Experimental and numerical research for the failure behavior of the clinched joint using modified Rousselier model

The ductile fracture of the clinched joint is studied by the experiments and simulations using a modified Rousselier model. Although tension failure has been successfully predicted by the classical Rousselier damage model, its predictive capability on shear failure is seldom discussed. The microstructure of the clinched joint reveals that the ductile fracture occurs in the neck thickness under the shear and tensile force. So this paper is mainly concerned with application of a modified Rousselier damage model developed by the Guo on the description of the failure behavior of the clinched joint. The three experimental specimens were designed in order to calibrate the damage coefficients kω and the initial void volume fraction f0. The material parameters of the modified Rousselier model were identified by an inverse method comparing the experimental results with the numerical results. The modified Rousselier model could capture both tension and shear failure behavior of the clinched joint. The numerical results and the experimental results indicate the Lode parameters in the new damage evolution model can capture the failure behavior and the evolution process during the clinching process.