大跨度可开合空间网架屋盖风致效应

大跨度屋盖结构作为风敏感性较强的结构,风荷载是其控制荷载之一,可开合屋盖由于外形和结构的多变性,其风致效应更为复杂.以某大跨度可开合空间网架屋盖结构为研究对象,利用刚性测压风洞试验实测了屋盖内外表面的风压系数,对比了开合状态下屋盖表面风压的分布特征.基于本征正交分解(POD)及瞬态动力有限元分析,得到屋面节点的位移响应...

Wind-induced effect of a large-span openable truss roof

Large span roof structures are wind-sensitive structures, and wind load is one of the governing design loads. The wind-induced effect of openable roofs is more complicated due to the variability of shape and structure. Taking a large-span openable truss roof as the focus of this research, its wind pressure distribution was measured by the pressure measurement of wind tunnel test with rigid model and the wind pressure distribution of closed and open roof states were compared. The roof displacement response was subsequently calculated through transient dynamic analysis based on wind pressure reconstruction by the proper orthogonal decomposition (POD) method. The characteristics of the displacement response and wind vibration factors were analyzed for both closed and open states. The influence of structural damping on wind vibration factors was also clarified. The results show that the cantilever structure formed by the opening of the roof will enhance the flow separation so that the minimum net pressure of the open roof is lower than that of the closed roof. In the closed roof state, the background response dominates the wind-induced vibration, and the correlation between the background and resonant response is rather weak. For the open state, however, the results were the opposite. For symmetrical roof structures, the wind vibration factor for symmetrical roof area presents a tendency opposite to the mean displacement response. The wind vibration factors show the obvious nonlinear relationship with the structural damping ratio. When the damping ratio decreases, the wind vibration factors increase and become more sensitive to the damping ratio. The sensitivity of the wind vibration factors to the damping ratio is closely related to both the mean displacement response and the ratio of resonant component.