# Influence of fracture criteria on dynamic fracture propagation in a discrete chain

## TL;DR

This paper investigates how different fracture criteria, especially history-dependent ones, influence the dynamic crack propagation in a discrete chain, revealing that such criteria can enable steady-state regimes at low subsonic speeds.

## Contribution

It introduces and compares history-dependent fracture criteria with classical threshold elongation criteria in a discrete chain model, highlighting their impact on crack dynamics.

## Key findings

- History-dependent criteria enable steady-state crack propagation at low subsonic speeds.
- Classical criteria do not predict steady-state regimes in this range.
- Significant qualitative differences in load and crack opening behavior are observed.

## Abstract

The extent to which time-dependent fracture criteria affect the dynamic behavior of fracture in a discrete structure is discussed in this work. The simplest case of a semi-infinite isotropic chain of oscillators has been studied. Two history-dependent criteria are compared to the classical one of threshold elongation for linear bonds. The results show that steady-state regimes can be reached in the low subsonic crack speed range where it is impossible according to the classical criterion. Repercussions in terms of load and crack opening versus velocity are explained in detail. A strong qualitative influence of history-dependent criteria is observed at low subsonic crack velocities, especially in relation to achievable steady-state propagation regimes.