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Research activities. E. Nikolaidis B. Ramaswamy B. Dheenadayalan A. Keerti S. Mathew P. Soundappan D. Tiwary Vibration and Reliability Lab Friday, April 20, 2001. Overview. 1.Design under uncertainty. 3. Knowledge-based design tools. 2. Structural dynamics. - PowerPoint PPT Presentation
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1
Research activitiesE. Nikolaidis
B. Ramaswamy
B. Dheenadayalan
A. Keerti
S. Mathew
P. Soundappan
D. Tiwary
Vibration and Reliability Lab
Friday, April 20, 2001
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Overview
1.Design under uncertainty
2. Structural dynamics
3. Knowledge-based design tools
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Design under uncertaintyNoiselevel (db)
Cost ($)
Design concept 1
Design concept 2
Design concept 3
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Profit is uncertain and depends on selection of design concept
Profit ($)
Probability density of profit
0Loss
Which design is better ?
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Goals
• Study and understand advantages and limitations of methods for modeling uncertainty (classical probability, Bayesian probability, fuzzy sets, imprecise probabilities)
• Study methods for modeling a decision-maker’s preferences and attitude toward risk
• Address issues of lack of data and high computational cost
• Develop tools for making design decisions under uncertainty by combining the above methods
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2. Structural Dynamics; Modeling and suppressing internal resonances in
vibration isolators
Front of the car
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Transmissibility of real isolator
1
Transmissibility
1
System resonance, n
Isolator Resonances
n
Actual
Ideal
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Using DVA’s to suppress internal resonances
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Global Vehicle Model
Global OptimizerGlobal design variables
Local models
Load and stiffness requirements for components
Optimal safety factor of components
Knowledge-based design tools; considering details upfront in design
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Traditional design optimization versus local/global optimization
6000
6500
7000
7500
8000
8500
9000
wei
gh
t (l
b)
nominal
no global/local
global/local
100 84 85
infeasible feasible