Fatigue analysis of a mechanical press by means of the hybrid multi-body simulation

During the past decade in the automotive industry more and more conventional sheet metal components were replaced by high-strength sheet metal components. The processing of these modern sheet metals lead to an increase of the loads applied to the metal forming machines. In comparison to conventional sheet metals an extensive cutting-shock can be observed while cutting high-strength sheet metals. Hence, the components of the press start to oscillate and therefore the possibility of an early crack initiation increases. Thus, it has become necessary to investigate the specific demands while cutting modern sheet metals and take them into account during the design process of further presses. Within the framework of the presented project, conventional as well as high-strength sheet metals were cut and their loads were recorded. Additionally, a hybrid multi-body simulation model of a mechanical press was established and validated by means of measurements at a real press available at the Institute of Forming Technology and Machines (IFUM). Subsequently, the multi-body simulation model was coupled with a fatigue analysis software package. By means of the coupled simulation the fatigue life of the structural components of the press was determined. The entire approach was validated by means of test structures. The test structures were designed for a short fatigue life, manufactured and mounted the press available at the IFUM. A good correlation of the virtually determined and real fatigue life of the test structures was achieved.