大跨度屋盖结构脉动风振响应的参与振型

为了选取大跨屋盖结构脉动风振响应的主导振型,提出了振型能量参与系数及其累积参与系数的计算方法.在总结振型背景响应、振型共振响应的计算方法的基础上,给出了脉动风荷载在背景响应及各振型背景响应上做功的平均值,提出了背景响应振型能量参与系数计算公式和主导振型的选取方法;给出了振型共振响应内能的表达式,提出了共振响应的振型能量参与系数的计算公式和振型选取方法.数值算例表明,振型位移响应对总位移响应的贡献大小符合振型能量参与系数之间的相互关系.背景位移响应的计算精度可通过背景响应振型参与系数及其累积参与系数来控制,而共振响应累积振型能量参与系数则反映了参与计算振型的共振响应总能量与背景响应总能量之比.

Dominant modes of fluctuating wind-induced response for large-span roof

The mode energy participation factor and the cumulated factor are presented in order to identify the dominant modes of fluctuating wind-induced response for a large-span roof. After summarizing the calculation methods of mode background response and mode resonant response,the expressions of mean works done by the fluctuating wind load through the displacements of total background response and mode-background responses are given. The mode energy participation factor and the selection method of dominant modes for background response are presented. The internal energy of resonant response of a mode is investigated,and the mode energy participation factor and the selection method of dominant modes for resonant response are presented. It is indicated in the example that the contribution of displacement response of a mode to the total displacement is dependent on its energy participation factor. The accuracy of total background response is concerned with both the energy participation factor of background response of the chosen mode and the cumulated factor of background response while the cumulated energy participation factor of resonant response is the ratio of total energy of resonant response related to the chosen mode to the energy of total background response.