Teilprojekt P5 – Compressive Failure in Porous Materials

Teilprojekt P5 - Compressive Failure in Porous Materials

(Third Party Funds Group – Sub project)

Overall project: Skalenübergreifende Bruchvorgänge: Integration von Mechanik, Materialwissenschaften, Mathematik, Chemie und Physik (FRASCAL)
Project leader: ,
Project members:
Start date: 2. January 2019
End date: 30. June 2023
Acronym: GRK2423 - P5
Funding source: DFG / Graduiertenkolleg (GRK)
URL: https://www.frascal.research.fau.eu/home/research/p-5-compressive-failure-in-porous-materials/


Materials such as solid foams, highly-porous cohesive granulates, for
aerogels possess a mode of failure not available to other solids. cracks
may form and propagate even under compressive loads (‘anticracks’,
‘compaction bands’). This can lead to counter-intuitive
modes of failure – for instance, brittle solid foams under compressive
loading may deform in a quasi-plastic manner by gradual accumulation of
damage (uncorrelated cell wall failure), but fail catastrophically under
the same loading conditions once stress concentrations trigger
anticrack propagation which destroys cohesion along a continuous
fracture plane. Even more complex failure patterns may be observed in
cohesive granulates if cohesion is restored over time by
thermodynamically driven processes (sintering, adhesive aging of newly
formed contacts), leading to repeated formation and propagation of zones
of localized damage and complex spatio-temporal patterns as observed in
sandstone, cereal packs, or snow.

We study failure processes associated with volumetric compaction in
porous materials and develop micromechanical models of deformation and
failure in the discrete, porous microstructures. We then make a scale
transition to a continuum model which we parameterise using the discrete
simulation results.