Measurement precision and uncertainty estimation are important factors for all residual stress measurement techniques. The values of these quantities can help to determine whether a particular measurement technique would be viable option. This paper determines the precision of hole-drilling residual stress measurement using repeatability studies and develops an updated uncertainty estimator. Two repeatability studies were performed on test specimens extracted from aluminum and titanium shot peened plates. Each repeatability study included 12 hole-drilling measurements performed using a bespoke automated milling machine. Repeatability standard deviations were determined for each population. The repeatability studies were replicated using a commercially available manual hole-drilling milling machine (RS-200, Micro-Measurements). An updated uncertainty estimator was developed and was assessed using an acceptance criterion. The acceptance criterion compared an expected percentage of points (68%) to the fraction of points in the stress versus depth profile where the measured stresses ± its total uncertainty contained the mean stress of the repeatability studies. Both repeatability studies showed larger repeatability standard deviations at the surface that decay quickly (over about 0.3 mm). The repeatability standard deviation was significantly smaller in the aluminum plate (max ≈ 15 MPa, RMS ≈ 6.4 MPa) than in the titanium plate (max ≈ 60 MPa, RMS ≈ 21.0 MPa). The repeatability standard deviations were significantly larger when using the manual milling machine in the aluminum plate (RMS ≈ 21.7 MPa), and for the titanium plate (RMS ≈ 18.9 MPa). The single measurement uncertainty estimate met a defined acceptance criterion based on the confidence interval of the uncertainty estimate.

中文翻译：

---

钻孔残余应力深度剖面测量的精度和更新的不确定性估计器

测量精度和不确定性估计是所有残余应力测量技术的重要因素。这些量的值可以帮助确定特定的测量技术是否是可行的选择。本文使用可重复性研究确定钻孔残余应力测量的精度，并开发了更新的不确定性估计器。对从铝和钛喷丸处理板中提取的试样进行了两项可重复性研究。每个可重复性研究包括使用定制的自动铣床进行的 12 次钻孔测量。确定每个群体的重复性标准偏差。使用市售的手动钻孔铣床（RS-200，Micro-Measurements）复制了可重复性研究。开发了更新的不确定性估计器，并使用验收标准进行了评估。验收标准将预期的点百分比 (68%) 与应力与深度曲线中点的分数进行比较，其中测量的应力 ± 其总不确定度包含重复性研究的平均应力。两项可重复性研究都表明，表面有较大的可重复性标准偏差，并且衰减很快（超过约 0.3 毫米）。铝板（最大 ≈ 15 MPa，RMS ≈ 6.4 MPa）的重复性标准偏差明显小于钛板（最大 ≈ 60 MPa，RMS ≈ 21.0 MPa）。在铝板 (RMS ≈ 21.7 MPa) 和钛板 (RMS ≈ 18.9 MPa) 中使用手动铣床时，重复性标准偏差明显更大。