Numerical Modelling of Shape Aberrations due to Blanking.

摘要

The aim of the present study was to investigate the shape aberrations due to blanking. These deformations not only cause shape aberrations but can also lead to problems in subsequent manufacturing steps. The shape aberrations are caused by two factors: the stresses introduced by the inhomogeneous deformation during the shearing operation can lead to a modification of the dimensions. Another reason for the deflections of the plate after separating can be caused by internal stresses that were already present in the plate. By removing a part of these stresses a new equilibrium must be found which also causes shape aberrations. This thesis proposes a method that is able to calculate these shape aberrations for complex products. For this purpose the finite element method is used. Because it is not feasible to do a fully three-dimensional finite element calculation of the blanking process for complex products, a different method is proposed. The starting points for this method are the residual stresses that arise due to the blanking process.