Micro-to-meso scale mechanisms for modelling the fatigue response of cohesive frictional materials

MAITRA, S.; CAGGIANO A.,; YANG S.,; DIEGO SAID SCHICCHI; KOENDERS E.A.B.

Guimarães

Conferencia; Proceedings of the RILEM-SC2020, 10th-14th March 2020; 2020

This work deals with a research study on the fatigue behavior of cohe-sive frictional materials like concrete or mortars. A two-scale approach will be proposed for analyzing concrete specimens subjected to either low- or high-cycle fatigue actions. The multiscale technique is based on a combination of a micro-scale procedure, to describe the microstructural defects affecting the cyclic re-sponse, which is subsequently homogenized to the upper meso- and macroscopic failure. More specifically, projected microscopic representative volume ele-ments, equipped with a fracture-based model and combined with a continuous inelastic constitutive law that accumulates damages induced by cycle behaviors, represents the lower scale. A plastic-damage based model, for concrete subjected to cyclic loading, is developed combining the concept of fracture-energy theories (within the family of fictitious crack approaches) with stiffness degradation, the latter representing the key phenomenon occurring in concrete under cyclic re-sponses. The work will numerically explore the potential of the various tech-niques for assessing the fatigue formation and growth of (micro-, meso- and macro-) cracks, and their influence on the macroscale behavior.