Variation analysis of precision mechanical assembly considering form errors and local deformation

A method to analyze the effect of form errors and local deformation on the assembly accuracy and its stability in a non-rigid assembly system is proposed. The contact finite element method was used to obtain local deformation of mating surfaces, which was superposed onto form errors to obtain real mating surface data of assemblies. Then mating variation was obtained by establishing virtual contact planes. Finally, an experiment of the assembly of two cylindrical components was carried out to verify the validity of the proposed method. By comparing the calculation accuracies of 3D assembly with and without taking into account local deformation, the results showed that the effects of local deformation of mating surfaces on calculation accuracy of mating variation was not neglectable compared with form errors.