| According to wind damage survey for every year, damage of low-rise buildings accounts for more than half among the total wind damage. Low-rise buildings overall damage mainly caused by local failure, whereas the local damage is mostly caused by the openings on the structure. Openings on the low-rise buildings are partly due to the function needed, or the door window damage caused by impact of flying debris. The internal wind pressure of the buildings increases dramatically in a very short time after the openings formed. Thus, the combination of external and internal wind pressure is required to be considered for the wind resistance design of the buildings. However, study on wind-induced characteristics of low-rise buildings with openings around the world is still in the exploratory stage, the engineers in structural design usually ignore or roughly estimate the wind-induced internal pressure. Besides, wind pressure values for the buildings with openings are not specified in the current building codes in different countries. It is obvious that great danger potential is embedded in the wind design of buildings. To this end, study is carried out systematically for the wind-induced characteristics of low-rise buildings with openings to provide helpful results for the wind resisting design of low-rise buildings.Based on the principles of computational fluid dynamics (CFD), numerical simulation is utilized to simulate the wind-induced pressure characteristics of TTU building, an international standardized low-rise building model. Through comparison and analysis between the numerical results and the existing wind tunnel experiment results, the reliability and accuracy of numerical simulation is validated for studying the wind-induced pressure characteristics of low-rise buildings with openings.Secondly, wind-induced pressure characteristics of low-rise buildings with multiple main openings are studied. Among the current research results of wind-induced pressure characteristics of low-rise buildings with openings, most of them are focus on the buildings with a single main opening. For low-rise buildings with multiple dominant openings, the study is rather limited. Wind-induced pressure principles of low-rise buildings with dominant openings on a single wall and multiple walls for different wind velocities and wind azimuths are studied in this paper. Comparison is made between the principles of wind-induced pressure principles with a single dominant opening and those with multiple dominant openings. Principles of wind--induced pressure characteristics of low-rise buildings with multiple dominant openings are concluded. "Consistency effects " is firstly proposed, that is, for low-rise buildings with multiple dominant openings on multiple walls, when the openings on the windward wall, the openings on the leeward wall and wind azimuth are on a straight line, the wind-induced pressure on the windward and leeward walls would reach its maximum (except the 90° wind azimuth case). The research results provide reliable basis for wind resisting design of low-rise buildings with multiple dominant openings.Finally, wind-induced pressure characteristics of a new type low-rise building, i.e., cable dome are studied. Currently, study on wind-induced pressure characteristics of cable domes is little. Wind-induced pressure principles are studied for various opening locations, wind azimuths and wind velocities. Detailed analysis is carried out for the mean wind pressure coefficients variation principles of cable domes with openings to provide reliable references for the wind-resisting design of cable domes with openings.The main conclusions include:(1) "Consistency effects " exists, that is, for low-rise buildings with multiple dominant openings on multiple walls, when the openings on the windward wall, the openings on the leeward wall and wind azimuth are on a straight line, the wind-induced pressure on the windward and leeward walls would reach its maximum (except the 90° wind azimuth case). (2) For low-rise buildings with multiple openings on multiple walls, the mean wind-induced pressure both on the windward and leeward walls tend to be increasing, which is due to the increase of the "blocking action" of the buildings for the wind. (3) For low-rise buildings with openings on three walls, from 0° to 60° wind azimuths, the mean wind-induced pressure on the windward and leeward walls are both positive, which is different in the case of openings on a single wall and two walls. (4) Cable dome structure within a single building, when the lord opened the mouth of the cave and low when other things being equal, the average wind pressure coefficient of the hole in that increases with the increase of wind speed, but differ in the average wind pressure coefficient of the windward cable dome structure most within the range of greater than 1.Cable dome structure in single hole, along with the height of open hole structure at the top of the average wind pressure coefficient of positive and negative changes obviously (5) Due to the geometrical characteristics of cable domes, when location of openings and wind azimuths change, there are points or lines on the surface of the structure where the mean wind-induced pressure coefficients are zero. (6) wind-induced characteristics of cable domes with openings change a lot compared with those without any openings, and great attention should be paid in the wind-resisting design of such structures. |
