小孔法测量残余应力时孔边塑性应变的有限元分析及修正  

FEM ANALYSIS AND A CORRECTION ON PLASTICITY EFFECT AT THE HOLE EDGE WHEN USING THE CENTRE HOLE METHOD FOR MEASURING RESIDUAL STRESS

作　　者：张晓宏[1] 赵海燕[1] 蔡志鹏[1] 吴甦[1] 

机构地区：[1]清华大学机械工程系,北京100084

出　　处：《机械工程学报》2005年第3期193-200,共8页Journal of Mechanical Engineering

基　　金：北京市自然科学基金资助项目(3042010)

摘　　要：小孔法测量高残余应力时,小孔周围材料接近于屈服状态,由于产生塑性变形而引入塑性附加应变,使得测量结果产生很大的误差。研究了应变释放系数与主应力之间的双轴比、主应力方向与应变花方向夹角以及应力水平之间的关系,通过有限元数值试验的方法对应变释放系数进行标定,使其包含有塑性附加应变的影响,并利用标定后的应变释放系数对焊接残余应力测量结果进行了修正,得到了较好的结果。Significant error of the measuring result may arise when measuring high residual stress by means of the centre hole method. And because the material around the hole is close to the yield limit, plastic deformation induced plastic strain. The strain release coefficients related with the angle between the principal direction of stress and the direction of the strain gauge, the biaxiality ratio, and the equivalent stress are studied . Then by FEM (Finite element method) the strain release coefficients including plasticity effects are recalculated, which we used to measure and calculate the residual stresses induced by welding in welded Aluminum plate.

关 键 词：小孔法 残余应力 焊接 有限元 

分 类 号：TG4[金属学及工艺—焊接]