大跨屋盖的完全三分量等效静力风荷载

Refined three components method for determining equivalent static wind loads of large span roof

惯性风荷载法物理意义不明确,传统三分量叠加法忽略背景-共振耦合效应,本文提出一种完全三分量的等效静力风荷载方法。利用完全三分量方法研究了开孔屋盖的等效静力风荷载,研究结果表明,阵风荷载因子法除在等效节点处有较好的精确性外,其他非等效节点处的等效静力风荷载均偏离正常分布,不适宜求解大跨屋盖等效静力风荷载;完全三分量法具有明显物理意义,其背景部分可采用全模态的LRC法实现,比截断模态的惯性风荷载法更加精确;忽略背景-共振耦合效应的传统三分量法低估等效静力风荷载10%左右,完全三分量法可考虑背景-共振耦合效应,相应于传统三分量法更加精确。

For overcoming the defect of traditional three components method and inertial wind load method,a refined three-components procedure is proposed to determining ESWLs by stochastic dynamic method. The ESWLs of opening roof are calculated by refined three components method, it is shown that, （1） the GLF method can estimate the ESWLs on the equivalent node correctly, which can not estimate the ESWLs on the non-equivalent node,and it is not proper to large span roof. （2）The refined three-components method is described significantly with physical means, and is accurate as the same as full modes inertial wind load method in theory, as well as is more accurate than inertial wind load method with part of modes. （3） The ESWL is under-estimated about 10% by traditional three components method. The refined three-components method can take account into the coupling effect between BESWL and RESWL, which is more accurate than traditional three components method,, which can be used successfully in the wind resistance of large span roof.