Time‐varying frequency‐based scaled flexibility identification of a posttensioned concrete bridge through vehicle–bridge interaction analysis

Abstract

Dynamic testing methods have been widely used in engineering practice for investigating dynamic properties of bridges; however, only basic dynamic parameters (i.e., natural frequencies, damping ratios, and unscaled modal shapes) can be identified, which are insufficient for condition assessment and health monitoring. To address this limitation, this article takes a three-span posttensioned concrete bridge as testbed; more useful structural parameters including mass-normalized mode shapes and scaled flexibility matrix are intended to be identified from moving vehicle-induced responses. For identifying scaled flexibility matrix, structural scaling factor between arbitrarily scaled mode shapes and mass-normalized mode shapes needs to be calculated firstly. In this article, time-varying frequencies of vehicle-bridge interaction (VBI) system were adopted for structural scaling factor identification, and the sensitivity of parameters identification error on calculated scaling factor was also investigated. The effectiveness of the proposed method was verified by in situ measurements of the studied three-span concrete bridge. In field testing, static load test and classical impact vibration testing were performed on this bridge for verifying the correctness of the proposed method. The good agreement between predicted deflections by using the scaled flexibility and reference values illustrates the reliability of the proposed method.

Efficient Dynamic Performance Prediction of Railway Bridges Situated on Small-Radius Reverse Curves

“…Researchers have employed various numerical models and analysis methods to address vehicle-bridge interaction. Tese studies contribute to structural dynamics and encompass theoretical, numerical simulation, and real-world experimental aspects [1][2][3][4][5]. Tese investigations often utilize diferent vehicle models, such as moving force models, moving mass models, quarter-vehicle models, and fullvehicle models [6][7][8][9][10][11][12][13][14][15].…”

A method for time‐varying reliability calculation of RC bridges considering random deterioration process

“…Many scholars have studied the probability of failure models of bridges concerning time. [1][2][3][4][5][6] Cornell proposed a second-order moment model for computing structural safety. 7 Ang and Cornell proposed a First Order Reliability Method (FORM) for reliability calculation, which quickly gained wide applications in various fields.…”

“…MBridge reliability refers to the probability of a bridge structure completing its intended design function under specified conditions and within a specified timeframe. Many scholars have studied the probability of failure models of bridges concerning time 1‐6 . Cornell proposed a second‐order moment model for computing structural safety 7 .…”

Identification of gradually varying physical parameters based on discrete cosine transform using partial measurements

“…For instance, the cumulative structural damage evolves from minor to severe, leading to gradually changing vibration characteristics 25 . For the vehicle‐bridge coupling system, the mass distribution of the system varies with time due to the vehicle movement, which also results in the gradually varying features of the system 26–28 . What is more, a gradually changing of structural physical parameters may occur and terminate in several seconds, for example, during earthquake.…”

“…25 For the vehicle-bridge coupling system, the mass distribution of the system varies with time due to the vehicle movement, which also results in the gradually varying features of the system. [26][27][28] What is more, a gradually changing of structural physical parameters may occur and terminate in several seconds, for example, during earthquake. Huang et al 9 evaluated the gradually varying stiffness parameter of a five-story shear-building subject to seismic excitation.…”