Evolutionary Structural Optimization Design With Maximum Structural Scale Constraint

As an important branch of topology optimization,the bi-directional evolutionary structural optimization method(BESO)improves from the evolutionary structural optimization method(ESO),which has higher optimization efficiency and guarantees the reliability of the optimization results.At present,this method has been widely recognized and applied in many fields,but no relevant maximum scale control mechanism has been clearly proposed.In this paper,based on the many research work of the density variable method and level-set method,combined with the optimization characteristics of the BESO method,a evolutionary structural optimization design with maximum structural scale constraint is proposed.This mechanism is based on the numerical characteristics of the 0-1 solution optimized by the BESO method,delimits the affected area around each unit,then calculates the area and determination criteria.The area of all regions is condensed into one single variable by the P-norm,and the condensed variable is constrained to a specific value using the adjoint method until all regions meet the scale constraint requirements.Although the result inevitably sacrifices the partly rigidity of the structure,but the effect of the overall constraint does not depend on the specific working conditions,and has a clear effect of constraining the local scale of the overall structure.The article shows the results of several calculation examples,such as the optimization of the midpoint loaded cantilever beam,MBB beam,Half-Wheel and other structures to verify the effectiveness of the method.By comparing the parameters of the optimization process,the influence of the introduction of the maximum scale constraint on the optimization process and results is analyzed.Several results and data prove that this method can obtain different porous structures according to the scale of the maximum constraint.This method makes the distribution of holes and materials in the structure more uniform,and can be applied to the optimization of bionic structures.In addition,by delaying the introduction of constraints,or combining this constraint method with the design of the shellinfill structure,can further significantly improve the performance of the structure,so that the structure meets the maximum scale constraint while having better stiffness performance.Finally,this article provides a process for post-processing and analyzing the optimized structure using Adobe Illustrator software.