화학공학소재연구정보센터
Journal of Adhesion, Vol.88, No.4-6, 534-551, 2012
Mode II Fracture Toughness of Adhesively Bonded Joints as a Function of Temperature: Experimental and Numerical Study
In this work, an experimental and numerical study is performed to evaluate the effect of temperature on the Mode II fracture toughness of a high temperature epoxy adhesive. Mode II fracture testing on end notch flexure (ENF) test specimens was performed at room temperature (RT) and high temperatures (100, 150, and 200 degrees C) and the Mode II fracture toughness, G(IIc), as a function of temperature was obtained. It is shown that at temperatures well below the glass transition temperature, the fracture toughness, G(IIc), increases with temperature and decreases as the temperature approaches T-g, while above T-g a drastic decrease in fracture toughness was observed. Furthermore, cohesive zone models, in which the failure behaviour is expressed by a bilinear traction-separation law, were used to define the adhesive behaviour in Mode II and to predict the adhesive load-displacement (P-delta) curves as a function of temperature. The simulation response matched the experimental results very well at temperatures below T-g. The sensitivity of the various cohesive zone parameters in predicting the overall mechanical response of the joint was examined as well for a deeper understanding of this predictive method.