Numerical computation of dynamic stress intensity factor for impact fracture toughness test

A new procedure was developed in order to estimate the stress intensity factor for impact fracture toughness tests. The dynamic stress intensity factor is evaluated from the static stress intensity factor and the impact response function as a correction factor for inertia effect. The impact response function for arbitrary profile of dynamic load is computed by superposing the step response function for the specimen subjected to the step impact load. The step response function is evaluated from dynamic and static crack opening displacements, which can be calculated by finite element method. A numerical computation of the dynamic stress intensity factor was carried out for a problem of Thau and Lu. The accuracy of the present method was verified from the comparison of the numerical result with the analytical one. The impact fracture experiment conducted at Brown University was simulated to estimate the stress intensity factor in view of the dynamic fracture mechanics.