In order to assess the proper resistance of elastic-plastic materials for stable crack growth in Mode I under plane-strain conditions with large-scale yielding, a fracture criterion based on a rate of the crack-tip energy dissipation with crack extension was proposed. The criterion can be expressed as T_W = (T_W)_c, where T_W is a newly developed tearing parameter defined as T_W = (1/R)(E/σ₀²)(d_p/da). The parameter T_W is a dimensionless representation of the increment of plastic work done, d_p/da, in a circular region of characteristic radius R at the growing crack tip, and T_W is related directly as the amplitude to the singularity field at a growing crack tip.

A procedure of experimental determination of (T_W)_c was described, where the crack-tip energy dissipation, W_p, was evaluated by means of the recrystallization-etch technique, and the width of recrystallized region observed parallel to the growing crack surface was used as the characteristic radius R. With special reference to a nonlinearity of the J-resistance curve for a wide range of crack extension, a conventional estimation procedure of the rate of crack-tip energy dissipation in terms of γ[=(½)β²σ₀²R(T_W)_c] was also described.

Furthermore, the T_W criterion was verified experimentally and numerically in comparison with other candidate tearing parameters T_J[=(E/σ₀²)(dJ/da)] and T_δ[=(E/σ₀) (dδ/da)]. A significant superiority of T_W over T_J and T_δ [crack-opening angle (COA)] was emphasized as a characterizing parameter for crack growth. It was shown that the critical value of T_W during crack growth was not affected by specimen size, side groove depth, and an amount of crack extension.