Robust Material Modeling for Sheet Metal Bending

Funding: ReCIMP
Contact: Fabian Schmitz M.Sc.
Status: Completed

Technical design of high-strength steels for bent structural parts in vehicles is a particular challenge. Firstly, the parts must endure a reverse bending during use; secondly, high-strength steels partially have strongly varying hardening properties. Simulations of the bending process require an accurate description of the material behavior.


Initially, a new testing device (see figure a) has been developed to compare different material concepts. With the help of the new testing device bending radius and bending angle can be adjusted independently. Subsequently, another device has been used for controlled reverse bending. Additionally, air-bending tests have been conducted to determine a material-dependent correlation of bending radius and bending angle (see figure b). Furthermore, a complete parameter identification for two coupled damage models has been performed. It has been found that the predicted damage values correlate very good with the experimentally determined crack classification of the specimen surface (see figure c).



a) Bending device, b) Correlation of bending radius and bending angle, c) Prediction of bending quality