薄板剪应力起皱研究  

STUDY OF THE SHEAR STRESS WRINKLING IN SHEET METAL FORMING

作　　者：孙振忠[1] 杨玉英[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《工程力学》2006年第7期35-39,共5页Engineering Mechanics

基　　金：国家自然科学基金面上项目(50378068)

摘　　要：以Hill关于弹塑性失稳理论为基础,建立了剪应力起皱失稳的速度场分布,给出了临界起皱剪应力理论计算结果,分析了板料屈服强度、硬化指数、板厚方向性指数及板料厚度对临界剪应力的影响,并与实验和数值模拟结果进行了对比。研究表明:薄板在剪应力作用下可以产生起皱,临界剪应力理论计算、实验及数值模拟结果基本相符,临界剪应力随屈服强度σs减小、硬化指数n值的增大、板厚方向性指数r值的增大、板料厚度t的增大而增大。Based on Hill＇ elastic-plastic instability theory, the velocity field for sheet instability which is caused by the shear stress during sheet metal forming is developed, and the theoretical formula of the wrinkling critical shear stress is proposed. The influences on the critical shear stress of the yield strength, the strain-hardening exponent, the plastic anisotropy, and the sheet thickness are analyzed, and are compared to the results of experiment and numerical simulation. The obtained results show that the wrinkling of sheet metal is induced by the effect of shearstress. The theoretical results for the overall tendency of the critical shear stress are similar to the experimen- tal and numerical ones, and the critical shear stress increases with the decreasing in yield strength σs, the increasing in strain-hardening exponent n, the increasing in plastic anisotropy r, and the increasing in sheet thickness t.

关 键 词：板料 剪应力 起皱 实验 数值模拟 

分 类 号：O34[理学—固体力学] TG315.2[理学—力学]