Modelling and numerical simulation of steel sheet fine blanking process

Abstract The steel sheet metal blanking is widely used for the manufacture of mechanical parts for automotive industry. The general concept of blanking seems a simple one but governing parameters are many and have a complex relation-ship, which directly affects the quality of the produced parts. The latter is assessed using three main criterions: the burr amount, the appearance of the cut edge and dimensional accuracy. However, the optimization of these parts depends on full understanding of the shearing process. The paper presents results of the investigations on numerical computations and experimental verification concerning the influence of selected parameter of the cutting process on the stress state of cold-rolled steel sheets being cut. The commercial code Lsdyna® has been chosen to simulate this process. The material testing and the characterization are carried out in order to fit the constitutive model parameters to the experimental data and to establish the sheet metal constitutive law. The identified model is, then, used for numerical simulations which are performed using LsDyna/Explicit software of various fine blanking tests. The aim of this paper is to predict the shear stress and plastic strain distribution in shearing zone during blanking versus punch-die clearance. The assumption of a deformable punch or not has also been considered. The finite elements predictions have been compared with experimental results. The numerical results of the validation simulations were in agreement with the experimental data with an approximate error margin of 31%, since the springback phenomena after unloading and tools warming up during the cutting procedure have not been considered.