An integrated approach for numerically predicting the failure of resistance spot welds

In this study, a numerical approach was proposed to predict the failure of resistance spot welds, into which theoretical and empirical models as well as finite element (FE) model are integrated. In this approach, the hardness of spot welds was first evaluated and the estimated hardness was then used to determine the local mechanical properties. The weld geometry and boundary conditions were faithfully followed when generating the FE model. A Gurson-type damage model and a cohesive zone model were simultaneously considered for the two main failure modes, i.e. pull-out failure and interface failure. The predictions were validated by experimental observations. The successful estimation of critical nugget size, as an exemplary application, demonstrated the utility and reliability of this approach.

Automated summary

This study proposes a numerical approach that integrates theoretical and empirical models with finite element (FE) model to predict the failure of resistance spot welds. By evaluating the hardness of spot welds and using it to determine the local mechanical properties, this approach faithfully follows the weld geometry and boundary conditions when generating the FE model. It considers both a Gurson-type damage model and a cohesive zone model for pull-out failure and interface failure and validates the predictions with experimental observations. The successful estimation of critical nugget size demonstrates the utility and reliability of this approach.