A robust poly-reference frequency-domain identification method to extract dynamic properties from vibration data

Abstract

When performing vibration tests on structural systems, engineers face the challenge of extracting the dynamic properties from the measured data in an accurate and robust manner. Though several methods exist for this purpose, in some circumstances, they fail to provide clear estimates for these properties, particularly when applied to noise-contaminated data. Here we propose a robust and accurate method formulated in frequency-domain modal model for extracting dynamic properties from vibration data. The method is applied to three application examples, namely the vibrations simulated with the aid of a finite element model and the real-life vibration measurements of a platform specimen and of a full-scale concrete heritage court building. Its performance is thereafter assessed by the so-called stabilization diagrams, the relative error between estimated and exact properties, the modal assurance criterion, and by comparing the synthesized frequency functions to their measured counterparts. This assessment shows that the proposed approach tends to provide clearer and more accurate identification results than those from the state-of-the-art identification methods.