Data and model uncertainties in complex aerospace engineering systems

Abstract : Parametric probabilistic approaches allow data uncertainties to be modelled, but have some difficulties to represent model uncertainties. It has been recently shown that both model and data uncertainties can be taken into account with a non-parametric approach. Moreover, it is known that with increasing complexity of a mechanical system, model uncertainties also increase. Based on these considerations, both parametric and non-parametric probabilistic approaches are used on a complex system of aerospace engineering constituted of a satellite coupled with its launcher. First, a parametric probabilistic model is constructed for analysing the sensitivity of the response due to data uncertainties. Then, the non-parametric probabilistic model is introduced with the same uncertainty level in order to study the sensitivity of the response with respect to the model and the data uncertainties. The dynamical responses obtained with these two probabilistic approaches are analysed in order to quantify the sensitivity of the structure to data uncertainties as well as model uncertainties.