大跨度屋盖结构等效静风荷载研究

有关等效静风荷载理论的研究，以往多针对高层、高耸结构展开。大跨度屋盖结构与高层、高耸结构形式相比，最大的不同在于要考虑多阶振型的影响。由此带来的问题有：对于结构的不同构件和不同响应类型，其等效原则不是惟一的；结构振动模式与荷载分布形态密切相关；如何考虑多阶振动模态的组合。针对以上3个问题，分别探讨了相应的解决思路，并初步给出了关于结构等效背景分量和等效共振分量的确定方法。研究表明：该方法在保证控制点等效的同时，还能使结构其他部位的等效响应更接近于实际可能出现的最不利响应，因而能够更加准确地反映出大跨度屋盖结构风振响应的本质特征。

Research on equivalent static wind loadings of large-span roof structures

Concerning equivalent static wind loading(ESWL) theory,people have done a lot of works on high-rise buildings and large-span bridge structures.But compared to these two type structures,the biggest difference lying in the studies of ESWL theory on large-span roof structures is the frequencies of vibration modes which are normally very close,ie,they occur within a narrow frequency range.Consequently,it is impossible to estimate the wind-induced response of a long-span structure's roof in terms of lower frequency vibration modes alone,as is normally adequate for the analysis of high-rise buildings.The problems that bring from this are: for different component of structure and different response,its equivalent principle does not be sole;structural vibration modes and load distribution patterns have some internal links;how to consider the combination of multi-vibration-mode.Authors discussed some solutions to these three problems firstly,then,put forward a preliminarily theoretical framework for deciding the ESWL on large-span roof structures,finally,gave some detail formulas for calculating background components and resonant components of ESWL.It is proved that the method of this paper provides a good characterization of the ESWL distribution with the actual extreme wind loading on large-span structures.