The relation between the J-integrals around Γ1 and Γ2 leads to the constraint and an expression for "K" in terms of the far-field stress where "β" = 1 for plane stress and "β" = 1 − "ν"2 for plane strain ("ν" is the Poisson's ratio). The asymptotic expansion of the stress field and the above ideas can be used to determine the stress and strain fields in terms of the J-integral: where formula_23 and formula_24 are dimensionless functions. These expressions indicate that "J" can be interpreted as a plastic analog to the stress intensity factor ("K") that is used in linear elastic fracture mechanics, i.e., we can use a criterion such as "J" > "J"Ic as a crack growth criterion.