基于裂纹柔度法的残余应力检测误差分析及处理方法

Error Analysis and Treatment in Residual Stress Detecting for Crack Compliance Method

对裂纹柔度法残余应力计算中的误差传递进行了深入分析。应用误差传递函数对包含协方差、建模误差在内的Legendre插值模型的收敛、稳定性进行了分析,建立了应力误差估算方法。验证实验表明:通过应变偏差可确定满足最小应力不确定度条件最佳收敛阶,由此估算的应力误差与实际结果基本一致。

Error propagation in residual stress measurement for crack compliance method is comprehensively analyzed.The error propagation formulation including covariances and model error was presented to analyze convergence and stability of Legendre interpolation.The way of uncertainty estimation in stress calculation were established.The validity test shows that an optimal order for Legendre interpolation can usually be chosen by the misfit of measuring stain data to meet the needs of minimizing stress error that are well consistent with the actual results.