Stochastic analysis of structures with passive seismic control

Abstract

In modern building design, the installation of passive control devices such as friction cross-bracings and viscoelastic dampers is considered an attractive option for controlling structural damage due to an earthquake. These control devices, like safety valves, allow earthquake energy dissipation at purposely designed locations such that ductility demands on other structural members are greatly reduced. The paper presents a nonlinear stochastic analysis procedure for large building structures equipped with passive control devices using the method of equivalent linearization. A generalization of this method, based on the Monte Carlo simulation technique, is elaborated for linearizing a multidimensional hysteretic restoring force law in a manner compatible with existing finite element programs. To illustrate the procedure, response statistics of a nonlinear oscillator, a friction damped structure, and a 10-storey building subjected to random excitation are analyzed. The study highlights that friction connections are useful in controlling seismic response of building structures. Key words: stochastic dynamics, Markov process, equivalent linearization, earthquake, passive control, Monte Carlo simulation, hysteresis, filtered white noise, covariance, friction cross-bracing.