Investigation into the Energy Absorbing Properties of Composite Sandwich Materials used in Formula 1

1
Investigation into the Energy Absorbing
Properties of Composite Sandwich Materials used
in Formula 1 Structures

• Andrew Lamb

2
Contents

• Design For Safety
• FIA Testing Regulations
• Current Design Process
• Objectives
• Advantages of Computational Crashworthiness
  Prediction
• BAR Nosecone Structure
• Samples Required to Build Property Database
• Current Research Projects
• Optical Measuring Methods
• Material Testing
• Computational Simulations
• Summary and Questions

3
Design For Safety
Decesaris Austria 1985
Alonso - Brazil 2003
Alonso Monaco 2004
Schumacher Silverstone 1999
4
FIA Frontal Impact Test

• 2nd Highest energy test
• First being the new Rear Impact Test introduced
  in 2006 regulations
• Nosecone structure mounted to impact trolley
• Net Mass 780kg
• Impact Velocity 14m/s
• Average Deceleration must not exceed 40 g
• Dummy must not exceed 60 g for more than
  cumulative 3ms

5
Standard Design Process

• Design process to achieve crashworthiness is
  experimentally based

Testing and Redesign until Satisfactory Result
Structure Pass
Prototype Impact Testing to fulfil FIA Regulations
Structure Ready for Further Tests and Race!
Conceptual Design Improved Aerodynamics, new
materials, etc
6
Objectives
FE Model Predicts Crashworthiness FE Modelling
code PAMCRASH currently not equipped to
accurately represent composite materials

• Investigate energy absorbing properties of the
  composite sandwich structure
• Improve computational material models to
  accurately determine crashworthiness of a Formula
  1 structure

Potentially Superior Structure Ready in Reduced
Time and Cost!
Concept Design
Prototype Testing to Validate FE Prediction and
Pass FIA Regulations
7
Investigated Structure

• The structure under investigation is the 2004 BAR
  006 nosecone structure

• Aluminium-Composite Sandwich Structure
• Composite Fabric 2x2 Twill Pre-preg
• Aluminium Honeycomb 10mm thick
• 4.5 and 8.1 densities used
• Bonded using adhesive Film

8
Test Samples
Wedge Impact Samples
Honeycomb Panels
Composite Coupons
DCB Samples
9
Laminate Testing With Optical Methods
eXX
eyy

• Laminate testing used to build up a database of
  properties, including damage, to produce accurate
  FE Models

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Composite Damage Analysis and Modelling

• Damage parameters determined from cyclic testing
• Numerical model is a single shell based on
  multi-layered ply data

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Honeycomb Compression
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Multi-axial Analysis of Honeycomb

• Optical Analysis used to determine grip
  displacements

• Arcan method developed initially to produce
  uniform plane stress to test fibre reinforced
  materials
• Modifications made to apparatus to adequately
  test cellular solids

13
DCB Composite Honeycomb Sandwich
Starter Crack between Honeycomb and Composite
Aluminium Plate Reinforcement with Dot Pattern
Crack Propagation Through Honeycomb Centreline
Dynamic Delamination Test Apparatus
14
Nosecone Numerical Modelling
Anisotropic Honeycomb Solid Element
Ladeveze Damage Shell Element
Contact Tie Interface to Represent Adhesive
Properties

• Modifications to material codes within PAMCRASH
  required to produce accurate representation of
  composite material, honeycomb cellular solid and
  adhesive bond

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Summary

• Current experimentally based design methodologies
  are expensive, time consuming and inefficient
• On-going advancements in testing methods to
  accurately determine material properties/behaviour
  
• Improvements underway on constitutive numerical
  modelling to represent honeycomb core, adhesive
  and composite material accurately
• FE modelling presents possibility of reducing
  costs, development time and improving structural
  efficiency
• Benefits to other industrial applications
  include
• Aerospace (bird strike, debris), Automotive,
  Military, etc

16
Questions
Thank you for your attention a.j.lamb_at_cranfield.ac
.uk