ACCURATE EVALUATION OF STRAIN-ENERGY RELEASE RATE IN UNIDIRECTIONAL FRP COMPACT-TENSION SPECIMEN

Strain-energy release rate of a standard compact-tension unidirectiona l C(T) specimen of S-glass-epoxy Scotchply 1002 is evaluated using a f inite element method (FEM). Initially failure mode (cracking direction ) is theoretically predicted and the strain-energy release rate is est imated using a crack-closure integral approach where branch-crack is m odelled along the cracking direction instead of fibre orientation. The strain-energy release rate is evaluated for fibre orientations of 0 d egrees, 45 degrees, 60 degrees, 75 degrees and 85 degrees and compared with the fracture toughness (available in literature) and thus the fr acture loads (crack initition loads) obtained. The results are found t o be in very good agreement with the test data. This approach is simpl e and accurate for the evaluation of strain-energy release rate of the unidirectional fibre reinforced composite C(T)specimen. (C) 1997 Else vier Science Ltd.