Dynamic Response of an Elastic Tube-like Nanostructure Embedded in a Vibrating Medium and under the Action of Moving Nano-Objects

Traditional bridge monitoring and damage identification techniques typically rely on full-bridge coverage of sensors, such as displacement or strain sensors. However, this approach proves economically unfeasible for the vast numbers of small- and medium-span continuous beam bridges. In response to the need for rapid damage identification and integrity assessment of continuous beam bridges, a novel bridge safety monitoring method relying solely on bearing reaction forces is proposed. Firstly, the analytical expressions for the bearing reaction influence lines of a three-span continuous beam bridge under damage conditions were derived. Secondly, a rapid structural damage localization method based on the bearing reaction influence lines was proposed. Finally, feasibility and applicability were confirmed through numerical simulations and experimental validation. Additionally, the discussion includes the implementation of the warning classification and threshold setting using data from bearing force monitoring. The research demonstrates that utilizing a limited amount of bearing reaction force information can not only identify damage areas in a “non-full-coverage” manner, but also facilitates early warning and the integrity assessment of bridges. In the future, there is potential for large-scale application in medium- and small-span continuous beam bridges.

Section: Research On Bridge Integrity Assessment Methods Based On Bea...mentioning

confidence: 99%

Research on Bridge Integrity Assessment and Early Warning Monitoring Methods Based on Bearing Reaction Force

Li,

Gan,

Zhao

et al. 2024

“…These assumptions are commonly adopted in VSM studies for theoretical derivation. Nevertheless, the full interactions of the moving vehicle with the beam, the consideration of the shear deformation and rotary inertia of the beam, damping, and non-constant vehicle velocity are meaningful for follow-up works [30,31].…”

Section: Theoretical Formulations Of the Problemmentioning

confidence: 99%

“…The beam element where the vehicle axle acts is a new VBI element as it considers both the motion of the beam element and the vehicle. The equations of motion of the VBI element and normal beam element are provided in [22,30]. The vehicle axle distance d = (l 1 + l 2 ) must be larger than the length of the beam element L e to ensure each vehicle axle acts on different beam elements.…”

Section: Finite Element Simulation Of the Vbi System With Damagementioning

confidence: 99%

Theoretical and Experimental Investigations of Identifying Bridge Damage Using Instantaneous Amplitude Squared Extracted from Vibration Responses of a Two-Axle Passing Vehicle

Liu,

Zhou,

Zhang

et al. 2024

Identifying bridge damage using a movable test vehicle is highly regarded for its mobility, cost-effectiveness, and broad monitoring coverage. Previous studies have shown that the residual contact-point (CP) response between connected vehicles is free of the impact of vehicle self-vibrations and road roughness, making it particularly suitable for the indirect extraction of bridge modal properties. However, most experimental campaigns regarding contact-point (CP) responses focus on a single-axle testing vehicle within a non-moving state. This study aims to theoretically and experimentally identify bridge damage using the instantaneous amplitude squared (IAS) extracted from the residual CP response of a two-axle passing vehicle. First, the closed-form solution of the residual CP acceleration was derived for a two-axle vehicle interacting with a simply supported beam. The IAS index was constructed from the driving frequency of the residual CP acceleration. Then, numerical investigations using finite element simulation were conducted to validate using the IAS index for indirect bridge damage identification. The application scope of the approach under various vehicle speeds and road roughness grades was examined. Finally, a laboratory vehicle–bridge interaction system was tested to validate the approach. Numerical studies demonstrated that bridge damage could be directly determined by observing the IAS abnormalities, which were baseline-free. The IAS from the residual CP response outperformed the IAS from CP responses in identifying bridge damage. However, it was better to use the IAS when the vehicle speed was no greater than 2 m/s and the grade of the road surface roughness was not high. Laboratory tests showed that it was possible to identify bridge damage using the IAS extracted from the residual CP acceleration under perfect road surfaces. However, it fell short under rough road surfaces. Hence, further experiments are required to fully examine the capacity of the IAS for bridge damage identification in practical applications.

“…In the moving mass model illustrated in Figure 1c, the force applied on the ground is represented by Equation ( 1), considering the lateral inertial of the moving object. By disregarding the lateral inertia, Equation (1) simplifies to Equation ( 2), transforming the model into the moving load shown in Figure 1a [18,19].…”

Section: Vehicle Load Modelmentioning

confidence: 99%

Structural Vibration Comfort: A Review of Recent Developments

Xie,

Hua

2024

With continuous improvements in the social economy and living standards of individuals, the vibration comfort of building structures has gradually been emphasized by academic and engineering communities, such as vehicle-induced vibrations in buildings near traffic, human-induced vibrations in large-span structures, wind-induced vibrations in super-high-rise buildings, and machinery-induced structural vibrations. Comfort-based structural analysis is distinct from traditional safety-based structural analysis, and its theoretical systems and unified guidelines have not yet been established. This paper reviews recent research on structural vibration comfort, including major load categories and their impacts, comfort-based structural analysis, evaluation methods, and vibration-mitigation measures. By presenting the shortcomings of the existing research, potential topics for future study are suggested.