Narendra Kumar Bodaballa

arXiv2026

Subsampling of avalanches in the fiber bundle models of fracture

We study the subsampling of the avalanches in the fiber bundle model of fracture. In cases where only a part of the system is observed for the micro-failure events, the recorded avalanche statistics gets distorted compared to the actual fracture events. We show that, particularly in the cases where the load redistribution is localized, this distortion is significant. Surprisingly, however, near an elastic failure regime, the distortion is minimized, suggesting a much reduced observational capacity could still represent the actual failure dynamics in the case of fracture of elastic solids.

cond-mat.stat-mech↗

arXiv2023

Avalanche shapes in fiber bundle model

We study the temporal evolution of avalanches in the fiber bundle model of disordered solids, when the model is gradually driven towards the critical breakdown point. We use two types of loading protocols: (i) the quasi-static loading, and (ii) loading by a discrete amount. In the quasi-static loading, where the load is increased by the minimum amount needed to initiate an avalanche, the temporal shapes of avalanches are asymmetric away from the critical point and become symmetric as the critical point is approached. A measure of asymmetry follows a universal form $A\sim (σ-σ_c)^θ$, with $θ\approx 0.25$, where $σ$ is the load per fiber and $σ_c$ is the critical load per fiber. This behavior is independent of the disorder present in the system in terms of the individual failure threshold values. Thus it is possible to use this asymmetry measure as a precursor to imminent failure. For the case of discrete loading, the load is always increased by a fixed amount. The dynamics of the model in this case can be solved in the mean field limit. It shows that the avalanche shapes always remain asymmetric. We also present a variable range load sharing version of this case, where the results remain qualitatively similar.

cond-mat.stat-mech↗