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Simulating and Optimizing the Dynamic Chassis Forces of the Audi E-Tron
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 30, 2020 by SAE International in United States
Annotation ability available
Event: 11th International Styrian Noise, Vibration & Harshness Congress: The European Automotive Noise Conference
With battery electric vehicles (BEV), due to the absence of the combustion process, the rolling noise comes even more into play. The BEV technology also leads to different concepts of how to mount the electric engine in the car. Commonly, also applied with the Audi e-tron, the rear engine is mounted on a subframe, which again is connected to the body structure. This concept leads to a better insulation in the high frequency range, yet it bears some problems in designing the mounts for ride comfort (up to 20Hz) or body boom (up to 70Hz).
Commonly engine mounts are laid-out based on driving dynamics and driving comfort (up to 20Hz). The current paper presents a new method to find an optimal mount design (concerning the stiffness) in order to reduce the dynamic chassis forces which are transferred to the body (>20Hz). This directly comes along with a reduction of the sound pressure level for the ‘body boom’ phenomena.
We use multibody simulation along with a sophisticated tire model in the time domain in order to capture the correct excitation and structural dynamics behavior. Along with an optimizer, we rely on design of experiments (DOE) in order to find the optimal setup for engine-mount stiffness and therefore directly reduce the sound pressure level.
CitationUhlar, S., "Simulating and Optimizing the Dynamic Chassis Forces of the Audi E-Tron," SAE Technical Paper 2020-01-1521, 2020, https://doi.org/10.4271/2020-01-1521.
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