| In the fields of aerospace and automotive industry,lightweight has always been the basic principle and important development trend of structural parts design.The torque arm is the core part of the landing gear system,which is responsible for transmitting the lateral load on the landing gear prop during the takeoff and landing of the aircraft.The lightweight design of the torque arm is one of the methods to improve the endurance and maneuverability of the aircraft.In this paper,a new lattice design method is proposed based on the structure optimization of torsion arm parts,and the effectiveness of this method is verified by numerical simulation and experiments.Topological optimization of the torsion arm was carried out according to the force condition of the parts.The influences of different constraints such as symmetry constraint,size constraint and design space on the optimization results were analyzed,and the topological optimization parameters of the parts were determined.According to the optimization results,the geometric model was reconstructed as the lattice design region of the torsion arm structure.Torque arm lattice on the one hand,using the multi-scale structure in the design of parallel optimization method,give priority to the single cell size of mesoscopic design,namely reference macro-scale parts condition of topology optimization for standard cube crystal cell redesign mesoscopic cell structure,according to the results under different working conditions,the optimization of cell combination,The combined cell structure suitable for the actual working conditions of the parts was filled into the design area of the torsion arm parts,and the comprehensive performance of the combined cell structure was verified by using homogenization process,and compared with the cell structure optimized under single working conditions.At the macro scale,the optimized cell is used to fill the torsion arm parts and the simulation calculation is carried out.The simulation results are compared with the homogenization treatment results at the micro scale to judge whether the combined cell structure is better than other cell types in the multi-scale lattice design.On the other hand,in order to compare with regular lattice structure,irregular lattice structure is designed by using the method of grid division according to the traditional lattice design idea.In addition,the effects of different filling forms and cell size on the performance and lightweight of parts were studied.The performance of two different lattice filling types in actual working conditions is discussed by numerical simulation.The metal additive manufacturing technology is used to print the forming torsion arm original model,regular lattice filling model and irregular lattice filling model.Considering the actual size of torsion arm parts can not be formed in the existing equipment,scale reduction model based on similarity theory and dimensional analysis.The lightweight effect of regular lattice structure and irregular lattice structure is analyzed.At the same time,the mechanical properties of the model are tested and analyzed,and the results are compared with the conclusion of numerical simulation.The results of mechanical test prove that the multi-scale optimization of regular lattice structure has higher practical application value and stronger pertinence. |
