Damage fatigue simulation in quasi-brittle material using a version of discrete element method

Abstract

The simulation of the damage process is a challenge for researchers nowadays. In ductile materials, the continuum damage mechanics is based on the plasticity framework, but quasi-fragile materials have some characteristic phenomena such as localization and size effects, among others, that cannot be taken into account with this approach. The discrete element method has demonstrated considerable success in simulating the damage process in this kind of material. One of the advantages of this approach consists of capturing the transition between continuum and cracked regions in a natural way. In the first part of this work, extensive validation of the proposed numerical method is done, where fissures are introduced in a lattice structure. The variations of the mechanical properties are evaluated and compared to the analytical responses based on continuum damage theory. In the second part, an application considering the damaging process due to cyclic load history simulates a fatigue process with special attention on the transition between the continuum to macro-cracks nucleation. Finally, in the framework of quasi-brittle materials, a discussion about the performance of this approach in quantifying damage is presented.