DAMAGE MODELS AND IDENTIFICATION PROCEDURES FOR CRASHWORTHINESS OF AUTOMOTIVE LIGHT MATERIALS

Abstract

IN ORDER TO IMPROVE PREDICTIONS OF CRASHWORTHINESS OF AUTOMOTIVE LIGHT MATERIALS IN FINITE ELEMENT SIMULATION, THE ABILITY OF THE EXPLICIT FINITE ELEMENT CODES TO TAKE COMPLEX FAILURE INTO ACCOUNT HAS TO BE INCREASED. IN CONSEQUENCE, DAMAGE MODELS BASED ON THE FRAMEWORK OF CONTINUUM MECHANICS ARE PRESENTED. THE FIRST ONE FOCUSSES ON THE DEVELOPMENT OF ELLIPSOIDAL MICROVOIDS DURING PLASTIC STRAIN, AND THE SECOND ONE USES A GLOBAL DAMAGE VARIABLE WHICH EVOLVES WITH THE STRAIN ENERGY DENSITY RELEASE RATE. AN ORIGINAL DAMAGE PARAMETERS IDENTIFICATION PROCEDURE BASED ON AN INVERSE TECHNIQUE WITH STATIC AND DYNAMIC TESTS IS USED. THE PREVIOUS DAMAGE FRAMEWORK IS APPLIED TO MAGNESIUM, ALUMINIUM AND HIGH STRENGTH STEEL MATERIALS.