硬化材料正向螺旋挤压的上限解法  

Upper Bound Analysis of Axisymmetric Forward Spiral Extrusion of Hardening Material

作　　者：张黔[1] 彭炎荣[1] 罗文波[1] 

机构地区：[1]湘潭大学土木工程与力学学院,湖南湘潭411105

出　　处：《湘潭大学自然科学学报》2016年第2期9-15,61,共8页Natural Science Journal of Xiangtan University

基　　金：国家自然科学基金项目(11572275);湖南省研究生科研创新项目(CX2014B270)

摘　　要：基于一个运动学许可速度场,用上限理论分析了硬化材料轴对称螺旋挤压过程的塑性成形问题,将理论解与实验结果进行比较发现用上限理论分析所得的结果是真实解的上限.分析变形挤压力与各个参数的关系,结果发现:在挤压比一定时,半锥角有一个最佳值使得挤压力最小;挤压力随着挤压比、材料硬化指数、库伦摩擦系数、剪切摩擦系数及模具各个部分的长度的增加而增加.综合各个影响挤压力的因素,发现挤压比对挤压力的影响最为显著.与理想塑性材料上限理论分析相比,考虑材料硬化特性所得出的上限解适用范围更为广泛.Based on an admissible velocity field, the plastic forming problem of strain hardening materialis analyzed by upper bound theory. A reasonable agreement between experimental results and the upperbound solution is observed. The relationship between deformation extrusion pressure and each structural parameteris analyzed. The results show that the optimum value of half cone angle has the lowest extrusionp ressure, and the extrusion pressure increases with the extrusion ratio, material hardening exponent, coulombfriction coefficient, shear friction coefficient, and the length of each part. Extrusion ratio has the mostsignificant factor on extrusion pressure. It turns out that the upper bound solution of the hardening behaviorof material is of greater applicability.

关 键 词：上限理论 加工硬化 轴对称螺旋挤压 塑性成形 

分 类 号：O344.5[理学—固体力学]