Multi-Objective Optimization Of Shell For BT50-AVM32 Angle Milling Head

Five-axis linkage NC machine tool is the mother machine of manufacturing industry development,and the angle milling head as one of its key components,its performance directly affects the machining accuracy of the machine tool.The angle milling head shell as the largest connecting part,its static deformation and dynamic response will have a direct effect on the cutter displacement.This paper takes the BT50-AVM32 angle milling head as the research object,starting from the performance optimization of its shell,and performs multi-objective optimization on it.The main contents of the full text include:(1)Firstly,the finite element model of the BT50-AVM32 angle milling head shell is established,and the geometry cleaning and mesh division are carried out,and then the Working conditions of the BT50-AVM32 angle milling head are determined,and the size of the cutting force and the force of the shaft system are obtained by calculation,and the force of the shell is obtained by Newton’s third law.Use the Workbench simulation software for static and dynamic analysis.(2)Based on the static and dynamic analysis results,the mathematical model of topology optimization with variable density method is constructed by means of average frequency method and compromise programming method.Grey fuzzy analytic hierarchy process is used to determine the weight of static and dynamic targets in topology optimization.Finally,taking the minimum natural frequency and static compliance of dynamic targets as objectives and volume fraction as constraints,the conceptual model of topology optimization is obtained.(3)Multi-objective size optimization of the topology optimized concept model is carried out.Firstly,the key size is determined and the experimental factor level table is constructed,and the optimal Latin hypercube sampling method with uniformization and fast is used to construct the sample space point.The sample space points are fitted with the twoorder response surface with the total deformation of the shell and the displacement of the tool center as the objective.The NSGA-Ⅱ genetic algorithm is used to solve the response surface model with equivalent stress and mass as constraints and minimum total deformation of the shell and minimum displacement of the tool center as objectives.The optimal solution of the size is obtained and the best size scheme is obtained by introducing it into the angle milling head shell.By comparing the performance parameters before and after optimization,it is found that the low-order natural frequencies of the angle milling head shell after optimization have been effectively improved,the stiffness of the shell has increased,the maximum stress has decreased,and the displacement of the tool center has decreased.This optimization method makes the structural layout of the angle milling head shell more reasonable and effective,improves the performance of the angle milling head,and realizes the structural scheme design.