Predicting onset and orientation of localisation bands using a cohesive-frictional model

In this study, a localisation band idealised as zero-thickness surface and represented by a cohesive-frictional model is directly incorporated into the structure of a new constitutive modelling approach and is activated once a stress-based condition is met. The embedded cohesive-frictional model provides a natural way to detect both the onset and orientation of localisation bands. This is different from existing continuum approaches based on the loss of positiveness of the determinant of the acoustic tensor. The formulation in this approach also creates a strong link between quantities describing the localisation band in the model and experiments, facilitating the calibration of model parameters.