NLTHA （nonlinear time history analysis） is impractical for widespread used by the professional engineer because it requires long and inefficient computational time involving complexities when six DOF （degree of fre...NLTHA （nonlinear time history analysis） is impractical for widespread used by the professional engineer because it requires long and inefficient computational time involving complexities when six DOF （degree of freedom） per node is applied. The NLTHA nowadays is predicted by MPA （modal pushover analysis）. In this method, effects of higher modes on the dynamic response are considered to estimate seismic demands for structures. In this study, the effect of the reduction of number of DOF is analyzed using 3D NLTHA together with MPA of a rigid connection RC bridge under large earthquake motion. The results are compared with the 6 DOF NLTHA in terms of response of the structure and CPU time to obtain the most efficient computational effort. Result of NLTHA showed that the computational time of the structure both for 4 DOF （without two lateral torsional effects） and 3 DOF （without two lateral torsional and vertical displacements） was reduced significantly compared to the structure using 6 DOF. The reduction of computational time was close to fifty percent both for 4 and 3 DOF＇s. When the maximum responses between NLTHA and MPA are compared, it is found that the differences are insignificant.展开更多
Great progress has been made in study on dynamic behavior of the damaged structures subject to deterministic excitation.The stochastic response analysis of the damaged structures,however,has not yet attracted people&#...Great progress has been made in study on dynamic behavior of the damaged structures subject to deterministic excitation.The stochastic response analysis of the damaged structures,however,has not yet attracted people's attention.Taking the damaged elastic beams for example,the analysis procedure for stochastic response of the damaged structures subject to stochastic excitations is investigated in this paper.First,the damage constitutive relations and the corresponding damage evolution equation of one-dimensional elastic structures are briefly discussed.Second,the stochastic dynamic equation with respect to transverse displacement of the damaged elastic beams is deduced.The finite difference method and Newmark method are adopted to solve the stochastic partially-differential equation and corresponding boundary conditions.The stochastic response characteristic,damage evolution law,the effect of noise intensity on damage evolution and the first-passage time of damage are discussed in detail.The present work extends the research field of damaged structures,and the proposed procedure can be generalized to analyze the dynamic behavior of more complex structures,such as damaged plates and shells.展开更多
文摘NLTHA （nonlinear time history analysis） is impractical for widespread used by the professional engineer because it requires long and inefficient computational time involving complexities when six DOF （degree of freedom） per node is applied. The NLTHA nowadays is predicted by MPA （modal pushover analysis）. In this method, effects of higher modes on the dynamic response are considered to estimate seismic demands for structures. In this study, the effect of the reduction of number of DOF is analyzed using 3D NLTHA together with MPA of a rigid connection RC bridge under large earthquake motion. The results are compared with the 6 DOF NLTHA in terms of response of the structure and CPU time to obtain the most efficient computational effort. Result of NLTHA showed that the computational time of the structure both for 4 DOF （without two lateral torsional effects） and 3 DOF （without two lateral torsional and vertical displacements） was reduced significantly compared to the structure using 6 DOF. The reduction of computational time was close to fifty percent both for 4 and 3 DOF＇s. When the maximum responses between NLTHA and MPA are compared, it is found that the differences are insignificant.
基金supported by the National Natural Science Foundation of China (Grant No. 11072076)
文摘Great progress has been made in study on dynamic behavior of the damaged structures subject to deterministic excitation.The stochastic response analysis of the damaged structures,however,has not yet attracted people's attention.Taking the damaged elastic beams for example,the analysis procedure for stochastic response of the damaged structures subject to stochastic excitations is investigated in this paper.First,the damage constitutive relations and the corresponding damage evolution equation of one-dimensional elastic structures are briefly discussed.Second,the stochastic dynamic equation with respect to transverse displacement of the damaged elastic beams is deduced.The finite difference method and Newmark method are adopted to solve the stochastic partially-differential equation and corresponding boundary conditions.The stochastic response characteristic,damage evolution law,the effect of noise intensity on damage evolution and the first-passage time of damage are discussed in detail.The present work extends the research field of damaged structures,and the proposed procedure can be generalized to analyze the dynamic behavior of more complex structures,such as damaged plates and shells.
