Optimising towards robust metal forming processes

Product improvement and cost saving have always been important goals in the metal forming industry. Numerical optimisation can help to achieve these goals, but optimisation with a deterministic approach will often lead to critical process settings, such that the slightest variation in e.g. material behaviour will result in violation of constraints. To avoid a high scrap ratio, process robustness must be considered in the optimisation model. Optimising for robustness includes Robust Manufacturing (RM) techniques, Optimisation Under Uncertainty (OUU) methods and Finite Element (FEM) simulations of the processes. In this paper, we review RM and OUU. Subsequently, the combination of Statistical Process Control (SPC), robust and reliability based optimisation methods, and FEM-based process simulation implemented in AutoForm-Sigma is presented. An automotive deep drawing application demonstrates the potential of strategies that optimise towards robust metal forming processes.