Critical crack-length during fracture

TL;DR

This study uses numerical simulations of a fiber bundle model to explore how material strength relates inversely to crack growth, identifying the critical crack length that leads to failure and how it varies with disorder and system size.

Contribution

It introduces a detailed analysis of the critical crack length in a fiber bundle model, revealing its dependence on disorder strength and system size, and clarifies the relationship between maximum and critical cracks.

Findings

Inverse correlation between material strength and crack size.

Maximum and critical cracks often differ unless disorder is very low.

Phase diagram delineates regimes of crack vulnerability based on disorder and size.

Abstract

Through controlled numerical simulations in a one dimensional fiber bundle model with local stress concentration, we established an inverse correlation between the strength of the material and the cracks which grow inside it - both the maximum crack and the one that set in instability within the system, defined to be the critical crack. Through Pearson correlation function as well as probabilistic study of individual configurations, we found that the maximum and the critical crack often differ from each other unless the disorder strength is extremely low. A phase diagram on the plane of disorder vs system size demarcates between the regions where the largest crack is the most vulnerable one and where they differ from each other but still shows moderate correlation.