Speaker
Description
Cracks and the associated frictional forces that arise under combined compressive and shear loads at the crack surfaces can significantly impact the material behaviour, which is particularly relevant if the load direction changes after the formation of the cracks.
The phase-field method is a powerful method for the simulation of cracks and their propagation, enabling automatic handling of crack propagation, including the detection of the direction and length of the propagation, and it can even capture the coalescence and branching of cracks. However, to the best of the author's knowledge, no generalisable method for the simulation of crack surface friction under combined compressive and shear loads within the phase-field method has been published yet. This contribution can therefore be considered as a first attempt in this direction.
Since the cracks are not modelled discretely in the phase-field method but are represented by a reduction of the material stiffness, which is applied in a certain width that is determined by the internal length parameter, this represents a particular challenge.
Coulomb's friction law is used for the simulation of crack surface friction, and it is adapted for the calculation of the stick and slip state analogously to elastoplastic models.
The method has been tested with a set of numerical tests showing promising results indicating that the approach has the potential to correctly represent crack surface friction in rather general cases. Thus the approach can be a valuable contribution to a more accurate modeling of material behaviour and failure within the framework of the phase-field method.
