Experimental and numerical optimisation of the sheet products geometry using response surface methodology

In this paper, two types of shapes were retained in order to investigate the behaviour of automotive safety parts that are obtained by successive sequences of blanking and bending. Firstly, experiments have been conducted in press tools for a sufficient number of process parameters combinations, particularly, die radius and clearance. Design of experiments and response surface methodology (RSM) were adopted to plot results obtained using the two-specimen geometries. Secondly, numerical model based on elastic plastic theory and ductile damage has been developed for the prediction of material behaviour during forming. The numerical approach was applied to study the mechanical responses of bent parts obtained by using each specimen shapes. The same parameters used for conducting experiments were retained for numerical simulation. However, the maximum bending load obtained for the two investigated cases were treated by application of response surface method. The damage values show a clear difference between the two considered specimen shapes. Numerical bending results compared to experimental values show the reliability of the proposed model for each case. The effects of geometry parameters on the bent parts and convenience of the obtained graphics were discussed in details.