Determination of dynamic fracture initiation toughness of elastic-plastic materials at intermediate strain rates

An earlier paper dealt with the experimental techniques used to determine t he dynamic fracture properties of linear elastic materials. Here we describ e those most commonly used as elastoplastic materials, limiting the study t o the initiation fracture toughness at the intermediate strain rate (of aro und 10(2) s(-1)). In this case the inertial forces are negligible and it is possible to apply the static solutions. With this stipulation, the analysi s can be based on the methods of testing in static conditions. The dynamic case differs basically, from the static one, in the influence of the strain rate on the properties of the material.