SIST EN 1999-1-5:2023/oprA1:2026
(Amendment)Eurocode 9 - Design of aluminium structures - Part 1-5: Shell structures
- Abstract
1.1 Scope of EN 1999-1-5
(1) EN 1999-1-5 applies to the structural design of aluminium structures, stiffened and unstiffened, that have the form of a shell of revolution or of a round panel in monocoque structures.
(2) EN 1999-1-5 covers additional provisions to those given in the relevant parts of EN 1999 for design of aluminium structures.
NOTE Supplementary information for certain types of shells is given in EN 1993-1-6 and the relevant application parts of EN 1993 which include:
- Part 3-1 for towers and masts;
- Part 3-2 for chimneys;
- Part 4-1 for silos;
- Part 4-2 for tanks;
- Part 4-3 for pipelines.
(4) The provisions in EN 1999-1-5 apply to axisymmetric shells (cylinders, cones, spheres) and associated circular or annular plates, beam section rings and stringer stiffeners, where they form part of the complete structure.
(5) Single shell panels (cylindrical, conical or spherical) are not explicitly covered by EN 1999-1-5. However, the provisions can be applicable if the appropriate boundary conditions are duly taken into account.
(6) Types of shell walls covered in EN 1999-1-5 can be (see Figure 1.1):
- shell wall constructed from flat rolled sheet with adjacent plates connected with butt welds, termed “isotropic”;
- shell wall with lap joints formed by connecting adjacent plates with overlapping sections, termed “lap-jointed”;
- shell wall with stiffeners attached to the outside, termed “externally stiffened” irrespective of the spacing of stiffeners;
- shell wall with the corrugations running up the meridian, termed “axially corrugated”;
- shell wall constructed from corrugated sheets with the corrugations running around the shell circumference, termed “circumferentially corrugated”.
[Figure 1.1 - Illustration of cylindrical shell form]
(7) The provisions of EN 1999-1-5 are intended to be applied within the temperature range defined in EN 1999-1-1. The maximum temperature is restricted so that the influence of creep can be neglected. For structures subject to elevated temperatures associated with fire, see EN 1999-1-2.
(8) EN 1999-1-5 does not cover the aspect of leakage.
1.2 Assumptions
(1) The general assumptions of EN 1990 apply.
(2) The provisions of EN 1999-1-1 apply.
(3) The design procedures are valid only when the requirements for execution in EN 1090-3 or other equivalent requirements are complied with.
(4) EN 1999 is intended to be used in conjunction with:
- European Standards for construction products relevant for aluminium structures;
- EN 1090-1, Execution of steel structures and aluminium structures - Part 1: Requirements for conformity assessment of structural components;
- EN 1090-3, Execution of steel structures and aluminium structures - Part 3: Technical requirements for aluminium structures.
- Status
- Not Published
- Public Enquiry End Date
- 28-May-2026
- Technical Committee
- KON - Structures
- Current Stage
- 4020 - Public enquire (PE) (Adopted Project)
- Start Date
- 30-Mar-2026
- Due Date
- 17-Aug-2026
SIST EN 1999-1-5:2023/oprA1:2026 is a CEN draft amendment to Eurocode 9, Part 1-5, for the design of aluminium shell structures. It updates the shell-structure rules used for stiffened and unstiffened aluminium shells, mainly by aligning references and revising buckling-related clauses and Annex A parameters. If approved, it will amend EN 1999-1-5:2023.
What does SIST EN 1999-1-5:2023/oprA1:2026 specify?
SIST EN 1999-1-5:2023/oprA1:2026 specifies changes to the Eurocode 9 rules for aluminium shell structures. The underlying standard applies to shells of revolution and round panels in monocoque structures, with additional provisions for aluminium design beyond the general parts of EN 1999.
The scope text covered by this amendment includes axisymmetric shells such as cylinders, cones and spheres, together with associated circular or annular plates, beam section rings and stringer stiffeners when they are part of the complete structure. It also distinguishes common shell wall forms used in practice:
- isotropic
- lap-jointed
- externally stiffened
- axially corrugated
- circumferentially corrugated
The scope also points users to the temperature range in EN 1999-1-1, notes that creep is neglected at the permitted maximum temperature, and directs fire design to EN 1999-1-2. Leakage is outside the scope. The amendment itself is organized as a foreword plus eight modification items covering the whole document, the Introduction, Clause 1, Clause 2, Clause 8.2.4.4, and Annex A.
What are the key requirements of SIST EN 1999-1-5:2023/oprA1:2026?
SIST EN 1999-1-5:2023/oprA1:2026 mainly updates references and the buckling-related calculation framework. For a designer, the practical effect is that the document now points more precisely to the companion Eurocodes and to the annex parameters used in shell buckling checks.
1. Whole-document references are aligned
The amendment replaces references to EN 1990 with EN 1990-1, and updates references to EN 1999-1-1, EN 1999-1-2, EN 1999-1-3 and EN 1999-1-4 to their +A1:2026 versions. In practice, users need to verify that they are working from the same edition family across the full aluminium Eurocode set.
2. The Introduction is brought in line with the second-generation Eurocodes
The Introduction now lists the Eurocode family and states that EN 1999, for new structures, is intended for direct application with EN 1990-1 and the other Eurocodes. This matters because shell design is not used in isolation - actions, geotechnical basis, and the other material Eurocodes remain part of the design package.
3. Scope assumptions and execution remain tied to the Eurocode system
The scope and assumptions still rely on the general assumptions of EN 1990 and the rules of EN 1999-1-1, and they require execution to EN 1090-3 or equivalent requirements. In practice, the design method depends on proper fabrication and conformity control, not only on calculation.
4. Clause 2 updates the basis document for normative references
Clause 2 now points to EN 1990-1 as the basis document. That gives a clear reference for load combinations and the structural design framework used with this part.
5. Buckling resistance of unstiffened welded shells is updated
Clause 8.2.4.4 replaces Table 8.5 with Table 8.1 for the load-case factors used in the buckling resistance check of unstiffened welded shells. The table distinguishes load cases, tolerance classes and material classes. In practice, designers must choose the correct shell case and class before checking stability.
6. Annex A buckling parameters are made more explicit
Annex A updates the meridional, circumferential and shear buckling parameter clauses so that the alloy factor and slenderness parameter are explicitly included in the symbol definitions. This helps keep the calculation trail consistent when the annex is used for buckling assessment.
What terms does SIST EN 1999-1-5:2023/oprA1:2026 define?
- Shell of revolution - A shell with a rotationally symmetric form, such as a cylinder, cone or sphere.
- Monocoque structure - A structure in which the shell itself carries the main loads.
- Axisymmetric shells - Shells with circular symmetry about an axis; the document explicitly includes cylinders, cones and spheres.
- Externally stiffened - A shell wall with stiffeners attached on the outside, regardless of stiffener spacing.
- Lap-jointed - A shell wall formed by overlapping adjacent plates and joining them with lap joints.
- Buckling resistance - The design resistance used to check stability of the shell under compression, torsion or shear.
- Meridional buckling parameter - A parameter used in Annex A for buckling behaviour along the shell meridian.
- Circumferential buckling parameter - A parameter used in Annex A for buckling behaviour around the shell circumference.
Who uses SIST EN 1999-1-5:2023/oprA1:2026?
SIST EN 1999-1-5:2023/oprA1:2026 is used by structural engineers, aluminium design offices, checking authorities, fabricators and execution teams working on shell structures. It is also relevant to quality managers and conformity-assessment bodies involved in EN 1090-3 execution control. Buyers and specifiers use it when they need the design basis for aluminium shells in industrial, civil or infrastructure work.
What changed in SIST EN 1999-1-5:2023/oprA1:2026 from the previous edition?
SIST EN 1999-1-5:2023/oprA1:2026 will amend EN 1999-1-5:2023. The changes stated in the draft are:
- replacement of EN 1990 references with EN 1990-1
- replacement of references to EN 1999-1-1, -1-2, -1-3 and -1-4 with their +A1:2026 versions
- revision of the Introduction to list the Eurocode family and add the direct-application statement with EN 1990-1
- deletion of paragraph (4) in Clause 1.2
- update of the normative reference to EN 1990-1
- revision of the buckling table in 8.2.4.4
- symbol additions in Annex A buckling parameter clauses
Which standards are used with SIST EN 1999-1-5:2023/oprA1:2026?
| Standard | What it contributes |
|---|---|
| EN 1990-1 | Basis of structural and geotechnical design for new structures |
| EN 1999-1-1:2023+A1:2026 | General rules for aluminium structures |
| EN 1999-1-2:2023+A1:2026 | Design for fire conditions |
| EN 1999-1-3:2023+A1:2026 | Companion aluminium design part named in the amendment |
| EN 1999-1-4:2023+A1:2026 | Companion aluminium design part named in the amendment |
| EN 1993-1-6 | Supplementary information for certain shell types |
| EN 1993-3-1 | Supplementary information for towers and masts |
| EN 1993-3-2 | Supplementary information for chimneys |
| EN 1993-4-1 | Supplementary information for silos |
| EN 1993-4-2 | Supplementary information for tanks |
| EN 1993-4-3 | Supplementary information for pipelines |
| EN 1090-1 | Conformity assessment of structural components |
| EN 1090-3 | Technical execution requirements for aluminium structures |
What does the SIST EN 1999-1-5:2023/oprA1:2026 document contain?
SIST EN 1999-1-5:2023/oprA1:2026 contains a foreword and a structured set of amendments to the parent standard. It gives replacement text for the Introduction, Clause 1 and Clause 2, and targeted changes to Clause 8.2.4.4 and Annex A.
The technical content includes one revised load-case table for buckling checks and several symbol updates in Annex A. The document is therefore mainly a maintenance amendment: it adjusts references, aligns companion standards, and refines the buckling calculation language used in shell design.
Relations
- Amends
kSIST FprEN 1999-1-5:2022 - Eurocode 9 - Design of aluminium structures - Part 1-5: Shell structures - Effective Date
- 30-Jul-2025
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Frequently Asked Questions
SIST EN 1999-1-5:2023/oprA1:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Eurocode 9 - Design of aluminium structures - Part 1-5: Shell structures". This standard covers: 1.1 Scope of EN 1999-1-5 (1) EN 1999-1-5 applies to the structural design of aluminium structures, stiffened and unstiffened, that have the form of a shell of revolution or of a round panel in monocoque structures. (2) EN 1999-1-5 covers additional provisions to those given in the relevant parts of EN 1999 for design of aluminium structures. NOTE Supplementary information for certain types of shells is given in EN 1993-1-6 and the relevant application parts of EN 1993 which include: - Part 3-1 for towers and masts; - Part 3-2 for chimneys; - Part 4-1 for silos; - Part 4-2 for tanks; - Part 4-3 for pipelines. (4) The provisions in EN 1999-1-5 apply to axisymmetric shells (cylinders, cones, spheres) and associated circular or annular plates, beam section rings and stringer stiffeners, where they form part of the complete structure. (5) Single shell panels (cylindrical, conical or spherical) are not explicitly covered by EN 1999-1-5. However, the provisions can be applicable if the appropriate boundary conditions are duly taken into account. (6) Types of shell walls covered in EN 1999-1-5 can be (see Figure 1.1): - shell wall constructed from flat rolled sheet with adjacent plates connected with butt welds, termed “isotropic”; - shell wall with lap joints formed by connecting adjacent plates with overlapping sections, termed “lap-jointed”; - shell wall with stiffeners attached to the outside, termed “externally stiffened” irrespective of the spacing of stiffeners; - shell wall with the corrugations running up the meridian, termed “axially corrugated”; - shell wall constructed from corrugated sheets with the corrugations running around the shell circumference, termed “circumferentially corrugated”. [Figure 1.1 - Illustration of cylindrical shell form] (7) The provisions of EN 1999-1-5 are intended to be applied within the temperature range defined in EN 1999-1-1. The maximum temperature is restricted so that the influence of creep can be neglected. For structures subject to elevated temperatures associated with fire, see EN 1999-1-2. (8) EN 1999-1-5 does not cover the aspect of leakage. 1.2 Assumptions (1) The general assumptions of EN 1990 apply. (2) The provisions of EN 1999-1-1 apply. (3) The design procedures are valid only when the requirements for execution in EN 1090-3 or other equivalent requirements are complied with. (4) EN 1999 is intended to be used in conjunction with: - European Standards for construction products relevant for aluminium structures; - EN 1090-1, Execution of steel structures and aluminium structures - Part 1: Requirements for conformity assessment of structural components; - EN 1090-3, Execution of steel structures and aluminium structures - Part 3: Technical requirements for aluminium structures.
1.1 Scope of EN 1999-1-5 (1) EN 1999-1-5 applies to the structural design of aluminium structures, stiffened and unstiffened, that have the form of a shell of revolution or of a round panel in monocoque structures. (2) EN 1999-1-5 covers additional provisions to those given in the relevant parts of EN 1999 for design of aluminium structures. NOTE Supplementary information for certain types of shells is given in EN 1993-1-6 and the relevant application parts of EN 1993 which include: - Part 3-1 for towers and masts; - Part 3-2 for chimneys; - Part 4-1 for silos; - Part 4-2 for tanks; - Part 4-3 for pipelines. (4) The provisions in EN 1999-1-5 apply to axisymmetric shells (cylinders, cones, spheres) and associated circular or annular plates, beam section rings and stringer stiffeners, where they form part of the complete structure. (5) Single shell panels (cylindrical, conical or spherical) are not explicitly covered by EN 1999-1-5. However, the provisions can be applicable if the appropriate boundary conditions are duly taken into account. (6) Types of shell walls covered in EN 1999-1-5 can be (see Figure 1.1): - shell wall constructed from flat rolled sheet with adjacent plates connected with butt welds, termed “isotropic”; - shell wall with lap joints formed by connecting adjacent plates with overlapping sections, termed “lap-jointed”; - shell wall with stiffeners attached to the outside, termed “externally stiffened” irrespective of the spacing of stiffeners; - shell wall with the corrugations running up the meridian, termed “axially corrugated”; - shell wall constructed from corrugated sheets with the corrugations running around the shell circumference, termed “circumferentially corrugated”. [Figure 1.1 - Illustration of cylindrical shell form] (7) The provisions of EN 1999-1-5 are intended to be applied within the temperature range defined in EN 1999-1-1. The maximum temperature is restricted so that the influence of creep can be neglected. For structures subject to elevated temperatures associated with fire, see EN 1999-1-2. (8) EN 1999-1-5 does not cover the aspect of leakage. 1.2 Assumptions (1) The general assumptions of EN 1990 apply. (2) The provisions of EN 1999-1-1 apply. (3) The design procedures are valid only when the requirements for execution in EN 1090-3 or other equivalent requirements are complied with. (4) EN 1999 is intended to be used in conjunction with: - European Standards for construction products relevant for aluminium structures; - EN 1090-1, Execution of steel structures and aluminium structures - Part 1: Requirements for conformity assessment of structural components; - EN 1090-3, Execution of steel structures and aluminium structures - Part 3: Technical requirements for aluminium structures.
SIST EN 1999-1-5:2023/oprA1:2026 is classified under the following ICS (International Classification for Standards) categories: 91.010.30 - Technical aspects; 91.080.17 - Aluminium structures. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 1999-1-5:2023/oprA1:2026 has the following relationships with other standards: It is inter standard links to kSIST FprEN 1999-1-5:2022. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN 1999-1-5:2023/oprA1:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2026
Evrokod 9 - Projektiranje konstrukcij iz aluminijevih zlitin - 1-5. del: Lupinaste
konstrukcije
Eurocode 9 - Design of aluminium structures - Part 1-5: Shell structures
Eurocode 9 - Bemessung und Konstruktion von Aluminiumtragwerken - Teil 1-5:
Schalentragwerke
Eurocode 9 - Calcul des structures en aluminium - Partie 1-5 : Coques
Ta slovenski standard je istoveten z: EN 1999-1-5:2023/prA1
ICS:
91.010.30 Tehnični vidiki Technical aspects
91.080.17 Aluminijaste konstrukcije Aluminium structures
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
EN 1999-1-5:2023
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
March 2026
ICS 91.010.30; 91.080.17
English Version
Eurocode 9 - Design of aluminium structures - Part 1-5:
Shell structures
Eurocode 9 - Calcul des structures en aluminium - Eurocode 9 - Bemessung und Konstruktion von
Partie 1-5 : Coques Aluminiumtragwerken - Teil 1-5: Schalentragwerke
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 250.
This draft amendment A1, if approved, will modify the European Standard EN 1999-1-5:2023. If this draft becomes an
amendment, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
inclusion of this amendment into the relevant national standard without any alteration.
This draft amendment 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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1999-1-5:2023/prA1:2026 E
worldwide for CEN national Members.
EN 1999-1-5:2023/prA1:2026 (E)
Contents Page
European foreword . 3
1 Modifications throughout the whole document . 4
2 Modifications to the Introduction . 4
3 Modification to Clause 1, “Scope” . 4
4 Modification to Clause 2, "Normative references" . 5
5 Modifications to 8.2.4.4 "Buckling resistance of unstiffened welded shells" . 5
6 Modifications to A.3.2.3, "Meridional buckling parameter" . 5
7 Modifications to A.3.3.3, "Circumferential buckling parameter" . 5
8 Modifications to A.3.4.3, "Shear buckling parameters" . 5
...