Low Carbon Vehicle Technology Project
(LCVTP)
WS 7 Lightweight Structures - Technology Review
November 17th 2011
Gerain
t
Willia
ms
WMG
Work stream 7.5 Light weight seating
Mike Cromarty
Tata Motors European Technical Centre
Light Weight Seating: Overview
Work stream objectives
Target & Scope: April Event Recap
Future Architecture:
Design Development
Prototype Process
Testing Phase
Correlation
Conclusions
Consultation & Collaboration with Industry Experts
DESIGN
PROCESS
MATERIALS
VALIDATION
Light Weight Seating: Work stream objectives
Objective:
Reduce the weight of seating systems without
compromise of performance criteria
Light Weight Seating: Initial research
 Literature review of light weight vehicles and seating technology
 Appreciation of carbon impact drivers from cradle to grave
 22 technology reviews held with suppliers
 15 benchmark seat teardown activities carried out
 Customer focused interviews
 Brainstorming activities
 Boundary Diagram P Diagram Design FMEA
This initial research was used to establish a project scope with realistic
and achievable targets
Light Weight Seating: Initial target setting
1. Current Architecture: 20% weight reduction target
''2 Years
2. Future Architecture: 40% weight reduction target
''5 Years
3. Blue Sky Architecture: 65% weight reduction target
''10 Years
Light Weight Seating: Current
Current Architecture:
 Analyse and understand function, structure and weight distribution.
 Carry out Carbon Analysis using Gabi software.
 Purchase and tea rdown of benchmark assemblies
 Consider opportunities for weight reduction by material substitution using
existing processes.
 Output: literature study and physical benchmark data to support the
Future Architecture sub-work stream
Light Weight Seating: Future
Future Architecture:
 Opportunities for reducing weight through use of emerging technologies.
 Create DFMEA and DVP in order to establish basic design targets
 Carry out research study using the example of a seat backrest
 Measure performance of prototype assemblies
 Provide correlation between theoretical and actual performance
 Output: Technology proposal with test data and CAE correlation
Light Weight Seating: Blue Sky
Blue Sky Architecture:
 Literature review of disruptive technologies
 Engagement with advanced technology suppliers including those outside the
automotive industry
 Collate data from future technology sub-work stream where appropriate
 Output: Produce technology road map
2020
Light Weight Seating: “Future” Project Scoping
The Seat Structure was chosen as the area for research which
presented the best opportunity for weight reduction by the use of new
materials, processes. This area also offers the opportunity for
scaleability to all three rows and to other areas of the vehicle.
Light Weight Seating: Back Rest Exemplar
The Backrest has all necessary elements for extrapolation to a full seat assembly

Structure and loading

Ergonomic shape

Provision of built in feature such as trimming, suspension
 Joining methods to different assemblies such as steel mechanisms

Relevant to whole vehicle seat function
'V JLR Limo Green provided benchmark for proportion, package and comfort
'V Ford Fiesta seat provided benchmark for contemporary steel design
Light Weight Seating: Decision Matrix
Weight
STEEL
10-35%
ALUMINIUM
20-50%
MAGNESIUM
30-50%
GF/PA6 COMPOSITE
45-55%
Relatively Good
Material LCA
Average
Knowledge
Opportunity
Relatively Poor
A detailed decision matrix was created and discussed at length by the team.
CARBON
FIBRE
50-60%
Materials and processes were considered in terms of their weight saving opportunity when
considered as part of an overall seat assembly
It was agreed that a composite solution offered the most opportunity in terms of potential weight
save, low carbon potential, innovation and new research, realistic lead-time and investment costs
Light Weight Seating: Design Verification

Key tests were defined to support CAE studies

DVP defined for physical test activity to evaluate core functions

Results from physical testing correlated with CAE models
Seat
DVP incl.
ECE17
FMVSS
202a and
207
6 Key
Tests
3 CAE Load Cases
Correlate
8 Indicative Physical Tests
Light Weight Seating: Initial Concept Work
A multi loadcase topology optimisation was set up in Optistruct to
understand the major load cases influencing the seat back structure
6 Key
Tests
3
CAE
Load
Cases
Light Weight Seating: CAE Development
Initial CAE assessments were completed with isotropic material
assumptions.
Throughout the project, the partners built up their capability to model the
structure as an orthotropic model, assessing the composite plies. This
technique would produce an optimal ply lay up and enable further
topology optimisations to be carried out, with the objective of further
mass reduction.
These techniques were applied to the basic model and reproduced in the
physical parts for test correlation.
Light Weight Seating: Manufacture
An aluminium stamping tool was manufactured from which in excess of
50 seats have been produced
40 Seats have been subjected to physical testing
Light Weight Seating: Inspection
External:
All test parts subjected to visual inspection
All parts weighed
22 parts measured using CMM programme
6 parts scanned
Internal:
Sample parts sectioned and inspected
Sample parts inspected using CT scanning
Sample parts inspected using Ultrasonic Scanning
Light Weight Seating: Correlation
Light Weight Seating: Optimisation
Prod
Benchmark
Carbon Fibre
Comparator
LCVTP
Backrest
LCVTP Hybrid
Structure
LCVTP
Optimised
Light Weight Seating: Thermoplastic Opportunity
Thermoplastic
Stamping
Steel Assembly
CF Thermoset
17.0kg
12.0kg
10.7kg
>200k p.a.
70k p.a.
500 p.a.
Light Weight Seating: Environmental evaluation
 Initial Gabi model demonstrates
that an overall saving in Co2 is realised
 A fully functional parameterised model
si nearing completion
 Scenario Analysis will demonstrate the carbon impact of
> different materials
> different structures
> manufacturing processes
> locations
Concept Summary
 Thermoplastic composites have potential to replace automotive structural parts
 Design tools are available for the development of bespoke composite designs
 Indications are a 33% weight save in the case of a front seat assembly
 The weight save provides an overall environmental advantage compared to steel
 Thermoplastic composites have potential to be produced via volume processes
 Costs are between Carbon Fibre and Steel
 Form and performance capabilities are good, stable and repeatable
 Composites enable “thin seat” styling cues and improved vehicle packaging