NUMERICAL PREDICTION OF VARIOUS FAILURE MODES IN SPOTWELDED METALS

초록

This paper aims to predict failure modes of spotwelded metals using an available failure criterion, namely, the ESI-Wilkins-Kamoulakos (EWK) rupture model, in the PAM-CRASH finite element (FE) commercial software. By accounting for the hydrostatic pressure and the stress asymmetry, the EWK model can successfully predict different failure modes in the welding strength tests, including the shear mode, which cannot be predicted by Gurson's model. Moreover, characteristics of the spotweld, including residual stress, phase distributions, sizes and material roper ties of different zones, are obtained from an analysis with the SYSWELD software and are then mapped into the failure prediction model to achieve a realistic description of the weldment. Both the simulated results of the FE model combining solid and shell elements and those of the model with only solid elements show rather good consistency with the welding strength test data.

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