Modeling of Assembly Deviation with Considering the Actual Working Conditions

Abstract

Generally, it would be more realistic to consider that the components of an assembly are flexible typically undergo some deformations. In addition, with the mobility of the parts, there is normally a wear between the contact surfaces. Ignoring the dynamic working conditions with these deformations and wear could lead to an inaccurate assembly deviation and further affect the performance, reliability and service life of products. This paper proposes modeling of assembly deviation by considering the actual working conditions to obtain the time-variant assembly gap during the service time. First, the dimensional and geometric tolerances of the parts are simulated by Monte Carlo simulation, and the assembly deviation caused by the tolerances is obtained based on modified Unified Jacobian–Torsor model. Second, the deformation of the surfaces of the parts induced by mechanical and thermal loads are calculated by finite element analysis. Third, the wear depth between the contact surfaces is derived by conducting wear tests under the simulating working condition. By integrating the deformations and wear into tolerance analysis model, the final assembly deviation is constructed by considering the actual working conditions. Finally, the proposed model is applied to the blade bearing of controllable pitch propeller (CPP) for determining the effect of the actual working conditions on its service life.