A strain-rate-dependent cohesive zone model for peel-loaded thick and flexible adhesive layers of various geometries prone to stick–slip failure

In the present publication, a well-established cohesive zone model for mode I peel loading from literature is extended to depend on the initial geometry of the adhesive layer and the strain rate prior to crack propagation. Furthermore, the extension includes a simple stick–slip model, allowing for a numerical description of instabilities during crack propagation. The model parameters are calibrated using double cantilever beam tests for two different soft adhesives. The impact of the model parameters on the fracture behavior is investigated and the predictive quality is demonstrated for adhesive layer thicknesses ranging from 0.75 to 12 mm and strain rates over four orders of magnitude from extremely slow (creep) to moderately fast. The model is used to simulate creep rupture peel tests, where the energy release rate was externally controlled to be constant. Finally, experimentally observed stick–slip instabilities during crack propagation within a specific range of strain rates could be predicted with the model. • A cohesive zone model is proposed for peel fracture in flexible adhesive layers. • The model parameters are functions of strain rate and layer thickness. • The model includes a simple approach to describe unstable stick–slip crack growth. • The model was successfully used to describe creep fracture.