Abstract Since its proposal, the simplified Spb method has been successfully applied to the fracture toughness evaluation of metallic and polymer materials. However, some points of this methodology remain unclear, like the applicability on standardized geometries in which ηpl depends on the a/W ratio. In order to discuss this and other aspects, theoretical analyses of the Spb method were made and some experimental tests were performed. The theoretical analysis revealed that considerable differences in C(T) and SE(T) geometries could be present when the same ηpl factor for both blunt notched and pre-cracked specimens is used. To minimize these differences, the use of the most general expression of the Spb method in addition to ηpl factors provided by the standards for geometries where ηpl change with a/W is proposed. The proposed experimental methodology, based on the load separation and on ηpl factors provided by the standards, proved to be suitable for C(T) geometry, whereas for SE(T) geometry the results indicate that more research is still needed.

中文翻译：

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对 η 取决于的几何方法的分析

摘要 自提出以来，简化的Spb 方法已成功应用于金属和聚合物材料的断裂韧性评估。然而，该方法的某些要点仍不清楚，例如标准化几何形状的适用性，其中 ηpl 取决于 a/W 比。为了讨论这个和其他方面，对 Spb 方法进行了理论分析并进行了一些实验测试。理论分析表明，当钝缺口和预开裂试样使用相同的 ηpl 因子时，C(T) 和 SE(T) 几何形状可能存在相当大的差异。为了最小化这些差异，建议使用 Spb 方法的最通用表达式，以及由几何标准提供的 ηpl 因子，其中 ηpl 随 a/W 变化。