The Research On Key Technology Of Metal Plastic Forming Simulation Based On Parallel Computation

Sheet metal forming is an important process with utilizing the plasticity of metal to transform a sheet metal blank into a part with shell configuration by dies. In order to shorten the development cycle, some numerical computational software fitting for sheet forming simulation process were developed. With the complexity of geometry models of blank forming and reduction of the size of iterative step, the blank model needs meshing more fine finite element grids. For improving the computation efficiency, the simulation process will cost much more computational time. In order to solve large scale sheet forming problems, we introduce parallel strategy with simulation process and develop sheet forming explicit dynamics simulation system based on the Mindlin-Reissner theory and the Belytschko-Tsay shell element. We build the initial partition system according to the characters of finite element grids and programmed the interface program connecting the FEM parallel and partition system .Commonly bulk forming problems simulations adopt finite element method. The mesh distortions maybe occur while large deformation problems are solved by FEM. The underlying structure of these methods which originates from their reliance on a mesh is not well fit for the treatment of discontinuities which do not coincide with the original mesh grids. Thus, the most viable strategy for dealing with moving discontinuities in method with moving discontinuities in methods based on meshes is to remesh in each step of the evolution so that mesh grids remain coincident with the discontinuities throughout the evolution of the problem. This can, of course, introduce numerous difficulties such as the need to project between meshes in successive stages of problem, which leads to degradation of accuracy and complexity in the computer program, not to mention the burden associated with a large number of meshes. Currently, the adaptive mesh grids method is limited for tetrahedron element, so the rapid and credibility remesh method is the hard mission in computational mechanics fields. Meshless methods do not require costly mesh generation remeshing. Furthermore, meshless methods implement a functional basis and allow arbitrary placement of points, therefore the solution and its derivatives may be obtained directly where they are needed and with better accuracy than with finite element method where interpolation is required. Limitation of meshless method is the low computational efficiency due to high order interpolation. With the increasing size and complexity of the numerical structural models to solve, the analysis tends to be a very...