Aztek body work

Use of competitive benchmarking and computer simulations by GM led to significant improvements in vehicle NVH characteristics.

The importance of improving noise and vibration performance in automotive design increases with every new model. Perceived refinement by the consumer is affected by how successful a vehicle development team is in reducing low-frequency vehicle vibration. This vibration is a product of the interaction of resonant modes involving the vehicle rigid body, chassis subsystems, body flexing, and vibration of large components.

A GM development team established specifications for the 2001 Pontiac Aztek global body structure performance early in the design process to address NVH performance. The specifications were determined using frequency domain allocation of the vehicle-level resonant modes. Mode mapping, as it is called, involves partitioning blocks of frequency for the body structure and all major subsystems within the frequency domain for related vehicle vibration. Mode mapping also accounts for the forces from significant sources such as road, engine, and accessory inputs. Human-sensitivity considerations for fatigue and motion sickness also are included. Modal performance of competitive vehicles was measured and analyzed to understand the target market. The body-structure resonant frequency specifications then were chosen to position the Aztek favorably to the competition.