Estimating modal scale factors based on vehicle-induced variation of bridge frequencies. (15th February 2023)

• Record Type: Journal Article
• Authors: He, Yi; Yang, Judy P.; Yan, Zhitao
• Is Part Of: Engineering structures. Volume 277(2023)
• Publication Date: 2023-02-15
• Subjects: Vehicle-bridge interaction -- Frequency variation -- Scale factor -- Modal parameter -- Time-varying signal -- Synchrosqueezing transform; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2022.115424
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: A new formulation for estimating scale factors of mass-normalized mode shapes is proposed. The scale factors are formulated on the basis of vehicle-induced variation of bridge frequencies. The variations of higher-order modal parameters in the VBI system are firstly investigated. SST and multi-ridge extraction are adopted for precisely tracking time-varying frequencies. Numerical and experimental validation of the formulation for practical applications. Abstract: This paper presents a formulation for estimating scale factors based on the vehicle-induced variation of bridge frequencies. The scale factors of mass-normalized mode shapes are formulated to avoid dealing with randomly-scaled mode shapes from output-only modal tests. To this end, the variations of higher-order bridge frequencies and mode shapes during vehicle passage are firstly investigated, in which the synchrosqueezing transform and multi-ridge exaction algorithm are adopted in signal processing to precisely track the instantaneous frequencies in a vehicle-bridge interaction system. Various practical conditions such as pavement irregularity, bridge damping, measurement noise, vehicle speed, and bridge boundary conditions are investigated in the parametric study. The robustness of the formulation for estimating scale factors is demonstrated through the extracted time-varying bridge frequencies and mode shapes with higher-order modes included. The efficacy of using the proposed formulation is explored numerically and experimentally in signal processing for practical applications.