EN 1993-1-14:2025

Eurocode 3 - Design of steel structures - Part 1-14: Design assisted by finite element analysis

1.1   Scope of prEN 1993-1-14
(1) This document gives principles and requirements for the use of numerical methods in the design of steel structures, more specifically for the ultimate limit state (including fatigue) and serviceability limit state verifications. It also gives principles and requirements for the application of advanced finite element (FE) and similar modelling techniques for numerical simulation which also covers safety assessment.
(2) This document covers general methodologies such as the finite element method (FEM), finite strip method (FSM) or generalized beam theory (GBT) for modelling, analysis and design of steel structures made of the following members and joint configurations:
a)   hot-rolled profiles,
b)   cold-formed members and sheeting,
c)   welded plated profiles,
d)   stainless steel profiles,
e)   plate assemblies,
f)   shell structures,
g)   welded and bolted joints.
In addition to the general design rules, specific additional rules can also be found in the relevant standard parts in EN 1993.
(3) This document contains harmonized design rules in terms of the application of the numerical modelling methods, development of the numerical models, application of analysis types, result evaluation methods, and determination of the resistance of steel structures for different limit states.
1.2   Assumptions
(1) This document gives rules intended for engineers who are experienced in the use of FE.
(2) It is recognized that structural analysis, based upon the laws of physics, has been successfully researched, developed, historically or currently used for the design and verification of elements or whole structural frames. This remains appropriate for many structural solutions. However, when a more detailed understanding of structural behaviour is required, the methods described in this document can be useful for the professional design.
(3) Unless specifically stated, EN 1990, EN 1991 (all parts) and the other relevant parts of EN 1993-1 (all subparts) apply.
(4) The design methods given in EN 1993-1-14 are applicable if
-   the execution quality is as specified in EN 1090-2 and/or EN 1090-4, and
-   the construction materials and products used are as specified in the relevant parts of EN 1993 (all parts), or in the relevant material and product specifications.

Eurocode 3 - Bemessung und Konstruktion von Stahlbauten - Teil 1-14: Bemessung mithilfe von Finite-Element-Berechnung

1.1   Anwendungsbereich von prEN 1993-1-14
(1)   Dieses Dokument enthält Grundsätze und Anforderungen für die Anwendung numerischer Verfahren bei der Bemessung von Stahlbauten, insbesondere für die Nachweise des Grenzzustands der Tragfähigkeit (einschließlich Ermüdung) und der Gebrauchstauglichkeit. Es enthält auch Grundsätze und Anforderungen für die Anwendung fortgeschrittener Finite-Elemente  (FE) und ähnlicher Modellierungsverfahren für die numerische Simulation, die auch die Sicherheitsbeurteilung abdeckt.
(2)   Dieses Dokument behandelt allgemeine Vorgehensweisen wie die Finite-Elemente-Methode (FEM), die Finite-Streifen-Methode (FSM) oder die verallgemeinerte technische Biegetheorie (GBT) für die Modellierung, die Berechnung und Bemessung von Stahlbauten, die aus den folgenden Bauteilen und Verbindungskonfigurationen bestehen:
a)   warmgewalzten Profilen;
b)   kaltgeformten Bauteilen und Blechen;
c)   geschweißten Blechquerschnitte;
d)   Profilen aus nichtrostendem Stahl;
e)   plattenförmigen Bauteilen;
f)   Schalen;
g)   geschweißten und geschraubten Verbindungen.
Neben den allgemeinen Bemessungsregeln finden sich in den entsprechenden Normteilen der EN 1993 auch spezifische Zusatzregeln.
(3)   Dieses Dokument enthält harmonisierte Bemessungsregeln in Bezug auf die Anwendung der numerischen Modellierungsverfahren, die Entwicklung der numerischen Modelle, die Anwendung von Berechnungstypen, die Verfahren zur Ergebnisbewertung und die Bestimmung des Widerstands von Stahlbauten für verschiedene Grenzzustände.
1.2   Annahmen
(1)   Dieses Dokument enthält Regeln für Ingenieure, die in der Anwendung von FE erfahren sind.
(2)   Es wird anerkannt, dass die auf den Gesetzen der Physik basierende Tragwerksberechnung erfolgreich für die Bemessung und den Nachweis von Elementen oder ganzen Tragwerken erforscht, entwickelt, historisch oder gegenwärtig verwendet wurde. Dies ist für viele strukturelle Lösungen nach wie vor angemessen. Wenn jedoch ein detaillierteres Verständnis des Tragverhaltens erforderlich ist, können die in diesem Dokument beschriebenen Verfahren für die professionelle Bemessung nützlich sein.
(3)   Sofern nicht ausdrücklich angegeben, gelten EN 1990, EN 1991 (alle Teile) und die anderen relevanten Teile von EN 1993-1.
(4)   Die in prEN 1993-1-14 angegebenen Bemessungsverfahren sind anwendbar, wenn
-   die Ausführungsqualität den Vorgaben von EN 1090-2 und/oder EN 1090-4 entspricht und
-   die verwendeten Werkstoffe und Bauprodukte den einschlägigen Teilen von EN 1993 oder den einschlägigen Werkstoff- und Produktspezifikationen entsprechen.

Eurocode 3 - Calcul des structures en acier - Partie 1-14 : Calcul assisté par des analyses par éléments finis

1.1   Domaine d'application de la norme prEN 1993-1-14
(1) Le présent document donne les principes et les exigences pour l'utilisation des méthodes numériques pour le calcul des structures en acier, plus particulièrement pour les vérifications à l'état limite ultime (y compris la fatigue) et à l'état limite de service. Il donne également les principes et les exigences pour l'application des méthodes avancées de calcul aux éléments finis et des techniques de modélisation similaires pour la simulation numérique qui couvre également l'évaluation de la sécurité.
(2) Le présent document couvre les méthodologies générales telles que la méthode des éléments finis (FEM), la méthode des bandes finies (FSM) ou la théorie généralisée des poutres (GBT) pour la modélisation, l'analyse et le calcul des structures en acier composées des éléments et des configurations d'assemblage suivants :
a)   profilés laminés à chaud,
b)   profilés et plaques formés à froid,
c)   profilés reconstitués soudés,
d)   profilés en acier inoxydable,
e)   assemblages de plaques,
f)   structures en coques,
g)    assemblages soudés et boulonnés.
En plus des règles générales de calcul, des règles supplémentaires spécifiques peuvent également être trouvées dans les parties pertinentes de la norme EN 1993.
(3) Ce document contient des règles de calcul harmonisées en termes d'application des méthodes de modélisation numérique, de développement des modèles numériques, d'application des types d'analyse, de méthodes d'évaluation des résultats et de détermination de la résistance des structures en acier pour différents états limites.
1.2   Hypothèses
(1) Ce document donne des règles destinées aux ingénieurs expérimentés dans l'utilisation de FE.
(2) Il est reconnu que l'analyse structurale, basée sur les lois de la physique, a été étudiée, développée, utilisée historiquement ou actuellement avec succès pour le calcul et la vérification d'éléments ou de ouvrages structuraux complets. Cette méthode reste appropriée pour de nombreuses solutions structurales. Cependant, lorsqu'une compréhension plus détaillée du comportement structural est nécessaire, les méthodes décrites dans le présent document peuvent être utiles pour le dimensionnement.
(3) Sauf mention spécifique, l'EN 1990, l'EN 1991 (toutes les parties) et les autres parties pertinentes de l'EN 1993-1 s'appliquent.
(4) Les méthodes de calcul indiquées dans la norme prEN 1993-1-14 sont applicables si
-   la qualité d'exécution est conforme aux spécifications des normes EN 1090-2 et/ou EN 1090-4, et
-   les    matériaux de construction et les produits utilisés sont conformes aux parties pertinentes de la norme EN 1993, ou aux spécifications des matériaux et des produits.

Evrokod 3 - Projektiranje jeklenih konstrukcij - 1-14. del: Projektiranje na osnovi analize s končnimi elementi

General Information

• Status: Published
• Publication Date: 07-Oct-2025
• ICS: 91.010.30 - Technical aspects
• ICS: 91.080.13 - Steel structures
• Technical Committee: CEN/TC 250 - Structural Eurocodes
• Drafting Committee: CEN/TC 250/SC 3/WG 22 - EN 1993-1-14 – Design assisted by FEM
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 08-Oct-2025
• Due Date: 08-Apr-2025
• Completion Date: 08-Oct-2025
• Mandate: M/015 - Mandate addressed to CEN and CENELEC in connection with the drawing-up of a standardization programme relating to the standards published under the Low Voltage Directive in relation to the machinery sector
• Ref Project: kSIST FprEN 1993-1-14:2025 - Eurocode 3 - Design of steel structures - Part 1-14: Design assisted by finite element analysis

Overview

EN 1993-1-14:2025 - Eurocode 3: Design of steel structures - Part 1-14: Design assisted by finite element analysis (CEN) sets principles and requirements for using numerical methods in the design and verification of steel structures. The standard covers finite element and similar modelling approaches for verifying the ultimate limit state (including fatigue) and serviceability limit state, and for performing numerical safety assessments and advanced simulations.

Key topics and technical requirements

• Scope of methods: Finite Element Method (FEM), Finite Strip Method (FSM) and Generalized Beam Theory (GBT) for modelling, analysis and design.
• Member and joint types covered: hot‑rolled sections, cold‑formed members and sheeting, welded plated profiles, stainless steel profiles, plate assemblies, shell structures, and welded/bolted joints.
• Design states: Rules for ultimate limit state (ULS), fatigue and serviceability limit state (SLS) verifications.
• Modelling essentials: geometric modelling, support and load models, material models, and explicit treatment of imperfections and imperfection combinations.
• Analysis types: structural and thermal analyses are addressed.
• Validation and verification: Procedures for model verification and validation, including documentation and requirements for demonstrating model fidelity.
• Result evaluation and resistance determination: Harmonized rules for applying analysis results to determine structural resistance for different limit states.
• Annexes and specialist topics: Informative annexes on model factors, stress concentrations and normative limits on maximum strains for beam finite elements.

Practical applications

This Eurocode part is intended where traditional hand calculations or simplified approaches are insufficient and numerical simulation improves understanding or safety assessment, for example:

• Local buckling and plate assembly behavior in complex cross‑sections
• Detailed joint modelling (welded and bolted) for fatigue-sensitive connections
• Shell structure analysis (tanks, silos, curved roofs)
• Cold-formed and stainless steel member behaviour under service loads
• Thermal‑structural interaction studies

Using the standard ensures consistent, harmonized methodologies when applying FE, FSM or GBT to real design tasks and regulatory submissions.

Users and benefits

• Structural designers and engineers experienced in FE methods
• Software developers and validators creating compliant modelling tools
• Researchers and forensic engineers performing safety assessments
• Authorities and clients seeking documented, verified design by numerical analysis

Benefits include clearer rules for modelling, consistent verification/validation expectations, and improved traceability of FE‑assisted design decisions.

Related standards

• EN 1990 (Basis of design), EN 1991 (Actions on structures), other parts of EN 1993
• Execution/product standards: EN 1090-2, EN 1090-4
• National Annexes may specify Nationally Determined Parameters (NDPs) and implementation details.

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 1993-1-14:2023
01-december-2023
Evrokod 3 - Projektiranje jeklenih konstrukcij - 1-14. del: Projektiranje z analizo
končnih elementov
Eurocode 3 - Design of steel structures - Part 1-14: Design assisted by finite element
analysis
Eurocode 3 - Bemessung und Konstruktion von Stahlbauten - Teil 1-14: Bemessung
mithilfe von Finite-Element-Berechnung
Eurocode 3 - Calcul des structures en acier - Partie 1-14 : Calcul assisté par des
analyses par éléments finis
Ta slovenski standard je istoveten z: prEN 1993-1-14
ICS:
91.010.30 Tehnični vidiki Technical aspects
91.080.13 Jeklene konstrukcije Steel structures
oSIST prEN 1993-1-14:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 1993-1-14:2023
oSIST prEN 1993-1-14:2023
DRAFT
EUROPEAN STANDARD
prEN 1993-1-14
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2023
ICS 91.010.30; 91.080.13
English Version
Eurocode 3 - Design of steel structures - Part 1-14: Design
assisted by finite element analysis
Eurocode 3 - Calcul des structures en acier - Partie 1- Eurocode 3 - Bemessung und Konstruktion von
14 : Calcul assisté par des analyses par éléments finis Stahlbauten - Teil 1-14: Bemessung mithilfe von Finite-
Element-Berechnung
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 250.
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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1993-1-14:2023 E
worldwide for CEN national Members.

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prEN 1993-1-14:2023 (E)
Contents Page
European foreword . 4
0 Introduction . 5
1 Scope . 8
1.1 Scope of prEN 1993-1-14 . 8
1.2 Assumptions . 8
2 Normative references . 9
3 Terms, definitions and symbols . 9
3.1 Terms and definitions . 9
3.2 Symbols and abbreviations . 11
4 Basis of design and modelling . 14
5 Modelling . 15
5.1 Geometrical models . 15
5.2 Support and load models . 17
5.3 Material models . 18
5.4 Imperfections . 24
5.5 Imperfection combinations . 31
6 Analysis . 32
6.1 Structural analysis . 32
6.2 Thermal analysis . 34
7 Validation and verification . 35
7.1 General. 35
7.2 Verification . 36
7.3 Validation . 37
8 Design methodology . 38
8.1 Ultimate limit state . 38
8.2 Fatigue limit state . 44
8.3 Serviceability limit state . 54
9 Documentation . 54
Annex A (informative) Calculation of model factor (γ ) . 55
FE
A.1 Use of this Annex . 55
A.2 Scope and field of application . 55
A.3 Calculation of model factor (γ ) . 55
FE
Annex B (informative)  Stress concentrations . 57
B.1 Use of this Annex . 57
B.2 Scope and field of application . 57
B.3 Separation of stress concentration and numerical singularities . 57
B.4 Consideration of stress concentration in design . 58
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Annex C (normative) Limits on maximum strains for beam finite elements . 60
C.1 Use of this Annex . 60
C.2 Scope and field of application . 60
C.3 Strain limits . 60
Bibliography . 64

oSIST prEN 1993-1-14:2023
prEN 1993-1-14:2023 (E)
European foreword
This document (prEN 1993-1-14:2023) has been prepared by Technical Committee CEN/TC 250
“Structural Eurocodes”, the secretariat of which is held by BSI. CEN/TC 250 is responsible for all
Structural Eurocodes and has been assigned responsibility for structural and geotechnical matters by
CEN.
This document is currently submitted to the CEN Enquiry.
The first generation of EN Eurocodes was published between 2002 and 2007. This document forms part
of the second generation of the Eurocodes, which have been prepared under Mandate M/515 issued to
CEN by the European Commission and the European Free Trade Association.
The Eurocodes have been drafted to be used in conjunction with relevant execution, material, product
and test standards, and to identify requirements for execution, materials, products and testing that are
relied upon by the Eurocodes.
The Eurocodes recognize the responsibility of each Member State and have safeguarded their right to
determine values related to regulatory safety matters at national level through the use of National
Annexes.
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prEN 1993-1-14:2023 (E)
0 Introduction
0.1 Introduction to the Eurocodes
The Structural Eurocodes comprise the following standards generally consisting of a number of Parts:
— EN 1990, Eurocode: Basis of structural and geotechnical design
— EN 1991, Eurocode 1: Actions on structures
— EN 1992, Eurocode 2: Design of concrete structures
— EN 1993, Eurocode 3: Design of steel structures
— EN 1994, Eurocode 4: Design of composite steel and concrete structures
— EN 1995, Eurocode 5: Design of timber structures
— EN 1996, Eurocode 6: Design of masonry structures
— EN 1997, Eurocode 7: Geotechnical design
— EN 1998, Eurocode 8: Design of structures for earthquake resistance
— EN 1999, Eurocode 9: Design of aluminium structures
— New parts are under development, e.g. Eurocode for design of structural glass
The Eurocodes are intended for use by designers, clients, manufacturers, constructors, relevant
authorities (in exercising their duties in accordance with national or international regulations),
educators, soft-ware developers, and committees drafting standards for related product, testing and
execution standards.
NOTE Some aspects of design are most appropriately specified by relevant authorities or, where not
specified, can be agreed on a project-specific basis between relevant parties such as designers and clients. The
Eurocodes identify such aspects making explicit reference to relevant authorities and relevant parties.
0.2 Introduction to EN 1993 (all parts)
EN 1993 (all parts) applies to the design of buildings and civil engineering works in steel. It complies
with the principles and requirements for the safety and serviceability of structures, the basis of their
design and verification that are given in EN 1990 – Basis of structural and geotechnical design.
EN 1993 (all parts) is concerned only with requirements for resistance, serviceability, durability and
fire resistance of steel structures. Other requirements, e.g. concerning thermal or sound insulation, are
not covered.
EN 1993 is subdivided in various parts:
— EN 1993-1, Design of steel structures – Part 1: General rules and rules for buildings
— EN 1993-2, Design of steel structures – Part 2: Bridges
— EN 1993-3, Design of steel structures – Part 3: Towers, masts and chimneys
— EN 1993-4, Design of steel structures – Part 4: Silos and tanks
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prEN 1993-1-14:2023 (E)
— EN 1993-5, Design of steel structures – Part 5: Piling
— EN 1993-6, Design of steel structures – Part 6: Crane supporting structures
— EN 1993-7, Design of steel structures – Part 7: Sandwich panels (under preparation).
EN 1993-1 in itself does not exist as a physical document, but comprises the following 14 separate
parts, the basic part being EN 1993-1-1:
— EN 1993-1-1, Design of steel structures – Part 1-1: General rules and rules for buildings
— EN 1993-1-2, Design of steel structures – Part 1-2: Structural fire design
— EN 1993-1-3, Design of steel structures – Part 1-3: Cold-formed members and sheeting
NOTE Cold-formed hollow sections supplied according to EN 10219 are covered in EN 1993-1-1.
— EN 1993-1-4, Design of steel structures – Part 1-4: Stainless steel structures
— EN 1993-1-5, Design of steel structures – Part 1-5: Plated structural elements
— EN 1993-1-6, Design of steel structures – Part 1-6: Strength and stability of shell structures
— EN 1993-1-7, Design of steel structures – Part 1-7: Plate assemblies with elements under transverse
loads
— EN 1993-1-8, Design of steel structures – Part 1-8: Joints
— EN 1993-1-9, Design of steel structures – Part 1-9: Fatigue
— EN 1993-1-10, Design of steel structures – Part 1-10: Material toughness and through-thickness
properties
— EN 1993-1-11, Design of steel structures – Part 1-11: Tension components
— EN 1993-1-12, Design of steel structures – Part 1-12: Additional rules for steel grades up to S960
— EN 1993-1-13, Design of steel structures – Part 1-13: Beams with large web openings
— EN 1993-1-14, Design of steel structures – Part 1-14: Design assisted by finite element analysis
All parts numbered EN 1993-1-2 to EN 1993-1-14 treat general topics that are independent from the
structural type such as structural fire design, cold-formed members and sheeting, stainless steels,
plated structural elements, etc.
All parts numbered EN 1993-2 to EN 1993-7 treat topics relevant for a specific structural type such as
steel bridges, towers, masts and chimneys, silos and tanks, piling, crane supporting structures, etc.
EN 1993-2 to EN 1993-7 refer to the generic rules in EN 1993-1 and supplement, modify or supersede
them.
0.3 Introduction to prEN 1993-1-14
prEN 1993-1-14 gives principles and requirements for the use of numerical methods in the design of
steel structures, more specifically for the ultimate limit state (including fatigue) and serviceability limit
state verifications. It also gives principles and requirements for the application of advanced finite
element and similar modelling techniques for research purposes, which may also be used in design
processes.
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prEN 1993-1-14:2023 (E)
0.4 Verbal forms used in the Eurocodes
The verb “shall" expresses a requirement strictly to be followed and from which no deviation is
permitted in order to comply with the Eurocodes.
The verb “should” expresses a highly recommended choice or course of action. Subject to national
regulation and/or any relevant contractual provisions, alternative approaches could be used/adopted
where technically justified.
The verb “may" expresses a course of action permissible within the limits of the Eurocodes.
The verb “can" expresses possibility and capability; it is used for statements of fact and clarification of
concepts.
0.5 National Annex for prEN 1993-1-14
National choice is allowed in this standard where explicitly stated within notes. National choice includes
the selection of values for Nationally Determined Parameters (NDPs).
The national standard implementing prEN 1993-1-14 can have a National Annex containing all national
choices to be used for the design of buildings and civil engineering works to be constructed in the
relevant country.
When no national choice is given, the default choice given in this standard is to be used.
When no national choice is made and no default is given in this standard, the choice can be specified by
a relevant authority or, where not specified, agreed for a specific project by appropriate parties.
National choice is allowed in prEN 1993-1-14 through notes to the following clauses:
4(11) 4(15) 5.4.2(1) 7.1(2)
7.2(2) 7.3(1) 7.3(3) 7.3(6)
8.1.2(3) 8.1.2(5) 8.1.5(2) 8.1.5(3)
C.3(1)
National choice is allowed in prEN 1993-1-14 on the application of the following informative annexes:
Annex A Annex B
The National Annex can contain, directly or by reference, non-contradictory complementary
information for ease of implementation, provided it does not alter any provisions of the Eurocodes.
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prEN 1993-1-14:2023 (E)
1 Scope
1.1 Scope of prEN 1993-1-14
(1) This document gives principles and requirements for the use of numerical methods in the design of
steel structures, more specifically for the ultimate limit state (including fatigue) and serviceability limit
state verifications. It also gives principles and requirements for the application of advanced finite
element (FE) and similar modelling techniques for numerical simulation which also covers safety
assessment.
(2) This document covers general methodologies such as the finite element method (FEM), finite strip
method (FSM) or generalized beam theory (GBT) for modelling, analysis and design of steel structures
made of the following members and joint configurations:
a) hot-rolled profiles,
b) cold-formed members and sheeting,
c) welded plated profiles,
d) stainless steel profiles,
e) plate assemblies,
f) shell structures,
g) welded and bolted joints.
In addition to the general design rules, specific additional rules can also be found in the relevant
standard parts in EN 1993.
(3) This document contains harmonized design rules in terms of the application of the numerical
modelling methods, development of the numerical models, application of analysis types, result
evaluation methods, and determination of the resistance of steel structures for different limit states.
1.2 Assumptions
(1) This document gives rules intended for engineers who are experienced in the use of FE.
(2) It is recognized that structural analysis, based upon the laws of physics, has been successfully
researched, developed, historically or currently used for the design and verification of elements or
whole structural frames. This remains appropriate for many structural solutions. However, when a
more detailed understanding of structural behaviour is required, the methods described in this
document can be useful for the professional design.
(3) Unless specifically stated, EN 1990, EN 1991 (all parts) and the other relevant parts of EN 1993-1
apply.
(4) The design methods given in prEN 1993-1-14 are applicable if
— the execution quality is as specified in EN 1090-2 and/or EN 1090-4, and
— the construction materials and products used are as specified in the relevant parts of EN 1993, or in
the relevant material and product specifications.
oSIST prEN 1993-1-14:2023
prEN 1993-1-14:2023 (E)
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.
NOTE See the Bibliography for a list of other documents cited that are not normative references, including those
referenced as recommendations (i.e. through ‘should’ clauses) and permissions (i.e. through ‘may’ clauses).
EN 1090-2, Execution of steel structures and aluminium structures - Part 2: Technical requirements for
steel structures
EN 1090-4, Execution of steel structures and aluminium structures - Part 4: Technical requirements for
cold-formed structural steel elements and cold-formed structures for roof, ceiling, floor and wall
applications
EN 1990:2023, Eurocode - Basis of structural and geotechnical design
EN 1991 (all parts), Eurocode 1 - Actions on structures
EN 1993 (all parts), Eurocode 3 - Design of steel structures
3 Terms, definitions and symbols
For the purposes of this document, the following terms, definitions and symbols apply.
3.1 Terms and definitions
3.1.1
analysis requiring subsequent design check
analysis (e.g. LA, LBA, GNA, GNIA, MNA) performed for design checks, which results are different system
response quantities to be further used in the static check of the analysed structure
3.1.2
benchmark case
offers the inputs and outputs of the analytical or numerical solutions to verify the results by comparison
on simplified model, or experimental tests used to check the quality of the numerical model to be
validated
3.1.3
degree of freedom
DOF
number of independent motions that are allowed to the structure
Note 1 to entry: DOF can be defined as DOF per node (1 to 7 – maximum 3 translational, 3 rotational and
warping) and total number of DOFs for the whole structure as sum of all node's DOFs.
3.1.4
direct resistance check
analysis (e.g. MNA, GMNA, GMNIA) performed for design checks, which result is the ultimate resistance
of the analysed structure
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3.1.5
follower load
load changing direction as a function of the deformation of the analysed structure in a non-linear
analysis
3.1.6
global analysis
structural analysis of the complete structure or part of the structure under investigation, rather than
individual structural members or components treated separately
3.1.7
numerical model
numerical idealization to simulate and predict aspects of behaviour of a system used to represent the
structural behaviour of the analysed structure or a part of it
3.1.8
multi-level or combined model
modelling of the entire structure using different types of elements (e.g. coupling of beam, plate, shell or
solid elements) within one model, making the DOFs compatible at the intersection regions
3.1.9
numerical design calculation
numerical model and analysis type used for the static design check of a structure or a part of it
Note 1 to entry: Results of the numerical model can be (i) different system response quantities (SRQs) to be used
for further evaluation or (ii) resistances to be used for direct resistance check.
3.1.10
numerical simulation
complementation or extension of physical experiments to determine the direct resistance of a structure
3.1.11
second order analysis
geometrically non-linear analysis based on second order approximations (geometric stiffness or stress
stiffening approach)
3.1.12
standard design case
numerical model-based design check of failure modes for which Eurocode based design resistance
model also exists
3.1.13
sub-model
part of the entire structure modelled using equivalent support conditions representing the neglected
part of the structure
3.1.14
system response quantity
SRQ
relevant output value resulting from a certain analysis; it reflects the main objective of the analysis by
selecting the major parameters and the limitation of their errors in both validation and verification
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3.1.15
validation
comparison of the numerical solution and the experimental behaviour (or known accurate solutions)
3.1.16
verification
comparison of the numerical solutions and accurate analytical or numerical results
3.2 Symbols and abbreviations
3.2.1 Latin upper-case symbols
A elongation after fracture defined in the relevant material specification
C C material coefficient for hot-rolled steels
1, 2
E modulus of elasticity
E , E , E strain hardening modulus of the stress-strain curve for cold-formed structures covered
1 2 3
by prEN 1993-1-3
E tangent modulus of the stress-strain curve at the yield strength for cold-formed steel and
0.2
stainless steels
E strain hardening modulus for hot-rolled steels
sh
H total section depth of welded box-sections
L member length
L , L limits of the extrapolation region for tubular joints in fatigue design situation
r,min r,max
R structural resistance computed by the numerical model
comp
Rb,d design buckling resistance
R characteristic buckling resistance
b,k
R computed resistance for the check structural resistance case
check
R lowest elastic critical bifurcation load of the examined structure
cr
R calculated plastic resistances based on GMNA analysis
GMNA
R calculated buckling resistances based on GMNIA analysis
GMNIA
R calculated or known characteristic structural resistance
k,known
R known test result
test,known
R calculated plastic resistance based on MNA analysis
MNA
R plastic resistance of the examined structure or cross-section
pl
R design plastic resistance of the examined structure
pl,d
R characteristic plastic resistance of the examined structure
pl,k
V coefficient of variation of the ratio of the measured (or known) and computed results
X
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V design value of the shear force
Ed
V design value of the plastic resistance to shear force
pl,Rd
3.2.2 Latin lower-case symbols
a length of a panel or sub-panel
b width of a panel or sub-panel
b flange width
f
a , b , c , geometrical parameters of the residual stress patterns
rs rs rs
d , e , f , g ,
rs rs rs rs
h
rs
e amplitude of the equivalent geometric imperfection
e imperfection magnitude for distortional buckling mode
0,dist
f ultimate tensile strength
u
f yield stress
y
f basic yield strength of cold-formed steel
yb
h web depth
w
k characteristic fractile factor
n
m second strain hardening exponent for the Ramberg-Osgood type material model cold-
formed steel and stainless steels
m mean value of the ratio of the measured (or known) and computed results
X
n material coefficient for the Ramberg-Osgood type material model for cold-formed steel
and stainless steels
r radius of notch in fatigue design situation
t plate thickness
t web thickness
w
t chord member wall thickness in tubular joints
t brace member wall thickness in tubular joints
3.2.3 Greek upper-case symbols
Θ flank angle of the weld model in fatigue design situation
Ω project specific parameter that defines the maximum permissible level of plastic strain in
the structure
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3.2.4 Greek lower-case symbols
𝛼𝛼 imperfection factor
𝛼𝛼 minimum load amplifier of the design loads to reach the characteristic resistance of the
ult,k
most critical cross-section
𝛽𝛽 reference relative bow imperfection for lateral torsional buckling
LT
ε strain
ε total strain at 0,2 % proof stress for the Ramberg-Osgood type material model cold-formed
0,2
steel and stainless steels
ε total strain at 1 % proof stress for the Ramberg-Osgood type material model cold-formed
1,0
steel and stainless steels
ε maximum allowed plastic strain based on continuous strength method
csm
ε design value of the maximum longitudinal compressive strain
Ed
ε maximum plastic strain for bolts
mb
ε maximum allowed plastic strain for bolts
mpb
ε strain hardening strain for hot-rolled steels
sh
ε true-strain
true
ε ultimate strain
u
ε yield strain
y
relative slenderness
λ
𝜎𝜎 stress
𝜎𝜎 0,05 % proof stress for the Ramberg-Osgood type material model cold-formed steel and
0,05
stainless steels
𝜎𝜎 1 % proof stress for the Ramberg-Osgood type material model cold-formed steel and
1,0
stainless steels
𝜎𝜎 calculated stress change in a distance of 0,4·t from the weld toe in fatigue design situation
0,4t
𝜎𝜎 calculated stress change in a distance of 0,5·t from the weld toe in fatigue design situation
0,5t
𝜎𝜎 calculated stress change in a distance of 0,9·t from the weld toe in fatigue design situation
0,9t
𝜎𝜎 calculated stress change in a distance of 1,0·t from the weld toe in fatigue design situation
1,0t
𝜎𝜎 calculated stress change in a distance of 1,5·t from the weld toe in fatigue design situation
1,5t
𝜎𝜎 calculated stress change in a distance of 4 mm from the weld toe in fatigue design situation
4mm
𝜎𝜎 calculated stress change in a distance of 5 mm from the weld toe in fatigue design situation
5mm
𝜎𝜎 calculated stress change in a distance of 8 mm from the weld toe in fatigue design situation
8mm
𝜎𝜎 calculated stress change in a distance of 12 mm from the weld toe in fatigue design
12mm
situation
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𝜎𝜎 calculated stress change in a distance of 15 mm from the weld toe in fatigue design
15mm
situation
𝜎𝜎 tensile residual stress
rt
𝜎𝜎 compressive residual stress
rc
𝜎𝜎 , 𝜎𝜎 tensile residual stress of stainless steel welded or laser welded I-sections and welded box
ft wt
sections
𝜎𝜎 , 𝜎𝜎 compressive residual stress of stainless steel welded or laser welded I-sections and
fc wc
welded box sections
𝜎𝜎 elastic local critical bifurcation stress of the full cross-section
cr,cs
𝜎𝜎 elastic critical distortional bifurcation stress
cr,d
𝜎𝜎 nominal stress in fatigue design situation
nom
𝜎𝜎 geometric (hot spot) stress in fatigue design situation
HS
𝜎𝜎 effective notch stress in fatigue design situation
EN
𝜎𝜎 true-stress
true
𝜌𝜌 reduction factor to determine the design value of the reduced plastic resistance to bending
moment making allowance for the presence of shear forces
𝜌𝜌 reduction factor for the maximum allowed strain limit in beam elements considering
csm
interaction between bending and shear
𝛾𝛾 model factor covering the uncertainties of the numerical model and the executed analysis
FE
type
4 Basis of design and modelling
(1) The basis of design with numerical methods shall be in accordance with the general rules given in
EN 1990 and EN 1991 (all parts) and the specific design provisions for steel structures given in the
relevant parts of EN 1993-1 (all parts).
(2) Steel structures designed according to this document shall be executed according to EN 1090-2
and/or EN 1090-4 with construction materials and products used as specified in the relevant parts of
EN 1993, or in the relevant material and product specifications.
(3) Dynamic effect should be taken into account according to the relevant application part of EN 1993
(all parts). This document does not contain rules for dynamic analysis.
(4) This document gives design rules for the
a) ultimate limit state design (excluding fatigue),
b) fatigue design situation,
c) serviceability limit state design.
(5) Finite element analysis-based design may be executed by one of the following two methods, which
should be recognised as different and treated differently in the design process:
a) numerical design calculation,
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b) numerical simulation.
(6) The design methods differ regarding the (i) applied geometrical and material properties, (ii) results
of the analysis, (iii) validation and verification process, (iv) further evaluation method of output data
and (v) reliability assessment of the calculation results.
(7) Numerical design calculations may be different based on the analysis type and results; design rules
are given based on the following two categories:
a) analysis requiring subsequent design check,
b) direct resistance check.
(8) In the case of analysis requiring subsequent design check one of the following analysis methods
should be used: LA, LBA, GNA, GNIA, MNA. The results of the analysis are different system response
quantities which are to be further used in the design check of the analysed structure.
(9) In the case of direct resistance check one of the following analysis methods should be used: MNA,
GMNA, GMNIA. The result of the analysis is the ultimate resistance of the analysed structure,
determined according to 8.1.5.
(10) In the case of numerical design calculations, nominal values should be used for the geometrical
and stiffness parameters, e.g. Young’s modulus. Strength parameters, e.g. material properties, are taken
as nominal values from the product standards, which represent fractile values.
(11) Numerical simulations may be applied to complement or extend laboratory tests used in test-
based design.
NOTE The National Annex can give further rules and limitation on the application of numerical simulation.
(12) In the case of numerical simulations, measured (or mean) values should be used for geometrical
and material properties. The result of the analysis is the resistance of the analysed structure.
(13) Application of finite element analysis-based design methods should not bring significant resistance
increases compared to well-established traditional design methods, unless shown to be reasonable
through validation and verification of the employed finite element model according to Clause 7 covering
all relevant failure modes.
(14) The rules of prEN 1993-1-14 are independent of the software used. However, the capabilities of
the chosen software should be checked by the designer and it should be confirmed that the software is
applicable for the limit state check being used (see Clause 8).
(15) To ensure design quality, the applicability of the design using numerical methods should be linked
to design qualification and experience levels (DQLs).
NOTE Minimum appropriate qualifications and experience of personnel designing structures using numerical
models can be defined in the National Annex based on EN 1990:2023, Table B.1.
5 Modelling
5.1 Geometrical models
5.1.1 General rules for geometrical modelling and discretization
(1) The chosen finite element (linear or higher order element) shall be related to the chosen mesh
density, geometry complexity (curvature) and the solution method to ensure that the results meet both
the validation and verification requirements.
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(2) The discretization of the chosen model should be adequate and it should follow the geometrical
properties of the structure. A finer mesh may be used in zones where large gradients of stresses, strains
or temperatures are expected. Element shape properties should be of suitable quality to ensure
accuracy (element aspect ratio, jacobian ratio, warping factor, etc.).
(3) At locations with high stress or strain concentrations or at the location where failure of the
structure is anticipated, mesh refinement should be used to ensure the required accuracy, except for
fatigue verification which applies predefined mesh refinements according to 8.2.
(4) The accuracy of the chosen FE mesh (density, chosen element types) should be proven by model
verification according to Clause 7.
(5) Cold-formed steel cross-sections should be modelled with rounded corners, unless their effect is not
relevant according to prEN 1993-1-3.
(6) Where FE analysis is used in support of design calculations for the joints of cold-formed structures
covered by prEN 1993-1-3, the joint FE model should be validated by test results or verified against
appropriate design rules.
(7) Element types (such as truss or cable elements, etc.) not covered by the following clauses may also
be applied in the numerical model taking special care on their modelling specialties.
(8) A geometrically non-linear global analysis of beam structures (see 6.1.2) may normally be based on
second order theory.
NOTE As a general rule, the accuracy of calculations according to second order theory is sufficient for global
analysis of frame structures. In exceptional cases, more accurate geometrically non-linear calculations are
required, if the displacements are large enough to significantly change the stress resultants in the structure.
(9) The degrees of freedom (DOFs) of the chosen element should be made compatible within the
modelled structure and with the chosen boundary conditions.
5.1.2 Models using beam elements
(1) The system axis of the beam model should be identical to that of the centroid of the cross-sections,
or it should be chosen such that the effects of its displacement from the centroid of the cross-sections
are sufficiently small to ignore.
(2) If the system axis differs from the centroid line (or if shear and gravity centres differ and are
relevant in the calculation), either eccentricities should be included in the interpretation, or internal
force adjustment should be made by the numerical analysis.
(3) When using a beam model, the behaviour of the joints between the beam structural members should
be considered. The assumed stiffness (hinged joint, continuous joint, semi-rigid joint) should be
determined according to EN 1993-1-8.
(4) If torsion and/or stability problems involving torsion (e.g. lateral torsional buckling, torsional
buckling, torsional-flexural buckling, etc.) are being studied using beam models, the used elements
should be capable of capturing torsion-related warping effects (for example elements using 7 DOFs - 3
translational, 3 rotational and warping).
(5) Beam elements should include shear effects if relevant.
(6) Strain limits to determine the point at which cross-section failure occurs are given in Annex C.
NOTE The calculation of elastic critical loads (for lateral torsional buckling) for members of varying height can
require the use of specific beam elements.
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5.1.3 Models using plate or shell elements
(1) The middle surface of a plate or shell may be taken as the reference surface for modelling. Care
should be taken that the effects of eccentricities and offsets from mid-surfaces are properly included in
the model and that they realistically represent the structural behaviour of the modelled structure.
(2) Eccentricities and steps in the middle surface should be included in the model, if they induce
significant bending effects caused by the membrane stress resultants following an eccentric path.
(3) For the modelling of 3D surface bodies (plated, cold-formed and shell structures) shell elements
should be used having 5 or 6 DOFs at each node. The chosen elements should be able to model thin or
moderately-thick shells. Special shell elements with different DOFs may be used in specific shell
problems (e.g. shells of revolution, cylindrical, conical or spherical shells, etc.).
(4) Additional requirements modelling shell structures are given in prEN 1993-1-6.
(5) Care should be taken at zones where higher through thickness shear stresses occur.
5.1.4 Models using solid elements
(1) For the modelling of solid bodies loaded by either in-plane loads or loads perpendicular to their
plane, plane elements with 2 or 3 DOFs (only translational) at each node may be used for meshing (e.g.
plane stress/strain or axisymmetric problems).
NOTE Solid elements usually have 3 DOFs (only translational) at each node. Special care is needed to the
application of loads and supports defined in a compatible way with these three DOFs (i.e. bending moments and
rotational loads cannot be applied).
(2) The chosen mesh should be continuous at the intersection points, in the joint regions and at the
location of thickness changes.
(3) In solid models, bolts can be modelled by using the shank area with their nominal cross-section for
sufficiently accurate consideration of the stiffness of the bolt. Where stress checks on the shank or the
threaded area of the bolt are to be made, appropriate modifications should be made (e.g. the bolt
diameter corresponding to the stress area of the bolt may be used).
5.1.5 Multi-level and combined models
(1) In multi-level or combined models, continuous load, displacement and rotation transfer should be
provided at the interfaces between the different modelled parts.
(2) If different levels of modelling are used and different structural elements are connected, their
eccentricities should be included within the model.
(3) In multi-level or combined models, contact elements or other interface elements may be used to
couple the different model parts. The different DOFs of the different elements should be made
compatible as well as the discretization of different parts.
(4) Effects acting on the sub-model should be identical to the effects of the relevant modelled part
within the entire structure.
5.2 Support and load models
5.2.1 Definition of supports
(1) The support conditions in the numerical model should be chosen to reflect in a realistic or
conservative manner the behaviour of the physical supports in the real structure.
(2) Where sub-modelling is used, the chosen supports should be in compliance with the supporting
effect of the adjacent components of the global model. The chosen supports should consider the
stiffness properties and the deformation capacity of the adjacent structural components.
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(3) If concentrated or point supports are used in plate, shell or solid models, numerical stress
concentrations may occur near the supports, which should be investigated. Recommendations are given
in Annex B.
(4) Special care should be given to the definition of supports in non-linear analyses (specially in case of
plate, shell and solid elements) to avoid undesired clamping effects.
NOTE Supports that act as pinned supports in a linear analysis can produce undesired stiffening effects in a non-
linear analysis.
(5) Special boundary conditions for shell structures are given in prEN 1993-1-6.
(6) If a member of open section is subject to torsional rotations resulting from instability or applied
loads (e.g. cold-formed structures covered by prEN 1993-1-3), special care should be taken with the
warping conditions of the supports and joints.
(7) Care should be taken if symmetry conditions are applied and symmetry plane passes through
supports or loads.
NOTE Symmetry can only be used where the expected structural behaviour (failure mode, buckling mode,
deformed shape, loading and supporting conditions, etc.) has been verified to be symmetrical.
(8) In axisymmetric shells, the use of symmetry in one segment (cake slice) of the structure may be
effective. However, care should be taken to ensure that unsymmetrical buckling modes crossing the
symmetry plane are not critical. For further information, see
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