ISO 20337:2018 PDF

Fibre-reinforced plastic composites — Shear test method using a shear frame for the determination of the in-plane shear stress/shear strain response and shear modulus

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Title (English):

ISO 20337:2018

Fibre-reinforced plastic composites — Shear test method using a shear frame for the determination of the in-plane shear stress/shear strain response and shear modulus

Document status:: Active
Format:: Electronic (PDF)
Number of pages:: 12
Publication date:: November 21, 2018
Edition:: ISO IS 20337 edition 1 version 1
ICS:: 83.120

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Description (English):

This document specifies a method using a shear test apparatus for measuring the in-plane shear stress/shear strain response, shear modulus and shear strength of continuous-fibre-reinforced plastic composite materials with fibre orientations of 0° and 0°/90°. This method is applicable to thermoset and thermoplastic matrix laminates made from unidirectional layers/non-woven fabrics and/or fabrics including unidirectional fabrics, with the fibres oriented at 0° and 0°/90° to the specimen axis, where the lay-up is symmetrical and balanced about the specimen mid-plane. The method is suitable for determining shear properties in both the linear and nonlinear load-deformation range even at shear strains greater than 5 %. Short and long fibre-reinforced plastic composites can also be tested using this document.

Technical details

Technical committee: ISO/TC 61/SC 13 - Composites and reinforcement fibres
SKU: ISO 20337:2018

Abstract

Overview

ISO 20337:2018 specifies a standardized shear test method using a shear frame to determine the in‑plane shear stress–shear strain response, shear modulus and shear strength of fibre‑reinforced plastic composites. The method produces a state of pure shear in square specimens (fibres at 0° and 0°/90° orientations), avoiding edge effects and enabling reliable measurement in both the linear and nonlinear deformation ranges - including shear strains greater than 5%. It applies to thermoset and thermoplastic laminates, unidirectional layers, fabrics, non‑wovens, and short or long fibre composites when the lay‑up is symmetrical and balanced.

Key Topics and Requirements

Test principle: Square specimen clamped along all sides in a shear frame, deformed into a rhombus under axial load to produce pure in‑plane shear.
Measured outputs: In‑plane shear stress (τ12), shear strain (γ12), in‑plane shear modulus (G12) and maximum shear strength (τ12M).
Specimen geometry: Typical specimen size (165 ± 0.5) mm square; shear (free) area at least (105 ± 0.5) mm square; nominal thickness (4 ± 0.1) mm (select to prevent out‑of‑plane deflection).
Apparatus: Tensile testing machine compliant with ISO 7500‑1 (force measurement class 1); shear frame with uniform clamping and follower mechanism to maintain reproducible grip.
Strain measurement: Strain gauges (front and back faces) accurate to ±1% full scale or optical 3‑D systems; measure at 45° to coordinate axes; verify out‑of‑plane deflection.
Dimensional control: Micrometer or equivalent with maximum permitted error ≤ 0.01 mm for thickness measurement.
Test conditions & procedure: Specimen conditioning per standard atmospheres (e.g., ISO 291); prescribed test speeds and data collection practices; defined failure modes and test termination criteria.
Applicability: Suited for both linear and nonlinear shear characterization, including high shear‑elongation materials.

Applications and Users

ISO 20337:2018 is used by:

Composite materials R&D teams for material characterization and model calibration (shear modulus and nonlinear behaviour).
Quality control and test laboratories performing routine or comparative shear testing.
Composite manufacturers validating lay‑ups, resins and reinforcement systems (thermoset/thermoplastic).
Certification bodies and engineering teams for structural design data, finite element inputs, and failure analysis.

Practical benefits include consistent, reproducible shear properties across labs, capability to measure high‑strain shear behavior (>5%), and reduced edge‑related artefacts thanks to full‑edge clamping.

Related Standards

ISO 7500‑1 (calibration/verification of testing machines)
ISO 291 (conditioning/testing atmospheres)
ISO 12781‑1 (flatness)
ISO 1268, ISO 2818 (specimen production/preparation)

Keywords: ISO 20337:2018, shear test, shear frame, in‑plane shear, shear modulus, fibre‑reinforced plastic composites, composite shear testing, strain measurement.

Related standards

Standards mentioned in the description

Abstract

Overview

Key Topics and Requirements

Test principle: Square specimen clamped along all sides in a shear frame, deformed into a rhombus under axial load to produce pure in‑plane shear.
Measured outputs: In‑plane shear stress (τ12), shear strain (γ12), in‑plane shear modulus (G12) and maximum shear strength (τ12M).
Specimen geometry: Typical specimen size (165 ± 0.5) mm square; shear (free) area at least (105 ± 0.5) mm square; nominal thickness (4 ± 0.1) mm (select to prevent out‑of‑plane deflection).
Apparatus: Tensile testing machine compliant with ISO 7500‑1 (force measurement class 1); shear frame with uniform clamping and follower mechanism to maintain reproducible grip.
Strain measurement: Strain gauges (front and back faces) accurate to ±1% full scale or optical 3‑D systems; measure at 45° to coordinate axes; verify out‑of‑plane deflection.
Dimensional control: Micrometer or equivalent with maximum permitted error ≤ 0.01 mm for thickness measurement.
Test conditions & procedure: Specimen conditioning per standard atmospheres (e.g., ISO 291); prescribed test speeds and data collection practices; defined failure modes and test termination criteria.
Applicability: Suited for both linear and nonlinear shear characterization, including high shear‑elongation materials.

Applications and Users

ISO 20337:2018 is used by:

Composite materials R&D teams for material characterization and model calibration (shear modulus and nonlinear behaviour).
Quality control and test laboratories performing routine or comparative shear testing.
Composite manufacturers validating lay‑ups, resins and reinforcement systems (thermoset/thermoplastic).
Certification bodies and engineering teams for structural design data, finite element inputs, and failure analysis.

Related Standards

ISO 7500‑1 (calibration/verification of testing machines)
ISO 291 (conditioning/testing atmospheres)
ISO 12781‑1 (flatness)
ISO 1268, ISO 2818 (specimen production/preparation)

Keywords: ISO 20337:2018, shear test, shear frame, in‑plane shear, shear modulus, fibre‑reinforced plastic composites, composite shear testing, strain measurement.

ISO 20337:2018 PDF

Technical details

Abstract

Overview

Key Topics and Requirements

Applications and Users

Related Standards

Related standards

Abstract

Overview

Key Topics and Requirements

Applications and Users

Related Standards

Related standards

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