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The Revisions of the BS EN ISO 12215

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Presentations of the revisions of the BS EN ISO 12215-5.
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Jean-Baptiste R. G. Souppez
Lecturer in Yacht Design and Composite Engineering
jean-baptiste.souppez@solent.ac.uk
UK Principal Expert in Small Craft Structures
Jonathan Ridley
Head of Engineering
Jonathan.ridley@solent.ac.uk
THE REVISIONS OF THE BS EN ISO 12215
1 1 O C T O B E R 2 0 1 7
Marine Sector Showcase
Composite UK
Southampton
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017
CONTENTS
2
Motivations behind the revisions
Changes to the scope
Applicable methods for structural analysis
Double Curvature
Natural Stiffeners
Upgrades to composite theory
Webscant
Conclusions
The ISO 12215-5 is currently at DIS (Draft International Standard)
stage, open for voting until the 26th of October 2017
Disclaimer: The views expressed are those of the authors only and do not necessary reflect those of the WG18.
All information presented in subject to changes made by the WG18 and approval of the standard.
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 3
MOTIVATIONS BEHIND THE REVISIONS
Current version published in 2008
Significant changes have occurred in the marine and composite industry since then
The aims of the new version are:
Answer the feedback from industry
Improve the clarity of the standard to widen the range of users
Propose an improved consideration for single and double curvature
Refine the definition of natural stiffeners for round bilge hull
Offer a more modern approach to the mechanical properties of composites through CLT
Better definition of the pressures (including applications to large sandwich panels)
The revision work also allowed to improve a great many details.
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 4
CHANGES TO THE SCOPE
The definition of the local design pressures and design strength apply to both monohulls (ISO12215-5),
and soon multihulls (ISO 12215-7)
The scope has been extended to cover small crafts for professional use (workboats)
Speed limit extended beyond 50 knots and accelerations up to 8g for workboats
To bridge the regulatory no-man’s-land arising from the small craft upper limit being at 24m hull length
and the IMO regulation starting at 24m Load Line length, the Working Group decided that the ISO
12215 will now apply to an ‘enhanced’ definition of small crafts, i.e. a new upper limit of 24m Load
Line
Note: this is only for the ISO 12215, and has not been adopted by other working groups of the RCD.
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 5
APPLICABLE METHODS FOR THE STRUCTURAL ANALYSIS
1. Simplified Method
Based on simple thickness equation for metal, wood and GRP single skin
2. Enhanced Method
Ply by ply analysis for metal, wood and quasi-isotropic GRP
3. Developed Method
Application of CLT to all FRP structures
4. Direct Test
Relying on mechanical testing, applicable to all but primarily intended for FRP
5. FEM
Finite element methods using the ISO design pressures and properties, also mostly aimed at FRP
6. Drop Test
Applicable to vessels less than 6m in FRP and non-reinforced plastics
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 6
DOUBLE CURVATURE
The significant impact of double curvature for small crafts is not normally accounted for in rule-based
structures
Finite element methods have been employed to first validate the Timoshenko coefficient for curved
plates, and then utilised to develop new correction coefficient for the loading on a panel with double
curvature
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 7
NATURAL STIFFENERS
Natural stiffeners are well defined for a sharp angle between two plates
The problem is made more complex when looking at a highly curved plate
Further investigation into the effects of curvature on structures allows to define a new criteria for
natural stiffeners
Find, if possible, a circle that corresponds
approximatively to the shape of the hull. Its
connection to the hull is usually at the tangent
point with a parallel to the diagonal between
bottom at CL and deck edge. If the radius of this
circle is 0,40 the length of the diagonal, and if the
chord of contact or intersection between the circle
and the hull is > 0,8 R, the "turn of the bilge" is
considered strong enough to be a "natural"
stiffener.
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 8
UPGRADES TO COMPOSITE THEORY
Updated mechanical properties for CLT applications to reflect the developments over the last decade
Also features improved ‘guidance values’ for fibre weight fractions for a wider range of clothes and
lamination process (from Hand layup to prepreg in autoclave).
And a ‘boat building quality factor’ to reflect the production method and quality control during the
build process.
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 9
WEBSCANT
In order to validate the development of the standard and ensure a good application once launched, the
WEBSCANT website was created
http://www.webscant.com/
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 10
WEBSCANT
Webscant allows to input examples of
interesting yachts:
Well experience boat or component not
meeting the ISO 12215-5 (2008)
Well experience boat or component at the
limit of the ISO 12215-5 (2008)
Well experience boat or component easily
in accordance with the ISO 12215-5 (2008)
All data is kept secured, only accessible by
the Convenor of the ISO 12215 for
validation purposes
The larger the industry involvement,
the better the final standard will be.
Jean-Baptiste R. G. Souppez & Jonathan Ridley The Revisions of the BS EN ISO 12215 Marine Sector Showcase Composite UK - 2017 11
CONCLUSIONS
Significant amount of work gone into improving the standard
Revised Scope
Multihulls (Part 7)
Workboats (speed greater than 50 kts)
New 24m Load line limit
Main Changes
6 methods applicable for the structural analysis (from drop test to FEM)
Consideration for double curvature
Definition of natural stiffeners for highly curved panels
Upgrades composite theory
Webscant tool available to industry to support the validation
Also towards the end of their development and coming soon:
ISO 12215-7: Multihulls (including global loads)
ISO 12215-10: Rig loads and rig attachments (including composite chainplates)
Jean-Baptiste R. G. Souppez
jean-baptiste.souppez@solent.ac.uk
For more information, to obtain a copy of the draft standards
or to get involved with the validation process, please contact:
THANK YOU
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