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.