An Improved Time-Domain Damage Detection Method for Railway Bridges Subjected to Unknown Moving Loads

Abstract

There is considerable interest in structural health monitoring (SHM) and damage detection of bridges and considerable progress has been made in this field in recent years. However, several challenges such as sensitivity to low levels of damage and identification without the knowledge of the moving load remain and need to be precisely investigated by researchers. The current work addresses such challenges and proposes an efficient response sensitivity-based model updating procedure in time-domain for damage identification of railway bridges subjected to unknown moving loads. The bridge is modelled as an Euler-Bernoulli beam and the train is modelled as a set of sprung masses passing over the beam. Structural damage is considered as a reduction in the modulus of elasticity of the elements. Sensitivity analysis and Tikhonov regularization methods are adopted and used to solve the inverse problem of the model updating. To verify the efficiency of the model, two numerical models with multiple damage scenarios subjected to unknown moving loads are analyzed. In addition, the efficiency of the proposed method in the presence of measurement noise is also verified. Numerical results reveal that the proposed model-updating procedure simultaneously identifies structural damages as well as the unknown moving loads with an acceptable accuracy. The effect of critical parameters such as mass and speed of the moving vehicle on the accuracy of identification results is investigated as well. Based on the findings of this research, the proposed method can be adopted and applied to online and long-term health monitoring of real bridge structures.

Moving-Principal-Component-Analysis-Based Structural Damage Detection for Highway Bridges in Operational Environments

“…The duration of a vehicle passing the bridge is short, and the change due to the temperature effect is relatively small within this short time period. The traditional moving-load-driven methods have good interpretability, as these methods are based on the accurate vehicle–bridge interaction model [ 20 ]. These methods are suitable for controlled environmental conditions, but it is laborious and time consuming to ensure their performances due to their limited anti-noise ability [ 21 ].…”

Moving Principal Component Analysis Based Structural Damage Detection for Highway Bridges Under Moving Vehicles

“…The duration of a vehicle passing the bridge is short and the change due to the temperature effect is relatively small within this short-time period. The traditional moving load driven methods have a good interpretability as these methods are based on the accurate vehicle-bridge interaction model [20]. These methods are suitable to the controlled environmental conditions, and it is laborious and time-consuming to ensure their performances due to their limited anti-noise ability [21].…”

Analysis of Seismic Action on the Tie Rod System in Historic Buildings Using Finite Element Model Updating

“…It refers to updating the finite element (FE) numerical model to adopt more precise and accurate structural dynamics parameters based on the known dynamics or statical parameters obtained through experimental investigations of a structure [12][13][14][15][16] (Figure 2). During the model updating procedure, the most commonly used model updating parameters are the material [16][17][18][19][20][21][22][23] and geometrical characteristics [23][24][25][26] and boundary conditions [27][28][29], but their selection is generally based on performing the sensitivity analysis [30]. The selection of materials and the definition of their properties cause great difficulties in the development of a numerical model due to their specific mechanical properties.…”