一、概述为了预测诸如锻造、拉拔、挤压和轧制等体积成形工艺中的变形和变形力,人们已经发展了多种近似方法。其中,上限单元法(UBET)就是较为有效的一种,能用于解决闭式模锻、复合挤压等多种金属成形问题。由于该法使用简便,已经引起了有关学者和工程师的注意。使用 UBET 方法时,必须给每一单元区域寻找一运动学许可速度场。在大多数场合下, I. Overview In order to predict the deformation and deformation forces in volume forming processes such as forging, drawing, extrusion and rolling, a number of approximations have been developed. Among them, the upper bound unit method (UBET) is a more effective one, can be used to solve the closed die forging, composite extrusion and other metal forming problems. Due to its simplicity of use, the law has drawn the attention of scholars and engineers. When using the UBET method, a kinetochore speed field must be found for each cell area. In most cases,