基于刚（粘）塑性流动理论的自然单元法研究

将自然单元法与刚（粘）塑性流动理论相结合，对自然单元法在金属塑性成形过程数值模拟中的应用进行了研究。采用基于Voronoi图和Delaunay三角化结构的Non-Sibsonian插值方法构造近似速度场向量，实现无网格方法中速度边界条件的直接精确施加，提出了基于刚（粘）塑性流动理论的无网格自然单元法。运用不完全广义变分...

Natural element method based on flow theory of rigid plastic/viscoplastic mechanics

The properties of interpolation of nodal data, ease of imposing essential boundary conditions, not needing any user-defined parameters, and the computational efficiency are some of the most important advantages of natural element method. A new method for simulating the metal forming process is given by combining natural element method with the flow theory of rigid plastic/viscoplastic mechanics. Accurate imposition of velocity boundary conditions is accomplished directly by constructing vector of the displacement field by using the non-Sibsonian interpolation method, which are based on the Voronoi diagram and its dual Delaunay tessellation. The discrete governing equations of natural element method are developed by utilizing the generalized variational principle of rigid plastic/viscoplastic materials and accomplishing the incompressibility constraint condition by penalty method. The numerical simulation of a plain strain upset forging reveals the effectiveness and feasibility of the present method.