Standards Development

Scope

This document specifies a test method for determining the interfacial shear strength between a single fibre and a matrix by means of a pull-out test. The method can be used to measure the critical energy release rate.

The method is applicable to reinforcement fibres such as carbon fibres, glass fibres, basalt fibres and similar stiff reinforcement fibres and to thermoset, thermoplastic and fine-grained concrete matrices. It can be used for polymeric reinforcement fibres and for other inorganic matrices.

It is not applicable to:

1) elastomeric fibres and elastomeric matrices such as rubber;

2) matrices which cure or melt at temperatures above 400 °C;

3) matrices that show a strong tendency to bubble formation or expansion during the samplepreparation process;

4) foams

Purpose

The interfacial shear strength between fibres and matrix is one of the key quality parameters in fibrereinforced composites. So far macromechanical tests, e.g., on UD specimens, are established to measure the ILSS, however, those tests are affected by specimen imperfections such as fibre orientation or matrix porosity, and depend on fibre-content, -orientation, -length and -diameter. The test method described in this NWIP avoids such dependencies by means of a micromechanical single-fibre pull-out test and allows precise measurement of ILSS in a fast and efficient manner. (Please use this field or attach an annex)