QBC: Quasi-brittle cracking, coupled processes and hydraulic fractures

Minisymposium organized by

The realistic and accurate numerical modelling of crack initiation and propagation still constitutes a major challenge and the object of intense research activity in many areas of Engineering. In particular, this mini-symposium is focused on the fracture of quasi-brittle materials such as concrete, geo-materials (mainly rock), ceramics, ice, etc., subject to mechanical or environmental/multi-phase/multi-physics actions.

Under increasing mechanical loading, this type of materials undergo the formation of distributed micro-cracks, some of which may eventually coalesce into localized macro-cracks while the rest of them unload. Besides direct mechanical actions, cracking of quasi-brittle materials may be also caused by flow/diffusion/transport-induced actions. This includes for instance, but is not limited to: cracking of concrete materials due to durability-related phenomena (i.e. drying shrinkage, high temperatures, alkali-silica-reaction, sulphate attack, etc.); cracking (or opening of existing fractures) in rock masses due to fluid injections such as hydraulic fracture.

The highly heterogeneous nature of quasi-brittle materials also plays a key role in the cracking process, reason for which multi-scale models have also been proposed. Micro- or meso-mechanical models, based on the physics of microstructures and in which the heterogeneities are explicitly described and the degradation processes are established for the individual components, may help to simplify considerably the constitutive description, at the price of a higher computational cost.

On the other hand, numerical modelling of fluid-induced fractures does not usually require to represent the meso-scale, but it requires relatively fine meshes near the fracture front in comparison to the domain dimensions, which may lead to very large meshes. In all cases, therefore, the use of parallel high-performance computing (HPC) has been advocated.

The present mini-symposium is intended to gather contributions on all those and related topics. Classical models based on a continuum or a discrete approach, as well as more recent techniques such as XFEM, phase field, etc., and their implementation in an HPC environment, are welcome.