动载荷作用下幂硬化弹塑性弯曲裂纹塑性区  

Study on the Slightly Curved Elasticity-Plasticity Crack Tip of Power-Low Hardening Plasticity Area Under Dynamic Loads

作　　者：杨大鹏[1,2] 王红霞[3] 赵耀[2] 李天匀[2] 

机构地区：[1]郑州职业技术学院机械工程系,河南郑州450121 [2]华中科技大学船舶与海洋工程学院,湖北武汉430074 [3]郑州职业技术学院材料工程系,河南郑州450121

出　　处：《四川师范大学学报（自然科学版）》2015年第4期602-608,共7页Journal of Sichuan Normal University（Natural Science）

基　　金：国家自然科学基金重大研究计划(91016026)

摘　　要：主要研究动载荷作用下的硬化材料弹塑性弯曲裂纹尖端的塑性区问题.综合考虑动态作用应力,塑性区域边界上动态正应力与动态剪应力,利用二阶摄动方法计算硬化材料弹塑性弯曲裂纹尖端的动态塑性区.作图分析弹塑性弯曲裂纹尖端动态塑性区尺寸与材料硬化指数之间的变化关系.在幂硬化材料中,弹塑性弯曲裂纹尖端动态塑性区随着材料硬化指数n的增大而减少,当n等速均匀增加时,弹塑性弯曲裂纹尖端动态塑性区尺寸加速减少,减少的幅度越来越大.当材料的硬化指数相同时,弯曲裂纹尖端动态塑性区尺寸随动载荷的不断减小而逐渐减小.建立了一个计算硬化材料弹塑性弯曲裂纹动态塑性区尺寸的理论模型.In this article, elastic-plastic curved crack tip plasticity area in hardened material under dynamic loads has been studied and curved crack tip plasticity area has been calculated as a practical application of a second order perturbation method with the effects of dynamic applied stresses, dynamic normal and shear stresses on the boundaries of plasticity area, the relationship between curved crack tip dynamic plasticity area size and hardening exponents has been analysed. Curved crack tip dynamic plasticity area size decreases when hardening exponents increase in hardened material. The crack tip dynamic plasticity area size decreases as hardening exponents increasing evenly. Curved crack tip dynamic plasticity area size decreases when external loads decrease with the same hardening exponents. A theoretical model of curved crack tip dynamic plasticity area size calculation has been established in hardened material.

关 键 词：幂硬化材料 弯曲裂纹 动态塑性区 动态作用应力 二阶摄动方法 

分 类 号：TB301[一般工业技术—材料科学与工程]