PREDICTION OF VIBRATIONAL ENERGY DISTRIBUTION IN THE THIN PLATE AT HIGH-FREQUENCY BANDS BY USING THE RAY TRACING METHOD

At high frequencies, one is interested in both the energy distribution and the energy flow of connected vibrating structures. The prediction of time- and space-integrated energy quantity has been usually performed by the statistical energy analysis (SEA), whereas the vibration conduction analysis (VCA) was suggested for calculating the time-averaged spatial energy distribution in structures. However, the VCA has not been useful due to inaccuracies in predicting the energy distribution and estimating the vibration transmission through structural joints. In this article, the ray tracing method (RTM) for high-frequency plate flexural vibration is suggested for solving the foregoing problems. The ray tube concept is adopted for describing the emanating circular wave and the governing relationships are derived for incident, reflected, and transmitted ray tubes at the coupled boundaries. The proposed RTM is applied to the prediction of the time-averaged vibration distribution in a single square panel and two line-coupled square plates. In addition, a four-panel array is investigated for the performance of the proposed RTM in analyzing the vibration transmission characteristics by panel joints. The results reveal that an improved prediction of spatial energy distribution can be obtained compared with SEA and VCA. It is also noted that the performance of the RTM is very similar to that of the wave intensity analysis (WIA) although RTM results seems to be slightly better.