An Efficient Modal Parameter Identification Method Based on Free Vibration Response and the Energy Sorted Matrix Pencil Method

Ayubirad, Mohammad Sadegh; Ataei, Shervan

doi:10.22068/ijrare.349

Volume 11, Issue 1 (6-2024) IJRARE 2024, 11(1): 15-27 | Back to browse issues page

‎ 10.22068/ijrare.349

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Ayubirad M S, Ataei S. An Efficient Modal Parameter Identification Method Based on Free Vibration Response and the Energy Sorted Matrix Pencil Method. IJRARE 2024; 11 (1) :15-27
URL: http://ijrare.iust.ac.ir/article-1-349-en.html

An Efficient Modal Parameter Identification Method Based on Free Vibration Response and the Energy Sorted Matrix Pencil Method

Mohammad Sadegh Ayubirad

, Shervan Ataei

School of Railway Engineering, Iran University of Science and Technology, Tehran, Iran

Abstract: (280 Views)

Modal parameter identification of railway bridges is essential for comprehending their dynamic behavior. This understanding enables the development of numerical simulations that more accurately mirror their actual behavior. It also helps in monitoring changes in material condition through frequency variations over time and establishing the maximum speeds for trains crossing the bridge, all of which contribute to more effective and efficient management of infrastructure. This research presents a feasible and efficient methodology for determining the modal characteristics of railway bridges through analyzing their free vibration response. The methodology employs the energy sorted matrix pencil method (MPM). The standard MPM is known to identify both dominant and trivial modes, which can lead to erroneous results. By differentiating modes based on their energy levels, it is possible to isolate the dominant modes effectively, thereby avoiding the issues of mode mixing and mode splitting. Following an initial verification using synthetic multi-modal signals, the energy-sorted MPM is implemented in a real-world case study. It focuses on the modal parameter identification of a truss railway bridge under impact and service loads. The modal frequency and damping ratios were determined by analyzing the free decay responses. These identified modal damping ratios, observed under operational loads, were analyzed in comparison to those detected under impact tests. The successful application of the energy sorted MPM method in both theoretical and practical frameworks highlights its potential for structural health monitoring and maintenance of critical railway infrastructure.

Keywords: Damping ratio, Frequency estimation, Railway bridges, Structural health monitoring, Train loading

Full-Text [PDF 1339 kb] (51 Downloads)

Type of Study: Research | Subject: Railway track and structures