Abstract: In order to optimize the structure of the spherical hinge of a thrust rod and improve its fatigue life, a multi-objective optimization method for the spherical hinge of a thrust rod based on the finite element analysis (FEA) and genetic algorithm (GA) is proposed. The strain distribution characteristics of the rubber bushing and the stiffness parameters of the thrust rod are obtained at different precompression values and spherical hinge structures using FEA. Moreover, the relationships among the stiffness of the thrust rod, the precompression value of the rubber bushing, and the key structural parameters of the spherical hinge are obtained. On this basis, the multi-objective optimization model for the thrust rod spherical hinge is established using the genetic algorithm. The optimum scheme of the spherical hinge is obtained by using the multi-objective optimization model. The sample bench test results show that the fatigue life of the thrust rod spherical hinge is increased by seven times with the optimum scheme. The proposed multi-objective optimization method not only enriches the design theory of variable cross-section rubber-metal composite structure, but also provides a theoretical basis for the optimal design of thrust rods

Key words: vehicle engineering, structure optimization, finite element, genetic algorithm, rubber bushing, reliability