Model‐driven response reconstruction is widely applied to supplement inaccessible dynamic information in mechanical structural health monitoring. However, increasing complexity of structures with considerable degrees of freedom and nonshareability of substructures based on security issues make it inefficient, even impossible, to perform response reconstruction. To overcome these difficulties, a reconstruction strategy is presented by innovatively incorporating experimental approximation and model reduction. As the baseline of response reconstruction, the complete structural FEM is integrated by the defined FEM‐based substructures (FSs) and experiment‐based substructures (ESs). On one hand, FS aims to deal with low reconstruction efficiency and is transformed from the accessible substructure by the Crag–Bampton method that eliminates redundant matrix data when ensuring accuracy. On the other hand, ES is established to improve the condition of modeling difficulty that inaccessible FEM of local components is replaced by the approximate model, whose vibration characteristics are described through removing a predesigned fixture using experimental coupling measurement. The complete model is established by assembling the above substructures at the desired interface. Response reconstruction referred to the area of ES is realized through transferring frequency response functions among substructures. Otherwise, reconstruction could be directly accomplished by Eigen solution and inverse modal transformation. Response reconstruction cases of a numerical beam structure and an experimental flange‐tube assembly are applied to verify superiority and accuracy of the proposed method.

Steel‐truss rigid‐tied arch bridges are among the most important structural forms of high‐speed railway bridges in China. Train‐flow monitoring data indicate that the train loads associated with multiline intersections account for 46.22% of the total train load. The fatigue performance of rigid shortest hangers under train loads at multiline intersections is important. Based on the engineering background of the Nanjing Dashengguan Yangtze River Bridge, which is the first six‐line railway bridge in the world, the fatigue performance of the shortest hangers under train loads at multiline intersections is first evaluated via long‐term dynamic strain monitoring. Furthermore, the effects of train loading parameters such as the number of train intersections and the driving direction on the axial‐bending effect and fatigue performance of the shortest hanger are analyzed. Then, the fatigue performance parameters of all the shortest hangers of the bridge in 5 cases involving multiline intersections are analyzed through numerical finite‐element simulations, and the annual cumulative fatigue damage of all 12 shortest hangers considering the axial‐bending effect is calculated according to the monitored train loads. Finally, the inspection periods of the shortest hangers are recommended on the basis of the degree of fatigue damage. The fatigue performance of the shortest hangers is significantly affected by multiline intersections. Moreover, the bending strain of the shortest hangers has a significant effect on the fatigue effect and is positively correlated with the number of train intersections. The maximum value of annual fatigue damage is calculated for the shortest hanger at the southern end of the first span of the middle truss. The results provide a basis for decision‐making involving the detection, maintenance, and management of the shortest hangers of steel‐truss rigid‐tied arch bridges.

Hydraulic shock absorbers in passenger vehicles typically generate damping through valves and orifices that create a restricted fluid passage between the cylinder’s upper and lower chambers. Motivated by the proven effectiveness of inerters in various applications, this study investigates the integration of hydraulic inertance into this fluid passage to enhance absorber performance. While prior research has explored such integration, a systematic method for identifying optimal configurations of hydraulic stiffness, damping and inertance elements within the passage remains undeveloped. To address this gap, this study proposes a novel configuration‐optimisation framework for hydraulic absorbers using a predefined number of each element type. The absorber is modelled as a three‐terminal hydraulic network, and a graph‐based enumeration method is introduced to generate all feasible network layouts. Each candidate is then tuned and evaluated to determine the optimal design, which is subsequently realised using physical components considering necessary nonlinear and parasitic effects. A numerical case study involving a simplified car model demonstrates the framework’s effectiveness. The trade‐off between ride comfort and road handling ability is investigated. For a comfort‐oriented design scenario, using just one stiffness, one damping and one inertance element, the proposed method identifies a physical design that improves ride comfort by 19.4% compared with a conventional absorber with a single orifice in the fluid passage.

Investigations are conducted to explore the combined effects of acid–salt mist and sustained loading on concrete performance and examine how neutralization depth and compressive strength evolve with the degree of concrete damage. The results revealed that with increasing the deterioration period, the neutralization depth of the concrete first exhibited a rapid and slow alternation but then continued to increase rapidly. The compressive strength of the concrete first increased slightly but then decreased rapidly with increasing deterioration time. The degradation rate of the performance of the concrete under the coupled environmental effect and load was faster than that under the environmental effect only. The thickness of the damaged concrete layer increased with increasing deterioration time. On the basis of the growth law of neutralization depth stratification in concrete, a corresponding concrete strength calculation model was established, and the calculated results strongly agreed with the measured results.

A novel self‐centering (SC) rotational wedge–shaped friction damper (SRWFD), which can be used as the high‐performance connector for the joints of beam–column, column–foundation, and coupling beam–shear wall, was proposed and investigated in this study. The friction–self‐regulating function ensures a positive correlation between the axial compressive stress of the annular friction plates and the overall rotational angle of the damper. This design not only maintains excellent energy‐dissipation (ED) capability but also obviously reduces the additional restoring moment required during the unloading process, which is conducive to improving the SC capacity of the damper and reducing the cost. The structure and working principle of the SRWFD were first illustrated, followed by systematically experimental and numerical investigations to verify the innovative functional design and to reveal the influence of the material and pretightening force (PF) of superelastic SMA bolts, the friction coefficient between friction plates and connecting plates, the friction coefficient between wedge‐shaped protrusions and grooves, the effective diameter of SMA bolts, and the height of wedge‐shaped protrusions on the cyclic rotational behavior of the SRWFD. Results showed that the damper exhibited a symmetric flag‐shaped hysteresis characterized by satisfactory SC capacity and ED capability. Furthermore, when the protrusion slope is relatively small, the SC capacity of the SRWFD exhibits a small variation with increasing slope. However, once the protrusion slope exceeds a critical threshold, the overall rotational angle recovery ratio of the SRWFD rapidly increases from approximately 7.3% to about 97.2%. This phenomenon validates the innovative functional design of the novel SRWFD, which leverages the combined structure of annular hard friction plates, wedge‐shaped protrusions, and superelastic SMA bolts to achieve the friction–self‐regulating function. As a result, the restoring moment required to unload the device to a zero rotational angle is significantly reduced, and only a small critical restoring moment is needed to ensure excellent SC performance.

To address the limitations of traditional unscented Kalman filter (UKF)‐based algorithms—which typically require either additional displacement measurements or iterative optimization for load identification—this study proposes a fast and convenient load excitation identification algorithm. The method is developed based on a novel approach for calculating the weight factors in the unscented transformation. By appropriately adjusting these weight factors, the identification results align more closely with actual measurements, effectively mitigating the phenomenon of load drift. This enables the algorithm to operate using only acceleration measurements as observations. In addition, to facilitate rapid tuning, this study employs parameter sensitivity analysis to determine reasonable ranges for the covariance parameters and the key parameters governing the sigma point distribution. Numerical simulation results demonstrate that the proposed algorithm exhibits strong noise robustness, maintaining accurate load identification even under 20% measurement noise. The algorithm is also insensitive to initial state variables and shows strong adaptability to parameter variations. Furthermore, it is capable of accurately identifying the trend and effective values (e.g., peak and valley values) of the load even under incomplete acceleration measurement conditions. Shaking table test results further confirm that appropriately reducing the value of the measurement covariance matrix promotes algorithmic convergence while maintaining identification accuracy.

As subway train‐induced low‐frequency vibrations continue to rise, there is an increasing need for more effective vibration control strategies. Although current low‐frequency vibration reduction methods offer some solutions, further progress is necessary. This paper introduces a novel tuned liquid particle damper‐dynamic vibration absorber (TLPD‐DVA), which merges the principles of tuned liquid dampers (TLDs) and particle dampers (PDs). By capitalizing on the low‐frequency damping capabilities of TLDs, this approach incorporates particles suspended within the liquid to create a hybrid damping device capable of effectively attenuating vibrations across a wide low‐frequency range (10 to 80 Hz). A discrete element method‐computational fluid dynamics (DEM‐CFD) model for multiphase flow is employed to explore the damping mechanism, optimize system parameters, and develop a frequency‐dependent nonlinear damping device. The TLPD‐DVA is then applied to floating slab track systems to control low‐frequency vibrations, and a dynamic interaction model involving the coupled vehicle‐TLPD‐DVA‐floating slab track‐tunnel system is established to assess the system’s response. Harmonic response analysis of a floating slab track fitted with TLPD‐DVAs, along with dynamic mass and mass ratio indices, clarifies the vibration reduction mechanism. Additionally, field tests demonstrate that the TLPD‐DVA reduces vertical acceleration on the floating slab by up to 8 dB and on the tunnel wall by up to 10 dB within the low‐frequency range, surpassing the performance of tuned DVAs. The proposed TLPD‐DVA offers significant potential for vibration control in various civil engineering applications, including transportation infrastructure, building foundations, and vibration‐sensitive facilities.

Regular monitoring of cable forces is critical to ensuring the long‐term safety and performance of cable‐stayed bridges. While vision‐based methods offer noncontact, cost‐effective alternatives to traditional vibration‐based methods, most existing studies adopt an offline workflow in which videos are recorded and processed afterward. This study develops an embedded vision‐based sensing system for cable force monitoring. Unlike offline vision approaches, the system performs on‐site video acquisition, processing, and force estimation on‐site, enabling real‐time monitoring without external video transfer. First, an efficient and accurate visual object tracking (VOT) algorithm is proposed for real‐time displacement extraction from video sequences. We benchmark the algorithm’s accuracy and computational efficiency on a Jetson Orin Nano using a public shaking table test dataset. The results show that the algorithm achieves a good balance between accuracy and computational efficiency, making it suitable for deployment on edge computing devices. Subsequently, the cable vibration experiment indicates that the embedded vision‐based sensing system achieves maximum errors of 2.61% in cable frequency measurement and 5.68% in cable force estimation. In addition, the camera position did not materially affect system accuracy. Future work will enhance robustness under diverse field conditions and validate the system on full‐scale bridges.