结构模态参数识别的随机子空间法

参数识别是结构健康监测领域研究中的重点。随机子空间法是近些年发展起来的一种线性系统辩识方法,可以有效地从环境激励的结构响应中获取模态参数。在随机子空间识别方法中,确定系统的阶数是该方法中的关键工作。稳定图方法是一种比较新颖的确定系统阶次的方法。但该方法容易识别出虚假模态。针对这种情况对稳定图方法进行了改进,避免了虚假模态的出现,进而提高了随机子空间方法的识别精度。最后对此方法在一钢管混凝土拱桥上进行了验证,试验结果表明,该方法具有良好的识别效果。

Structural Model Parameters Identification with the Approach of Stochastic Subspace

Parameter identification is currently a main topic in the field of structure health monitoring research.Stochastic Subspace Identification(SSI) is a linear approach developed in recent years.In this way,structural modal parameters can be obtained from ambient vibration.The key work in SSI is to gain the order of the system.Stabilization diagram is a novel approach to define the rank of the system,but it fails to yield false modes.In this paper the stabilization diagram is improved in connection with the problem.So the false modes can be picked out,and the precision of identification is enhanced.Finally,the method is applied in an arch bridge of steel tube concrete and the result shows that it enjoys a better efficiency in identification for the approach.