液-固挤压复合材料有限元模拟中的关键技术问题处理

On Exploring Key Technical Problems in FEM Calculation of Plastic Deformation of Metal-Matrix Composites when Formed by Liquid-Solid Extrusion

液态浸渗挤压是一种金属基复合材料成形新工艺。通过对模拟过程中关键技术问题的处理 ,首次利用刚塑性有限元法对其应力应变场进行了模拟 ,给出了液 -固挤压过程的等效应变、应变率和应力的等值线图及网格变化图。实验结果与模拟结果的比较表明 ,本文对关键技术问题的处理是正确的 ,从而为该工艺的生产应用奠定了理论基础。

How to use FEM(finite element method) to calculate the plastic deformation of metal-matrix composites when formed by liquid-solid extrusion is the key to actually using this new technology in engineering applications. To our best knowledge, we are the first in China, if not in the world, to deal with key technical problems in such calculation. Section 2 deals with these problems, which are three in number: (1)liquid phase region(subsection 2.1), (2)remeshing(subsection 2.2), (3)boundary conditions(subsection 2.3). Subsection 2.1 contains our new contribution. Subsubsection 2.2.1 uses the well known criterion, eq.(4), to judge whether or not distortion is serious enough to require remeshing. When remeshing is required, subsubsection 2.2.2 discusses how to generate the new mesh system. Subsubsection 2.2.3 explains how to transfer information from the old mesh system to the new mesh system. Subsubsections 2.3.1, 2.3.2, 2.3.3 deal respectively with friction boundary conditions, dynamic boundary conditions, and oblique-plane boundary conditions. Simulation results for a specific example, given in Figs.2 through 7, indicate preliminarily that the key technical problems in calculation of plastic deformation of metal-matrix composites when formed by liquid-solid extrusion have been quite correctly solved.