Interval modal superposition method for impulsive response of structures with uncertain-but-bounded external loads

This paper is concerned with the problem of the dynamic response of structures with uncertain-but-bounded external loads. Based on the theory of complex modal analysis, and interval mathematics, a new non-probabilistic method-interval modal superposition method is proposed to find the least favorable impulsive response and the most favorable impulsive response of structures. Through mathematical analysis and numerical calculation, comparisons between interval modal superposition method and probabilistic approach are made. Instead of probabilistic density distribution or statistical quantities, in the presented method, only the bounds on uncertain parameters are needed, Numerical examples indicate that the width of the region of the dynamic response yielded by the interval modal superposition method is larger than those produced by probabilistic approach while the interval modal superposition method will required less computation effort.