Mechanical properties of an epoxy-based adhesive under high strain rate loadings at low temperature environment
Mechanical properties of an epoxy-based adhesive under high strain rate loadings at low temperature environment
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DOI：
10.1016/j.compositesb.2016.08.034
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发表时间：
2016-11-15
影响因子：
13.1
通讯作者：
Xu, Fujun
中科院分区：
文献类型：
--
作者：
Jia, Zhemin;Hui, David;Xu, Fujun
研究了一种环氧基胶粘剂在高应变率载荷下的低温拉伸性能。采用霍普金森拉伸杆与环境试验室相结合的方法进行了拉伸性能试验。研究了不同应变率的低温(-20℃和-40℃)下的力学参数，如强度、杨氏模量、破坏应变和断裂能。结果表明，在室温下，随着应变率的增加，复合材料的强度和刚度均显著增加。然而，低温下强度的提高并不显著。有趣的是，在RT和-20℃下，应变到破坏的速率随着应变率的增加而增加。从应力-应变曲线可以看出，在高应变率下，在RT和-20℃下出现了应变软化现象，这可以用高应变率时试件的局部温升来解释。在-40℃时，应变到破坏的应变随着应变率的增加而减小，应变软化消失。较大的环境温差和试件局部温升可能会减少应变软化现象。高应变速率对环氧胶低温拉伸性能的影响不同于文献中对聚氨酯胶粘剂的影响。(C)2016爱思唯尔有限公司。保留所有权利。
The tensile properties of an epoxy-based adhesive subject to high strain rate loadings at low temperatures were studied. Tensile split Hopkinson bar incorporating with an environmental chamber was utilized to conduct tensile property tests. Mechanical Parameters, like strength, Young's Modulus, strain to failure and fracture energy at low temperatures (-20 degrees C and -40 degrees C) with different strain rates were investigated. The results show that at room temperature (RT), the strength and stiffness both increase significantly with the increase of strain rate. However, the increment of strength at low temperatures is insignificant. Interestingly, at RT and -20 degrees C, strain to failure increase with the increase of strain rates. From the stress-strain curves, strain softening phenomenon at high strain rates are observed at RT and -20 degrees C. This could be explained by the localized temperature rise in the specimens when the strain rate reaches high. At -40 degrees C, strain to failure decreases with the increase of strain rate and strain softening disappears. The larger temperature difference between the environment and the localized temperature rise in the specimens may reduce the strain softening phenomenon. Effects of high strain rate on tensile properties of epoxy adhesive at low temperatures are different from that on polyurethane based adhesive in the literature. (C) 2016 Elsevier Ltd. All rights reserved.