SIMPLIFIED DATA REDUCTION METHODS FOR THE ECT TEST FOR MODE-III INTERLAMINAR FRACTURE-TOUGHNESS

Simplified expressions for the parameter controlling the load-point co mpliance and strain energy release rate were obtained for the edge cra ck torsion (ECT) specimen for Mode III interlaminar fracture toughness . Data reduction methods for Mode III toughness based on the present a nalysis are proposed. The effect of the transverse shear modulus G(23) On Mode III interlaminar fracture toughness characterization was eval uated. Parameters influenced by the transverse shear modulus were iden tified. Analytical results indicate that a higher value of G(23) resul ts in a lower load point compliance and lower Mode III toughness estim ation. The effect of G(23) on the Mode III toughness using the ECT spe cimen is negligible when an appropriate initial delamination length is chosen. A conservative estimation of the Mode III toughness can be ob tained by assuming G(23) = G(12) for any initial delamination length.