桥梁节段模型颤振导数的确定

FLUTTER DERIVATIVES IDENTIFICATION OF BRIDGE DECK

本文提出了一种以节段模型受到初始脉冲激励后的自由振动的阻尼和频率作为基本参数，在时域内识别二元非流线型体颤振导数的方法。在这一方法中，非耦合导数的确定与常规的方法没有根本的不同，而耦合导数是在指定的折算风速下根据各主振方向上的模型参数以及相应的非耦合导数通过求解非线性代数方程组得到。与目前常用的Ｓｃａｎｌａｎ方法相比，略去了实验必需的纯单一模态振动的要求，从根本上减少了对风洞实验技术的要求和工作量，而且识别精度有明显的提高。

A method, which uses the damping ratios and frequency of freedecaying oscillations as basic information to identify the flutter derivatives of a two dimensional bridge deck, is proposed. In this method, noncoupled flutter derivatives are identified by the Scanlan's method, while the coupled ones are determined by solving a system of nonlinear equations and using the parameters of the predominant modes for a given reduced wind speed. Compared with Scanlan's method in current use, the proposed method not only reduces the technical requirements to the wind tunnel tests, but also increases the accuracy of the identification.