Fracture toughness and fatigue crack propagation behavior of plain woven FRP.

Abstract

Investigation was made on estimation methods of the fracture toughness value and the fatigue crack propagation behavior by applying J-integral to the plain woven glass cloth FRP. Fracture toughness tests were done by an Instron testing machine. Repeated zero-tension fatigue tests were conducted under the constant stress amplitude with the test frequency 0.5 Hz by a hydraulic fatigue testing machine. As the result of this study, it was shown that the fracture toughness value of plain woven glass cloth FRP could be evaluated to some extent with the aid of the J-integral R-curve. And, the evaluation method of J-integral range (ΔJ) on the fatigue crack propagation behavior was experimentally confirmed by investigating the effects of the initial crack length and the test specimen configurations. Furthermore, the test results showed that the fatigue crack propagation curvecould be arranged by measuring the compliance changes of load-COD curves during the fatigue test.