Some Advantages of Advanced Inverse Methods to Identify Viscoplastic and Damage Material Model Parameters
Résumé
The chapter aims at providing an overview of the research activities performed in the two past decades in the field of materials characterisation under dynamic loadings (i.e. from 10-3/s to 10+3/s for structural crashworthiness and impact applications) and identification of parameters of constitutive behaviour and damage models. The different testing devices to load the material sample on the expected strain rate range are presented and discussed first, including the different experimental measurement techniques applied to analyse the stress-strain curves. From the normalised direct approach, two different numerical approaches, based on inverse problem resolution techniques, are introduced and discussed: the well-known Finite Element Model Updating method and the most advanced one based on the Virtual Fields Method, that enables to take the full advantages of full-field measurement techniques, such as the Digital Image Correlation method, into account. Applications for different materials or structures (including riveted and welded joints) and models, such as viscoplasticity and damage, are given to illustrate these advanced methods.