Fracture of Composites: Simulation by a Spring Network Model

TL;DR

This paper uses a spring network model to simulate fracture behavior in composite materials, revealing how composition and spring parameters influence breaking energy and fracture thresholds.

Contribution

It introduces a spring network simulation approach to analyze fracture in composites, highlighting the effects of composition and spring parameters on fracture energy and thresholds.

Findings

Maximum breaking energy occurs at intermediate compositions.

Certain spring parameter combinations prevent fracture up to a strain limit.

A fracture 'percolation threshold' can be defined based on parameters.

Abstract

Composite materials are often stronger than their constituents. We demonstrate this through a spring network model on a square lattice. Two different types of sites (A and B) are distributed randomly on the lattice, representing two different constituents. There are springs of three types connecting them (A-A, B-B and A-B). We assign two spring parameters for each type of spring. these are a spring constant and a breaking threshold. Here we show that intermediate compositions may require higher energy to induce the first sample-spanning break than either pure A or pure B. So the breaking energy goes through a maximum as the concentration of one component varies from 0 to 100%. The position and height of the peak depend on the spring parameters. Moreover, certain combinations of spring parameters can produce composites, which do not break upto a specified strain limit. Thus a fracture 'percolation threshold' may be defined.