Ferrara training 11297

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First Southern European Technology Conference
CAE Design approach to develop applicative
solutions in automotive polymer based systems
M. Chiara Ferrari, Filippo Gallieri Montecarlo,
June 7-9 2000
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DESIGN CAE Business Support Tool to develop
applicative solutions in automotive polymer based
systems
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Design CAE a powerful tool in the Business
Support Computer Aided Engineering Test
ing validation
Design
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CAE TOOLS
Product actual service conditions main
variables/part performances
Simulation computer calculation
replacing qualitative/empirical approach
Process tools and conditions process influence
on part
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New material/processes
Design solutions
CAE ADVANTAGES
Tests (homologation ...)
Production Process
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CAE ADVANTAGES

• New material/processes
• - no process tool building during the
  preliminary evaluation phase
• - critical issues investigated by simulation
• Design solutions
• - no prototype building up
• - several solutions evaluated and compared in
  short time
• - materials
• - mechanical constraints
• - geometry

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CAE ADVANTAGES

• Tests (homologation ...) - the number
  is dramatically reduced - main tests are
  focused on the final solution - possible
  flops are predicted and solved on the computer
• Production Process
• - avoiding tools judged inadequate once
  already set up
• - part quality - part performances
  foreseen in the design phase are respected
  - controlled defects due to process
• - time/costs are optimised

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CAE MONTELL

• Supporting to Montell product development
• - property profile for specific applications
• - directions for improvement
• Driving the customer to Montell materials
• - advanced properties
• - best material/design system
• Establishing Montell as a leading supplier
• to the technical industry
• - differentiated offering
• (product and service)

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• Internal
• new material/application development
• External
• penetration into the market

R D
CAE A KEY FACTOR FOR
Business
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Car dashboards from new concepts to first
applicative projects
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New concepts on dashboards
OBJECTIVE cost reduction
Computer simulation in the early feasibility
stage to compare solutions (materials, design,
thickness)
Dashboard system complexity causes a big
influence of design (shape, assembly solutions)
on final performances.
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New concepts on dashboards creep as a key issue
Cycle heating to 85C, 22 hours creep, cooling
to 23C Example of Z displacement distribution
after 22 hours creep at 85C and cooling to room
temperature
example Renault X76 customer Allibert
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New concepts on dashboards creep as a key issue
Cycle heating to 85C, 22 hours creep, cooling
to 23C Displacement comparison of selected
points
Material BR131G BR131G CR250F CR1152F Density
1.14 1.14 1.04 0.97 Thickness of
the dashboard 2.8 2.4 2.8
2.8 Upper right corner 0.85 0.79
1.25 2.25 of central console Top of
instrument cover 1.21 1.08 1.27
1.73 (visière) Bottom of glove box 2.35
2.43 2.43 2.45 Local relative
displacement 0.70 0.90 0.36 0.56 in
right horizontal area
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STRATEGY concurrent engineering and simulation
based design offered to selected partners
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• Montell Design Support
• - Static behaviour
• - Long term thermal stability (thermal/creep
  simulations)
• - Head impact simulation (ECE R 21 Standard)
• - Dynamic behaviour (Vibration)
• - Moldfilling simulation for all dashboard
  components
• Applicative project for dashboard development
  grades

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• Part performances (static, thermal/creep, head
  impact, vibration) main phases
• Preliminary feasibility calculation with
  simplified assumptions highlight of general
  behaviour, does it work?
• Detailed calculation - problem solving
  and optimisation on single components
• - evaluation of different material solutions
• Rework of design according to CAE guidelines
  (customer)
• Possible last calculation on final design

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Dashboard Head impact ECE R 21


IMPACT POSITIONS
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Dashboard Head impact ECE R 21
Fig 18
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Dashboard Thermal cycle AF
6 H
85?C
16 H
40?C
3 H
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Dashboard Thermal cycle AF


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Dashboard Thermal cycle AF
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Dashboard Component Manufacturing process design
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Dashboard Manufacturing process design

• Process simulation main phases
• Preliminary calculation - choice of
  best manufacturing process (injection
  molding?, traditional? sequential?) - evaluati
  on of different materials - evaluation of
  different gating solutions
• Final calculation - runner system
  balancing - investigation on process
  parameters influence (packing)
• Special calculations for critical parts
  (injection molding) - cooling - warpa
  ge

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Dashboard Manufacturing process design
Coiffe runner system finite element model 1
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Dashboard Manufacturing process design
Runner system dimensions mm
Cold sprues G1 , G3 , G4 , G5 , G6 Ø 6 to 10
Cold runners G1 , G3 , G4 , G5 , G6 Ø 10
G5
G4
Ø 24-8
Ø 20-8
G6
G1
Ø 20
G3
Ø 24-8
G2
Ø 20
Ø 20-8
Ø 20
i) Ø 16 ii) Ø 20
i) Ø 14-6 ii) Ø 22-8
Ø 20-8
G2 , Cold sprue Ø 5 to 8
G2 , Cold runner Ø 8
G1 , G2 , G3 , G5 , G6 Gates (width x length x
tk) thin area 20 x 2 x 1.8 thick area 20-0 x 8 x
8
G4 Gate (width x length x tk) thin area 120 x 2
x 1.8 thick area 120 x 8 x 8
This is the only difference between type i) and
type ii)
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Ddashboard Manufacturing process design
Molding machine parameters Variable limits for
PP
Mold temperature
Clamp force
40 deg.C
1300 Tonne
Max. Pressure
No Restraints
Variable limits for PP Max. Pressure 90?100
MPa Max shear stress 0.25 MPa Max. shear rate
100000 1/s
Melt temperature
250 deg.C
Fill time
6-8 sec
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Ddashboard Manufacturing process design
Fill time s Weld lines
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Dashboard Manufacturing process design
Pressure at end of filling MPa
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Dashboard Manufacturing process design
Clamp force trend Tonne
Max value 740 Tonne
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Dashboard Manufacturing process design
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HSBM Thin wall bumper concept
CAE support to concept development
Evaluation of thickness reduction feasibility
and design optimization
Structural performances
Molding technology
e.g. sequential injection
e.g. thermal/creep behaviour
CAE simulations as a key issue
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Thermal/creep cycle simulation on bumpers

• Temporary dilatation due to CLTE
• Possible permanent deformations
• due to dilatation and weight

High temperature effect
To allow evaluation of material behaviour and
design changes effect

• Simulation of the whole cycle (heating, creep,
  cooling)
• Material nonlinearities considered (CLTE vs.
  temperature,
• stress/strain vs. temperature, creep vs.
  time, temp., stress)
• Temperature distribution constant (e.g.oven) or
  variable
• along the surface and across thickness (e.g.
  sunload effect)

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Thermal/creep cycle simulation on bumpers
Local temporary deformation during high
temperature cycle
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Thermal/creep cycle simulation on bumpers
Local final deformation after high temperature
cycle and cooling
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CAE A KEY FACTOR FOR MONTELL
CUSTOMER WORLD
Design Idea
Preliminary Design
MONTELL DESIGN CAE WORLD
IN
Static
Impact
Thermal
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Creep
MATERIAL CHOICE
Prototype
DEVELOPMENT
Fatigue
Flops
SIMULATION
Vibration
IMPROVEMENTS
PROBLEM SOLVING
PRODUCTION
Injection molding
New material
OUT
Gas-assisted inj. Molding
FINAL DESIGN
MARKET
Thermoforming
Blow molding
Extrusion