Identification of a Continuum Damage Model from Micro-hardness Measurements Application to a Backward Extrusion Process

摘要

The identification procedure of Lemaitre's ductile damage law from micro-hardness tests performed on a tensile test specimen has been applied to a 16MnCr5 steel. Upsetting tests have been performed. Hardness measured on the discs enables one to deduce damage field. A procedure is proposed to identify the unilateral effect that takes into account of compressive stress states from confrontations between these hardness measurements and corresponding numerical simulations. First simulations of the industrial process enable one to exhibit a critical area near the edge of the punch, with a good agreement with the experimental observations (Figure 9).