Random Response Spectrum Based Structural Reliability Analysis

摘要

The random response spectrum is addressed in the present paper, in conjunction with a stochastic earthquake model exhibiting the physical nature of non-stationary. It bypasses the premise included in the original formulation of random response spectrum that the external excitation is viewed as a stationary process, which does not follow most practical engineering excitations, typically, earthquake ground motions. The forms of random response spectrum of relative displacement, relative velocity and absolute acceleration are constructed, respectively, and their probabilistic characteristics are investigated employing the probability density evolution method. Structural reliability analysis, using a novel method based on random response spectrum, is further carried out. This scheme provides a flexible strategy for structural reliability assessment since that the classical reliability methods, e.g. FORM and SORM, highly rely on the explicit expression and nonlinear degree at checking point of performance functions. The random response spectrum method, however, can readily solve the analytical solution of mean and standard deviation of response extreme-values. Two numerical cases are investigated for illustrative purpose, involving a single-degree-of-freedom structure and a ten-storey shear frame. In addition, a validation study on the response distribution in reliability assessment is investigated, in virtue of the developed random response spectrum method and probability density evolution method. The numerical results indicate the validity and applicability of the developed random response spectrum method for the reliability analysis of engineering structures.