Car Optimization Example

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Car Optimization Example

• David Rosen
• Georgia Tech

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Optimization Example

• Optimization of car body for
• noise-vibration-harshness (NVH) and
• crash test (roof crush during roll-over)
• 1999-2000
• SGI Origin 2000 supercomputer with 256 processors
• 3 days of computer time

Optimization of car body under constraints of
noise, vibration, and harshness (NVH) and
crash, J. Sobieszczanski-Sobieski, S. Kodiyalam,
and R.J. Yang, Structural and Multisciplinary
Optimization, 22, 295-306, 2001.
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Noise, Vibration, Harshness

• Investigate bodys vibration responses,
  stiffnesses.
• Body-In-Prime body structure and glass (no
  doors, hood, trunk).
• Element 68,000, Nodes 69,000
• 30 design variables (thicknesses, stiffnesses of
  joints)

4
Crash Simulation

• Roof crush during simulated roll-over.
• Body-in-prime doors
• Elements 127,000
• 20 design variables

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Results

• 72 hours CPU time on SGI Origin.
• Mass reduced by 15 kg (1255 to 1240 kg)
• Natural frequency increased by 10 (target)
• Stiffnesses improved 5 15
• Roof crush resistance improved 15
• Figure shows roofcrush after optimization

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Design Variables
Thicknesses