刚塑性无网格方法中精度影响因素的研究

将无网格方法引入金属塑性成形过程分析,基于刚塑性材料假设,采用移动最小二乘法对速度场进行逼近,利用变换法施加本质边界条件,实现了金属塑性成形过程的无网格方法模拟。在此基础上,结合典型锻造过程分析实例,重点研究了应用无网格方法分析金属塑性成形问题时,诸如:基函数、正交化与否、权函数、权函数影响域大小、积分方案、高斯积分阶次、节点分布密度以及针对体积闭锁问题而提出的体积应变率映射方法等对于模拟精度和效率的影响规律,给出了提高无网格模拟精度和效率的影响因素的选择方法。

Factors affecting computational precision of the rigid-plastic meshless method

The meshless method is introduced to the analysis of the metal forming processes.The meshless analysis of the plastic forming processes is realized with the hypothesis of the rigid-plastic material,the velocity field simulated by the moving least square method and the essential boundary condition employed by the transformation method.The factors that affect the computational precision and efficiency of the rigid-plastic meshless method,such as,the order of the basis function,the orthogonalization of the basis function,the weighted function,the compact support of the weighted function,the density of the scattered points,integration method,the quadrature rule of Gauss integration,the volumetric strain rate projection method,are studied.Using the analysis of the typical metal forming processes as examples,the effects of those factors mentioned above on the computational precision and efficiency are discussed.On the basis of summarizing the research results,the paper gives the guidelines of selecting various parameters for improving the computational precision and efficiency.