Study On The Influence Of Hot Bed Temperature Field On The Accuracy Of Forming Parts Based On FDM

Fused deposition rapid prototyping(Fused Deposition Modeling,FDM)is one of the widely used manufacturing technologies in material augmentation manufacturing.It is widely used in various fields because of its advantages of simple equipment structure,low manufacturing cost and safe operation.The forming process of melt deposition rapid prototyping technology is composed of a layer of melt state wire material,and the change of melt state and solid state will occur phase transformation during the molding process,which will cause stress between layers,resulting in deformation of the molding parts,and the cooling shrinkage of the wire material will also cause molding error.The precision of forming parts is an important problem which affects its application,so it has become an important subject in many research of melt deposition rapid forming technology.In this paper,finite element simulation analysis and experimental research methods are mainly used to study the precision of forming parts,the main research contents and methods are as follows :1)The common forming accuracy problems in melt deposition rapid prototyping technology are analyzed,the most important problems affecting the forming accuracy of forming parts are analyzed emphatically,the genesis of forming parts is analyzed from the forming principle of forming parts,and the theoretical model of warping deformation is established through analysis.Based on the theoretical model,the most important influencing factors are analyzed.2)The simulation process of temperature factors is assumed using heat transfer theory,and the ANSYS software APDL command flow and life-and-death element technology is used to simulate the molding parts.The effect of heat bed temperature and nozzle temperature on the forming part is analyzed and the stress is analyzed.In the thermal analysis of hot bed temperature and spray head,the change of inter layer temperature difference is mainly investigated,and the influence of inter layer temperature difference onforming parts is examined.In the stress analysis by thermal-structure coupling,the interlayer stress and the warpage deformation of the molded parts are obtained,and the optimum temperature of hot bed and nozzle are obtained by using the warpage deformation of the molded parts.3)According to the ANSYS simulation,the molding experiment is carried out.First,the forming test was carried out on the influence of hot bed temperature and nozzle temperature,and the deformation of the forming part was obtained by measuring the size error and shape error.he shape error of the molding part is studied emphatically,and the heat bed temperature and nozzle temperature are designed by using regression design method.the molding test is carried out according to the design parameters.the data are analyzed by Design-Expert software,and the optimal parameter combination is obtained.4)By analyzing the problems existing in the hot bed,the optimized the hot bed,and put forward a new hot bed working platform for heating wire distribution.By using the ANSYS simulation software,the thermal analysis of the two hot bed working platforms before and after optimization is carried out,and the temperature field distribution in the heat dissipation process is obtained,and the advantages of the optimized hot bed are obtained.On the basis of the simulation results,the Altium Designer software is used to optimize the design of the PCB aluminum substrate hotbed-MK3 commonly used in the market,and the molding part forming experiments are carried out on the two hot bed working platforms before and after the optimization,and the optimized hot bed working platform forming effect is found to be better by comparing the experiments.