Residual stress fields from cold expansion have been widely used to extend the fatigue life of aircraft structures. However, the spatial statistical character of these residual stress fields has not been established and has not been incorporated in current analysis methods. The objective of this study was to establish a spatial statistical method to quantify the residual stress field around a cold expanded hole. A framework called the Spatial Analysis of Residual Stress (SpARS) was developed utilizing spatial correlation, response surface modelling techniques and statistical resampling methods to characterize the residual stress field. Our results showed that tolerance bounds on residual stress can be quantified using this method. We also demonstrated the SpARS method using recently published round robin case studies. The newly developed model will be useful for aircraft structural fatigue crack growth analyses to incorporate residual stress fields for extending inspection intervals for fatigue and fracture critical structures.

中文翻译：

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利用空间统计量表征冷膨胀残余应力

来自冷膨胀的残余应力场已被广泛用于延长飞机结构的疲劳寿命。但是，这些残余应力场的空间统计特性尚未建立，也没有纳入当前的分析方法中。这项研究的目的是建立一种空间统计方法，以量化冷扩孔周围的残余应力场。利用空间相关性，响应面建模技术和统计重采样方法开发了一种称为残余应力空间分析（SpARS）的框架，以表征残余应力场。我们的结果表明，可以使用此方法量化残余应力的公差范围。我们还使用最近发布的循环案例研究证明了SpARS方法。