Study On Topology Optimization Of Additive Manufacturing Self Supporting Structure Based On Drape Constraint

Additive manufacturing is realized by creating parts in CAD data,which can shorten the time and cost of product development.Through topology optimization,additive manufacturing can manufacture very complex topology,which makes topology optimization a good design tool for additive manufacturing.In order to ensure the manufacturability of additive manufacturing,support materials are usually needed to overcome some constraints,such as drape constraint,minimum feature size constraint,material anisotropy constraint and so on,to prevent collapse in the manufacturing process.In this paper,the main objective is to optimize the load distribution of the structure.This paper starts with the basic principle of topology optimization,summarizes the existing problems,describes the advantages and necessity of the combination of topology optimization and additive manufacturing,and studies the traditional mathematical modeling method and optimization algorithm.Aiming at the complex design domain of additive manufacturing model,a new heuristic algorithm is proposed Topology optimization of continuum structure.The basic principle and acceleration module of the heuristic algorithm are analyzed,and its superiority is verified by comparing with the traditional method,which provides the necessary theoretical basis for the subsequent identification and filtering of the overhanging unit.Firstly,the traditional mathematical modeling method and optimization algorithm are studied.Aiming at the complex design domain of additive manufacturing model,a new heuristic algorithm is proposed to optimize the topology of continuum structure.According to the idea of finite element,the basic theory research and optimization process design are carried out.Combined with heuristic algorithm,the design domain meshing and element node degree of freedom labeling are carried out.Taking a typical two-dimensional beam as an example,the element stiffness matrix is deduced,and the corresponding loads and constraints are imposed on the optimized structure.The basic principle and acceleration module of heuristic algorithm are analyzed,and compared with traditional methods Verify its superiority,and provide the necessary theoretical basis for subsequent identification and filtering of suspension unit.Secondly,based on the above research of PDE filter,the process of introducing interpolation vector to avoid tedious unit information collection is analyzed.Aiming at the limitation of printing direction and the defect that the critical angle of overhanging is limited by the aspect ratio of the model,the density gradient and overhanging angle are redefined by node mapping to replace the unit displacement vector limited by the parallel direction of the substrate.Finally,it is compared with the start filter Combining with the hairstyle algorithm,the topology optimization examples are analyzed and compared through MATLAB.Finally,on the basis of the above research,for the updating of a large number of design variables,combined with a simplified series expansion algorithm based on material field,the material field is expressed as a linear combination of deterministic vectors and a small number of undetermined coefficients,and the variables are reduced to further reduce the calculation cost of topology optimization.Finally,combined with heuristic algorithm and PDE filter,several structural topology optimization examples under different load constraints are given in MATLAB to verify the feasibility of practical application.