大跨屋盖结构多目标等效静力风荷载
MULTIPLE TARGETS EQUIVALENT STATIC WIND LOAD FOR LONG-SPAN ROOFS
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摘要: 为解决大跨屋盖结构等效静力风荷载计算中存在的多个响应目标等效问题,对多目标等效静力风荷载分析方法进行了研究。根据结构风振响应特性,基于LRC法基本原理推导了构造大跨屋盖结构多目标等效静力风荷载的基本分量,包括背景分量、共振分量及其二者的耦合项分量,该基本分量能够实现与风振响应各分量的完全对应。在此基础上,建立了多目标等效静力风荷载的求解方程,同时为限制奇异荷载的出现,引入了边界条件方程,据此求解得到了能够满足大跨屋盖结构多个响应目标的等效静力风荷载。为提高精度,还根据目标响应与静力响应间误差对求得的多目标等效静力风荷载进行修正。最后,采用所提方法对国家体育场大跨屋盖结构多目标等效静力风荷载分析计算表明,所得等效静力风荷载作用下结构静力响应与多目标响应吻合较好,验证了所提方法的有效性。Abstract: In order to solve the multiple targets equivalent problem of equivalent static wind load (ESWL) calculation for long-span roofs, an analytical method was studied. According to the wind-induced response characteristics of long-span roofs and the load response correlation (LRC) theory, the background, resonant, and their coupling component fundamental load vectors were derived. The obtained fundamental load vectors can exactly match the wind-induced response components. On this basis, a fundamental equation of multiple targets ESWL was established, and a boundary condition equation was introduced to avoid the appearance of extraordinary load value, then the desired ESWL was obtained. In order to improve calculation accuracy, the obtained multiple targets ESWL was modified according to the difference between the target response and static response excited by the multiple targets ESWL. Finally, an illustrative example of multiple targets ESWL analysis for the roof structure of China National Stadium was provided to demonstrate the effectiveness of the proposed method.