Assembly variation analysis model based on fixture configurations for sheet metal parts

An assembly variation analysis model with fixture configurations was proposed to improve the current variation analysis efficiency of sheet metal parts. The variation change process of part,fixture and assembly were analyzed by studying the positioning and assembly process of sheet metal parts. Linear relationships among variations of parts,fixtures and assemblies were established with two locating principles of N-2-1 and 3-2-1. Moreover,in accordance with the different release modes of the fixture positioning points after the assembly,the assembly variation analysis model was established in the two modes of over-constrained release and full release. Finally,a case of sheet metal assembly was used to illustrate the effectiveness of the assembly variation analysis model.