Improvement of BIW NVH characteristics using a concurrent design optimization approach

The low frequency noise, vibration and harshness (NVH) characteristics play a critical role in the design of vehicle Body-In-White (BIW) structures. Lower order modes influence the structural reliability of the vehicle aswell as its ride and handling characteristics. Special consideration is given to ensure that they are spaced apart and not coincident with the frequencies of other vehicle subsystems (e.g. engine and chassis). The added stiffness required to improve the NVH characteristics comes at a cost: increased BIW mass, which affects vehicle dynamics, fuel economy, and point mobilities/structural inertances. This paper documents a procedure to balance BIW build cost, mass and structural performance through an integrated optimization process.