Development of Finite Slab Method for Calculation of Working Load and Pressure.

本文提出了一种计算冷锻过程中应力分布和变形的简单方法-有限板法。被锻造的材料被分成不同的变形区域，称为单元，如上限技术。此外，每个单元被切割成n个有限的板。单元界面处的应力边界条件由垂直于界面方向的平均应力给出。应力分量的计算使用的条件的体积恒定性和近似关系，如Levy-Mises流动规则和Mises屈服准则。将该方法改进为三维锻造问题的分析方法。编制了冷锻分析通用软件的基本方程程序。该软件可用于轴对称、近轴对称三维及直角坐标系下的问题，并将其应用于圆柱形坯料的方柱体闭式模锻、齿轮锻造、方杯反挤压等，平均压力的计算结果与实验结果及其它分析方法的结果比较一致，如板法和上限法。

A finite slab method FSM is proposed as a simple technique for calculation of stress distribution and deformation in cold forging. The material to be forged is divided into various deformation regions, called units, as in the upper bound technique. Additionally, each unit is cut into n finite slabs. The stress boundary condition at the interface of units is given by the mean stress in the direction normal to the interface. The stress components are calculated by the use of the conditions of volume constancy and approximate relations such as the Levy-Mises flow rule and the Mises yield criterion. The method is modified into a method of analysis for 3-dimensional forging problems. The programming of basic equations are arranged to a general-purpose soft for the analysis of cold forging. The soft is possible to use for the problems of axial symmetry, near axi-symmetric 3-dimension and system of Cartesian coordinates.The method is applied to some closed die forging, for example, square prism from a cylindrical billet, gear forging, backward extrusion of square cup, etc. The results of calculation on mean pressure are in comparative agreement of experimental results and those of another analytical techniques, such as slab method and upper bound method.