ISO 14129-1997 PDF

Full title and description

ISO 14129:1997 — Fibre‑reinforced plastic composites — Determination of the in‑plane shear stress/shear strain response, including the in‑plane shear modulus and strength, by the ±45° tension test method. Specifies a tensile test procedure using specimens with fibre orientations at ±45° to determine the in‑plane shear response of laminated composite materials.

Abstract

This International Standard defines a ±45° tensile test method to measure the in‑plane shear stress versus shear strain behaviour of fibre‑reinforced plastic (FRP) composites. It provides procedures for specimen preparation, test execution, calculation of shear stress and shear strain from measured axial data, determination of in‑plane shear modulus (from the linear region) and a practical criterion for reporting shear strength (stress at a maximum shear strain of 5% or less). The method is applicable to thermoset and thermoplastic matrix laminates composed of unidirectional layers and/or fabrics where the lay‑up is symmetrical and balanced.

General information

• Status: Published (confirmed).
• Publication date: December 1997 (1997‑12).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 83.120 (Plastics — Composite materials).
• Edition / version: Edition 1 (1997).
• Number of pages: 9.

Scope

Specifies a procedure for determining the in‑plane shear stress/shear strain response, including the in‑plane shear modulus and shear strength, of fibre‑reinforced plastic composites by the ±45° tension test method. The method is suitable for thermoset and thermoplastic matrix laminates manufactured from unidirectional layers and/or fabrics with fibres oriented at ±45° to the specimen axis, provided the laminate lay‑up is symmetric and balanced about the mid‑plane. Notes limitations for high shear‑elongation materials and prescribes a practical failure reporting criterion.

Key topics and requirements

• Specimen geometry and lay‑up: ±45° orientation, symmetric and balanced laminate construction and specified specimen dimensions.
• Specimen preparation and conditioning: requirements for preparation, surface finish and environmental conditioning prior to testing.
• Test equipment and fixturing: use of a calibrated tensile testing machine, appropriate grips, and extensometry or strain measurement suitable for shear strain determination.
• Measurement and calculation: conversion of axial load and axial strain to in‑plane shear stress and shear strain using the ±45° geometry.
• Shear modulus determination: derived from the linear portion of the shear stress–shear strain curve.
• Shear strength / failure criterion: reporting stress at maximum shear strain (practical criterion uses stress at a maximum shear strain of 5% or less due to high strain behaviour of some composites).
• Reporting: required information includes specimen geometry, laminate lay‑up, material type, specimen conditioning, strain measurement method, loading rate, and test environment.
• Limitations and normative references: harmonisation with tensile test standards for composites (e.g., ISO 527‑5) and advisories on applicability to high shear‑elongation materials.

Typical use and users

Used by composite materials laboratories, aerospace and automotive materials engineers, marine and sporting‑goods developers, research and development groups, certification bodies and quality control teams to characterise in‑plane shear behaviour for design allowables, constitutive modelling and comparative material evaluation.

Related standards

Closely related to ISO 527‑5 (tensile properties — test conditions for unidirectional FRP), and commonly cross‑referenced alongside ASTM composite shear test methods (for example ASTM D3518 and ASTM D7078) and alternative shear test methods (e.g., picture‑frame shear tests). National and regional implementations (EN / DIN variants) may also exist implementing ISO 14129 requirements.

Keywords

fibre‑reinforced plastics, FRP, in‑plane shear, shear modulus, shear strength, ±45° tension test, composite laminates, specimen preparation, ISO 14129

FAQ

Q: What is this standard?

A: ISO 14129:1997 is an International Standard that specifies the ±45° tension test method for determining the in‑plane shear stress–shear strain response of fibre‑reinforced plastic composites, including procedures to obtain shear modulus and a practical shear strength reporting criterion.

Q: What does it cover?

A: It covers specimen preparation, test execution, measurement and calculation methods to convert axial tensile data from ±45° specimens into in‑plane shear stress and shear strain, defines how to determine shear modulus, and gives guidance on reporting shear strength (stress at a specified shear strain limit).

Q: Who typically uses it?

A: Composite test laboratories, materials and structural engineers in aerospace, automotive, marine and sports industries, R&D teams, standards organizations and quality assurance personnel use the standard to characterise shear properties of laminated composites.

Q: Is it current or superseded?

A: The 1997 edition is the published edition. The standard has been reviewed and confirmed by ISO (confirmed review status noted by ISO); users should check with their national standards body or ISO catalog for the latest confirmation or amendments before procurement or formal citation.

Q: Is it part of a series?

A: It is part of ISO plastic/composite test standards and is harmonised where appropriate with related standards such as ISO 527‑5 (tensile testing of unidirectional FRP). It is commonly used alongside other composite test methods (ASTM and regional standards) for a complete material characterization.

Q: What are the key keywords?

A: In‑plane shear, shear modulus, shear strength, ±45° tension test, fibre‑reinforced plastics, composite laminates, ISO 14129.