稳态斜轧延伸过程的刚塑性伽辽金法模拟

Simulation of steady cross-rolling elongation process by rigid-plastic element-free Galerkin method

将无网格伽辽金法(Element-Free Galerkin Method,EFGM)与三维刚塑性流动理论相结合,对斜轧延伸过程进行了数值模拟。详细推导了斜轧延伸过程EFGM数值模型的刚度方程,给出了初始速度场和速度边界条件的建立方法和刚性区域的处理技术。得到的轧件的物理形态和金属流动的速度场均与实际情况相符,证明了采用EFGM计算斜轧延伸过程的可行性与正确性,将无网格算法引入到了斜轧领域。并将轧制力和壁厚的计算结果与实验结果进行了比较,结果发现:实验得到的轧制力结果偏小而壁厚值却偏大,其主要原因是由于在建模时做了简化和假定,同时也受轧机弹跳的影响。

In this paper,the cross-rolling elongation process is simulated by combining the element-free Galerkin method and three-dimensional rigid-plastic flow theory.The stiffness equation of numerical model on cross-rolling elongation process is deduced based on EFGM,the initial velocity field and the velocity boundary condition are built and the tricks for treating the rigid region is given.The physical forms of rolling piece and velocity filed of metal flow,which are obtained by EFGM,conform to those in actual conditions.It is proved that it is feasible and valid for cross-rolling elongation process to be calculated by EFGM.The element-free method is introduced to cross-rolling field.The calculated values of rolling force and wall thickness are compared with measured data.It can be shown that rolling force by measurements is smaller than calculated ones,but wall thickness is reverse.The main causes may be that the model is simplified and based upon assumptions,the bounce of the roll mill is also one important reason.