High Performance Catamaran Design

& Optimisation with Hyperworks

Julien ChausseeTeam Rafale - ETS

Team Rafale - ETS

Design & Build team

• 7 Masters Students• 15 Bachelor Students

• 1 professor : Simon Joncas• 1 aerospace Engineer : Julien Chaussée,

former member of the Invictus British team

L’équipe de navigation

Former Members of the Canadian 49er team:

• Marc Farmer helm• Tej Trevor Parekh crew•

The Challenge

Design and Build a 25ft C-Class Catamaran to compete in the Little Cup in Geneva in 2015

C-Class Catamarans

Vidéo de présentation

C-Class catamarans are sailed double-handed

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25ft

14ft

• Sail Area:

– 300 ft2 maximum

– No restriction on number of sails or design

• Crew:

– 2 crew

– 2 trapeze

PERFORMANCE

• Very fast boat

• Very light boat

• Rigid Wingsail:

• better power to drag ratio

• Less stay tension = less weight!

Hellcat (70’s)

450kg

17kts (35km/hr)

Soft sails

Aluminium mast and beams

Wooden hulls

190kg

20kts (37km/h)

All Composites construction

Rigid Wingsail

Still only displacement boat

Cogito (1996) Groupama C (2013)

170kg

35kts (65km/h)

Carbon Thin Ply Technology

Hydrofoils

C-Class History and Evolutions

Équipe ETNZ AC72

C-Class are a real Innovation laboratory for sailing!!!

1988 America’s Cup

Rafale C-Class – Design Overview

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Rafale C-Class• Modern C-Class Design

• Platform:

• Low buoyancy / low profile hull

• Full Carbon fiber sandwich constructions

• Hydrofoil:

• 2 main lifting board (1 in the water at a time)

• J-shape / “UpTip ” concept

• 2 T-foil rudders to stabilise the boat

• Wing:

• High Aspect Ratio

• Carbon and glass fiber structure

• 2 element concept

• Morphing trailing edge (front element)

• All up weight target: 400lbs

45ft

General Arrangement

Overlay of Hydros boat (Swiss team)

Case Study 1: Hydrofoil Optimisation

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Hydrofoils – Why Fly?

Hydrofoils – Why Fly?

Source: Andy Kensington – ETNZ, “Battle of the Boat” presentation, IPENZ Lecture 2014

Hydrofoil design brief

• Concept: J-Foil or “UpTip” shape

• Target Lift = Weight of Boat + Crew (~800lbf)

• Maximum Deflection: 90mm ` 100mm

• Single piece foil

• No metallic inserts

• Carbon Fiber skins + Foam core inside

• Target Weight: 12kg / 26lbs

Design ApproachUse of Hyperworks Composite Optimisation Process

Composite Free-Size

Free-Size Review and Refinement

Optimisation Perfromed by Francois Michaud

Initial Model & Setup

• Shell model with Solid core inside

2m

0.7m

R = 0.25m

Initial Model & Setup

Load Cases Constraint Value

Partially Submerged Foil 320 kgMax Deflection (at

elbow)90 mm

Foil fully submerged 550 kg

Failure Criteria

(Tsai-Wu)FSmin = 1.5

No Buckling λmin= 3

• Shell model with Solid core inside• Loads generated from CFD spatial pressure

distribution (see load cases below)• Carbon fiber UD properties• 0 / +45 / -45 / 90• Core material not included in the

optimisation• +45 and -45 plies linked• Minimum 5% plies in each direction

Vertical Constraint

Water level (fully submerged)

Water level Mini

HorizontalConstraint

Initial Results and Zone Definition

Upper Skin

Lower Skin After clean up of plies / zones

Results after Shuffling

Note:

• Laminate is symmetrical

• +45/-45 UD switched for woven in the end

• Added a 0/90 on OML (request

from our Partner Mystere Composites for ease of manufacture)

• Final Design Weight 11kg

ZONE ID

PLY ID 1 2 3 4 5 6

1 0°/90° 0°/90° 0°/90° 0°/90° 0°/90° 0°/90°

2 ±45° ±45° ±45° ±45° ±45° ±45°

3 0° 0° 0° 0° 0° 0°

4 0° 0° 0° 0°

5 ±45° ±45° ±45° ±45° ±45° ±45°

6 0° 0° 0° 0° 0°

7 0° 0° 0° 0° 0°

8 ±45° ±45° ±45°

9 0° 0°

10 0° 0°

11 ±45° ±45° ±45°

12 0° 0° 0° 0° 0°

13 0° 0° 0° 0° 0°

14 ±45° ±45° ±45° ±45° ±45° ±45°

15 0° 0° 0° 0°

16 0° 0° 0° 0° 0° 0°

17 ±45° ±45° ±45° ±45° ±45° ±45°

18 0°/90° 0°/90° 0°/90° 0°/90° 0°/90° 0°/90°

Ply Design Generation

• Initial ply shapes extracted from model with Hypermesh functionalities

• Exported to CATIA Composites Workbench for final design and ply flattening

… a few month later

Other Use of Hyperworks

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Analysis and Optimisation

• Full FEM of the plateform:– Sizing

– Stiffness analysis

• Rudder / foil analysis

• Main beam composites optimisation

• Mast Analysis and sizing

• Small components detailed Analysis

Conclusion

Thanks to

And Hyperworks:

• Significant time saving• And all targets achieved

A big Thank You to Our Sponsors and Partners

http://etsclassc-rafale.ca

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