Failure analysis and improvement of a non-metallic engineering part in an interference fit assembly process

Severe stress concentration and bad sealing performance are encountered in a non-metallic engineering part during an interference fit assembly process. Both numerical calculation and experimental test are employed to analyze the causes resulting in the assembly failure. Based on the finite element method (FEM), commercial computational software, ANSYS, is first used to simulate the whole assembly process with different boundary conditions. By comparing simulation results of the assembly process with various boundary conditions, it is found that deformation energy and friction force contribute differently to the reaction force at varying assembly depths. In virtue of these simulation results, an improved engineering part is designed and fabricated. Experimental test results show that stress concentration and sealing performance problems are basically solved compared to those in the original model. Moreover, reaction forces calculated from numerical simulation and measured from experimental tests agree reasonably with each other during the interference fit progress. This work is beneficial to the understanding of the interference fit process in engineering application and the avoiding of part failure resulting from inappropriate design.