The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Su Huan Chen - One of the best experts on this subject based on the ideXlab platform.
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Interval optimization of Dynamic Response for structures with interval parameters
Computers & Structures, 2004Co-Authors: Su Huan ChenAbstract:This paper presents an interval optimization method for the Dynamic Response of structures with interval parameters. The matrices of structures with interval parameters are given. Combining the interval extension of function with the perturbation theory of Dynamic Response, the method for interval Dynamic Response analysis is derived. The interval optimization problem is transformed into a corresponding deterministic one. Because the mean values and the uncertainties of the interval parameters can be elected as the design variables, more information of the optimization results can be obtained by the present method than that obtained by the deterministic one. The present method is implemented for a truss structure and a frame structure. The numerical results show that the method is effective.
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Dynamic Response analysis for structures with interval parameters
Structural Engineering and Mechanics, 2002Co-Authors: Su Huan Chen, Hua Dong Lian, Xiao Wei YangAbstract:In this paper, a new method to solve the Dynamic Response problem for structures with interval parameters is presented. It is difficult to obtain all possible solutions with sharp bounds even an optimum scheme is adopted when there are many interval structural parameters. With the interval algorithm, the expressions of the interval stiffness matrix, damping matrix and mass matrices are developed. Based on the matrix perturbation theory and interval extension of function, the upper and lower bounds of Dynamic Response are obtained, while the sharp bounds are guaranteed by the interval operations. A numerical example, Dynamic Response analysis of a box cantilever beam, is given to illustrate the validity of the present method.
C. Schwingshackl - One of the best experts on this subject based on the ideXlab platform.
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A Multiscale Approach for Nonlinear Dynamic Response Predictions With Fretting Wear
Journal of Engineering for Gas Turbines and Power, 2017Co-Authors: J. Armand, L. Pesaresi, L. Salles, C. SchwingshacklAbstract:Accurate prediction of the vibration Response of aircraft engine assemblies is of great importance when estimating both the performance and the lifetime of their individual components. In the case of underplatform dampers, for example, the motion at the fric-tional interfaces can lead to a highly nonlinear Dynamic Response and cause fretting wear at the contact. The latter will change the contact conditions of the interface and consequently impact the nonlinear Dynamic Response of the entire assembly. Accurate prediction of the nonlinear Dynamic Response over the lifetime of the assembly must include the impact of fretting wear. A multiscale approach that incorporates wear into the nonlinear Dynamic analysis is proposed, and its viability is demonstrated for an underplatform damper system. The nonlinear Dynamic Response is calculated with a mul-tiharmonic balance approach, and a newly developed semi-analytical contact solver is used to obtain the contact conditions at the blade-damper interface with high accuracy and low computational cost. The calculated contact conditions are used in combination with the energy wear approach to compute the fretting wear at the contact interface. The nonlinear Dynamic model of the blade-damper system is then updated with the worn profile and its Dynamic Response is recomputed. A significant impact of fretting wear on the nonlinear Dynamic behavior of the blade-damper system was observed, highlighting the sensitivity of the nonlinear Dynamic Response to changes at the contact interface. The computational speed and robustness of the adopted multiscale approach are demonstrated .
J. Armand - One of the best experts on this subject based on the ideXlab platform.
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A Multiscale Approach for Nonlinear Dynamic Response Predictions With Fretting Wear
Journal of Engineering for Gas Turbines and Power, 2017Co-Authors: J. Armand, L. Pesaresi, L. Salles, C. SchwingshacklAbstract:Accurate prediction of the vibration Response of aircraft engine assemblies is of great importance when estimating both the performance and the lifetime of their individual components. In the case of underplatform dampers, for example, the motion at the fric-tional interfaces can lead to a highly nonlinear Dynamic Response and cause fretting wear at the contact. The latter will change the contact conditions of the interface and consequently impact the nonlinear Dynamic Response of the entire assembly. Accurate prediction of the nonlinear Dynamic Response over the lifetime of the assembly must include the impact of fretting wear. A multiscale approach that incorporates wear into the nonlinear Dynamic analysis is proposed, and its viability is demonstrated for an underplatform damper system. The nonlinear Dynamic Response is calculated with a mul-tiharmonic balance approach, and a newly developed semi-analytical contact solver is used to obtain the contact conditions at the blade-damper interface with high accuracy and low computational cost. The calculated contact conditions are used in combination with the energy wear approach to compute the fretting wear at the contact interface. The nonlinear Dynamic model of the blade-damper system is then updated with the worn profile and its Dynamic Response is recomputed. A significant impact of fretting wear on the nonlinear Dynamic behavior of the blade-damper system was observed, highlighting the sensitivity of the nonlinear Dynamic Response to changes at the contact interface. The computational speed and robustness of the adopted multiscale approach are demonstrated .
Xuelin Wang - One of the best experts on this subject based on the ideXlab platform.
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Design sensitivity analysis of Dynamic Response of nonviscously damped systems
Mechanical Systems and Signal Processing, 2013Co-Authors: Li Li, Yujin Hu, Xuelin WangAbstract:Abstract The sensitivity problem of Dynamic analysis of linear nonviscously damped systems is considered. The assumed nonviscous damping forces depend on the past history of motion via convolution integrals over some kernel functions. The nonviscous damping model can be alternatively chosen from familiar viscoelastically damping structures and is considered as a further generalization of the familiar viscous damping. The computations of Dynamic Responses are reviewed for the purpose of design sensitivity analysis development. The Dynamic Response can be easily calculated using direct frequency Response method and modal superposition method when the Dynamic equation of motion of nonviscously damped systems is transformed into the frequency domain using the Laplace transform. It is shown that the Dynamic Response of nonviscously damped systems can be obtained using traditional modal analysis in a familiar manner used in undamped or viscously damped systems. The discrete Fourier transform and inverse discrete Fourier transform algorithms are also suggested to obtain the displacement in the time domain. Based on these expressions of Dynamic Response, the adjoint variable and direct differentiation methods, originally presented to obtain the Dynamic Response sensitivity of undamped or viscously damped systems, are both developed for efficiently and accurately calculating the sensitivity of Dynamic Response of nonviscously damped systems. Finally, some case studies are used to show the application, effectiveness and some characters of the derived formulas. The numerical sensitivity results show the sensitivity obtained using the developed methods are in excellent agreement with the finite difference results. However, the finite difference method suffers from computational inefficiency and possible errors.
Zhang Yin - One of the best experts on this subject based on the ideXlab platform.
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Dynamic Response of spherical void in saturated porous media
Journal of Shaanxi Normal University, 2003Co-Authors: Zhang YinAbstract:Based on the modified version of Biot′s theory for saturated porous media, the spherical symmetrical Dynamic Response of saturated porous media is investigated by using potential functions and Fourier transform. The Dynamic Response of spherical void in infinite saturated porous medium is discussed. Two examples of Dynamic Responses of the spherical void are also given. The results have some significance for engineering practices.
