脉动风下巨子型有控结构参数研究

Investigation to the Parameters of Mega-sub Controlled Frame Subjected to Random Wind Loads

对脉动风作用下影响巨子型有控结构动力响应的两个重要参数:附加阻尼和子结构刚度进行联合研究。分别研究了脉动风作用下有、无附加阻尼时,巨、子结构动力响应随子结构刚度变化的规律,并分析了附加阻尼在巨子型有控结构中的作用。通过三维曲面图,立体地描述附加阻尼与子结构刚度共同影响巨、子结构动力响应的规律,研究了两参数的内在关系。结果表明:附加阻尼能促使巨、子结构动力响应随子结构刚度变化的规律趋于一致,并能进一步提高巨子型有控结构抗风振能力;安装附加阻尼且刚度比RD在0.5附近时,巨、子结构动力响应最大;附加阻尼存在优化值,但该优化值不随子结构刚度变化而有明显改变。因此实际设计中,选择最优附加阻尼时可以不考虑刚度因素,但必须避开刚度不利区间。

Two important parameters, i.e. additive damping and sub-structural stiffness, in mega-sub controlled （MSC） frame are researched together under random wind loads. When additive damping ratio RC = 0 and RC = 3.5, changing rules of mega- and sub-structural dynamical responses with different sub-structural stiffness ratio （RD） are investigated, and the function of additive damping in MSC frame is analyzed. Common effects of both additive damping and sub-structural on MSC frame are depicted by 3D graphs, and the relations between the two parameters are examined. The results show that the changing rules of mega- and sub-structural dynamical responses with different RD are almost consistent and the wind-resistant performance of MSC frame is further improved due to the function of additive damping, mega- and substructural dynamical responses all reach the biggest around RD = 0.5, and that the optimum additive damping has nothing with structural stiffness. Therefore, in actual design, sub-structural stiffness can be neglected when choosing the optimum additive damping. However, it must be far away from the disadvantage stiffness range.