How analysis & optimization help meet the time constraints in F1 Simon Gardner | Head of Structures Sahara Force India Formula One Team
Background – Force India
Overall Jordan GP - started with 50 staff in 1991 4 race wins and 3rd in the constructor’s championship
Sahara Force India formula One Team Ltd - October 2007 Dr VJijay Mallya and the Mol Family with Sahara joining in 2010 2 podiums, briefly 2nd 2014.
Now increased to around 380 staff
Aerodynamics 120 staff down at the Wind tunnel 70 design & aero 50 manufacturing Design Office 260 staff at the Head Office 90 Engineers (Various) 90 manufacturing 60 traveling
Sahara Force India Formula One Team
Background – Force India
MAHPP power unit MAMG gearbox SFIF1 is a chassis supplier Chassis Bodywork (Aerodynamics surfaces) Suspension Braking Steering
Sahara Force India Formula One Team
Design Process
Aerodynamic / Tyres / Vehicle dynamic Design and structural Meet design and production intent Running strength Safety requirement Regulation Technical Directives (TDs) Production R&D testing (sometimes!) Testing/Racing Sahara Force India Formula One Team
Aerodynamics
Restrictions: TFLOPS + wind-on time = 25 Design Considerations
Aerodynamic Mass Stiffness (tyres and handling) Strength Time scales Cost Sahara Force India Formula One Team
Method of achieving these targets
Testing History Experience Hand calculations FEA Analysis Optimisation PartnershipSahara Force with India Sahara Formula Force One India Team Formula One Team
Optimisation
Multiple load cases Complex geometries Complex lay up
Topological optimisation Composite optimisation Sahara Force India Formula One Team
TOPOLOGICAL Sahara Force India Formula One Team
Typical Topological optimsation
Multiple load cases and defined volume Stiffness and strength limited Sahara Force India Formula One Team PRINCIPAL ROLL STRUCTURE DESIGN USING NON-LINEAR IMPLICIT OPTIMISATION IN RADIOSS BULK (2011)
Safety standards within Formula 1 are constantly evolving Principal roll over bars introduced in 1961 Comply with stringent FIA design limits & strength test FIA Formula 1 Technical Regs. 15.2 & 17
>70mm Sahara Force India Formula One Team
Topological
Fz = -90kN
Fy = 50kN 1. Linear topology optimisation Fx = ±60kN 2. Manual iteration non-linear analysis Sahara Force India Formula One Team LINEAR TOPOLOGY OPTIMISATION
Objective: minimise mass Manufacturing & symmetry constraints Linear stress limit in design domain
Initial design domain Element density CAD realisation of topology result
~75% MASS REMOVED Sahara Force India Formula One Team
Composite (Free size optimisation) Sahara Force India Formula One Team
Overview of Composite Design
Composites offer huge flexibility for designing optimised components Possible design considerations Material (stiffness and/or strength) Ply orientation angle Patch position Number of plies in a given orientation Ply stacking sequence Laminating orthotropic layers makes it possible to tune stiffness & strength into required regions Lightweight core materials can be used to improve bending performance Using traditional analysis methods, it is very difficult to obtain an optimum design – too many variables and very time consuming
Sahara Force India Formula One Team
Optimisation Process Summary
HyperMesh Optimisation Set up
OptiStruct HyperView Free Size Optimisation Post Processing
HyperMesh Modify ply shapes
OptiStruct HyperView Size Optimisation Post Processing
OptiStruct Stack Sequence HyperView Post Processing Optimisation Sahara Force India Formula One Team
Composite Optimisation of a Formula One Front Wing (2009)
A front wing typical generates ~30% of an F1 cars total downforce
~6kN total force typically generated
Stiffness can be tailored
Must be lightweight
Comply with stringent FIA deflection limits FIA Formula 1 Technical reg. 3.17.1
The objective of this study was to design a new front wing main plane for the 2008 VJM1 which exceeded the structural performance of it’s predecessor Sahara Force India Formula One Team
F1 Front Wing Design Requirements
The front wing must withstand both aerodynamic loading conditions as well as standard FIA Formula1 Technical Regulations:
Regulation Details 3.17.1 The outer most part of the wing may deflect no more than 10mm when a 500N (2009) load is applied vertically, loaded symmetrically.
3.17.1 The outer most part of the wing may deflect no more than 10mm when a 1000N (2014) load is applied vertically, loaded asymmetrically. Sahara Force India Formula One Team
Altair Optistruct was used to aid design of the 2008 front wing Ply boundaries & efficient material orientations identified Discrete number of plies Optimised stacking sequence achieved
The final design met all criteria (within a highly compressed time frame) The final design was able to: Meet both the internal and FIA regulation displacements Improve min. reserve factors Minimise mass Meet manufacturing constraints This method can be applied across the board for all composite components on the car Sahara Force India Formula One Team
Optimisation of a Composite Aerodynamic F1 Rear Wing (2008)
Introduction The design of the rear wing is critical to the performance of an F1 car The design must withstand large down forces generated by air flow at high speed All components must be lightweight but satisfy the strength & stiffness requirements: Structurally sound Satisfy FIA regulations To meet these requirements the rear wing can be constructed from the following layers: Multiple unidirectional layers Cloth layers Lightweight core The objective of this study was limited to optimising the composite plies in the rear wing end plate and the pillar Sahara Force India Formula One Team
F1 Rear Wing Design Requirements
The rear wing must withstand both aerodynamic loading conditions as well as standard FIA 2008 Formula1 Technical Regulations:
Regulation Details Bodywork may deflect by no more than one degree horizontally when a load of 3.17.3 1000N is applied to its extremities in a rearward direction
The uppermost aerofoil element may deflect no more than 5mm when a 500N 3.17.5 load is applied horizontally
The forward-most aerofoil element lying behind the rear wheel centre line may 3.17.6 deflect no more than 2mm when a 200N load is applied vertically
Bodywork may deflect no more than 2mm vertically when a 500N load is applied 3.17.7 simultaneously to each side Sahara Force India Formula One Team
Results Summary
Mass in design regions reduced by 15% Reserve factor under aerodynamic loading improved by 7% Met required FIA regulations Sahara Force India Formula One Team
In conclusion Formula 1 is a fast paced industry requiring quick and accurate solutions
Altair Hyperworks provides: Efficient meshing and analysis tools Optimisation
The optimisation techniques typically used are: Topological Composite
Sahara Force India Formula One Team
Simon Gardner Head of Structures
Sahara Force India Formula One Dadford Road Silverstone Northamptonshire NN12 8TJ United Kingdom