Numerical Simulation Of Metal Extrusion Forming Based On Material Point Method

Metal extrusion forming is a kind of large deformation problem, which involves geometric nonlinearity and material nonlinearity. Numerical simulation method is the main research method to solve this problem. The traditional finite element simulation has the mesh distortion, which needs to be re-division, and the time efficiency and precision can be affected by the grid. The material point method is divided into a group of physical information, such as the mass of the object, the velocity of motion, the stress and the strain. The movement of the particle represents the movement and deformation of the object. Using Lagrangian particle and Eulerian mesh double description, the momentum equation and the spatial derivatives are calculated in the background grid. In every step of the end of the computation, mesh distortion is discarded. New background grid is used. which avoid numerical difficulties due to the mesh distortion. It is suitable to solve metal extrusion problem. In this paper, based on the material point method the numerical simulation of metal extrusion forming process is carried out. The metal flow rule in the process of metal extrusion is discussed. It is a good guide for the extrusion forming of metal materials.The numerical simulation of metal extrusion forming process is carried out based on the material point method. The material point method program for metal extrusion forming process is written using Fortran Language by combining the material point theory and rigid-flexible contact algorithm. The simulation of metal extrusion forming process is realized. The experiment in literature is used to verify the correctness of the results simulated by material point method. With the same parameters, the metal flow law, particle displacement, equivalent stress and equivalent strain in metal extrusion forming process are simulated by material point method and the commercial software DEFORM. The results were analyzed and compared. The simulation results by both methods have the same numerical regularity. But when the deformation is large, the traditional finite element simulation has the mesh distortion, which need grid re-division. The material point method does not need the grid re-division, and has the advantage in time efficiency. It shows that the material point method is feasible and effective in the simulation of metal extrusion forming process.The influence of extrusion process parameters in extrusion forming process was studied based on material point method. The metal flow law of extrusion forming process, particle displacement, equivalent stress and equivalent strain in the different extrusion die angle, different lubricating conditions and different extrusion speed are simulated. The simulation results for metal extrusion forming production can be a guidance for the production of metal extrusion.This work provides a theoretical basis for application of material point method in simulation of the large metal deformation. At the same time, it also plays a guiding role in the production of metal extrusion.