大跨屋盖结构风致抖振响应研究

建立基于非定常风荷载的大跨屋盖结构风致动力响应的试验和分析方法。该方法采用多通道测压系统扩大同步测压点的数目,更全面地获得屋盖表面风压的时空特性,为准确计算结构风致响应奠定了基础。在动力分析方法上应用CQC法计算屋盖结构的风振响应,考虑多模态及模态间的耦合影响,编制了结构风致动力效应计算程序SWDP。最后对上海铁路南站工程屋盖结构的抖振响应结果进行了计算和分析。结果表明,采用多通道测压系统可以有效地扩大同步测压点的数目;基于非定常风荷载的CQC方法是计算复杂大跨屋盖结构风振响应的有效方法;背景响应对于总响应的贡献通常是不可忽略的。

A study on the wind-induced buffeting responses of large-span roof structures

A systematic method is developed for test and analysis of the non-steady wind pressure distributions in wind tunnel test of wind-induced dynamic responses of large-span roof structures.The parallel tube-manifold system is applied to augment the number of simultaneous measuring points to ensure that the non-steady wind pressures on a large-span roof can be obtained simultaneously from the rigid model wind tunnel test.The wind-induced buffeting responses can be computed by using the mode-superposition method(Complete Quadratic Combination method),to take the modal coupling effects into account,and a corresponding computer code-SWDP is developed.The characteristics of the buffeting responses of the roof structure of the Shanghai South Railway Station are analyzed.The results indicate:(1)the parallel tube-manifold system can effectively extend the number of simultaneous measurement points of wind pressures,(2)the non-steady wind load-based CQC method can be effectively employed for computing the dynamic responses of large roof structures,and(3) the background components usually contribute significantly to the total buffeting responses.