Numerical Analysis of the Residual Stresses Caused by Forming Process in Case of Conical Mini-Parts

Abstract

The research presented in this paper refers to numerical simulation related to deep drawing of conical mini-parts having different geometries as a function of side wall angle. The mini-parts are made from copper zinc alloy, having the thickness of 0.2 mm. Very important concerns in cold forming of conical mini-parts are the residual stresses due to their influence on the final shape of the part. During the forming process, due to different angles of the side wall, the residual stresses vary. After the mini-part is removed from the forming tools, the residual stresses modify the geometry of the part, causing dimensional errors. The residual stresses decrease the ability of the designer to draw some specific shapes because it may create forming problems such as wrinkling, tearing, and uncontrollable springback. The Dynaform 5.9.1 software was used to simulate the forming process. The part obtained after each simulation was analyzed and measured to quantify the effect of the residual stresses on the final geometry of part. All the parameters were maintained constant excepting the side wall angle. The obtained results for different side wall angles were compared to realize the behaviour of the conical mini-parts during and after deep drawing process.