Metamodel-based methods to verify the feasibility of a process control in deep drawing

Abstract

In production of deep drawn sheet metal parts it is often challenging to achieve a robust process. Especially in the production of kitchen sinks made out of stainless steel, the fluctuation of the process and material properties often lead to robustness problems. Therefore, numerical simulations are used to detect critical regions. By means of a series of finite element simulations with variable noise and design parameters, metamodels are computed for each quality criterion. Based on the metamodels, the influences of changing noise variables on the individual quality features are identified. To keep a constant product quality, the process settings (design parameters) should be adjusted. By means of new metamodel-based methods, the controllability of quality features is verified for user-defined production scenarios and visualised for each design and noise parameter. Thus it is possible to identify which design parameters are indispensable to control the desired quality feature and if it is controllable depending on the actual values of the noise variables. Furthermore the controllability of the entire part is analysed by using draw-in measurements for the feedback loop. Thereby it is possible to simulate, based on the metamodels, the effects of a series production, such as the heating of the tools during the first dozen of parts. Hence, the feasibility of a process control can be verified before realisation in order to optimize the concept of process control or even the process design.