The radial design for strain gauge rosettes used for hole-drilling residual stress measurements was established over 50 years ago and has remained almost unchanged since then. The design was developed to promote strain sensitivity, but was made without regard for ability to identify interior stresses. Consequently, only near-surface residual stresses can be identified. The aim of this study is to investigate rosette geometric features that may be refined to enable a significant increase in ability to identify interior stresses without significant loss of strain sensitivity. A finite element analysis was undertaken to model the influence of various geometrical factors on the depth response of a strain gauge rosette. It was found that that circumferentially oriented strain gauges allow residual stress measurements to be made to twice the depth of traditional radial strain gauges, with only minor loss in strain sensitivity. A new circumferential strain gauge rosette design based on the presented analysis is proposed for use where extended depth measurements are desired.

中文翻译：

---

用于大深度钻孔残余应力测量的圆周花环设计

用于钻孔残余应力测量的应变片花环的径向设计是在 50 多年前建立的，此后几乎保持不变。该设计旨在提高应变敏感性，但并未考虑识别内部应力的能力。因此，只能识别近表面残余应力。本研究的目的是研究玫瑰花结几何特征，这些特征可以进行改进，以显着提高识别内部应力的能力，而不会显着降低应变敏感性。进行了有限元分析以模拟各种几何因素对应变片花环深度响应的影响。结果表明，周向应变计允许进行残余应力测量，其深度是传统径向应变计的两倍，应变灵敏度损失很小。提出了一种基于所呈现分析的新圆周应变仪花环设计，用于需要扩展深度测量的地方。