Dynamic response analysis of stochastic truss structures under non-stationary random excitation using the random factor method

Abstract

The dynamic characteristics and responses of stochastic truss structures under non-stationary random excitation are investigated using a new method called the random factor method (RFM). Using the RFM, the structural physical parameters and geometry can be considered as random variables. Based on the assumption that the randomness on each element is the same for all elements, the structural stiffness and mass matrices can then respectively be described by the product of two parts corresponding to the random factor and the deterministic matrix. From the expressions of structural random response in the frequency domain, computational expressions for the mean value, standard deviation and variation coefficient of the mean square value of the non-stationary random displacement and stress response are developed by means of the random variable’s functional moment method and the algebra synthesis method. The influences of the randomness of the structural parameters on the dynamic characteristics, structural displacement and stress responses are demonstrated using a truss structure.