桥梁断面气动导数识别的模态参数插值方法研究

Complex Modal Parameters Interpolation Technique for Identifying Flutter Derivatives of Bridge Decks

由系统复模态的特征分析可知,同一折减风速(或折减频率)下系统的气动导数可唯一确定该折减风速(或折减频率)下系统振动模态参数,反之亦然.基于该思想可建立系统振动模态参数插值确定桥梁断面气动导数的方法.在此基础上,本文主要探讨了一种归一化提取可直接插值的模态参数的方法从而保证了模态参数插值求气动导数的可行性.数值算例验证表明,归一化提取可直接插值的模态参数的方法是适用的.

It has been noted that the complex modal parameters of a system could be computed from a characteristic analysis when the flutter derivative at a reduced wind velocity （ or reduced frequency ） is known. On the contrary , the flutter derivative can be obtained from the complex modal parameters of the system at a reduced velocity （ or reduced frequency ） .Based on this idea , a new method for identifying the flutter derivatives of bridge decks was proposed .In this paper , a method to obtain the complex modal parameters of a system from identified parameters was introduced .It makes sure that the flutter derivatives obtained by complex modal parameters interpolation technique is available .The applicability of the proposed method to extract the complex modal parameters from identified parameters was proved .