J-integral function for a centre-cracked tensile specimen

Abstract The equation which relates J to the area measured between the load v crack mouth opening displacement (CMOD) and the secant offset line in a centre-cracked tensile (CCT) specimen is investigated in this paper. The limits of the equation are evaluated for a range of power law hardening material behaviour using data given in the EPRI Handbook. Comparison with finite element results confirms that the equation gives good agreement with J contour integral values for crack length to specimen width ratios ( 0·25 ≤ a w ≤ 0·75 ) of practical interest and a wide range of material behaviour.