Vibro-acoustic modeling of roof panels for analysis of sound radiation from droplet impact

Sound generated by impacts between raindrops and roof panels of vehicles is an important factor on automotive qualities when driving in rainy conditions. Therefore, analytical method to control this phenomenon is necessary. In this research, a theoretical model for predicting characteristics of sound radiation by droplet impacts was proposed. An experiment for measuring forces generated by falling droplets was conducted. The characteristics of the measured forces were investigated in the frequency domain. A measurement on a plate was performed to understand sound radiation formed by droplet impacts. Correlations between acoustic characteristics and properties of the plate were identified. A vibro-acoustic model was developed to analyze the experimental results. Assuming generation of sound sources at each location due to the vibrating plate, radiation of sound fields was theoretically calculated and verified by comparing with the measured results. Under single and multi-layered conditions, influence facto...