An integral formulation with random parameters adapted to the study of thevibrational behaviour of structures in the middle- and high-frequency field

The fundamentals of a new boundary element formulation applied to the study of structural dynamics on a wide frequency range is proposed in this paper . Random geometrical parameters are introduced to the integral representati ons in order to model the increasing sensitivity of the harmonic vibrationa l responses to any parameter perturbation when the frequency increases. It is shown that the significant unknowns of the formulation are the expectati ons of the square boundary kinematic unknowns. Indeed, these variables are able to describe accurately the responses of the structures in the low-freq uency field and deliver a smooth response in the middle- and high-frequency field, corresponding to the global trend of the structural dynamic respons e in this frequency domain. The formulation is established for isolated and assembled one-, two- and three-dimensional structures. Numerical applicati ons illustrate the effectiveness of the method. (C) 2001 Academic press.