Hemming is a widely used joining technique in automotive construction for joining two sheets of metal by folding over the sheet edges. In car body construction in particular, hemming is used to join outer skin parts to inner parts, e.g. doors and engine hoods. A decisive factor for the quality of the assembly is the accuracy of the hemming operation. Otherwise, defects can occur, ranging from losses in surface quality to dimensional accuracy problems to cracks. Therefore, simulations are very important to validate the hemming process and to optimize the increase in efficiency.
In 2008, inpro started developments with the aim to develop a method to describe the hemming process including the hemming tools and to validate finite element simulations for the component. AutoForm, a leading manufacturer of planning tools for the processing of sheet metal components, was won as a cooperation partner. As part of the project, simulation software was developed that can simulate both the roller hemming process and the machine hemming process. In this way, the complex behavior of the component to be hemmed is predicted and analyzed. Based on the analyses, the tools can be adjusted to optimize the folding process.
Today, the software is distributed in a further developed form by the inpro cooperation partner AutoForm and is used in many manufacturing companies, in particular for the optimized design of folding processes, in early phases of product development and production planning as well as in method planning.