ISO 23930:2023

Fibre-reinforced plastic composites - Full-section compressive test for pultruded profiles

This document specifies a method for determining the compressive properties in the pultruded fibre reinforced plastic (FRP) using full-section compressive tests. It is applicable to pultruded FRP profiles. The scope is not limited to types of fibres and resins.

Composites plastiques renforcés de fibres - Essai de compression sur une section entière de profilés pultrudés

General Information

• Status: Published
• Publication Date: 30-Jan-2023
• ICS: 83.120 - Reinforced plastics
• Technical Committee: ISO/TC 61/SC 13 - Composites and reinforcement fibres
• Drafting Committee: ISO/TC 61/SC 13/WG 2 - Laminates and moulding compounds
• Current Stage: 6060 - International Standard published
• Start Date: 31-Jan-2023
• Due Date: 18-Mar-2023
• Completion Date: 31-Jan-2023

Overview - ISO 23930:2023 (pultruded FRP compressive test)

ISO 23930:2023 specifies a standardized full‑section compressive test to determine compressive properties of pultruded fibre‑reinforced plastic (FRP) profiles. The method is applicable to pultruded FRP regardless of fibre or resin type and is intended to evaluate the mechanical behaviour of the complete cross‑section (rather than only coupons). The standard notes that full‑section results are often lower than coupon tests but better represent real member performance and are therefore recommended for strength design of pultruded FRP compressive members.

Key topics and technical requirements

• Test principle: Uniaxial compression of the full pultruded profile section using a universal test machine; stress from applied force, strain from gauges/extensometers.
• Apparatus: Test machine compliant with ISO 7500‑1 and ISO 9513; force measurement Class 1. Parallel, well‑guided compression platens at least 5 mm larger than specimen; platen hardness ≥ 700 HV 0,2; surface roughness ≤ 6.3 µm (ISO 21920‑2).
• Strain measurement: Use strain gauges (grid length > 3 mm; k‑factor accuracy ≤ 1%). Gauges positioned according to cross‑section.
• Specimen geometry & limits: Cross‑sections include I, C, L, rectangular, circular, etc. Slenderness ratio < 3; width‑to‑thickness limits (free side plates < 5; plates without free edges < 8; non‑double symmetrical sections < 5). End platens contact faces must be parallel (parallelism error < 0.5 mm).
• Specimen prep & sampling: Minimum 3 specimens (5 recommended). Ends may be reinforced with bonded metal plates (reinforcement length < 1/3 specimen length). Use cutting methods that do not alter material properties (diamond blade, water jet).
• Conditioning & atmosphere: Follow ISO 291 Class 2; preferred (23 ± 2) °C, (50 ± 10) % RH; record temperature and humidity.
• Test speed & measurements: Compression speed v = 0.1 × h (mm/min) where h = specimen length. Dimensional accuracy per ISO 16012 (±0.1 mm for >10 mm; ±0.01 mm for ≤10 mm).
• Results & calculations: Full‑section compressive strength σc = Fc / A. Compressive modulus can be calculated by chord slope (e.g., between 0.05% and 0.25% strain) or regression slope. Record failure mode.

Applications - practical use of the standard

• Structural design and verification of pultruded FRP members (beams, columns, profiles) where full‑section behaviour is critical.
• Product development, quality control and material specification for pultrusion manufacturers.
• Performance comparison for different pultruded profile geometries, fibre/resin systems and manufacturing processes.
• Use in codes and component design where representative full‑section compressive properties are required.

Who should use this standard

• Pultrusion manufacturers, composite material engineers, structural designers, testing laboratories, and standards committees involved in FRP design and certification.

Related standards

• ISO 291 (conditioning), ISO 7500‑1 (test machine calibration), ISO 9513 (extensometer calibration), ISO 16012 (dimensional measurement), ISO 21920‑2 (surface texture).

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23930
First edition
2023-01
Fibre-reinforced plastic composites —
Full-section compressive test for
pultruded profiles
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
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or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
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Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 3
5.1 Test machine . 3
5.2 Compression platens . 3
5.3 Strain indicator . 3
6 Specimens. 4
6.1 Geometry . 4
6.2 Preparation of specimens . 4
6.3 Number of test specimens . 4
6.4 Sampling of test specimens . 4
6.5 Conditioning atmosphere. 4
7 Test procedure .5
7.1 Test atmosphere . 5
7.2 Measurement of initial dimensions of test specimen . 5
7.3 Test speed . 5
8 Calculation and expression results . 5
8.1 General . 5
8.2 Full-section compressive strength . 6
8.3 Strain . 6
8.4 Full-section compressive modulus . 6
8.4.1 General . 6
8.4.2 Chord slope . 6
8.4.3 Regression slope . 6
8.5 Failure mode . 7
9 Test report . 7
Annex A (informative) Calculation method of slenderness ratio and width-thickness ratio .9
iii
Foreword
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This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13,
Composites and reinforcement fibres.
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iv
Introduction
Previous attempts to determine compressive properties of pultruded FRP have been hampered by
experimental difficulty of clamping and different boundary conditions between test specimen and
actual specimen.
The procedure presented in this document uses the full-section compressive test to determine the
compressive properties of pultruded FRP. This test is convenient and able to evaluate the mechanical
properties of the full-section. The result of this test, despite being lower than that of the coupon test,
can better represent the properties across the full-section and thus, is recommended to be used in the
strength design of pultruded FRP compressive members.
v
INTERNATIONAL STANDARD ISO 23930:2023(E)
Fibre-reinforced plastic composites — Full-section
compressive test for pultruded profiles
1 Scope
This document specifies a method for determining the compressive properties in the pultruded fibre
reinforced plastic (FRP) using full-section compressive tests.
It is applicable to pultruded FRP profiles. The scope is not limited to types of fibres and resins.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 291, Plastics — Standard atmospheres for conditioning and testing
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 9513, Metallic materials — Calibration of extensometer systems used in uniaxial testing
ISO 16012, Plastics — Determination of linear dimensions of test specimens
ISO 21920-2, Geometrical product specifications (GPS) — Surface texture: Profile — Part 2 Terms,
definitions and surface texture parameters
3 Terms and definitions
For t
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