Prediction of shape aberrations due to punching, shearing and slitting

Operations such as punching, shearing and slitting introduce local deformations and residual stresses near the cut edges. These may cause shape aberrations in the products as well as adversely effect further processing. Hence a study is carried out aimed at developing a model for predicting the deformation due to the residual stresses caused by the cutting process. The model parameters should be deducible from the deformation of reference cut samples. The application of the models to an actual product should be possible with a linear-elastic finite element code. In this paper, the results of some experimental work on shape aberrations after punching and slitting of stainless steel are presented. The performance of a number of simple models is tested. It shows that the shape aberrations connected to a double-torque model give an acceptable correspondence to the experimental observations. However, the effect of the dimensions of the workpiece relative to the pattern of punched holes needs further investigation.