Mixed mode brittle fracture in PMMA - An experimental study using SCB specimens
Mixed mode brittle fracture in PMMA - An experimental study using SCB specimens
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DOI：
10.1016/j.msea.2005.11.002
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发表时间：
2006-02-15
期刊：
影响因子：
6.4
通讯作者：
Hassani, MM
中科院分区：
文献类型：
--
作者：
Ayatollahi, MR;Aliha, MRM;Hassani, MM
使用包含边缘裂纹的半圆弯曲 (SCB) 试样，对聚甲基丙烯酸甲酯 (PNMA) 进行了从纯 I 型到纯 H 型全范围的一系列混合 I/II 型断裂试验。断裂载荷和裂纹扩展路径是通过不同裂纹角度的实验获得的。结果表明，当使用 SCB 试样进行断裂试验时，尤其是在 II 型主导载荷条件下，传统的混合模式 L/H 断裂准则（例如最大切向应力 (NITS) 准则）高估了 PMMA 的断裂强度。然而，当采用广义 NITS 准则时，可以改进断裂载荷的预测。虽然纯模式 1 的裂纹扩展路径是直的，但它与纯模式 II 和模式 II 主要载荷条件的断裂起始角度存在显着偏差。结果表明，广义 NITS 准则预测的裂纹扩展路径也与断裂 SCB 样品中观察到的断裂路径非常一致。 (c) 2005 Elsevier B.V. 保留所有权利。
A series of mixed mode I/II fracture tests is conducted on polymethylmethacrylate (PNMA) in the full range from pure mode I to pure mode H using a semi-circular bend (SCB) specimen containing an edge crack. The fracture load and the path of crack growth are obtained from experiments for various crack angles. It is shown that the conventional mixed mode L/H fracture criteria such as the maximum tangential stress (NITS) criterion overestimate the fracture strength of PMMA when the SCB specimen is used for fracture tests, particularly for mode II dominant loading conditions. However, improved predictions of fracture load are achieved when a generalized NITS criterion is employed. While the path of crack growth is straight for pure mode 1, it deviates significantly from the angle of fracture initiation for pure mode II and mode II dominant loading conditions. It is shown that the path of crack growth predicted by the generalized NITS criterion is also in a good agreement with the observed fracture path in the fractured SCB samples. (c) 2005 Elsevier B.V. All rights reserved.