Research On Quality Accuracy And Equipment Optimization Based On FDM Rapid Prototyping

Fused Deposition Modeling Rapid Prototyping technology is the most widely used additive manufacturing technology in recent years,it can realize rapid production of CAD models to real objects,meet the high efficiency requirements and individualized needs of the contemporary society.It has played an important role in various industries and has been widely used.Fused Deposition Modeling Prototyping is a process of layer-by-layer accumulation of wire materials,the order of wire accumulation causes the temperature difference of the molded parts,and internal stress occurs due to uneven cooling and shrinkage of each part,it's easy to cause defects such as stress concentration,warpage and poor adhesion of molded parts.Therefore,in order to improve the precision of the molded part,this paper first analyzes the cause of warpage deformation and establishes the warping model,and then uses ANSYS software to simulate the temperature field and stress field of the molded part during the forming process,combine molding experiments to find the optimal combination of process parameters based on equipment optimization.The main research contents and methods adopted in this paper are as follows:1)According to the defects of workpiece precision caused by fused deposition,the research and development status of the precision of molding equipment,the performance of molding materials and the setting of process parameters,which have important influence on precision,are summarized at home and abroad.,through the analysis of problems in the research,determined by finite element analysis and on the basis of optimization of equipment for forming experimental research methods,to achieve the purpose of improving the accuracy of cavity structure molding parts.2)The process principle and molding process of fused deposition were analyzed.The theoretical model of warpage deformation of fused deposition molded parts was established by reasonable simplifying assumptions;The analysis establishes a reasonable scanning fill trajectory,and the temperature field and stress field of the molded part are simulated by thermal analysis of the finite element software ANSYS.The application of unit birth and death technology,phase change latent heat treatment and thermalstructural coupling,etc,providing the theoretical basis for the simulation numerical analysis.3)For uniform wall thickness parts,the temperature field simulation program is programmed with the APDL command stream of ANSYS in cylindrical coordinates,and the coaxial offset processing process is simulated by the element birth and death technology,by changing the different parameter values,the temperature cloud distribution of the molded part and the influence on the temperature field when the layer thickness,the molding chamber temperature and the scanning speed value are changed respectively are investigated.4)The orthogonal simulation test is carried out for the three process parameters.The indirect sequential coupling method is used to apply the simulation data of the temperature field to the molded part to simulate the stress field,and the maximum warpage deformation value under each parameter combination is obtained.Statistical analysis is carried out by means of SPSS statistical software,and the optimal parameter combination value is obtained from the analysis of the range diagram and variance.5)In order to meet the experimental conditions,the optimization of the equipment is carried out,and the molding test is carried out according to the interval of the simulation optimization analysis.The measurement results are basically consistent with the simulation results,the regression equations of various factors and warping deformation are solved,which provides theoretical basis and practical experience for improving the precision of molded parts.