Simulation Approach for the Prediction of Surface Deviations Caused by Process-Machine-Interaction During Broaching

Abstract

Broaching is a highly efficient metal machining process in mass production. Parts with high quality requirements are manufactured by broaching, which can be influenced by different factors. One of them is vibration caused by process-machine-interactions. Such vibrations can easily be investigated with external broaching, where these vibrations result in varying process forces and wavily profiled machining surfaces.This paper presents a 2D FEM-simulation approach for the prediction of surface rough-ness generated by broaching. In the simulation model, the solid machine structure that consists of a large number of machine parts is realized by using elements representing the stiffness and the dynamic properties of the machine structure. Thus, it is possible to avoid high calculation times. The broach is implemented as an elastic body and the resulting process forces are realized by an analytical model that considers the process parameters cutting thickness, cutting velocity and rake angle. These process parameters are calculated for each increment, which allows determining the resulting process forces and applying them onto the teeth. Finally, the presented simulation approach for the prediction of the surface roughness generated by broaching is validated by means of experiments. Broaches with different numbers of teeth are used for the experimental setup.