prEN 3873

Aerospace series - Test methods for metallic materials - Determination of fatigue crack growth rates using Corner-Cracked (CC) test pieces

This document specifies the requirements for determining fatigue crack growth rates using corner-crack (CC) test pieces. Crack development is measured using a potential-drop system, and the calculated crack depths can be corrected via marker bands created on the fracture surface during the test. Results are expressed in terms of the crack-tip stress-intensity range (ΔK), with crack depths and test stress level noted.

Luft- und Raumfahrt - Prüfverfahren für metallische Werkstoffe - Ermittlung der Ermüdungsriss-Wachstumsraten an Probestücken mit Eckanriss (Corner-Crack)

Dieses Dokument legt die Anforderungen für die Bestimmung der Geschwindigkeit des Ermüdungswachstums unter Verwendung von Eckanriss-Probestücken (Corner-Crack, CC) fest. Die Rissentwicklung wird mit einem Potentialabfallsystem gemessen, und die berechneten Risstiefen können über Markierungsbänder, die im Ver
lauf der Prüfung an der Bruchfläche erzeugt wurden, korrigiert werden. Die Ergebnisse werden in Form der Schwingbreite der Rissspitzen-Spannungsintensität(ΔK) dargestellt, wobei die Risstiefen und das
nungsniveau aufgezeichnet werden.

Série aérospatiale - Méthodes d'essais applicables aux matériaux métalliques - Détermination de la vitesse de propagation de fissure en fatigue à l'aide d'éprouvettes avec fissure en coin.

Aeronavtika - Preskusne metode za kovinske materiale - Ugotavljanje stopnje rasti utrujenostnih razpok, z uporabo preskusnih kosov s kotno razpoko (CC)

General Information

• Status: Not Published
• Publication Date: 09-May-2027
• ICS: 49.025.05 - Ferrous alloys in general
• ICS: 49.025.15 - Non-ferrous alloys in general
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 4/S 5 - Test Methods
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 13-Nov-2025
• Completion Date: 13-Nov-2025
• Ref Project: oSIST prEN 3873:2026 - Aerospace series - Test methods for metallic materials - Determination of fatigue crack growth rates using Corner-Cracked (CC) test pieces

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2026
Aeronavtika - Preskusne metode za kovinske materiale - Ugotavljanje stopnje rasti
utrujenostnih razpok, z uporabo preskusnih kosov s kotno razpoko (CC)
Aerospace series - Test methods for metallic materials - Determination of fatigue crack
growth rates using Corner-Cracked (CC) test pieces
Luft- und Raumfahrt - Prüfverfahren für metallische Werkstoffe - Ermittlung der
Ermüdungsriss-Wachstumsraten an Probestücken mit Eckanriss (Corner-Crack)
Série aérospatiale - Méthodes d'essais applicables aux matériaux métalliques -
Détermination de la vitesse de propagation de fissure en fatigue à l'aide d'éprouvettes
avec fissure en coin.
Ta slovenski standard je istoveten z: prEN 3873
ICS:
49.025.05 Železove zlitine na splošno Ferrous alloys in general
49.025.15 Neželezove zlitine na Non-ferrous alloys in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2025
ICS 49.025.05; 49.025.15
English Version
Aerospace series - Test methods for metallic materials -
Determination of fatigue crack growth rates using Corner-
Cracked (CC) test pieces
Série aérospatiale - Méthodes d'essais applicables aux Luft- und Raumfahrt - Prüfverfahren für metallische
matériaux métalliques - Détermination de la vitesse de Werkstoffe - Ermittlung der Ermüdungsriss-
propagation de fissure en fatigue à l'aide d'éprouvettes Wachstumsraten an Probestücken mit Eckanriss
avec fissure en coin. (Corner-Crack)
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-
STAN.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 3873:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 6
5 Test method . 7
5.1 General. 7
5.2 Parameters influencing crack growth . 8
5.3 Applicability of results . 8
6 Test equipment . 9
6.1 Test machine . 9
6.1.1 General. 9
6.1.2 Load control . 9
6.1.3 Load alignment . 9
6.2 Calibration . 9
6.3 Temperature measurement and control . 9
6.4 Gripping of test pieces . 10
7 Test pieces . 10
7.1 Corner-crack (CC) test piece . 10
7.2 Stress-intensity Factor calculation . 10
7.3 Test piece size . 11
7.4 Crack plane orientation . 11
7.5 Residual stresses . 11
8 Procedures before testing . 11
8.1 Condition of test pieces . 11
8.2 Heating . 11
8.3 Number of tests . 11
9 Test procedure . 12
9.1 General. 12
9.2 Determination of crack depth . 12
9.2.1 General. 12
9.2.2 Notch preparation . 12
9.2.3 Pre-cracking . 12
9.3 Procedure . 13
9.4 Increasing-K-test . 14
9.5 Measurement intervals . 14
9.6 End of test . 14
10 Health and safety . 15
11 Evaluation of test results . 15
11.1 Test piece measurement . 15
11.1.1 General. 15
11.1.2 Polynomial method . 15
11.1.3 Secant method . 16
11.2 Crack closure correction − ΔK . 16
eff
12 Test report . 16
13 Optional information in a test report . 17
Annex A (normative) Information on measuring crack depths in corner-crack test pieces
with the direct-current Potential-drop method . 19
Annex B (informative) Stress-intensity function for corner-crack test pieces . 23
Annex C (normative) Guidelines on test piece handling and degreasing . 25
Annex D (informative) da/dN Test report form . 34
Bibliography . 35
European foreword
This document (prEN 3873:2025) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document
has received the approval of the National Associations and the Official Services of the member
countries of ASD-STAN, prior to its presentation to CEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 3873:2010.
This document includes the following significant technical changes with respect to EN 3873:2010:
— New structural update;
— Adding Figure C.9 “Wire placement”;
— New Annex D “da/dN Test report form”.
1 Scope
This document specifies the requirements for determining fatigue crack growth rates using corner-
crack (CC) test pieces. Crack development is measured using a potential-drop system, and the
calculated crack depths can be corrected via marker bands created on the fracture surface during the
test. Results are expressed in terms of the crack-tip stress-intensity range (ΔK), with crack depths and
test stress level noted.
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.
EN ISO 3785, Metallic materials — Designation of test specimen axes in relation to product texture(ISO
3785)
EN 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 7500-1)
ASTM E1012, Standard practice for verification of test frame and specimen alignment under tensile and
compressive axial force application
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
crack depth
a
distance from the extrapolated original corner containing the notch to the centre of the crack front
(45° position)
Note 1 to entry: For the calculation of stress-intensity factor, the crack length shall be given in metres.
3.2
calculated (potential) crack depth
a
v
average crack depth due to the averaging nature of the potential determination method
Note 1 to entry: Calcula
...