Composite BIW Development using Genesis
Dr Roger Darlington (Jaguar Land Rover) Paul Bristo (Jaguar Land Rover) Martin Gambling (GRM) Adam Hargreaves (GRM) In partnership with GRM
Agenda
• Background
• Why Composites for BIW Structures? • The Dominant factors of Body in White Design
• The Composite BIW Development Process using Genesis
• Summary • Questions
Jaguar Land Rover
• Largest automotive manufacturer in the UK – 29,000 global employees.
• Luxury sports saloon and sports cars
• Premium all-wheel drive vehicles
• Pioneers and world leaders in Aluminium Body structures – proven history of successful lightweighting
• UK’s biggest R&D investor – in the top 100 globally for R&D spend
The VARCITY Project
• 3 Year research project worth a total value more than £17.0 million
• A 36-month project which aims to make a step change carbon fibre part manufacturing and joining
volume BIW structures targeting a 60% mass reduction over conventional steel BIW solutions
• Aim to investigate and develop design, simulation and manufacturing methods for composite BIW
design, culminating in the production of a demonstration of affordable composites BIW architectures.
Project Partners
Why Composites for Vehicle Bodies?
• Need to reduce CO2 emissions
• Best method - lightweighting
Why Composites for Vehicle Bodies?
• Need to reduce CO2 emissions
• Best method - lightweighting
• Lightweight • Stiff • High Strength • Highly tailorable using directional properties –
efficient
Challenges of Composites
• Difficult to predict exact structural performance
• Non Linear failure characteristics & many failure modes • High Cost
• Complex Manufacture
BIW Design Requirements
• Global Stiffness
• Local Stiffness
• Handling
• Durability
• Quality
• Safety
• Crash
• NVH
• Durability
• Provide mounting points for
all the other bits
BIW Development Process
Design of Panels Concept Design Analysis and Optimisation
Verification & Testing
Manufacture
Composite Analysis & Optimisation Processes in Genesis / Design Studio
Composite Tools - Why Genesis?
Robust, Established Composite Analysis Solver
OptiAssist 5.1 Dedicated composite optimisation
workflow
Genesis, Design Studio & OptiAssist
Efficient links to external tools
CATIA ANSA
ABAQUS LS-DYNA
Key Composite Optimisation Capabilities
Strength Constraints on Ply Pattern Design
Laminate/Ply Thickness Responses Laminate Variation Constraints
Discrete Optimisation
Composite Tools - Why Genesis?
Robust, Established Composite Analysis Solver
OptiAssist 5.1 Dedicated composite optimisation
workflow
Genesis, Design Studio & OptiAssist
Efficient links to external tools
CATIA ANSA
ABAQUS LS-DYNA
Key Composite Optimisation Capabilities
Strength Constraints on Ply Pattern Design
Laminate/Ply Thickness Responses Laminate Variation Constraints
Discrete Optimisation
Over a decade of practical application in composite industry
Overview of Genesis Development Process
Combined Loadcase Model
Candidate Laminate Setup in OptiAssist
Setup of Optimisation Data in OptiAssist
Initial Topometry to identify ply boundaries
Update of Laminate in Composite Modeller
Combined Sizing & Topometry of Laminate to
refine boundaries
Proving of non-linear loadcases in LS-Dyna
Output to CAD using Composite Reporter
GENESIS BIW Optimisation
Model
Combined Model Assembly
• Combined Simplified model constructed
• Allows all loadcases to be considered in single optimisation
• Key to achieving most efficient design
• Aluminium BIW assessed using same model to set targets for optimisation
Linearised Crash Load Cases:
FFB ODB Rear
Roof Crush Side Pole
Side Barrier
Modal
Bending
Linearised Crash
Hardpoint Stiffness
Torsion
Crash Loadcases - Linearisation
• Crash Loadcases are linearised to be considered within the combined optimisation
• Failure Index constraints to prevent failure within the passenger cabin laminates
LS Dyna Crash Result Genesis Static Inertia Relief
Loadcase Composite Failure Index
Optimisation Targets & Constraints
Loadcase Genesis Constraint
Static Torsion / Bending Displacement Constraint
First Mode Frequency Constraint
Hardpoint Stiffnesses Strain Energy Constraint
Linearised Crash Loadcases Failure Index Constraint
Seatbelt Anchorage Loadcases Failure Index Constraint
Manufacturing Min / Max Thickness Constraints
Laminate Interpretation Ply Variation Constraints
Objective Minimise Mass/Cost of Composite Material
OptiAssist Composite Modeller
• Composite modeller used to set up laminates on the BIW.
• All Global Ply IDs are assigned, allowing easy Design setup
OptiAssist Ply Design
• Generation of design data for the plies within the model
• Allows for simple set up of: • Sizing • Topometry • Orientation Design • Ply linking
• As laminate matures through the development process, fewer plies are designed, and sizing is favoured over topometry
Body Laminate Development Process
• Each panel of the vehicle progresses through 3 stages of laminate development:
Initial Topometry
Combined Sizing and Topometry
Fixed Laminate
CAD Surface input
Output Laminate to
CAD
All ply boundaries free
Candidate ply boundaries
Analysis Assessment
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0.2 0.4 0.6 0.8 1
Ply Variation
• Ply Variation smoothes out the laminate
topometry result.
• Results are easier to interpret into discrete
laminate zones.
• Penalty for this simplification is an increase in
overall mass (around 20%)
“Complexity”
Mas
s (k
g)
OptiAssist – Composite Reporting
• Ply patterns interpreted from the Genesis Sizing/Topometry
• Outputs to next stage of development process: • HTML Plybook & layup file for
Design Engineers • Layup file & Design Studio
Laminates for further CAE Studies • Makes data available for:
• CATIA • Simulia Abaqus • Laminate Tools • ANSA
Results Interpretation
• Results of Topometry interpreted to ply zones.
Export to Crash Analysis
• Design Studio Dyna export plugin allows for simple export to LS-Dyna for Non-Linear analysis of crash loadcases
Ply Pattern Export
• After the optimsation process, Composite
Reporter is used to export the laminate Data.
• CAD export available via Plybook, iges and
.layup creation.
• Export to other FE formats available via
element sets, and .layup format.
• Import Laminate option can also be used to
apply layup to different meshes.
Proving of Design
• In order to prove the capabilities of
the design, it is necessary to run models of the vehicle in other
solvers.
• Export routines allow the optimisation results to be used in:
• Dyna
• Abaqus • Nastran
Conclusions
• Mature composite optimisation process of Genesis & OptiAssist further developed to:
• Align to demands of automotive OEM development processes • Interface efficiently to several industry standard design and analysis tools
• More efficient manage large scale model and optimisation data
• Key optimisation capabilities such as strength-based constraints enable multiple
requirements of body design to be considered.
• Genesis process allows for both localised and global optimisation of laminates
• Process enables Jaguar to achieve maximum practical benefit of composite materials in BIW design
Acknowledgements
• The VARICTY project partners acknowledge Innovate UK who is co-funding this project as
part of the IDP11 Low Carbon Vehicles programme.