【摘要】 在应用裂纹柔度法计算残余应力时,插值函数及其阶数的选择对计算结果的精确性有着较大的影响。分别选用2—12阶勒让德多项式,2—9阶幂级数,2—7阶傅里叶级数作为插值函数,基于模型误差引起的应力不确定度、应变测量数据的误差引起的应力计算不确定度和总不确定度的最小化目标,得出了适合拟合预拉伸铝合金板7050-T7451内部残余应力分布规律最佳插值函数及其收敛阶。更多还原

【Abstract】 In the evaluation of the residual stress by the crack compliance method,different interpolation functions and their fit order had great effect on the calculation results.In this paper,the residual stress depth profiles in pre-stretched alloy plate 7050-T7451 were respectively determined by the method by using Legendre polynomials that the fit order was from 2 to 12,power series that the fit order was from 2 to 9,Fourier expansion that fit order was from 2 to 7.Be based on minimizing the uncertainties caused by model error,the strain errors in the measured data and total uncertainty,It was revealed that the calculations using Legendre polynomials with 9th fit order appears excellent results.It was also shown that the model error is the main error sources in the calculation of stress uncertainty.更多还原