风振响应中选择主导振型的主动预测法  

An active forecasting method for selecting the dominant modes of wind-induced response

作　　者：陈波[1] 武岳[2] 沈世钊[2] 

机构地区：[1]北京交通大学,北京100044 [2]哈尔滨工业大学,黑龙江哈尔滨150090

出　　处：《土木工程学报》2008年第5期40-45,共6页China Civil Engineering Journal

基　　金：国家自然科学基金重点资助项目(50338010);中国博士后科学基金(20070410909)

摘　　要：针对大跨度空间结构多振型参与结构振动的特点,提出一种在频域内分析该类结构风振响应的应变能主动预测法。该方法的基本原理是:以用应变能大小评价各振型在风振响应中的参与程度这一方法为基础,结合振型响应的简化分析方法,给出风振响应中各振型响应的应变能简化计算方法;根据各振型的响应谱特征,将大跨度空间结构分为由背景响应或共振响应占主导地位的两类结构,对每一类结构,定义应变能预测指标,该方法只需要简单的几个基本参数(如结构振型和风荷载信息)就可以快速计算各振型的应变能贡献大小,衡量各振型在风振响应中的参与程度,从而达到快捷选择大跨度空间结构风振响应中主导振型的目标,能够显著提高振型分解法的计算效率。最后,将该方法用于一单层球面网壳,结果表明:应变能主动预测法可以快捷、准确地选择风振响应中的主导振型,计算得到的节点位移响应谱和均方根响应与准确值吻合较好。With regard to the multimode buffeting response characteristics of large-span space structures, an active forecasting method for selecting the dominant modes of wind-induced response is proposed. The principles of this method are： a simplified method is suggested to calculate the modal strain energy and to analyze the modal response, and the contribution of each mode to the dynamic response is weighed by its modal strain energy; according to the characteristics of the response spectrum, large-span space structures are divided into two categories, whose wind-induced response is dominated by background response or resonant response, and an indicator to weigh strain energy is defined. In this method, a few parameters with respect to fluctuating wind loads and structural models are sufficient to estimate the contribution of each mode to the fluctuating response. This method is efficient for choosing the dominant vibration modes of wind-induced response, and can reduce the computational expense of modal superposition method. The wind-induced response of a single layer reticular shell is analyzed, and the results indicate that this active forecasting method can select the dominant modes quickly and accurately.

关 键 词：风振响应 大跨度空间结构 应变能 主导振型 

分 类 号：TU393.3[建筑科学—结构工程] TU312.1