Wavelets-based method for variation analysis of non-rigid assemblies

This paper proposes a new method based on wavelets analysis and finite element method (FEM) for the variation analysis of non-rigid assemblies. It is well known that the part fabrication variation, coupled with the part's deformation during the assembly process, is one of the main factors affecting the assembly quality. But little investigation has been done on how component variations with different scales contribute to the final dimensional variation of non-rigid assemblies. The proposed approach takes the part variation as a signal and applies wavelets transform to decompose it into different scale components. The deformation of non-rigid assemblies that corresponds to these different scale components is calculated by using FEM. Since the part variation is resulted from manufacturing, manufacturing engineers can apply this method to get valuable information to avoid major variation causes in manufacturing process and make a better process plan. The proposed method is illustrated through a case study on an assembly of two flat sheet metal parts.