Dynamic modeling for rate-dependent and mode-dependent cohesive interface failure analysis

Accurate modeling of interface failure represents an important consideration for analysis cases such as adhesive bonds or phase interface failure of inhomogeneous materials. In the current work, a cohesive element based model for interface failure has been developed in the context of a butterfly-type Hopkinson Bar interface specimen. Simulation has enabled insight into the dynamic in-situ stress state and crack growth under impact for property determination and test specimen evaluation. A failure criterion has been successfully employed and agrees closely with experimental results at multiple strain rates. Strain rate effects and fracture mode effects are implemented to modify the allowable strain to failure at the interface. Calculated fracture toughness values and crack propagation rates have compared closely to published experimental results at multiple strain rates. An analytical parametric evaluation of the interface failure model has been performed to illustrate the relative importance of material properties and failure behavior.