Abstract
This study has investigated the characteristics and source of the vibrating and scattering behavior of roof tiles with the aim of providing a better insight to the mechanism. 100 roof tiles were set up in 10 lines and 10 rows on a pitched roof in the downstream of the flow from a wind tunnel. These experiments were followed by series of tests where the slope angle of the roof tiles was changed. The vibrations of the roof tiles were simultaneously measured by the two accelerometers, and the motions of the vibration and scattering were observed by the high-speed video camera. The frequency response function and coherence function of roof tile were measured by an impact hammer test under no flow condition. Just before scattering of the roof tiles, both vibrations of a higher frequency mode and vibrations of lower frequency mode appeared simultaneously in the roof tiles. The values of the higher frequencies were corresponding to the values of resonant frequencies of the roof tiles. It was thought that the scattering of roof tiles was influenced by the vibration of the lower frequency mode. The frequencies of the vibration were measured by a high-speed video camera system. The values of the lower frequencies were 10Hz∼20Hz. The mechanism of the scattering of the roof tiles could be understood by means of the information from the accelerations and the images of roof tiles.
