Control of Mechanical and Fracture Properties in Two-phase Materials Reinforced by Continuous, Irregular Networks

TL;DR

This paper investigates how the topology of irregular reinforcement networks in two-phase composites influences their mechanical and fracture properties, enabling tailored design for improved strength and damage tolerance.

Contribution

It introduces a stochastic algorithm to design and control the microstructure topology and geometry, allowing precise tuning of composite properties and fracture behavior.

Findings

Controlled microstructure topology affects fracture propagation

Design of spatial reinforcement networks can tailor fracture resistance

Microstructural tuning improves damage tolerance

Abstract

Composites with high strength and high fracture resistance are desirable for structural and protective applications. Most composites, however, suffer from poor damage tolerance and are prone to unpredictable fractures. Understanding the behavior of materials with an irregular reinforcement phase offers fundamental guidelines for tailoring their performance. Here, we study the fracture nucleation and propagation in two phase composites, as a function of the topology of their irregular microstructures. We use a stochastic algorithm to design the polymeric reinforcing network, achieving independent control of topology and geometry of the microstructure. By tuning the local connectivity of isodense tiles and their assembly into larger structures, we tailor the mechanical and fracture properties of the architected composites, at the local and global scale. Finally, combining different reinforcing networks into a spatially determined meso-scale assembly, we demonstrate how the spatial propagation of fractures in architected composite materials can be designed and controlled a priori.