Hemming is a joining technology used extensively in the automotive industry to join two sheets by hemming the sheet edges. In particular, hemming is applied in bodywork for connecting outer panels with internal components, for example, in doors and bonnets.
Hemming accuracy is invariably decisive for assembly quality. Inaccurate hemming may lead to defects, ranging from a loss in surface quality to dimensional issues or cracks. Therefore, simulations to guarantee the hemming process quality, and to optimise efficiency improvements are of the utmost relevance.
In 2008, inpro started developments to design a descriptive method for the hemming process, including the elaboration of hemming tools, and the validation of finite-element simulations for components. AutoForm, a leading manufacturer of planning tools for machining sheet metal parts, was recruited as a cooperation partner. During the project, simulation software was developed to simulate both the roll hemming process and machine hemming. The system allows the prediction and analysis of the components‘ complex behaviour that is to be hemmed. In turn, this analysis allows the tool to be fine-tuned for an optimal folding process.
An enhanced version of the software is now distributed by inpro’s cooperation partner AutoForm. It is presently used by numerous manufacturing companies, especially to optimise the design of hemming processes, in early stages of product development and production planning, as well as in method planning.