CAE Design approach to develop applicative solutions in automotive polymer based systems

DESIGN & CAE ACTIVITY DESIGN & CAE ACTIVITY

Montecarlo, June 7-9 2000Montecarlo, June 7-9 2000

CAE Design approachCAE Design approachto develop applicative solutionsto develop applicative solutions

in automotive polymer based systemsin automotive polymer based systems

M. Chiara Ferrari, Filippo GallieriM. Chiara Ferrari, Filippo GallieriMontecarlo, June 7-9 2000Montecarlo, June 7-9 2000

First Southern European Technology Conference



DESIGN & CAEDESIGN & CAEBusiness Support ToolBusiness Support Tool

to develop applicative solutions in to develop applicative solutions in automotive polymer based systemsautomotive polymer based systems



Design & CAE: a powerful tool in the Business SupportDesign & CAE: a powerful tool in the Business Support

Computer Aided EngineeringComputer Aided Engineering

Testing & validationTesting & validation

DesignDesign



ProcessProcess

tools and conditions

process influence on part

CAE TOOLSCAE TOOLS

SimulationSimulation

computer calculation replacing

qualitative/empirical approach

ProductProduct

actual service conditions

main variables/part performances



CAE ADVANTAGESCAE ADVANTAGES

New material/processesNew material/processes Design solutionsDesign solutions

Tests (homologation ...)Tests (homologation ...)Production ProcessProduction Process



• 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





• 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



• 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)

CAE & MONTELLCAE & MONTELL



CAE:CAE:A KEY FACTOR FOR A KEY FACTOR FOR

• Internal:new material/application development

• External: penetration into the market

R & D

Business



Car dashboards:Car dashboards:from new concepts to from new concepts to first applicative projectsfirst applicative projects


Montecarlo, June 7-9 2000Montecarlo, June 7-9 2000New concepts on dashboards New concepts on dashboards

OBJECTIVE:cost reduction

Dashboard system complexitycauses a big influence of design(shape, assembly solutions) onfinal performances.

Computer simulationin the early

feasibility stageto compare solutions

(materials, design, thickness)


Montecarlo, June 7-9 2000Montecarlo, June 7-9 2000New concepts on dashboards: creep as a key issueNew concepts on dashboards: creep as a key issue

Cycle: Cycle: heating to 85°C, 22 hours creep, cooling to 23°Cheating to 85°C, 22 hours creep, cooling to 23°CExample of Z displacement distribution after 22 hours creep

at 85°C and cooling to room temperature

example: Renault X76customer: Allibert


Montecarlo, June 7-9 2000Montecarlo, June 7-9 2000New concepts on dashboards: creep as a key issueNew concepts on dashboards: creep as a key issue

Cycle: Cycle: heating to 85°C, 22 hours creep, cooling to 23°Cheating to 85°C, 22 hours creep, cooling to 23°C

Displacement comparison of selected points

Material BR131G BR131G CR250F CR1152FDensity 1.14 1.14 1.04 0.97Thickness of the dashboard 2.8 2.4 2.8 2.8

Upper right corner 0.85 0.79 1.25 2.25of 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 0.56in right horizontal area



STRATEGY:STRATEGY:concurrent engineering andconcurrent engineering andsimulation based design offered simulation based design offered to selected partnersto selected partners



• 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



Part performances (static, thermal/creep, head impact, vibrationPart performances (static, thermal/creep, head impact, vibration) ) main phasesmain 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


Montecarlo, June 7-9 2000Montecarlo, June 7-9 2000Dashboard: Head impact ECE R 21Dashboard: Head impact ECE R 21

IMPACT POSITIONS



A B C D E F G

Max. intrusion instant [s] 0,0125 0,0225 0,015 0,02 0,0175 0,025 0,015

Max. intrusion [mm] 48,3 86,6 57 77,3 82,6 99,8 60,1

Max. acceleration [g] 83,2 55 68 46 76 39,5 55

Time range Acceleration > 80g [s] 3,5 0 0 0 0 0 0

Dashboard Max. Plastic strain [%] 48 46,3 57,3 40,7 55 70,3 max

ECE R 21 - Result comparison

Case

Fig 18

Dashboard: Head impact ECE R 21Dashboard: Head impact ECE R 21



40C

85C

16 H

3 H

6 H

Dashboard: Thermal cycle AFDashboard: Thermal cycle AF






X DISPLACEMENTS

-5,00E-01

-4,00E-01

-3,00E-01

-2,00E-01

-1,00E-01

0,00E+00

1,00E-01

2,00E-01

3,00E-01

4,00E-01

5,00E-01

0,00E+00 1,00E+02 2,00E+02 3,00E+02 4,00E+02 5,00E+02 6,00E+02 7,00E+02 8,00E+02 9,00E+02 1,00E+03

PDB LOWER

PDB UPPER




Dashboard Component:Dashboard Component:Manufacturing process designManufacturing process design


Montecarlo, June 7-9 2000Montecarlo, June 7-9 2000Dashboard : Manufacturing process designDashboard : Manufacturing process design

Process simulation: main phasesProcess simulation: main phases

• Preliminary calculation: - choice of best manufacturing process

(injection molding?, traditional? sequential?)- evaluation 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- warpage



Coiffe & runner system finite element model 1

Dashboard: Manufacturing process designDashboard: Manufacturing process design



Runner system dimensions [mm]

Cold spruesG1 , G3 , G4 , G5 , G6

Ø= 6 to 10

G1

G2

G4

G5

G3

Ø= 20-8

i) Ø= 14-6ii) Ø= 22-8

Ø= 24-8

Ø= 20-8

Ø= 20

Cold runners G1 , G3 , G4 , G5 , G6

Ø= 10

G1 , G2 , G3 , G5 , G6 Gates(width x length x tk)

thin area 20 x 2 x 1.8thick area 20-0 x 8 x 8

G6

Ø= 20

Ø= 20

Ø= 24-8

Ø= 20-8

G2 , Cold sprue Ø= 5 to 8

G2 , Cold runner Ø= 8

G4 Gate(width x length x tk)

thin area 120 x 2 x 1.8thick area 120 x 8 x 8

i) Ø= 16ii) Ø= 20

This is the only difference between type i) and type ii)




Fill time6-8 sec

Melt temperature250 deg.C

Mold temperature 40 deg.C

No Restraints

Clamp force1300 Tonne

Max. Pressure

Molding machine parameters & Variable limits for PP

Variable limits for PP:

Max. Pressure = 90100 MPaMax shear stress = 0.25 MPaMax. shear rate = 100000 1/s

Ddashboard: Manufacturing process designDdashboard: Manufacturing process design



Fill time [s] & Weld lines

Ddashboard: Manufacturing process designDdashboard: Manufacturing process design



Pressure at end of filling [MPa]




Clamp force trend [Tonne]

Max value = 740 Tonne




A B

Clamp force peak [Tonne] 740 800

Nozzle Pressure at end of filling [MPa] 36 46

Nozzle Pressure peak [MPa] 61 61

Max cavity shear stress [MPa] 0,185 0,16

Min [°C] 215,3 212,3

Max [°C] 255,7 255,7

Min [°C] 193,8 194,1

Max [°C] 254,8 260,3

SOLUTION

Flow front Temperature

Temperature at end of filling

Table : Filling phase result summary



Montecarlo, June 7-9 2000Montecarlo, June 7-9 2000HSBM Thin wall bumper concept

CAE support to concept development

Structural performances Molding technology

Evaluation of thickness reduction feasibility and design optimization

e.g. thermal/creep behaviour e.g. sequential injection

CAE simulations as a key issue


Montecarlo, June 7-9 2000Montecarlo, June 7-9 2000Thermal/creep cycle simulation on bumpersThermal/creep cycle simulation on bumpers

High temperature effect• Temporary dilatation due to CLTE• Possible permanent deformations due to dilatation and weight

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)



Local temporary deformationduring high temperature cycle



Local final deformation afterhigh temperature cycle and cooling



!

CAE: A KEY FACTOR FOR MONTELL CAE: A KEY FACTOR FOR MONTELL

Design Idea Preliminary Design

PrototypeFlops

PRODUCTIONPRODUCTION

IN

CUSTOMER WORLDCUSTOMER WORLD

FINAL DESIGNFINAL DESIGN

MONTELL MONTELL DESIGN & CAE WORLDDESIGN & CAE WORLD

OU

T

IMPROVEMENTSIMPROVEMENTSPROBLEM SOLVINGPROBLEM SOLVING

DEVELOPMENTDEVELOPMENTMATERIAL MATERIAL

CHOICECHOICE

StaticStatic

ImpactImpact

ThermalThermal

CreepCreep

FatigueFatigue

VibrationVibration

Injection moldingInjection molding

Gas-assisted Gas-assisted inj. Moldinginj. Molding

ThermoformingThermoforming

Blow moldingBlow moldingExtrusionExtrusion

New materialNew material

Documents

CAE Design approach to develop applicative solutions in automotive polymer based systems