One of the best experts on this subject based on the ideXlab platform.
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three dimensional finite element prediction of crack closure and fatigue crack growth rate for a corner crack
International Journal of Fatigue, 2006Co-Authors: S Simandjuntak, H Alizadeh, David J Smith, Martyn J PavierAbstract:Abstract The effect of plasticity induced crack closure on fatigue crack growth rate has been examined for the case of a 2024 aluminium alloy plate with two lateral corner cracks emanating from a central hole. The plate was subjected to constant amplitude loading and a combination of constant amplitude and single overload loading prior to the measurement of the opening load. The opening load was measured by comparing the strain ahead of the crack tips with the far field strain as the load on the specimen was cycled. Measurements were also made of the growth rate of the crack in fatigue. A three-dimensional finite element Quarter Model was developed of the plate with a central hole and corner cracks. The geometry of the Model forced the crack to assume a constant aspect ratio of bore length to surface length as the crack grew. Two different aspect ratios of 1:1 and 1.5:1 were considered. The load on the Model was cycled and the crack extended by releasing nodes so as to predict the development of a plastic wake behind the advancing crack. The opening load was predicted from the finite element displacement versus load results. These opening load predictions agreed favourably with the experimental measurements. The finite element Model was also used to predict the fatigue crack growth rate. This was achieved by first evaluating the effective stress intensity factor range from the stress distribution ahead of the crack tip. A Paris law fit to high R -ratio test data was then made to allow the corresponding growth rate to be calculated. Encouraging comparisons of the finite element predictions of fatigue crack growth rate with experimental measurement were obtained.
David J Smith - One of the best experts on this subject based on the ideXlab platform.
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three dimensional finite element prediction of crack closure and fatigue crack growth rate for a corner crack
International Journal of Fatigue, 2006Co-Authors: S Simandjuntak, H Alizadeh, David J Smith, Martyn J PavierAbstract:Abstract The effect of plasticity induced crack closure on fatigue crack growth rate has been examined for the case of a 2024 aluminium alloy plate with two lateral corner cracks emanating from a central hole. The plate was subjected to constant amplitude loading and a combination of constant amplitude and single overload loading prior to the measurement of the opening load. The opening load was measured by comparing the strain ahead of the crack tips with the far field strain as the load on the specimen was cycled. Measurements were also made of the growth rate of the crack in fatigue. A three-dimensional finite element Quarter Model was developed of the plate with a central hole and corner cracks. The geometry of the Model forced the crack to assume a constant aspect ratio of bore length to surface length as the crack grew. Two different aspect ratios of 1:1 and 1.5:1 were considered. The load on the Model was cycled and the crack extended by releasing nodes so as to predict the development of a plastic wake behind the advancing crack. The opening load was predicted from the finite element displacement versus load results. These opening load predictions agreed favourably with the experimental measurements. The finite element Model was also used to predict the fatigue crack growth rate. This was achieved by first evaluating the effective stress intensity factor range from the stress distribution ahead of the crack tip. A Paris law fit to high R -ratio test data was then made to allow the corresponding growth rate to be calculated. Encouraging comparisons of the finite element predictions of fatigue crack growth rate with experimental measurement were obtained.
H Alizadeh - One of the best experts on this subject based on the ideXlab platform.
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three dimensional finite element prediction of crack closure and fatigue crack growth rate for a corner crack
International Journal of Fatigue, 2006Co-Authors: S Simandjuntak, H Alizadeh, David J Smith, Martyn J PavierAbstract:Abstract The effect of plasticity induced crack closure on fatigue crack growth rate has been examined for the case of a 2024 aluminium alloy plate with two lateral corner cracks emanating from a central hole. The plate was subjected to constant amplitude loading and a combination of constant amplitude and single overload loading prior to the measurement of the opening load. The opening load was measured by comparing the strain ahead of the crack tips with the far field strain as the load on the specimen was cycled. Measurements were also made of the growth rate of the crack in fatigue. A three-dimensional finite element Quarter Model was developed of the plate with a central hole and corner cracks. The geometry of the Model forced the crack to assume a constant aspect ratio of bore length to surface length as the crack grew. Two different aspect ratios of 1:1 and 1.5:1 were considered. The load on the Model was cycled and the crack extended by releasing nodes so as to predict the development of a plastic wake behind the advancing crack. The opening load was predicted from the finite element displacement versus load results. These opening load predictions agreed favourably with the experimental measurements. The finite element Model was also used to predict the fatigue crack growth rate. This was achieved by first evaluating the effective stress intensity factor range from the stress distribution ahead of the crack tip. A Paris law fit to high R -ratio test data was then made to allow the corresponding growth rate to be calculated. Encouraging comparisons of the finite element predictions of fatigue crack growth rate with experimental measurement were obtained.