Reconstruction Of Digital Model By Shrinkage Deformation Based On Finite Element Simulation Of Electron Beam Fuse Additive Manufacturing

The electron beam fuse additive manufacturing has the advantages of high heat source energy density,fast forming speed,free from air interference and excellent mechanical properties.It is suitable for manufacturing large metal components with complex structure,and has a wide prospect and important application value in aerospace and other fields.But at the same time,there are also some problems,such as heat input concentration loss is slow,material free forming constraints are few,which seriously affect the mechanical properties and dimensional accuracy of the formed workpiece.For the defects of large shrinkage deformation in the additive manufacturing of electron beam fuse,the traditional solution is to manually add allowance compensation according to the empirical method,which cannot meet the requirements of automatic and intelligent manufacturing.In this paper,based on ABAQUS software and NX secondary development platform,a finite element calculation model was built to simulate the processing process of electron beam fuse additive manufacturing.Deformation characteristics were analyzed and finite element mesh nodes were extracted to realize allowance compensation.And NX secondary development technology is used to realize the function of transforming the surface node point cloud data into digital analog entities.The main work includes:(1)The finite element model of electron beam fuse additive manufacturing process is established.Based on ABAQUS simulation software,taking TC4 as the research object,the thermal-elasto-plastic finite element method was adopted to simulate the material stacking and adding process with the birth and death element technology,and the loading of segment-double ellipsoid moving heat source was realized through the DFlux interface in ABAQUS.The distribution of stress and deformation in the simulation results is analyzed.(2)A margin compensation algorithm based on node deformation is proposed.According to the results of finite element simulation,the initial node is iteratively corrected based on the deviation between the node position after machining deformation and the expected position,until the deviation meets the accuracy requirements,so as to realize the function of the overall margin compensation of the model.At the same time,based on the NX secondary development platform,the surface reconstruction of the finite element mesh node point cloud data is carried out,and then transformed into the digital analog entity,so as to facilitate the data docking and conversion of the subsequent modules of the design process of electron beam fuse additive manufacturing.In this paper,a finite element model is built to simulate and predict the stress and deformation of electron beam fuse additive manufacturing by taking square plate parts and right Angle parts as examples.Based on the deformation results,the validity of the allowance compensation algorithm is verified,and the results after compensation are reconstructed numerically.