TY - JOUR
T1 - Effects of elevated temperatures on mechanical behavior of epoxy adhesives and CFRP-steel hybrid joints
AU - Ke, Lu
AU - Li, Chuanxi
AU - He, Jun
AU - Dong, Shuai
AU - Chen, Can
AU - Jiao, Yang
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2020/3/1
Y1 - 2020/3/1
N2 - High environmental temperatures can significantly degrade the mechanical behavior of CFRP-steel composites, due to the reduced bond performance of epoxy adhesives. Here, we systematically investigate the effects of elevated temperatures on the mechanical behavior of epoxy adhesives and CFRP-steel hybrid joints. First, the glass transition behavior and mechanical properties of four distinct epoxy adhesives subjected to elevated temperatures were studied via dynamic mechanical analysis (DMA) and tensile tests. The failure process of CFRP-steel double-lap joints was subsequently investigated under different elevated temperatures. Digital image correlation (DIC) technique was utilized to capture the full-field strains on the specimens during the testing. The results indicate that adhesive Araldite 2014 possesses the highest glass transition temperature, followed by adhesive J133. However, adhesive J133 possesses the highest tensile strength and toughness under all testing temperatures and forms the most robust bonding between CFRP and steel at these temperatures. The bond strength is reduced by over 50% at 70 °C compared with that at room temperature, and the degradation of bond strength is correlated with that of the tensile strength of the adhesives. We also find that it is more appropriate to use Tg,o as an indicator to determine the working temperature limit of epoxy adhesives.
AB - High environmental temperatures can significantly degrade the mechanical behavior of CFRP-steel composites, due to the reduced bond performance of epoxy adhesives. Here, we systematically investigate the effects of elevated temperatures on the mechanical behavior of epoxy adhesives and CFRP-steel hybrid joints. First, the glass transition behavior and mechanical properties of four distinct epoxy adhesives subjected to elevated temperatures were studied via dynamic mechanical analysis (DMA) and tensile tests. The failure process of CFRP-steel double-lap joints was subsequently investigated under different elevated temperatures. Digital image correlation (DIC) technique was utilized to capture the full-field strains on the specimens during the testing. The results indicate that adhesive Araldite 2014 possesses the highest glass transition temperature, followed by adhesive J133. However, adhesive J133 possesses the highest tensile strength and toughness under all testing temperatures and forms the most robust bonding between CFRP and steel at these temperatures. The bond strength is reduced by over 50% at 70 °C compared with that at room temperature, and the degradation of bond strength is correlated with that of the tensile strength of the adhesives. We also find that it is more appropriate to use Tg,o as an indicator to determine the working temperature limit of epoxy adhesives.
KW - Bond behavior
KW - Digital image correlation
KW - Elevated-temperature effect
KW - Epoxy adhesive
KW - Glass transition temperature
KW - Mechanical behavior
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U2 - 10.1016/j.compstruct.2019.111789
DO - 10.1016/j.compstruct.2019.111789
M3 - Article
AN - SCOPUS:85076957722
SN - 0263-8223
VL - 235
JO - Composite Structures
JF - Composite Structures
M1 - 111789
ER -