Reliability-based Design Optimization for Inelastic Frame Structures with Viscous Dampers

Abstract

This study aims to establish a framework of dynamic reliability based design optimization to minimize the cost of retrofitting of viscous dampers for structures located in the near-fault region. In the framework, the cost of dampers is considered as objective function to be minimized, which is taken to be proportional to the designed force to sustain, and the locations of dampers are taken as design variables. The dynamic reliability of the structure is considered as the performance constraint. Firstly, a stochastic model of near-fault ground motions is established, and the corresponding near-fault impulsive ground motions are synthesized. Then, the probability density evolution method (PDEM) is employed to solve the dynamic reliability of structures by means of equivalent extreme event method. Because the design variables, namely, the locations of viscous dampers are integer variables, the computational effort will increase with the number of design variables. Accordingly, material interpolation technique in topological optimization of continuum is adopted to transform the integer variables into continuous ones. Finally, numerical example demonstrate the efficiency of design optimization of inelastic frame with viscous dampers in given reliability performance constraint.