ISO 24360:2022

Composites and reinforcements fibres - Carbon fibre reinforced plastics (CFRPs) and metal assemblies - Determination of the cross tension strength

This document specifies a method for determining the cross tensional strength of the bonded plates of carbon fibre reinforced plastics (CFRPs) to metal assemblies, with a standard specimen loaded in cross tension and under specified conditions of preparation, conditioning and testing. This method is intended for testing those bonded plates used in bonding carbon fibre reinforced plastics (CFRPs) to metal assemblies.

Titre manque

General Information

• Status: Published
• Publication Date: 31-Mar-2022
• ICS: 83.120 - Reinforced plastics
• Technical Committee: ISO/TC 61/SC 13 - Composites and reinforcement fibres
• Drafting Committee: ISO/TC 61/SC 13/WG 7 - Composites and metal assemblies
• Current Stage: 6060 - International Standard published
• Start Date: 01-Apr-2022
• Due Date: 11-Sep-2022
• Completion Date: 01-Apr-2022

Overview

ISO 24360:2022 specifies a standardized test method for determining the cross tension strength (CTS) of bonded assemblies between carbon fibre reinforced plastics (CFRPs) and metals. The standard defines specimen designs, preparation, conditioning and testing procedures for a cross‑tension test using a standard specimen loaded in cross tension. It applies specifically to bonded plates used to join CFRPs to metal components and is intended to support reliable, comparable strength data for engineering, certification and quality control.

Key topics and requirements

• Test principle: Measure the maximum cross tension force on a standard cross specimen and calculate CTS as the maximum force divided by the bonded area (MPa).
• Specimen types: Two specimen preparations are described (Type A - bonded coupons; Type B - cut laminate cross specimen). Notches and ply cuts are specified to create the cross‑tension geometry.
• Bonded area: Square bonded area is 25 mm × 25 mm (lapped area). A round bonded area (Ø 20 mm) is recommended to reduce scatter in CTS results (Annex A).
• Number of tests: A minimum of 5 valid test results is required to compute statistical values (mean, standard deviation).
• Test modes and equipment: Tests may be performed in tensile or compressive clamp configurations. Force measurement systems shall comply with ISO 7500‑1 class 1 accuracy. Tests are performed at room temperature and a load–displacement curve should be recorded.
• Failure classification: Record failure modes in accordance with ISO 10365; any non‑standard failure behavior must be reported.
• Test report content: Mandatory items include reference to ISO 24360:2022, bonding process and conditions, materials, specimen dimensions, bonded area shape/size, individual CTS values, mean and standard deviation, failure descriptions and any special remarks.

Applications and users

ISO 24360:2022 is practical for:

• Aerospace and transport manufacturers using CFRP–metal assemblies where bonded joints are critical.
• Materials and structural test laboratories performing comparative adhesive‑joint testing.
• Design, certification and quality teams (type certification, MRO - maintenance, repair and overhaul) needing validated joint strength data.
• Adhesive and surface treatment developers evaluating bonding processes and surface preparation effects on joint strength.

Benefits include enabling reliable comparison of CFRP–metal bond strength, detecting degradation or ionic migration issues in adhesive layers, and supporting conformity evidence for engineering certification.

Related standards

• ISO 7500‑1 - Calibration and verification of static uniaxial testing machines (force measurement accuracy).
• ISO 10365 - Adhesives - Designation of main failure patterns (failure classification).

Keywords: ISO 24360, CFRP, carbon fibre reinforced plastics, cross tension strength, CTS, CFRP‑metal assemblies, bonded plates, adhesive joints, test specimen, bonded area, ISO testing standard.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 24360
First edition
2022-04
Composites and reinforcements
fibres — Carbon fibre reinforced
plastics (CFRPs) and metal assemblies
— Determination of the cross tension
strength
Reference number
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
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
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2  Normative reference .1
3  Terms and definitions . 1
4 Test specimen . 2
5 Test equipment and testing procedure . 4
6 Test report . 8
Annex A (informative) Optimization of bond area for the reduction in CTS value scatterings .9
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13,
Composites and reinforcement fibres.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
This document specifies a method for determining the cross tensional strength of the bonded plates
of carbon fibre reinforced plastics (CFRPs) to metal assemblies, with a standard specimen loaded in
cross tension and under specified conditions of preparation, conditioning and testing. This method is
intended for testing only those bonded plates used in bonding carbon fibre reinforced plastics (CFRPs)
to metal assemblies.
The potential benefits to the users of CFRP-metal assemblies of implementing the cross tensional
strength of the bonded plates of carbon fibre reinforced plastics (CFRPs) to metal assemblies based on
this document are:
a) expanding CFRP applications to the fields of the combinations with metallic components;
b) the detection or the prevention of physical properties loss - such as ion migration and time-related
degradation in sealant film, injected calking layer and glass fibre reinforced plastics (GFRPs) layer;
c) demonstrating the conformity to specified conditions for type certification requirements in the
engineering such as aircraft developments;
d) evaluating the procedures for maintenance, repair and overhaul (MRO) in the engineering
operations such of CFRP aircrafts.
It is not the intent of this document to imply the need for:
1) omitting relevant field tests for CFRP related engineering;
2) generally specifying the dimensions of test specimen to represent CFRPs related bonded or
fastened structures;
3) superimposing test results for specific applications of the parameters that exceed the range of this
document.
v
INTERNATIONAL STANDARD ISO 24360:2022(E)
Composites and reinforcements fibres — Carbon fibre
reinforced plastics (CFRPs) and metal assemblies —
Determination of the cross tension strength
SAFETY STATEMENT — Persons using this document should be familiar with normal laboratory
practice, if applicable. This document does not purport to address all of the safety problems, if
any, associated with its use. It is the responsibility of the user to establish appropriate safety and
health practices and to ensure compliance with any regulatory conditions. It is recognized that
some of the materials permitted in this document might have a negative environmental impact.
As technological advances lead to more acceptable alternatives for such materials, they will be
eliminated to the greatest extent possible. At the end of the test, care should be taken to dispose
of all waste in an appropriate manner.
1 Scope
This document specifies a method for determining the cross tensional strength of the bonded plates
of carbon fibre reinforced plastics (CFRPs) to metal assemblies, with a standard specimen loaded in
cross tension and under specified conditions of preparation, conditioning and testing. This method is
intended for testing those bonded plates used in bonding carbon fibre reinforced plastics (CFRPs) to
metal assemblies.
2  Normative reference
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 7500-1, Metallic materials — Calibration and verificat
...