Transient dynamics in structures with non-homogeneous uncertainties induced by complex joints

Abstract

This paper deals with numerical models for the prediction of the transient dynamical response induced by shocks upon structures with complex joints and shows experimental comparisons. The usual numerical methods for analysing such structures in the low- and medium-frequency ranges consist in using reduced matrix models constructed with the elastic modes. The contribution of the higher modes is very sensitive to the model errors and to the data errors. In this paper, a non-parametric probabilistic method is applied to construct the random matrix model allowing model errors and data errors to be taken into account. The paper presents an extension of the non-parametric method for the case of non-homogeneous model errors through the structure. A dynamic substructuring method is then used and the non-parametric probabilistic model of random uncertainties is used in each substructure with its own level of uncertainties. This approach is applied to a dynamical system made of two plates attached by a complex joint. Experiments have been performed and are used to validate the probabilistic predictive model.