| The three-dimensional metal plastic forming technique is widely used in themanufacturing of metal parts. The metal forming is a large deformation processrefering to a lot of non-linear problems, such as non-linear geometry, contact, etc. Inpresent, the flow of metal in the forming process effectively and intuitively by thefinite element method(FEM) is simulated and reproducted. But FEM is a numericalmethod based on mesh, the lost of computational accuracy and even the halt ofsimulations will be inevitable because of the mesh distortion during the simulation ofmetal deformation process. The meshfree method has widely used in engineeringproject in recent decades because it is based on the node approximation instead ofmesh. The3-D metal bulk forming is simulated by the SPH meshless methodcombining with the large deformation theory, and the feasibility and computationalefficiency of this method is analyzed in this paper.The theoretical model of3-D metal bulk large deformation forming is builtedaccording to the theory of the SPH method and the large elastic-plastic deformationtheory. The forming process for free upsetting process of circle metal blank isanalyzed by SPH meshless method and the finite element method respectively. Bycomparing the results of two methods, the feasibility of SPH meshless method isverified, and the distortion of the grid is avoided effectively. But the computationalefficiency of SPH method is much lower than that of FEM.To solve the problem of low efficiency of SPH method, the large deformationproblem is simulated by using the coupled method of FEM and SPH. The process ofupsetting forging of metal and the free forging with half a spherical punch aresimulated, compared with the results of the finite method. SPH method is verifiedfeasible and effective, not only the distortion of the grid is avoided but also thecomputational efficiency is improved greatly.In a word, a new method is developed for3-D large deformation metal bulkforming in this paper. |
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