SIXTH FRAMEWORK PROGRAMME PRIORITY [6.2] [SUSTAINABLE SURFACE TRANSPORT] 012497 DEVELOPMENT OF BEST PRACTICES AND IDENTIFICATION OF BREAKTHROUGH TECHNOLOGIES

SIXTH FRAMEWORK PROGRAMME PRIORITY [6.2] [SUSTAINABLE SURFACE TRANSPORT]012497 DEVELOPMENT OF BEST PRACTICES AND IDENTIFICATION OF BREAKTHROUGH TECHNOLOGIES IN AUTOMOTIVE ENGINEERING SIMULATION - AUTOSIM

Summary

Barcelona – results & setting the scene:Materials Characterisation

Trevor Dutton, NAFEMS/Dutton Simulation

Summary of topics presented and discussion from 1st AUTOSIM workshop, Barcelona, January 2006


Initial topics - Materials Characterisation

Initial topics from Munich:

– Composites, foams, new materials

– Fracture mechanics & durability

– Manufacturing simulation

– Constitutive models and material data

– Modelling connections

Not yet fixed – initial suggestions for discussion

Objective: To refine the list of topics to be addressed during the course of the AUTOSIM project


Composites, Foams, New Materials

Crashworthiness of composites

– energy absorbed in delamination

Structural foams for stiffness

Polymers (inc. fibre reinforced)

Crushable foams for occupant protection

Specialist materials for occupant models

New metals e.g., magnesium, HSS


Fracture Mechanics & Durability

Fatigue Life Prediction

Creep & time-related phenomena

Probabilistic methods

Modelling Crack Growth

– Automatic re-meshing

– Damage models

– Element-free methods

Links to:

– Manufacturing simulation

• effects of forming & assembly (esp. residual stress)

– Weld / Bond Modelling

– Material properties / material models

• S-N data etc. (new materials)

• Crack initiation (initial defects?)


Manufacturing Simulation

New Processes = new analysis & data needs– confirm feasible e.g., hot forming of Boron steel

Cost analysis & optimisation?Effects of forming (sheet metal)

– Work hardening (including hardening model)– Thinning– Residual stress– Shape distortion– Effect on residual ductility (material failure)– Phase change (e.g., TRIP steel)

Effects of forming (forging)– Residual stress – Shape distortion on cooling– Effect on residual ductility (material failure)– Phase change


Manufacturing Simulation (cont.)

Effects of forming (casting)

– Defects (porosity, inclusions)

– Shape distortion on cooling

Effects of forming (moulding)

– Directional properties

– Weld line

Assembly and Paint Process (& Heat Treatment)

Process flow, handling, logistics

NB Links to Integration Theme

Eagerness for using new materials but

manufacturing issues not appreciated


Cowper Symonds Strain Rate Enhancement

0

100

200

300

400

500

600

700

800

900

0.00 0.10 0.20 0.30 0.40 0.50 0.60True Strain

Tru

e S

tre

ss (

Mp

a)

Strain rate 0.1/s

Strain rate 10/s

Strain rate 100/s

Constitutive Models / Material DataDo we have the models needed to represent the effects believed to be

important?– Effects of forming– Multi Physics (one model for all applications?)– Model complexity vs. Ease of Use– Analysis efficiency

What data do we need and how is it to be managed?– Full range of parameters

• Strain rate, Failure, etc– Micro-characterisation– Use of optimisation– Material Suppliers?

Links to Confidence Theme5M element models but wrong input data!


Modelling Connections

Different types:

– Welds; Spotwelds, MIG, laser, …

– Joining; SPR, clinching

– Bonding

Stiffness

Failure, including ductility


Presentations • FENET

– Topics for consideration• Smart use of materials• Innovations based on new materials

– Method of classification (TRL, SoP, PLI)• Modelling elastomerics x2

– Variety of Models– Differing Degrees of Data Required– Complexity vs. acceptability of results

• Simulation of new metal forming processes– New materials need new processes– Need to be able to simulate with confidence (e.g., TRIP steel)– Balance complexity / accuracy / computation cost

• Materials Issues / Effects of forming– Importance of manufacturing simulation in predicting product performance– Software Usability vs. User Skill


Requirement Indices - FENET

Technological Maturity

– Material related issues all at 5 bar one (at 6) i.e., method (no better than) validated on test cases

– Hence, these issues are far from “ready for use” in the opinion of FENET members

State of Practice

– Contrastingly, most issues are 6 or above and many are deemed necessary for sign off (9)

Priority Level

– Reflecting this, most issues are seen as high priority


Discussion Points• Place of Materials in the project

– Links to both Integration & Confidence themes, e.g.;• Effects of forming in Integration• Confidence depends on data and models

• Number & complexity of material models– Help with selection – recommended values?– Availability of relevant data– Use of optimisation for data fitting– Micro-characterisation – may eventually eliminate test dependency

• Desire to utilise new materials demands forming simulation plus consideration of effects of forming

– Best Practice?– Other new materials / new processes that should be considered?

• Usability– Relates to Front Loading– Training / Benchmarking– Software design implications

Integration Issue?


Way forward

• Use Materials theme to explore “gaps” determined from Confidence and Integration theme?

• How to determine topics for further review / detailed presentations?

– Questionnaire

• Based on FENET topics – expanded following discussion

• Based on FENET classification


Topics for Questionnaire

New MaterialsMetals (including High Strength & Ultra High Strength Steels, Aluminium, Magnesium, Stainless Steel) as well as Polymers, Composites, Foams, Elastomerics

Material Data, especiallyStrain rate sensitivity, Fracture / Failure, Fatigue life, Creep, Formability

Material ModellingConstitutive Models, Multi-physics aspects, Micro-characterisation, Multi-scalar Modelling, Algorithms, Buckling / post-buckling, Fracture Mechanics, Damage / deterioration modelling

Modelling ConnectionsSpotwelds, Continuous welds, Self-piercing rivets, Clinching, Bonding

Manufacturing SimulationForming simulation, Effects of Forming, Assembly simulation, Paint simulation, Process Flow, Handling, Logistics, Cost analysis


Questionnaire Results …

… tomorrow!

Documents

SIXTH FRAMEWORK PROGRAMME PRIORITY [6.2] [SUSTAINABLE SURFACE TRANSPORT] 012497 DEVELOPMENT OF BEST PRACTICES AND IDENTIFICATION OF BREAKTHROUGH TECHNOLOGIES