DAMAGE EVOLUTION AND FORMING LIMIT PREDICTIONS OF AN AL2023-T3 ALUMINUM-ALLOY

In this paper, a plastic damage evolution equation for A12024-T3 sheet s is proposed based on the Continuum Damage Mechanics (CDM) and an exp erimental stress-strain relationship. The forming limit strains of alu minium sheets are predicted based on a modified M-K mode which include s the effect of material damage. The theoretical results show that the conventional over-estimations of limit strains in balanced biaxial st ate are reduced significantly by taking the material damage into consi deration. The predicted Forming Limit Curves are agreement with the ex perimental curves even without the assumption of an initial groove on the sheet metal surface.