Experimentally valided approach for the simulation of the forging process using mechanical vibration

In this study, an experimental setup of a forging process has been designed which allows to apply vibrations to the lower die of amplitude ranging from 0 to 80µm at frequencies varying from 1 to 130Hz thanks to the use of a stack piezoelectric actuator fed by an electronic inverter. In order to explore those results, a coupling model has been developed to provide a design tool in a mechatronic frame which consists of an analytical model of the forging process based on simplified visco-plastic laws and a state space model of the piezoelectric actuator based on a finite element approach [1]. The coupling model can be used to analyse the important parameters of the whole process in order to optimize the forging process design using mechanical vibrations or to control the process if necessary. A finite element simulation of forging process using mechanical vibration based on finite element software Forge2008® is also presented in this study. The results obtained by experiment, finite element simulation and simulation using the model above are compared in the case of simple upsetting, with good agreement. Moreover, it can be concluded that high frequencies are not required to observe this phenomenon. Finally visco-plasticity phenomenon is not self-sufficient to explain completely the force reduction.