A study is presented for the large deflection dynamic response of rigid- plastic circular plate resting on potential fluid under a rectangular pressure pulse load. By virtue of Hankel integral transform technique,this...A study is presented for the large deflection dynamic response of rigid- plastic circular plate resting on potential fluid under a rectangular pressure pulse load. By virtue of Hankel integral transform technique,this interaction problem is reduced to a problem of dynamic plastic response of the plate in vacuum.The closed-form solutions are derived for both middle and high pressure loads by solving the equations of motion with the large deflection in the range where both bending moments and membrane forces are important.Some numerical results are given.展开更多
For studying the driving role of dynamic pressure in water-induced damage of asphalt pavement, based on the fast Lagrangian finite difference method and Biot dynamic consolidation theory, fluid-solid coupling analysis...For studying the driving role of dynamic pressure in water-induced damage of asphalt pavement, based on the fast Lagrangian finite difference method and Biot dynamic consolidation theory, fluid-solid coupling analysis of the pavement is conducted considering asphalt mixtures as porous media. Results reveal that the development and dissipation of the dynamic pore pressure are coinstantaneous and this makes both the positive and negative dynamic pore pressure and seepage force alternate with time. Repetitive hydrodynamic pumping and sucking during moisture damage is proved. The dynamic pore pressure increases with vehicle velocity. Effective stress and deflection of pavement decrease due to the dynamic pore water pressure. However, the emulsification and replacement of the asphalt membrane by water are accelerated. The maximum dynamic pore pressure occurs at the bottom of the surface course. So it is suggested that a drain course should be set up to change the draining condition from single-sided drain to a two-sided drain, and thus moisture damage can be effectively limited.展开更多
This study investigates the forced vibration of functionally graded hexagonal nano-size plates for the first time.A quasi-three-dimensional(3D)plate theory including stretching effect is used to model the anisotropic ...This study investigates the forced vibration of functionally graded hexagonal nano-size plates for the first time.A quasi-three-dimensional(3D)plate theory including stretching effect is used to model the anisotropic plate as a continuum one where small-scale effects are considered based on nonlocal strain gradient theory.Also,the plate is assumed on a Pasternak foundation in which normal and transverse shear loads are taken into account.The governing equations of motion are obtained via the Hamiltonian principles which are solved using analytical based methods by means of Navier’s approximation.The influences of the exponential factor,nonlocal parameter,strain gradient parameter,Pasternak foundation coefficients,length-to-thickness,and length-to-width ratios on the dynamic response of the nanoplates are examined.In addition,the accuracy of an isotropic approximate instead of the anisotropic model is studied.The dynamic behavior of the system shows that mechanical mathematics-based models may get better results considering the anisotropic model because the dynamic response can cause prominent differences(up to 17%)between isotropic approximation and anisotropic model.展开更多
Analytic expressions of the dynamic coefficient(DC)factor and vibrational behavior of a uniformly elastic isotropic beam with a simple boundary condition caused by accelerating masses with varying velocities are analy...Analytic expressions of the dynamic coefficient(DC)factor and vibrational behavior of a uniformly elastic isotropic beam with a simple boundary condition caused by accelerating masses with varying velocities are analyzed.The motion of this problem is described by a fourth-order partial differential equation,which governs its behavior.The weighted residual method converts the governing equation into a sequence of linked second-order differential equations to facilitate the analysis.A rewritten version of Struble's asymptotic method further simplifies the transformed governing equation.This modification aids reduction in the complexity of the equation.The closed-form response is contrasted across three force motions:acceleration,deceleration,and uniform motion.The study thoroughly examines how different velocities and frequencies of the moving force affect the dynamic behavior of the beam.The study also examines the influence of load velocity on the DC of the beam subjected to pinned–pinned boundary conditions.展开更多
This article presented a new data fusion approach for reasonably predicting dynamic serviceability reliability of the long-span bridge girder.Firstly,multivariate Bayesian dynamic linear model(MBDLM)considering dynami...This article presented a new data fusion approach for reasonably predicting dynamic serviceability reliability of the long-span bridge girder.Firstly,multivariate Bayesian dynamic linear model(MBDLM)considering dynamic correlation among the multiple variables is provided to predict dynamic extreme deflections;secondly,with the proposed MBDLM,the dynamic correlation coefficients between any two performance functions can be predicted;finally,based on MBDLM and Gaussian copula technique,a new data fusion method is given to predict the serviceability reliability of the long-span bridge girder,and the monitoring extreme deflection data from an actual bridge is provided to illustrated the feasibility and application of the proposed method.展开更多
基金The study is supported by National Natural Science Foundation of China.
文摘A study is presented for the large deflection dynamic response of rigid- plastic circular plate resting on potential fluid under a rectangular pressure pulse load. By virtue of Hankel integral transform technique,this interaction problem is reduced to a problem of dynamic plastic response of the plate in vacuum.The closed-form solutions are derived for both middle and high pressure loads by solving the equations of motion with the large deflection in the range where both bending moments and membrane forces are important.Some numerical results are given.
基金The National Natural Science Foundation of China (No.50708056)Reward Fund for Excellent Young and Middle-Aged Scientists of Shandong Province(No.2008BS09015)+1 种基金the Natural Science Foundation of Shandong Province (No.Q2006F02)Key Technologies R & D Program of Shandong Province (No.2008GG10006009)
文摘For studying the driving role of dynamic pressure in water-induced damage of asphalt pavement, based on the fast Lagrangian finite difference method and Biot dynamic consolidation theory, fluid-solid coupling analysis of the pavement is conducted considering asphalt mixtures as porous media. Results reveal that the development and dissipation of the dynamic pore pressure are coinstantaneous and this makes both the positive and negative dynamic pore pressure and seepage force alternate with time. Repetitive hydrodynamic pumping and sucking during moisture damage is proved. The dynamic pore pressure increases with vehicle velocity. Effective stress and deflection of pavement decrease due to the dynamic pore water pressure. However, the emulsification and replacement of the asphalt membrane by water are accelerated. The maximum dynamic pore pressure occurs at the bottom of the surface course. So it is suggested that a drain course should be set up to change the draining condition from single-sided drain to a two-sided drain, and thus moisture damage can be effectively limited.
文摘This study investigates the forced vibration of functionally graded hexagonal nano-size plates for the first time.A quasi-three-dimensional(3D)plate theory including stretching effect is used to model the anisotropic plate as a continuum one where small-scale effects are considered based on nonlocal strain gradient theory.Also,the plate is assumed on a Pasternak foundation in which normal and transverse shear loads are taken into account.The governing equations of motion are obtained via the Hamiltonian principles which are solved using analytical based methods by means of Navier’s approximation.The influences of the exponential factor,nonlocal parameter,strain gradient parameter,Pasternak foundation coefficients,length-to-thickness,and length-to-width ratios on the dynamic response of the nanoplates are examined.In addition,the accuracy of an isotropic approximate instead of the anisotropic model is studied.The dynamic behavior of the system shows that mechanical mathematics-based models may get better results considering the anisotropic model because the dynamic response can cause prominent differences(up to 17%)between isotropic approximation and anisotropic model.
文摘Analytic expressions of the dynamic coefficient(DC)factor and vibrational behavior of a uniformly elastic isotropic beam with a simple boundary condition caused by accelerating masses with varying velocities are analyzed.The motion of this problem is described by a fourth-order partial differential equation,which governs its behavior.The weighted residual method converts the governing equation into a sequence of linked second-order differential equations to facilitate the analysis.A rewritten version of Struble's asymptotic method further simplifies the transformed governing equation.This modification aids reduction in the complexity of the equation.The closed-form response is contrasted across three force motions:acceleration,deceleration,and uniform motion.The study thoroughly examines how different velocities and frequencies of the moving force affect the dynamic behavior of the beam.The study also examines the influence of load velocity on the DC of the beam subjected to pinned–pinned boundary conditions.
基金This work was supported by Natural Science Foundation of Gansu Province of China(20JR10RA625,20JR10RA623)National Key Research and Development Project of China(Project No.2019YFC1511005)+1 种基金Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2020-55)National Natural Science Foundation of China(Grant No.51608243).
文摘This article presented a new data fusion approach for reasonably predicting dynamic serviceability reliability of the long-span bridge girder.Firstly,multivariate Bayesian dynamic linear model(MBDLM)considering dynamic correlation among the multiple variables is provided to predict dynamic extreme deflections;secondly,with the proposed MBDLM,the dynamic correlation coefficients between any two performance functions can be predicted;finally,based on MBDLM and Gaussian copula technique,a new data fusion method is given to predict the serviceability reliability of the long-span bridge girder,and the monitoring extreme deflection data from an actual bridge is provided to illustrated the feasibility and application of the proposed method.
