Abstract A specimen-size-effect is found in the experimental fatigue crack growth behavior of single-edge-cracked fracture specimens, where the specimen length-to-width ratio was varied by about a factor of four. This effect appears form the geometric correction factor (GCFS) used for the calcuation of the stress intensity range in fracture mechanics. It is shown that the net-section-based fracture mechanics approach provides a unique correlation of crack growth data, for all specimen sizes, on the basis of the change in the net-section strain energy serving as the crack driving force parameter. The fatigue crack growth data could be correlated extremely well, when an effective specimen length, including the elastic strain energy of the specimen portion within the grips, is included in the calculations. This effective length can be determined by shear-lag analysis. It is also demonstrated that a true size-independent fatigue crack growth behavior can be obtained through the net-section based approach.

中文翻译：

---

试样尺寸对疲劳裂纹扩展的影响的性质和提取与尺寸无关的行为的净截面断裂力学方法

摘要 在单边裂纹断裂试样的实验疲劳裂纹扩展行为中发现了试样尺寸效应，其中试样长宽比变化约四倍。这种效应出现在用于计算断裂力学应力强度范围的几何校正因子 (GCFS) 中。结果表明，基于净截面应变能的变化作为裂纹驱动力参数，基于净截面的断裂力学方法为所有试样尺寸提供了裂纹扩展数据的独特相关性。当有效试样长度（包括夹具内试样部分的弹性应变能）包含在计算中时，疲劳裂纹扩展数据可以非常好地相关联。该有效长度可以通过剪切滞后分析来确定。还证明了通过基于净截面的方法可以获得真正的与尺寸无关的疲劳裂纹扩展行为。