Employing shimming for clamping compliant sheet-metal parts

The purpose of clamping is to hold the part against locators and to resist the effects of manufacturing process forces. As initial matching gaps exist between the part and the locators, these gaps are forced to close during the clamping action by deforming the part to the nominal position. This is especially true for compliant sheet-metal parts. One way to reduce clamping deformation is to apply shim spacers between the part and its corresponding clamp, which slightly changes the normal clamping position of the part. However, it is generally very time-consuming to determine the optimal shim size for each clamp. An algorithm for clamp shimming optimisation is proposed in this paper. Application results of an industrial part demonstrated that the proposed algorithm effectively achieves the objective.