钢结构残余应力测定中应力释放系数的有限元分析

Finite element method analysis of the strain release factors for measuring residual stresses in steel structure by blind-hole ethod

盲孔法是测量钢结构残余应力的高效简单的方法,应力释放系数A、B对盲孔法测量结果的精确性有重要意义。应用有限元分析软件ANSYS,建立带盲孔的板件的有限元模型,施加单向均匀拉伸应力场,对盲孔法应力释放系数A、B的测定进行有限元分析计算。通过对测量距离D、孔径、孔深、等参数的分析,发现盲孔附近应力释放大致在D/d<5范围内,在此范围内,A、B随着D/d的增大而减小,同时孔径的变化对于A、B的影响很小,而孔深的增大时A、B的绝对值有所增大,但幅度很小。通过对不同板厚的分析,发现应力释放系数A随板厚增大而增大,B则相反。

Blind-hole method is a highly effective method for measuring residual stresses in steel members.Stress releasing factors A and B are of great importance for the accuracy of the measurement.With finite element analysis software ANSYS,a model of plate with blind hole is established and unidirectional uniform tensile stress field is exerted on the model in order to calculate stress releasing factors A and B.By analyzing parameters such as measuring distance D,diameter and depth of the hole,it is evidenced that the stress releasing region around the hole generally lays among where D/d5.In this area,absolute value of A and B decreases as D/d increases,while variation of hole diameter make little influence on A and B.Absolute value of A and B slightly increases as hole depth increases.Moreover,factor A increases as plate thickness increases while factor B obey the opposite trend.