NONSTATIONARY RESPONSE OF STRUCTURAL SYSTEMS

This paper presents a procedure for calculating the nonstationary mean square response of multidegree-of-freedom linearly elastic structural systems to multiple segmented nonstationary random forcing functions. Each forcing function is a stochastic process generated by adding a series of covariance stationary zero mean random forcing functions which are each shared by deterministic functions that do not overlap in the time domain. The procedure is used to compare the transient and stationary aspects of the response of structural systems to forcing functions that are time-variant in intensity and frequency content. The magnitudes of the modal displacement autocorrelation functions are studied in comparison with the cross-correlation functions between any two normal modes.