均化接触应力的双线性材料刚度优化设计

Optimization Design of Bilinear Material Stiffness for Contact Stress Homogenization

装配连接界面是承载和保障机械装备实现既定功能的载体,其连接界面接触应力分布均匀性是影响机械装备磨损、疲劳、裂纹的关键因素,对机械装备高性能服役具有“锚定”作用。为改善连接界面接触应力分布均匀性,开展了材料刚度优化设计研究。首先,以接触应力方差为目标函数,以弹性模量为设计变量,基于渐进优化原理,构建了一种材料刚度优化设计方法。然后,分别针对有无摩擦工况下两个典型接触问题开展了材料刚度优化设计。结果表明,材料刚度优化可大幅降低接触应力方差,验证了本方法在提升连接界面接触应力分布均匀性上的有效性。进一步研究不同问题、不同摩擦因数取值下摩擦行为对优化结果的影响,发现摩擦行为的影响程度大小与问题边界、约束等情况密切相关。

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.