Damage cluster distributions in numerical concrete at the mesoscale

Abstract

We investigate the size distribution of damage clusters in concrete under uniaxial tension loading conditions. Using the finite-element method, the concrete is modeled at the mesoscale by a random distribution of elastic spherical aggregates within an elastic mortar paste. The propagation and coalescence of damage zones are then simulated by means of dynamically inserted cohesive elements. Dynamic failure analysis shows that the size distribution of damage clusters follows a power law when a system-spanning cluster is first observed, with an exponent close to that of percolation theory. This is found for a range of selected mesostructural parameters, material defects, and applied strain rates. In all cases, the system-spanning cluster occurs prior to the onset of local decohesion, a regime of crack nucleation and propagation, and eventual material failure. The resulting fully damaged crack surfaces after failure are found to be only weakly correlated with the percolated damage region structures.

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“…For example, the buildup and release of elastic energy at geological fault is what causes earthquakes, and the intricate details of the slip zone, the propagation of slip fronts and waves radiated through the various geological media are still active areas of research (Kammer et al, 2012(Kammer et al, , 2014Roch et al, 2022). Similarly, understanding fracture in heterogeneous materials such as concrete, masonry or ceramics necessitates the modeling of interaction of crack fronts with complex materials (A. I. Cuba Ramos et al, 2018;Taheri Mousavi et al, 2015;Yilmaz et al, 2017), the representation of residual shear stresses in the contact of newly-formed crack surfaces (Pundir & Anciaux, 2021;Zhang et al, 2017), and the accurate characterization of transient dynamics (Corrado & Molinari, 2016;Vocialta et al, 2018) and material structure evolution (A. I. Cuba Ramos et al, 2018;Gallyamov et al, 2020).…”