Multibarrier Kinetics of Brittle Fracture: I, Stress Dependence of the Subcritical Crack Velocity

A general equation for the subcritical crack velocity in brittle materials is derived using steady‐state, multibarrier kinetics. It provides a basis from which specialized expressions can be developed for the crack velocity in specific cases. One social equation for v=v(K) at constant temperature, derived from the general expression, has a mathematic form that fits data representative of a wide variety of specific cases. Examples are presented and the equation is discussed in terms of its physical foundations.