基于盲孔法的水下承压结构残余应力测试研究

Research on underwater structure residual stress measurement by using blind-hole method

对盲孔法测残余应力中的等轴三角应变花应变释放系数进行有限元标定和塑性修正,得到了塑性修正后的应变释放系数;采用盲孔法对高强度钢水下承压结构典型部位的焊接残余应力进行测量,根据测试得到各测点的释放应变值,结合修正后的应变释放系数计算得到了水下承压结构典型测点的残余应力值。结果表明,水下承压结构焊缝附近纵向残余应力可达0.5倍屈服极限,周向残余应力可达0.4倍屈服极限。

The calibration and plastic correction of the strain release coefficients of triaxial equiangular strain gauge in blind-hole residual stress measurement method were presented by using finite element method. the residual stress of the high strength steel underwater structure were measured by the blind-hole method using the plastic corrected coefficients. It is shown that the longitudinal residual stress reaches approximately 0.5σs near the weld toe while the circumferential residual stress reaches approximately 0.4σ_(s).