With Altair Inspire on the Road Towards a Simulation Driven Product Development Process
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Transcript of With Altair Inspire on the Road Towards a Simulation Driven Product Development Process
Integrating Simulated Loads with Measurements and Strength
Testing Dr. Henrik Wentzel
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Outline
• Problem description
• Current practise
• Challenges & future development
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
This talk is about choosing appropriate fatigue design loads
Design load
Customer load
?
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Heavy loads Poor roads
Hurried drivers Heavy duty
Verifying strength
Strength is verified on the test track, and ultimately by the customers.
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Designing for strength
Development requires sound engineering principles supported by FE-simulations using
limited geometry and simplified design loads
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Appropriate design loads
• A good design load:
– Fast to evaluate
– Easy to understand
– Appropriate
Examples: NCAP (Appropriate, Easy to understand, Fast is a relative term)
Allows for optimization
with FEA!
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Appropriate fatigue design loads
• No accepted standards, each OEM has unique methods.
• Examples: quasi static, random noise, harmonic, transient,…
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
This talk is about choosing appropriate fatigue design loads
Design load
Customer load
?
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Fatigue design loads are generated by:
• Measure loads on existing products.
• Simulate vehicles on the test track in the design phase.
• Use vehicle simulations to derive development loads.
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Static inverse force method (yesterday)
Physical Calibration
Measurement Design load FEA
optimization
εtest (t) εref =g·Pref Pdesign = g-1·εtest
Pdesign
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Pdesign
Design load used for optimization
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Simulating the static inverse force method
Unit load
εref =g·Pref
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Static inverse force method (today)
FEA Calibration Measurement Design load FEA
optimization
εtest (t) εref =g·Pref Pdesign = g-1·εtest
Pdesign Pref
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Simulating a vehicle on road is difficult
Major challenges:
• Model assembly
• Tyre modelling
• Suspension modelling
Low quality design loads suboptimization
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Measuring the design load is difficult
• Many interface forces can not be measured, for example the forces through the cabin suspension.
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Dynamic inverse force method (today) FEA Calibration Measurement Design load
atest (t) aref =g·Pref Pdesign = g-1·atest
Pref
aref
Pref
The design forces are the forces that give measured response.
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Dynamic inverse force method (today)
In the simulation model it is easy to measure the interface forces in the cabin
suspension.
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Future trend/possibility - sensors
• Today 6 accelerometers on every vehicle.
• Manual download.
• Trend (internetification): Lots of low quality data
Downloading a Scania
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Future: sensors-models-loads
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Measure usage
Dynamic inverse methods
Measure interface loads
Pdesign
Optimize
Challenge – vehicle models
• Model assembly is a bottleneck.
• Stress-evaluation of truck 107 nodes.
• Managing such a model in the preprocessor.
• Integration between MBD and FEA
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014
Future work
• lots of low quality data
• high quality models
• integration between MBD and FEA
Develop new practices for specifying the design
load based on:
Recognizing that some users may still
subject the vehicle to unforseen loads…
2014-06-26 Info class Public, RTCC/Hwentzel/ATC2014