Abstract Large displacement has a considerable effect on determination of mode I interlaminar fracture toughness of composite. It is found that the mode I interlaminar fracture toughness of composite double cantilever beam (DCB) with piano hinge under large displacement is greatly underestimated by using the data reduction methods in the ASTM D5528 and ISO 15024 standards. The nonlinear J-integral, nonlinear beam theory, and finite element method are used to study the effect of large displacement on the determination of the interlaminar fracture toughness of composite. These standards are improved by this paper. Accurate and consistent fracture toughness can be obtained by using the J-integral method and the corrected ASTM/ISO data reduction methods.

中文翻译：

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大位移效应对复合材料I型层间断裂韧性测定的修正

摘要 大位移对复合材料I型层间断裂韧度的测定有相当大的影响。通过使用ASTM D5528和ISO 15024标准中的数据简化方法发现，大位移下钢琴铰链复合材料双悬臂梁（DCB）的I型层间断裂韧性被大大低估。采用非线性J积分、非线性梁理论和有限元方法研究大位移对复合材料层间断裂韧度测定的影响。本文对这些标准进行了改进。使用 J 积分方法和修正后的 ASTM/ISO 数据简化方法可以获得准确且一致的断裂韧性。