Optimization Design of Bilinear Material Stiffness for Contact Stress Homogenization

Assembly contact interface is a carrier that can guarantee the realization of the specified functions of the mechanical equipment. The uniformity of the contact stress distribution, as the key factor affecting the wear, fatigue and crack of the mechanical equipment, plays a decisive role on the high performance of the mechanical equipment. With the purpose of homogenizing the contact stress field, a material stiffness optimization design is investigated. The variance of the contact stress is defined as the objective function and the Yong's modulus is treated as the design variable. Firstly, a material stiffness optimization method is developed based on the evolutionary optimization techniques. Then, two typical contact problems with or without friction are investigated. The results show that after the proposed material stiffness optimization, the variance of the contact stress could be reduced significantly, which verifies the effectiveness of the proposed material stiffness optimization method on improving the uniformity of the contact stress distribution. Moreover, based on these two contact problems, the friction behavior is introduced and analyzed. It is find that with various friction coefficients, the influences of friction behavior on the optimization results are closely related to the boundary and constraints of the problem. © 2022 Journal of Mechanical Engineering.