This paper documents the development process of the 2001 Pontiac Aztek body structure for improved noise & vibration performance. Successful vehicle development under an accelerated timing schedule demands clearly defined body structure vibration performance targets and critical dependence on the math based modeling process.
Specifications for global body structure vibration performance were generated through a two step process. First, a benchmarking activity was undertaken to comprehend competitive vehicle performance. Secondly, a frequency domain “mode map” was constructed to minimize vehicle subsystem interaction.
Computer simulation models were developed to predict the body structure performance. A coarse full body structure model was used to define body structure section size and joint requirements. Detailed analysis models of body joint areas were used to synthesize the joint design. This process led the design efforts to minimizing body structure mass while optimizing vibration performance.
A comprehensive measurement plan was executed to confirm the frequency performance of the body structure. Modal tests were performed at several points in the prototype body build process to confirm the analysis modeling efforts.
The 2001 Pontiac Aztek body structure vibration performance is dramatically improved over that of the previous generation from which it was conceived. Increases in body structure stiffness of 47%, 40% and 89% are seen in the three lowest frequency global body structure modes.