两种坐标系下上限法求解棒材挤压变形力的对比研究  

The contrastive research of force of bar extrusion deduced by upper bound theorem in two coordinates

作　　者：徐慧[1] 郭胜利[2] 朱福顺[2] 李兴志[2] 李天生[2] 张兴平 

机构地区：[1]湖南建材高等专科学校,湖南衡阳421008 [2]内蒙古工业大学材料科学与工程学院,内蒙古呼和浩特010051 [3]宁夏东方钽业股份有限公司,宁夏石嘴山753000

出　　处：《重型机械》2006年第1期17-21,共5页Heavy Machinery

摘　　要：利用上界定理,推导了在柱坐标系下锥模挤压棒材挤压变形力的理论计算公式,给出了B.Avitzur在球坐标系下推导的上限算式和相关教材所给主应力法求解的公式,并经生产实验反复对比验证。结果表明:上限法求解的两公式计算结果都比较接近实测值,前者(本文所给公式)的相对误差为-2.5%左右,后者的相对误差为6.8%左右;主应力法求解公式的相对误差为13.5%左右。本文推导的挤压力理论计算公式具有一定的工程实用性,为挤压模具的设计和挤压工艺的制定提供了理论依据。The force for bar extrusion about cone dies has been studied theoretically and the formula was determined by upper bound theorem in the cylindrical coordinate. And the formula deduced by B. Avitzur using upper bound theorem in the spherical inordinate and determined by means of block method in the related book were given. These formulas were validated repeatedly in the course of production. It is found that theoretical results of extrusion force given by the two calculating formulas using upper bound theorem are close to those of the producing experiments. The former （given in this paper） average value of relative error is about - 2.5% and the later 6.8% respectively. The average value of relative error of calculating formula determined by means of block method is about 13.5 %. The formula given in this paper has certain utility in the engineering and affords a theoretical basis for designing cone die and setting down the process of extrusion.

关 键 词：上界定理 挤压力 棒材 

分 类 号：TG376[金属学及工艺—金属压力加工]