Objective:
Fracture mechanics based total fatigue life model proposed previously was applied to T700 carbon/vinyl ester composite laminate for marine applications.
Approach and Results:
The model included the delamination growth in subcritical, linear, and unstable domains. Mode-I fracture test was conducted to obtain the fracture resistance GIR as a function of delamination growth. Fatigue onset life test was conducted to determine the threshold energy release rate GIth. Constant amplitude cyclic opening displacement fatigue test with displacement ratio R = 0.1 was conducted to establish the delamination growth rate, da/dN, as a function of maximum cyclic energy release rate normalized by fracture resistance, GImax /GIR. The equation generated fits the test data very well in both subcritical and linear domains while gives limiting solution in unstable domain, because of lack of test data in this domain.
Results:
Delamination growth rate equation covering the all three regimes was developed for T700/VE marine composite. The equation can be used to calculate the life for any cyclic loading.
