Abstract This study describes a simplified procedure to estimate the Weibull stress parameter, m, using cleavage fracture toughness values measured from testing high constraint fracture specimens. The estimation procedure builds upon the conventional toughness scaling methodology (TSM) based on the Weibull stress coupled with the weakest link model to correct measured toughness distributions for high constraint fracture specimens with identical in-plane dimensions but varying thickness. The approach thus requires a correspondence between predictions based upon the Weibull stress methodology and the weakest link model for measured toughness values under high constraint conditions. Applications of the proposed procedure to analyze specimen geometry effects on fracture toughness values in a typical structural steel provide predictions that agree remarkably well with experimental data for shallow crack bend specimens with different thickness. These exploratory studies demonstrate the potential capability of the proposed estimation procedure which can greatly simplify engineering integrity assessments based upon the Weibull stress model.

中文翻译：

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威布尔应力参数 m 的简化估计程序，以及用于预测解理断裂韧度的试样几何相关性的应用

摘要 本研究描述了一种使用从测试高约束断裂试样中测得的解理断裂韧度值来估计威布尔应力参数 m 的简化程序。估计程序建立在基于威布尔应力和最弱链接模型的传统韧性缩放方法 (TSM) 的基础上，以校正面内尺寸相同但厚度不同的高约束断裂试样的测量韧性分布。因此，该方法需要基于威布尔应力方法的预测与高约束条件下测得的韧性值的最弱链接模型之间存在对应关系。应用所提出的程序来分析试样几何形状对典型结构钢断裂韧性值的影响，提供的预测与不同厚度的浅裂纹弯曲试样的实验数据非常吻合。这些探索性研究证明了提议的估计程序的潜在能力，可以大大简化基于威布尔应力模型的工程完整性评估。