Dimensional Variation Modeling of Aircraft Compliant Part Assembly Considering Clamping Force Change

Compliant parts are widely applied to aircraft structures. Due to the ease of deformation of compliant parts in assembly,the prediction of assembly variation is especially important for assembly quality control. A dimensional variation model considering the clamping force change in assembly is proposed based on the method of influence coefficient(MIC). First,the assembly process is decomposed into several steps including positioning,clamping,joining,and spring-back. Then,the force-displacement relationship is formulated according to the varied force conditions on the parts in each assembly step. Finally,two examples are illustrated to validate the proposed assembly variation model. The results show the impact of clamping force change is significant on the assembly variation,and the proposed model can predict the assembly variation more accurately than the referred method without clamping force correction at the over-constrained locating points of fixture.