Role of spatial patterns in fracture of disordered multiphase materials

TL;DR

This paper investigates how spatial patterns and layer offsets in disordered multiphase materials influence fracture behavior, revealing that layer misalignment reduces strength and alters stress distribution without affecting avalanche statistics.

Contribution

It introduces a two-phase spring network model that captures the effects of architecture and disorder on fracture, highlighting the impact of layer offsets on material strength.

Findings

Layer offsets decrease overall strength and fracture toughness.

Avalanche statistics are unaffected by layer offsets.

Power law exponents are smaller than in models without cracks.

Abstract

Multi-phase materials, such as composite materials, exhibit multiple competing failure mechanisms during the growth of a macroscopic defect. For the simulation of the overall fracture process in such materials, we develop a two-phase spring network model that accounts for the architecture between the different components as well as the respective disorders in their failure characteristics. In the specific case of a plain weave architecture, we show that any offset between the layers reduces the delocalization of the stresses at the crack tip and thereby substantially lowers the strength and fracture toughness of the overall laminate. The avalanche statistics of the broken springs do not show a distinguishable dependence on the offsets between layers. The power law exponents are found to be much smaller than that of disordered spring network models in the absence of a crack. A discussion is developed on the possibility of the avalanche statistics being those near breakdown.