Finite Element Methods play an integral role in the day to day engineering process of automotive manufacturing. Yet there are technical roadblocks which need to be dismantled to move the industry forward, in terms of accuracy, convergence and computational efficiency. This is even more true for some very challenging manufacturing process simulations that requires highly transient multi-physics couplings. In this talk, the current issues faced by automotive manufacturing engineering in forming and welding shall be discussed, with our exploration of using advanced numerical methods such as meshfree in simulations.

Formability simulation is applied to body stampings during die design and has been for years. However, there exist huge savings potential in the die design, build, and tryout, which account for 50% of a stamped part cost, if significant advances in prediction of springback and/or fracture could be attained.

Remote laser welding offers significantly shorter weld time and great flexibility but defects such as hot cracking and undercut affect the load bearing capability of welds. Existing FEMs are not able to consider material mixing, material loss, free surface, and microstructuraland material property evolution during melting and solidification which are important for prediction of undercut and cracking sensitivity, and also critical for calculation of residual stress and thermally-induced distortion. In addition, the integration of the thermal-fluid analysis solvers with existing FEM solvers still needs to be done so that the material melting and mixing result from the thermo-fluid analysis can be integrated into the thermo-mechanical analysis for accurate predictions of stress and distortion.

Lastly, convergence issues with FEMs lead one to mesh-free approaches to accommodate large localized deformations as in ultrasonic welding of battery tabs, and self-piercing-riveted aluminum to steel body assemblies. In these applications, the choice of numerical algorithms becomes even more critical.