Research On Optimization Method Of Non-design Space Size In Topology Optimization Weight Reduction Design

With the emergence of 3D printing technology,topology optimization technology has developed rapidly,especially the combination of topology optimization and 3D printing technology has attracted widespread attention in the aerospace field.In the current weight reduction design of civil aircraft structures,the topological structure obtained by topology optimization is mainly processed through advanced manufacturing methods such as 3D printing technology,and the original structure is replaced under the condition that the connection method and load constraints remain unchanged,so the connection The part and part of the bearing surface are set as a non-design space without topological optimization design area,which can not only meet the replacement requirements of the optimized structure,but also improve the calculation efficiency of the topology optimization design.In this paper,with the volume of the structure as the constraint,a SIMP interpolation model(Solid Isotropic Material with Penalization)with minimum flexibility as the goal and including non-design space size parameters is established.The constraints are based on the Mises stress yield criterion and the maximum allowable displacement of the structure.The topology structure is selected to establish the calculation method of the minimum volume ratio and the optimal non-design space volume,thus completing the establishment of the non-design space size optimization method in the topology optimization weight loss design.In this paper,a non-design space size optimization method program is written in the Abaqus finite element software based on the Python language.Taking a civil aircraft structure as an example,the reliability of the method is verified and compared with the optimization results of the topology optimization commercial software Solid Thinking Inspire The optimal non-design space size obtained by the topology optimization software is the same as the optimal non-design space size obtained by the method in this paper,and the weight loss of the civil aircraft structure is 35%.It proves that the non-design space size optimization method established in this paper has a high engineering reference significance.Compared with the topology optimization software,the method established in this paper can achieve automatic optimization of non-design space size,shorten the design cycle,and save A lot of labor costs.In addition,in this paper,the cantilever beam structure and the above civil aircraft structure are taken as examples to analyze the influence of the design variable threshold and the initial value of the volume ratio on the final topology optimization results in the non-design space size optimization method,while taking the cantilever beam structure as an example The effect of grid size on non-design space size optimization is studied.The pseudo-density threshold is recommended to be between 0.3 and 0.6,and the initial volume ratio is around 0.5.It is recommended to obtain the optimal The scope of the design space,and then the purpose of reducing the grid size in the optimal non-design space range to find the optimal conclusion,the final cantilever structure weight reduction of 33.86%.