Stochastic seismic response analysis and reliability assessment of passively damped structures

Viscous dampers have demonstrated their value for vibration control of civil engineering structures subjected to seismic excitations due to their effective energy dissipation capabilities and excellent durability characteristics. In most existing designs of practical applications on structural control with viscous dampers, just several ground motions with different risk levels are included. Logical treatment on the randomness inherent in the occurrence and propagation of earthquakes has still not received sufficient appeal. In this paper, stochastic seismic response analysis and reliability assessment of passively damped structures are carried out through experimental investigations and numerical simulations. Complete shaking-table tests on a framed structure with viscous dampers are involved, where the base excitation is represented by a physical stochastic ground motion model. For the numerical analysis and reliability assessment, the probability density evolution method and the theory of extreme value distribution are employed. Experimental and numerical investigations indicate that the seismic performance of the controlled structure with viscous dampers is significantly improved compared with that of the uncontrolled structure, and the structural safety is essentially enhanced.