Crack growth behavior in filament winding composites under mode-I loading test: destructive and non-destructive investigations

In this work, an experimental investigation of crack growth in filament winding composites (FWCs) was carried out. First, two glass composite laminates with different stacking sequences [± Ɵ°] 6 with Ɵ = 50°, 60° were considered to evaluate their effect on the energy release rate: initiation ( G IC ) and propagation (R-curve), during the mode-I loading test. For this purpose, double cantilever beam (DCB) specimens were cut from real pipe according to the ASTM D5528 standard. Second, ultrasonic non-destructive tests via the pulse-echo contact method were used to follow the crack growth in FWCs. Based on the DCB test results, it was found that the stacking sequence of laminate had significant effects on the initiation ( G IC ) and propagation (R-curve) behavior. Also, from ultrasonic measurements, it was observed that the crack position and propagation were clearly detectable. In addition, scanning electron microscopy (SEM) micrographs were examined to analyze the morphology of fracture surfaces and to provide a better understanding of the fundamental mechanisms of damage in FWCs.