Abstract It is well known that making of specimens, experimental set up, fixtures and testing procedure could inevitably affect the experimental accuracy, which will actually induce the disturbance from weak Mode-II loading on the specimen in K-based Mode-I fracture toughness tests. How to quantitatively analyse the disturbance effects is quite interesting and challenging work. In present article, an energy-based modelling on multiple underlying cracks initiation from a crack tip has been suggested to capture and quantify the disturbance effects. Conventional experimental data processing will lead to higher Mode-I fracture toughness values, which would affect the accuracy of fracture assessment, and cannot truly reflect the fracture property of materials. The current investigation has revealed that three theoretical predictable values of K-based Mode-I fracture toughness may be measured in tests if weak Mode-II loading acting on the specimen is inevitable, which is helpful to identify the real value of the fracture toughness and better understand scattered experimental data.

中文翻译：

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弱模式II加载对基于K的模式I断裂韧性试验的干扰效应

摘要 众所周知，试件的制作、实验装置、夹具和测试程序不可避免地会影响实验精度，这实际上会在基于 K 的 I 型断裂韧度试验中对试件产生弱 II 型加载的干扰。 . 如何定量分析扰动效应是一项非常有趣且具有挑战性的工作。在本文中，已建议对从裂纹尖端引发的多个底层裂纹进行基于能量的建模，以捕获和量化扰动效应。常规的实验数据处理会导致较高的Mode-I断裂韧度值，影响断裂评估的准确性，不能真实反映材料的断裂特性。