National foreword

This British Standard is the UK implementation of EN 17149‑3:2025.

The UK participation in its preparation was entrusted to Technical Committee RAE/3/-/11, Railway Applications - Structural requirements and Welding.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2025.

This European Standard was approved by CEN on 27 October 2024.

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. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists 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, Czechia, 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.

European foreword

This document (EN 17149‑3:2025) has been prepared by Technical Committee CEN/TC 256 “Railway applications”, the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by July 2025, and conflicting national standards shall be withdrawn at the latest by July 2025.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document is part of the EN 17149 series, Railway applications — Strength assessment of railway vehicle structures, which consists of the following parts:

Part 1: General;
Part 2: Static strength assessment;
Part 3: Fatigue strength assessment based on cumulative damage.

Any feedback and questions on this document should be directed to the users’ national standards body. A complete listing of these bodies can be found on the CEN website.

According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: 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 the United Kingdom.

Introduction

If a fatigue strength assessment is necessary for rail vehicle structures, this assessment may be made with an endurance limit approach or a cumulative damage approach.

An endurance limit approach is based on the assessment of the stress ranges (e.g. derived from the design load cases or from measurements) against an admissible endurance limit. Such an approach is applicable in combination with the loads given in the EN 12663 series or EN 13749.

A fatigue strength assessment based on cumulative damage takes into consideration stress spectra with variable amplitudes and numbers of cycles or stress time histories. This document provides the basic procedure and criteria for a pragmatic method to be applied for fatigue strength assessments based on the cumulative damage approach.

This document does not provide any procedures or criteria for an endurance limit approach. However, the fatigue strength data included in this document can also be applicable for an endurance limit approach.

The main body of the document is based on the nominal stress approach, but the consideration of variable amplitudes and number of cycles using methods described in this standard may equally be applied with the structural stress and the notch stress approach (additional information for these assessment methods is included as informative annexes).

Within this document, the term fatigue strength assessment is always related to the cumulative damage approach unless otherwise noted.

1 Scope

This document describes a procedure for fatigue strength assessment based on cumulative damage of rail vehicle structures that are manufactured, operated and maintained in accordance with standards valid for rail system applications.

This document is applicable for variable amplitude load data with total number of cycles higher than 10 000 cycles.

An endurance limit approach is outside the scope of this document.

The assessment procedure is restricted to ferrous materials and aluminium.

This document does not define design load cases.

This document is not applicable for corrosive conditions or elevated temperature operation in the creep range.

This document is applicable to all kinds of rail vehicles; however, it does not define in which cases a fatigue strength assessment using cumulative damage is to be applied.

2 Normative references

3 Terms and definitions

4 Stress determination

4.1 General

4.2 Parent material

4.3 Welded joints

5 Fatigue strength

5.1 Parent material

5.2 Welded joints

5.3 Determination of the fatigue strength of parent material and welded joints by laboratory tests

6 Partial factors covering uncertainties

6.1 General

6.2 Partial factor for loads γ_L

6.3 Partial factor for the component fatigue strength γ_M

7 Procedure of the fatigue strength assessment based on cumulative damage calculation

7.1 General

7.2 Stress determination

7.3 Determination of the design stress spectrum

7.4 Damage calculation for each single stress component

7.5 Assessment of fatigue strength

7.6 Critical plane approach

Bibliography

BS EN 17149-3:2025

Railway applications. Strength assessment of rail vehicle structures - Fatigue strength assessment based on cumulative damage

Current

Published:

31 Jan 2025