Experimental Study of Flow-Induced Vibrations and Scattering of Roof Tiles by Wind Tunnel Testing

Abstract

The tremendous destruction caused by recent typhoons in Japan has caused a substantial upsurge in interest in the subject of global warming among news media and the wider public. There are concerns that global climate change may have played a significant role in these events. Some believe that global warming is responsible for an increase in the frequency of destructive natural events. Typhoons cause the destruction of tiles on the rooftops of Japanese residences. The wind load on a roofing element is created by the difference between the external and internal pressures. The net wind load is, in general, determined by the building flow field, wind gustiness, and the element flow field (Peterka et al, 1997; Cermak, 1998). Although these parameters directly influence the external pressure distribution on a roofing element, the development of internal pressure, which indirectly depends on these parameters, is governed by a dynamic response that varies according to different roofing elements. The pressure distribution on an external roof surface and internal pressure distribution have been determined in numerous studies (Hazelwood, 1980; Ginger, 2001). Element wind loading may differ significantly from the load derived from the external pressure distribution. Internal pressure is governed by the wind permeability of the surface, which is determined by openings, such as gaps between tiles or venting devices, and by the equilibrating resistance through and underneath a wind permeable surface (Kramer et al, 1979).