High-rate mode II fracture toughness testing of polymer matrix composites using the Transverse Crack Tension (TCT) test

This paper describes the novel high-rate transverse crack tension (TCT) test to determine mode II fracture toughness for high strain rates and compares this to quasi-static fracture toughness obtained with the standardized End Notch Flexure (ENF) test and the modified Transverse Crack Tension (mTCT) test suggested in the literature. The novel, miniaturized mTCT specimen is used to determine the fracture toughness under quasi-static and high-rate loading conditions with an electro-mechanical test machine and a Split Hopkinson Tension bar, respectively. For the high-rate tests, almost no interfering oscillations were observed in the load signal. A novel data reduction scheme allows achieving repeatable results with a very small standard deviation. The fracture toughness for the tested composite at a loading rate of about 5 m/s was found to be at least 50% higher than the one obtained under quasi-static loading.