Seismic reliability analysis of energy-dissipation structures by combining probability density evolution method and explicit time-domain method

Abstract

Hysteretic dampers such as buckling restrained braces (BRBs) have been widely used for improving the performance of civil structures exposed to seismic hazard. In this study, a hybrid approach, which combines the probability density evolution method (PDEM) and the explicit time-domain method (ETDM), is proposed for system reliability analysis of energy-dissipation structures with hysteretic dampers under seismic excitations. The PDEM can capture the probability density function (PDF) of system limit-state function for a structure by constructing a virtual random process associated with the limit state. The system failure probability of the structure can be directly evaluated through the integration of the PDF of system limit-state function over the failure domain. However, hundreds of deterministic nonlinear time-history analyses corresponding to the selected representative points need to be conducted in the solution procedure of PDEM, leading to high computational cost when applied to large-scale energy-dissipation structures. To enhance the efficiency of PDEM, the ETDM with dimension-reduced iteration scheme is incorporated into PDEM to conduct the required nonlinear time-history analyses with high efficiency, in which only a small number of degrees of freedom associated with the hysteretic dampers are considered in the iteration process. A real engineering building with 32 BRBs is investigated to illustrate the accuracy and efficiency of the proposed method and its feasibility to practical structures.