Novel lightweight connecting bracket design with multiple performance constraints based on optimization and verification process

In this paper, a complete optimization design verification process is proposed and a novel structure of connecting brackets is presented, solving the fatigue failure of chassis connecting brackets operating on harsh roads. First, an endurance road test and fatigue life analysis were applied to the truck equipped with the original brackets, verifying the fatigue damage of the structure. Based on the solid isotropic material with penalization method, a novel lightweight connecting bracket layout was obtained by using the method of moving asymptotes (MMA) for topology optimization under multiple working conditions with multiple performance constraints. Moreover, the derivatives of objective and constraint functions concerning design variables were applied for the MMA. Considering manufacturability and functionality, the improved model based on the topology optimization results was further optimized by size optimization. Finally, fatigue life analysis and an endurance road test were conducted using the optimal design. Compared with the original structure, the novel brackets showed better stiffness, strength and fatigue performance while reducing the total mass by 15.2%. The whole optimization and validation process can provide practical ideas and value for developing multi-performance suspensions in the pre-product development stage.