轮廓法测试残余应力中的数据处理

摘要

使用轮廓法测量铝合金T形构件淬火残余应力,重点研究了测量误差的数据处理.采用包络处理、左右轮廓平均、Gauss混合模型拟合以及节点插值处理后,得到最终轮廓值,并将其作为边界条件反向加载到应力重构有限元模型中,得到待测面应力场.使用X射线衍射法对待测面边界处应力进行修正.将测量结果和有限元模拟淬火结果进行对比,利用统计学方法分析对比结果.结果表明:轮廓法和X射线衍射法结合可以很准确地描述T形构件淬火残余应力场.T形构件淬火残余应力最大拉应力出现在筋条和腹板交界处,靠近腹板一侧.%The quenched residual stresses of T-shaped aluminum alloy were tested using the con-tour method,and the data processing of measurement errors was focused.The final contours were cal-culated by envelop processing,contour averaging,Gauss mixed model fitting and node interpolation, and then were reversed and loaded to the stress reconstruction FEM model as boundary conditions. Then the mapping of residual stresses along the cross section to be measured were obtained.The stresses at the edge were modified using X-ray diffraction method.The comparisons of measured re-sults with quenching FEM results were analyzed via statistical methods.The results indicate that the quenched residual stress fields may be described accurately by combining contour method and X-ray diffraction method.The maximum tensile residual stress of the T-shaped specimen occurs at the junc-tion of the rib and web,and close to the web.