Topology Optimization of Fuselage - Nicolas Kawski, STELIA Aerospace

The aeronautical sector is facing many concurrent challenges since OEMs have to ensure their commitments in terms of delivery, whereas eco-responsibility, eco-efficiency and sustainable development are becoming more and more significant requirements. In this environment, competition between all players of the sector increase with new comers, offering low cost capabilities and strong investments.

In order to support its customers and introduce more innovation into its products, STELIA Aerospace invests in new fields of research & technology through radical evolutions of developing airframes. Thus, STELIA Aerospace aims at adding topology optimization as a new technology brick to its development process, in order to increase the number of potential configurations for a given aircraft section and consequently dramatically reducing the weight and cost of an aerostructure.

Successful results have already been obtained on local components such as fittings and brackets. Further developments are achieved on larger structures such as cross beams and complete floors. Then architectures of complete sections are also considered and studied, proposing a radical step compared to conventional aircraft architectures composed by panels, stiffened with orthogonal stringers. Then, from these breakthrough results, trade-offs are defined considering existing manufacturing processes and new technologies such as additive manufacturing.

Transcript

1. TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE NICOLAS KAWSKI – RESEARCH DEPARTMENT METALLIC ENGINEERING LEADER EATC 2015 – 01.10.2015
2. Revenues : 2,5 Billions $  World Top 3 on aerostructure market & seats segments (First/business class & pilots) 6,100 employees R&D : 185 Millions € 10 sites in the world and a global presence 670 Nose Fuselage delivered in 2014 86 fully equipped & tested ATR Wings delivered in 2014 A reliable network of suppliers, a dedicated site for R&T 01-10-2015 TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 2 2
3. TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE  High speed machining  Automatic riveting  High speed drilling robotized  Final assembly  Functional tests (ATR wings)  Automated fiber placement  Autoclave curing  Filament winding & RTM  CNC machining  Metallic-Composite Assembly  3,2 million parts manufactured / year and 4,3 million purchased parts  Focused on large & complex manufactured parts  Highly technological solutions  Large range of technologies & products  40,000 seats delivered since 1973  25,000 seats in operation worldwide  All Airbus aircraft fly with Stelia cockpit seats  STELIA SEATS cabin interior products are installed on Airbus and Boeing aircraft  50+ prestigious airlines  2,000+ PAX delivered each year  350,000 bended tubes manufactured / year  50,000 welded pipes manufactured / year 3 Metallic parts & assemblies Composite parts and assemblies Elementary parts Pilot seats Business cabin seats Systems – Tubes & Pipes 3 01-10-2015
4. 4 NOSE FUSELAGE CENTER FUSELAGE BARRELS & HALF- BARRELS WINGS, WINGS TIPS & DORSAL FAIRING ATR Airbus S14A Dassault Falcon F7X All Airbus Programs Family Bombardier Main landing Gear Bay A350/ A380 HELICOPTERS REAR FUSELAGE & DOORS A400M Ramp Door COMPLETE WORK PACKAGES TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 4 01-10-2015
5. Design Design 7 3D elementary parts Architecture Design Justification Topology optimization Sizing optimization Architecture Design Justification Major components and subassemblies Global architecture Complexity Background Differenciation - - ++ ++ - - - - ++ Accelerate global development process Propose alternative and weight & cost savings in architecture level TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE Potential applications 7 2014 2016 01-10-2015
6. Example performed on a goose neck fitting • Fitting structures ensuring the link between the aircraft primary structure and the nose landing gear doors • Static, fatigue and damage tolerance loads Current elementary parts in Al-Li • 5% weight savings • 2,5 times more expensive than classical Aluminum alloy • Better behavior in fatigue & damage tolerance Can topology optimization propose alternative solutions in terms of weight and costs ?? TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 8 01-10-2015
7. Allocation space & loading Topology optimization campaign Set of Design Calculations & validation Static and fatigue analyses Initial geometry TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 9 01-10-2015
8. Design Production process Material Geometry Weight Price index 1 Baseline Machining 2050-T84 1,89 kg - 2 Topological optim. – raw results ALM AS7G06 1,59kg x6 3 Topological optim. – designed from #2 ALM AS7G06 1,71kg x6 4 Topological optim. – alternative design Machining 2050-T84 1,79kg + 10% 1 Baseline Machining 2050-T84 3,10 kg - 2 Topological optim. – raw results Machining 7175-T7351 3,30 kg - 15%-20% 3 Topological optim. – designed from #2 Machining 7175-T7351 3,17 kg - 15%-20% TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE Alternative designs using additive manufacturing and complex machining Alternative designs using alternative material 10 01-10-2015
9. Application of topology optimization to floor beams Definition of the crossbeam interfaces points in order to manage boundaries and jonctions Maximum allocation space TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 11 01-10-2015
10. Pressure load case Depressurization load case Load case review Combined Load cases 3D Model TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 12 23-09-2015
11. 13 Weight = 0,77* CurrentWeight LABEL Traverse 1 – RF mini COND_ZCR1_DOWN_A320_V2 1.05 COND_ZCR2_DOWN_A320_V2 1.13 DSG 48 000 RF 3,66 SF 5 RF calculation p DSG SF N RF 1 ) (   RF calculation RF 2,58 SF DSG 5 48 000 p DSG SF N RF 1 ) (   Traverse 16: RF min = 1.35 Frame 16: RF min = 1.80 TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE DesignedCrossbeam 13 Buckling Fatigue 23-09-2015
12. 14 Topology optimization applied to aircraft architecture Based on a A320NEO baseline 201 load cases • Same aerodynamic shape • Same passenger and cargo door positions • Same landing gear position Design space is the complete fuselage, including landing gear bay, floor and front pressure bulkhead 2 material are considered : Fuselage: Aluminium E= 74 000 MPa & ν = 0.303  Upper & Lower Cap: Titanium E= 115 000 MPa & ν = 0.278 TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 14 23-09-2015
13. • Classical orbital stiffeners on forward cylindrical fuselage • Highly loaded Frames around the door • Longitudinal stiffeners on upper and lower panels • Triangle stiffeners around the landing gear bay TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE Nose and forward fuselage 15 23-09-2015
14. TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 16 Definition of trade-offs Several architectures have been defined and are currently evaluated • Based on Assembly (riveting, bonding or welding) • Based on integral panels • Based on additive manufacturing technologies 23-09-2015
15. TOPOLOGY OPTIMIZATION OF NOSE AND FORWARD FUSELAGE 17 Topology optimization integrated as a elementary step of aircraft development Full efficiency proved for 3D components and subcomponents • Fatigue and damage tolerance have to be managed at the very beginning of the sizing process For architecture level • Buckling is the main sizing criteria, which is difficult to be fully considered • Current work is performed to evaluated different trade-offs 23-09-2015
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