Numerical Simulation Of Warping Deformation Of PLA Cuboid In FDM And Optimization Of Process Parameters

PLA material is a new type of degradable plastic material with better mechanical properties than ABS material.Commonly used as FDM printing materials,it has been widely used in biomedicine,electronics,automobiles and other fields.However,the accuracy of 3D printed products has been hindering the future development of this advanced manufacturing technology.This paper studies the relationship between the process parameters and warpage of the PLA cuboid 3D printing process in FDM,in order to find the optimal process parameters.Starting from the principle of FDM technology,this paper analyzes the influence of layer thickness,molding speed,extrusion temperature and hot bed temperature on the quality of molded parts.According to the FDM transient thermal direct coupling model,APDL language and life and death unit technology are used to determine the molding path.Redesign the loading method of the boundary conditions to realize the numerical simulation of the direct coupling of the temperature field and the stress field.Through the finite element simulation,firstly analyze the changes of the temperature field and the stress field at each time as a whole,and further analyze the temperature changes of each process parameter on the FDM intermediate node,the temperature gradient at different times,and the equivalent stress change of the intermediate node to obtain the instant in the Z axis The amount of deformation.The results show that: you can reduce the layer thickness,extrusion temperature,or increase the molding speed.The hot bed temperature is beneficial to reduce the internal stress of the molded part,thereby reducing the amount of warping deformation.Design the layer thickness,take the L27(313)orthogonal test with the forming speed,extrusion temperature and hot bed temperature as factors,carry out the average value and variance analysis of the experimental data,and obtain the parameter that minimizes the warpage deformation as the layer thickness 0.1 mm,molding speed 60 mm/s,extrusion temperature 200 ?and hot bed temperature 90 ?.However,the selected combination of process parameters is limited to the local optimum.Using BP neural network,MEA-BP and GA-BP neural network,respectively,the PLA cuboid warping deformation prediction model was established,and the prediction accuracy was compared.The results show that the accuracy of the MEA-BP prediction model is 3.01%,which is 2.38 times higher than the BP neural network and 27.8% higher than the GA-BP neural network.And the running time of MEA-BP is 6.09 s,which is 39.9 times lower than the running time of GA-BP neural network.