Generalized Failure Criteria for Computational Modeling of Dynamic Failure

In the present paper, a framework for defining the dynamic failure of materials at a general stress state is developed. Method of extending conventional quasi-static failure criteria into their dynamic formulation is proposed that utilizes a concept of incubation time of failure. The incubation time property has been previously employed in formulating the dynamic failure condition that offers a more physically meaningful and robust alternative to popular dynamic failure prediction methods involving strain rate dependency of the strength of the material. Making use of the appropriately defined incubation times and stress invariants that are commonly involved in formulation of the quasi-static failure criteria, their dynamic counterparts can be delivered. The generalization has been carried out for three popular failure criteria. Challenges of generalizing the incubation time-based criterion to arbitrary load histories have been discussed, and a method of implementing it in such cases has been presented.