Research On Precision And Temperature Field Finite Element Analysis Based On The Fused Deposition Molding Parts

Fused deposition modeling is an important method in rapid prototyping, which has more and more important position in manufacturing industry. The forming precision is affected by many factors. The two factors are analyzed in this paper. The contents and results are as follows:(1) To analyze the accuracy of the fused deposition modeling, there are four error reasons: CAD model transformation for the STL file format generated the error, slicing caused the error, fuse width caused the error, material cooling contraction caused the error, and the method of improving the accuracy are given.(2) After the STL format model is cut, the cross section contour point is connected with a straight line, which is not fitted the actual contour. The fitting methods of section profile of STL model are analyzed, and their advantages and disadvantages are compared.(3) Considering the diversity of the section profile of the actual production, the fitting of the section contour points using the combination of straight line segments, circular arcs and NURBS curves is proposed. The fitting results show that the error of the fitting contour is reduced by 48.502%, and the quality of the slice contour can be obtained more accurately, and the contour line is more smooth.(4) Consider fused deposition modeling features, using APDL language combined with the technique of element birth and death, in the forming process of the temperature field analysis model is established. considering the influence of the convection and heat conduction and latent heat, and analysis of the temperature gradient of fused deposition modeling process at a certain moment analysis, different time temperature field characteristic analysis and,different initial temperature of the temperature gradient distribution characteristics, influence of different paths on temperature fluctuation and the effect of different speed on temperature fluctuation to provide a reference for the selection of the process of fused deposition modeling.(5) Different initial temperatures were obtained by simulating the melt deposition. The higher initial temperature should be chosen in the condition that the conditions permit, but the softening temperature of the ABS material should not exceed 101℃.(6) Through the simulation of the formation of the different forming path of the melt deposition: the best molding path is from the bottom to the top along the short side forming path.(7) The different initial temperatures were obtained by simulating the melt deposition process of the ABS material, the 200mm/s velocity was the best molding speed, and the molding process was not more than that.In this paper, the fitting algorithm of section profile and the simulation of temperature field in the molten deposition process are studied, which provides an important reference for improving the accuracy of the melt forming part.