Research On Finite Element Simulation And The Support Structure Optimization In Fused Deposition Modeling

Fused deposition modeling(FDM)is a fast developing 3D printing technology in recent decades.It has been widely applied in machinery,medical treatment,military and other fields.The most obvious feature of this technology is the short cycle of the product design and the ability to provide personalized products according to the individual needs of the customer.However,the molding accuracy and efficiency limit the development of FDM technology.In order to improve the accuracy and efficiency of FDM technology,the finite element simulation of the molding process is carried out,and the generation of the support structure is optimized in this thesis.The main research contents are as follows:(1)A general finite element model meshing and fused deposition modeling simulation method based on voxelization and automatic sorting of voxel elements is proposed.By voxelizing the STL model and orthogonal parallel scanning sorting of the voxel elements,this method can establish a fused deposition modeling finite element simulation model of any shape.Using the proposed method,a finite element simulation model of the temperature field is established in ANSYS software.The influence of the scanning speed,the molding chamber temperature and the nozzle temperature on the temperature field of the parts is analyzed.(2)Based on the temperature field analysis,the thermal stress coupling principle of fused deposition modeling is analyzed.By means of element type conversion,setting of material property parameters and determination of boundary conditions,a finite element example simulation model of thermal stress field analysis is established in ANSYS software.The effects of the scanning speed,the molding chamber temperature and the nozzle temperature on the stress and displacement fields of parts are analyzed by applying the results of the temperature field analysis as a load to the analysis of stress field.(3)A fused deposition modeling experimental platform with adjustable molding chamber temperature is established.The effects of the scanning speed,the molding chamber temperature and the nozzle temperature on the warpage of the parts during the process of fused deposition modeling are studied by the orthogonal test.The experimental results show that the optimal level parameters of the fused deposition molding process based on ABS material in the analyzed conditions are scanning speed 50mm/s,molding chamber temperature 80°C,and nozzle temperature 180°C.The experimental results also show that the fused deposition modeling finite element simulation method proposed in this thesis is correct.(4)A fused deposition modeling tree-like support structure generation method based on L-system and octree is proposed.Here,the octree data structure is used to design algorithm which can get the intersection data of space rays and the mesh model quickly and the L-system grammar composition thought is used to generate tree-like support structure with symmetrical structure,then the topological relation for each branch structure is established to prune.Finally,based on the optimal level parameters obtained by the orthogonal experiment,the proposed support structure generation method is experimentally studied.The results show that compared with Cura software and Meshmixer software,the support structure generation method proposed in this thesis can effectively save the printing consumables and time while improving the stability of the support structure.