Random Response Analysis of Frictional Base Isolation System

In this work, the response analysis of a randomly excited nonlinear system is considered. The system resembles a frictional base isolation system under random earthquake excitation. The equivalent linearization technique and the stochastic averaging method are used to estimate the response statistics. The applicability of the recently suggested method of equivalent nonlinear system is also examined. The resulting mean‐square responses as evaluated by various approximation techniques are compared with those obtained from the performed Monte Carlo digital simulations. It is shown that the stochastic averaging method leads to more accurate stationary response statistics when compared with the equivalent linearization technique. Furthermore, the accuracy of the results obtained by the method of equivalent nonlinear system is quite sensitive to the form of equivalent system selected.