A robust CRE-based approach for model updating using in situ measurements

This paper presents a systematic approach for comparing a numerical model to test results performed in situ on a structure with time-dependent behavior. A crucial issue for an engineer is to be able to assess the quality of models, based on a series of measurements. Dealing with in situ measurements as experimental reference for model updating involves two major difficulties: the excitations can be multiple and affected by large disturbances. The validation process we propose is based on the mechanical concept of Constitutive Relation Error (CRE) and aims at reducing the Lack Of Knowledge (LOK) attached to both the excitation forces and the parameters of the numerical model. The updated values can be computed inside confidence intervals that correspond to the lower contours of the CRE-based residual to minimize. The proposed method will be illustrated with a numerical example taken from the aerospace industry and applied for correcting a simple Ariane 5 model by comparison with flight measurements.