Numerical analysis of failure in sheet metal forming with experimental validation
Keywords:
damage and coalescence models, sheet metal-forming, simulation of failure, neckingAbstract
As fracture in metal forming is maint y due to the development of ductile damage and in arder to represent the damage of anisotropie sheet-metals, an extension of the Gurson madel is presented and implemented in the context of plane-stress state for shell elements. With the damage madel, a failure criterion has to be used to signify the void coalescence but it is questionable whether the critical void volume fraction is a material constant. The void coalescence failure mechanism by internai necking is cons ide red by using the Thomason 's plastic limit-load model. The paper closes with a numerical and experimental study of the failure of rectangular strips of a titanium alloy in severa/ Nakazima's experiments conducted by the authors. The potential advantage of using the Gurson mode[ with the Thomas on' s void coalescence mode[ is discussed in the framework of sheet metal forming simulation.
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