大跨屋盖时域多目标等效静力风荷载计算方法

UNIVERSAL EQUIVALENT STATIC WIND LOADS FOR LONG-SPAN ROOFS IN TIME DOMAIN

根据大跨屋盖结构多振型参与结构风振,等效静力风荷载存在多目标的特点,提出时域多目标等效静力风荷载的分析方法。该方法的基本思路是:利用时域分析得到的位移响应时程,计算结构的广义恢复力时程,对广义恢复力进行POD分解,得到广义恢复力的本征模态,以此构造多目标等效静力风荷载的基本向量;引入约束方程组和权值因子,用加权约束最小二乘法得到基本向量的最优组合系数,从而得到多目标等效静力风荷载。该方法能够再现风振响应特点,在保证关键目标等效精度的同时,得到较合理的多目标等效静力风荷载分布。最后,将该方法应用于某大跨屋盖,验证了该文方法的有效性和精度。

Long-span roofs are characterized with multimode buffeting responses as well as multiple objectives for equivalent static wind loads.A new method of analyzing universal equivalent static wind loads in time domain is proposed.According to time domain displacement responses,a generalized restoring force was calculated.Then POD analysis was conducted to obtain the eigenmodes,dominating eigen-modes were selected as the basic vectors to express universal equivalent static wind loads.With constraint equations and weight factors,a least-squares method was employed for calculating the combination factors of these basic vectors.Universal equivalent static wind loads were obtained reflecting the characteristics of wind induced response,and to ensure the equivalent accuracy for key objectives.Finally,a long-span roof was considered to verify the validity and accuracy of this method.