Structural system identification by utilizing transmissibility coherence from limited measured data

Yun-Lai Zhou,Ni Zhen,Cao Hongyou,Li Zhang,Magd Abdel Wahab

doi:10.1088/1742-6596/842/1/012020

Abstract

System identification performs as a core issue in structural dynamic analysis. In this study, transmissibility coherence is introduced for system identification with recalling the existing techniques based on transmissibility. Unlike previous approaches that require four-point measurement, the proposed methodology in this study only requires two-point measurement. The merit behind this approach is that the transmissibility coherence can be employed to estimate the subtraction of transmissibility between two reference points, by using auto- and cross-spectrum analysis. Verification using experimental data proves the feasibility of the proposed technique.

Highlights

System identification, one core issue in structural dynamic analysis, has appealed lots of attention during last decades
Comparing Equation (5) and Equation (6), one can find the merit of transmissibility coherence (TC) based frequency extraction method, which only relies on two-point measurement, and this gives a possibility in simplifying the extraction of frequencies, and an alternative apart from the previous techniques
One can find that the peak of TC(5, 2) corresponds to the peaks of T(5, 2), this implies the potential interrelation between them

Summary

Introduction

One core issue in structural dynamic analysis, has appealed lots of attention during last decades. The key idea is to extract the structural dynamic characteristics, namely resonant frequency, mode shape and so on. This underwent two decades using experimental modal analysis (EMA) and operational modal analysis (OMA). Even the structural characteristics generated by system identification are not the only ones, but they are of great importance compared with other techniques in SHM [14,15,16,17,18,19,20,21]. Modal parameters are widely used in damage detection, localization, and quantification [4]. In SHM, damage detection can be evaluated using direct methods or indirect methods.

Methods

Results

Conclusion