基于欧氏距离的网架单点最优激励位置研究

Study of single optimal excitation position based on Euclidean distance in spatial truss structure

针对网架结构频率比较密集的特性,构建了1种基于欧氏距离的模态分离方法。计算各阶模态对响应的贡献(即加权系数),构造加权系数的模式向量、目标向量,定义目标函数,欧氏距离最小的目标函数即为最优激励位置。并以一个两向正交正放网架结构为例,在完好、单损伤和多损伤情况下,通过欧氏距离分离法获得该结构不同状态下的单点最优激励位置。最后用模拟获得的最优激励点进行激振,采集响应信号,用希—黄变换方法计算结构模态,验证单点最优激励位置选取方法的有效性。该方法为网架结构现场检测的单点激励位置选取提供可行的方案。

According to the characteristics of frequency-intensive on spatial truss structures,a method of modal separation based on Euclidean distance was established to solve this question.Firstly,modal weighting coefficient was calculated,in addition mode vector and objection vector were obtained also.As the Euclidean distance between mode vector and objection vector obtained minimize,the optimal excitation position can be also received.Secondly,the optimal excitation position of an orthogonal spatial truss structure can be gained using this method in case of structural intact,single-damage and multi-damages.To verify the validity of this method,excitation this structure by optimal excitation position,collecting response signals,the structural modal can be calculated by hilbert-huang transform.This method can give a feasible way to realize damage testing of spatial truss.