BS ISO 19375-2024 PDF

Full title and description

STB BS ISO 19375-2024 — Fibre‑reinforced composites — Measurement of interfacial shear strength by means of a micromechanical single‑fibre pull‑out test. This standard specifies a micromechanical test method (single‑fibre pull‑out) to determine the interfacial shear strength between a single reinforcement fibre and a surrounding matrix and to derive related parameters such as the critical energy release rate.

Abstract

ISO 19375:2024 defines the apparatus, specimen preparation, test procedure, calculations and reporting requirements for a single‑fibre pull‑out test used to characterise the fibre–matrix interface in fibre‑reinforced composites. The method is intended for stiff reinforcement fibres (for example carbon, glass, basalt) embedded in thermoset, thermoplastic or fine‑grained concrete matrices. The standard also states limitations and materials/matrix types for which the method is not applicable.

General information

• Status: Published (active international standard)
• Publication date: November 2024
• Publisher: International Organization for Standardization (ISO); national/adopted editions may be published by national bodies (presented here with the STB BS designation as requested)
• ICS / categories: 83.120 (Materials for general engineering; fibre‑reinforced composites)
• Edition / version: Edition 1 (2024)
• Number of pages: 44

Scope

This document specifies a test method for determining the interfacial shear strength between a single fibre and a matrix by means of a micromechanical single‑fibre pull‑out test and for deriving the critical energy release rate where applicable. It is applicable to stiff reinforcement fibres (for example carbon, glass, basalt) and to thermoset, thermoplastic and fine‑grained concrete matrices. The standard is not applicable to elastomeric fibres or elastomeric matrices, to matrices that cure or melt above approximately 400 °C, to matrices that tend to produce significant bubbling/expansion during sample preparation, or to foam matrices.

Key topics and requirements

• Definition of test principle: micromechanical single‑fibre pull‑out to characterise fibre–matrix interface.
• Detailed specimen preparation instructions, including fibre embedment length, fibre alignment and matrix curing/conditioning.
• Requirements for test equipment and grips to ensure repeatable, low‑compliance loading and accurate load‑displacement measurement.
• Test procedure: loading rate, preconditioning, and criteria for test termination (complete pull‑out or fibre fracture).
• Calculation methods for interfacial shear strength and optional derivation of critical energy release rate from load‑displacement data.
• Reporting requirements: specimen geometry, materials, conditioning, test parameters, measured data and uncertainty considerations.
• Limitations and applicability statements (materials and temperature limits; exclusions for elastomeric systems and foams).
• Guidance on interpretation, sources of scatter, and recommendations for repeat tests and statistical treatment.

Typical use and users

This standard is used by materials and composites manufacturers, independent testing laboratories, research institutions and university research groups involved in composite materials development, quality control and failure analysis. Typical applications include interface characterisation during materials research, development of new fibre‑matrix systems, quality assurance of composite production, and comparative testing of surface treatments or sizing agents on reinforcement fibres.

Related standards

Standards that practitioners commonly consult alongside ISO 19375:2024 include other international and national test methods for composite characterisation and micromechanical testing (for example microbond and single‑fibre fragmentation tests), general composite testing standards and relevant ASTM/ISO collections for fibre and matrix property measurement. Users should also consider applicable standards for specimen conditioning, tensile testing of fibres and matrix characterisation to provide complementary data for interface interpretation.

Keywords

interfacial shear strength; single‑fibre pull‑out; fibre‑reinforced composites; micromechanical testing; fibre–matrix interface; critical energy release rate; carbon fibre; glass fibre; basalt fibre; thermoset; thermoplastic; test method; composite materials.

FAQ

Q: What is this standard?

A: ISO 19375:2024 is an international test method specifying a micromechanical single‑fibre pull‑out procedure to measure the interfacial shear strength between a single reinforcement fibre and a surrounding matrix in fibre‑reinforced composites.

Q: What does it cover?

A: It covers specimen preparation, test apparatus, test execution (loading rates, measurement), calculation of interfacial shear strength and optional determination of critical energy release rate, plus reporting and limitations on applicability (materials and temperature constraints).

Q: Who typically uses it?

A: Composite manufacturers, independent and in‑house testing laboratories, academic researchers, materials scientists and quality‑assurance personnel who need reproducible, micromechanical characterisation of fibre–matrix interfaces.

Q: Is it current or superseded?

A: This is the current first edition published in November 2024. Users should verify whether any national adoptions or amendments exist in their country and check for later revisions after 2024.

Q: Is it part of a series?

A: It is a stand‑alone international test method within the body of ISO test methods for composite materials and is produced under the work of ISO/TC 61 (plastics) subcommittees concerned with composite testing. It complements other micromechanical and macromechanical composite test standards rather than being a numbered sequence in a strict series.

Q: What are the key keywords?

A: interfacial shear strength; single‑fibre pull‑out; fibre‑matrix interface; micromechanical testing; fibre‑reinforced composites; critical energy release rate.