A study was undertaken to develop a numerical estimation method for vehicle interior sound and vibration based on 5.4L V8 engine radiated sound and mount vibration and to quantify the contributions of vibroacoustic paths to vehicle interior sound and vibration. The modal analysis included acoustic and mechanical excitation of the frame and body assembly of a light truck. It was performed to estimate the sound and vibration transmission characteristics from the engine compartment to vehicle interior. The respective frequency response functions were then combined with frequency based source (engine radiated sound and forces transmitted through the mounts) data to estimate the response at the receivers. The response was characterized as the binaural sound pressure and driver's seat track triaxial acceleration. The results were verified by actual vehicle interior sound and vibration measurements and subjective (jury) evaluations at relevant operating conditions.; The subjective evaluations indicated that, despite similar overall levels measured, the differences in perceived sound may still exist and are due to differences in transfer path contribution to interior sound, as seen from interaural sound measurements (between left and right ear). The adverse changes in interior vibration comfort were related to the change in rate of change of acceleration known as jerk. The Z-direction acceleration of the seat was found to be sufficient in describing interior vibration; the directions of vibration were indiscernible by the jury in subjective evaluations.; Although there were slight differences in transfer path contribution the effect of using a more production efficient cast iron crank engine compared to a more durable steel crank engine, both used in the study, is negligible in terms of interior sound and vibration as indicated in estimated, objective and subjective results.
展开▼
