Structure Optimization Of Launching Path Of Large Diameter Gun Launch Load Along Frame

Under the background of the National Defense 973 Project and National Natural Science Foundation, to improve the stiffness and strength, and optimize the load transfer path, in this study, topology optimization, size optimization and parameter optimization of the top carriage and cradle of a large caliber towed gun are performed using the structural optimization method and genetic algorithm.The structural optimization method, variable density method, parameter optimization and NSGA-Ⅱ algorithm are deeply studied. Firstly, the finite element(FE) model of the recoil part, the top carriage and the cradle is established using Hypermesh software, and simulated in Optistruct module, the static stiffness and strength of the structure is obtained. Then the FE model is input into Abaqus software. Through implicit dynamic analysis, the load transfer path and dynamic response are achieved.Topology optimization and size optimization of the top carriage are conducted under multiple load cases. The plate shape and stiffener layout of the top carriage are modified through topology optimization, and the thickness of the main panel size is redesigned through size optimization. The stiffness and strength of the top carriage are improved at 0°,51° and 70° working condition. The cradle is also optimized at 51° working condition using the size optimization method.The plate shape of the top carriage is not an optimal result after topology optimization, meanwhile the stiffener layout and the bushing shape of the cradle have a major impact on the stiffness and strength, it is also necessary to optimize the main panel sizes of the top carriage and the cradle. Therefore, using the parameter optimization method continues to optimize the top carriage and the cradle.The parameter model of the assembly of the top carriage and the cradle which were optimized is built using python language in Abaqus software. In Isight software, the plate shape of the top carriage, the stiffener layout and the bushing shape of the cradle are optimized combined with NSGA-Ⅱ algorithm. Meanwhile, the design of experiment method is used to select the panels which have a greater effect on the stiffness and strength of the top carriage and cradle. Then, the sizes of these panels are optimized together using parameter optimization method.The methods and results in this paper provide reference to structure design and the study to decrease muzzle disturbance of the large caliber towed gun.