INDIRECT ANALYSIS OF BOUNDARY STRESSES

One of the crucial difficulties in numerical simulation of metal formi ng is to describe precisely the boundary conditions, especially fricti on. Adequate friction laws have to be engineered and implemented but n eed to be ascertained experimentally. This contribution puts forward f or use in massive forming a new model test based on the bulging test. To determine the local boundary stresses in the contact area at any gi ven time, we make use of the fact that the tool's elastic deformation is readily measurable. It will be demonstrated that this permits both a qualitative evaluation of friction and a quantification of unknown f actors in a friction law - the latter by analysing numerically the who le system.