Multiscale Modelling of Stick-Slip Transition of Rough (Fractal) Surfaces

Bernardino  Chiaia; Mauro Borri-Brunetto

doi:10.4028/www.scientific.net/MSF.539-543.2594

Paper Titles

Kinetics of the Austenite-to-Ferrite Phase Transformation - From the Intrinsic to an Effective Interface Mobility
p.2570

Modelling the Dependence of Uniform Elongation on Grain Size
p.2576

A Coupled-Volume Approach to the Multi-Scale Modelling of Quasi-Brittle Materials
p.2582

A Multi-Scale Model of Martensitic Transformation Induced Plasticity at Finite Strains
p.2588

Multiscale Modelling of Stick-Slip Transition of Rough (Fractal) Surfaces
p.2594

Out of Plane Models for Composite Brickwork-Like Materials
p.2601

Multiscale Modelling of the Mechanical Behaviour of Oriented Semicrystalline Polymers
p.2607

Nonlocal Interface Mechanical Model
p.2613

Structural Models of Progressive Interface Failure under Shear Stresses
p.2619

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Multiscale Modelling of Stick-Slip Transition of Rough (Fractal) Surfaces

Abstract:

The apparent shear strength of rock discontinuities is lower than that of small scale samples. At the same time, the sliding behavior is characterized, in situ, by marked instabilities. Numerical algorithms permit to calculate contact forces at any point, and to describe the stick-slip transition. On the other hand, the critical aspects are not captured by classical theories. Multiscale simulations show that the contact domain between rough surfaces is a lacunar set. This explains the size-dependence of the apparent friction coefficient. By applying an increasing tangential force, the regime of partial-slip comes into play. However, the continuous and smooth transition to fullsliding predicted by the Cattaneo-Mindlin theory is not occurring in real situations. We implement a numerical renormalization group technique, taking into account the redistribution of stress consequent to partial-slip. This permits the critical value of the tangential force to be found. The critical force is less than the one predicted by Coulomb’s theory, and depends on the specimen size and on the topology of the interface.