Damage detection of railway tracks is vital to ensure normal operation and safety the rail transit system. Piezoelectric sensors, which are widely utilized receive ultrasonic wave, may be disturbed in system due strong electromagnetic interference (EMI). In this work, a hybrid sensing proposed validated by utilizing lead-zirconate-titanate (PZT) actuator fiber Bragg grating (FBG) sensor evaluate damage conditions tracks. The conventional guided wave-based method direct wave detect damages...

Corrosion monitoring of steel bars has drawn extensive attention in recent decades. Conventional ultrasonic method, utilizing direct waves to detect damage, is adequate for severe pitting corrosion but suffers from low sensitivity incipient corrosion. Coda wave technique, a very sensitive method subtle changes medium using later arrival packets, innovatively introduced monitor bars, especially the early stages. The decorrelation coefficient (DC) values are calculated quantify variations both...

The traditional probability of detection (POD) method, as described in the Department Defense Handbook MIL-HDBK-1823A for nondestructive evaluation systems, does not take time dependency data collection into account. When applied to situ sensors measurement flaw sizes, such fatigue-induced crack length and corrosion-induced mass loss, validity reliability method is unknown. In this paper, POD their associated assessment detectable sizes are evaluated using a size-of-damage-at-detection...

Tunnels for subways and railways are a vital part of urban transportation systems, where shield tunneling using assembled segmental linings is the predominant construction approach. With increasing operation time varying geological conditions, tunnels usually develop defects that compromise both structural integrity operational safety. One common issue separation segment joints may cause water/mud penetration corrosion. Existing inspection strategies can only detect openings after their...

In this study, a smart rock, which is magnet embedded in concrete ball and whose direction always pointing downwards, proposed to monitor bridge scour depth. Based on the theory of magnetic field, distribution magnet-induced field (MMF) induced by rock was derived. An algorithm developed localize position rock. Field tests were conducted at pier three different times. Both intensities ambient (AMF) total (TMF) measured with magnetometer. Results showed that presence steel reinforcement or...

Abstract A large number of slopes appear along the line during railway construction, which will pose a threat to safety operation. Slope monitoring plays an important role in ensuring Aiming at difficulties sensor multiplexing, low accuracy, and disturbance by trains, this paper proposes slope method based on integrated fusion detection inclination vibration. Instability failure characteristics K3 Shuohuang Railway dynamic under excitation train load are analyzed finite element (FEM)...

Coastal concrete structures, such as cross-sea bridges and tunnels, are susceptible to the penetration of chloride ions, which can lead deterioration passive film on rebar surface, consequently accelerating corrosion process. Conventional methods for monitoring ions typically require in situ drilling sample collection, thereby compromising efficiency accuracy. Additionally, real-time early warning cannot be achieved. To address these challenges, this work introduces a fluorescent-probe-based...

In this Letter, a high-accuracy, two-dimensional displacement sensor is proposed, designed, and demonstrated based on the concept of an extrinsic Fabry-Perot Interferometer. The composed two bundled single-mode optic fibers in parallel plasmonic metasurface resonators inscribed gold substrate via focused ion beam. fiber end surface are with small cavity between. change or Z-component determined from pattern interference fringes. X-component displacement, perpendicular to Z component,...

In this study, graphene/silver nanowire (Gr/AgNW)-based, Fe-C coated long period fiber gratings (LPFG) sensors were tested up to 72 hours in 3.5 w.t% NaCl solution for corrosion-induced mass loss measurement under four strain levels: 0, 500, 1000 and 1500 µε. The crack interfacial bonding behaviors of laminate Gr/AgNW layer structures characterized using Scanning Electron Microscopy (SEM) electrical resistance measurement. Both optical transmission spectra impedance spectroscopy (EIS) data...

As-grown graphene via chemical vapor deposition (CVD) has potential defects, cracks, and disordered grain boundaries induced by the synthesis transfer process. Graphene/silver nanowire/graphene (Gr/AgNW/Gr) sandwich composite been proposed to overcome these drawbacks significantly as AgNW network can provide extra connections on layers enhance stiffness electrical conductivity. However, existing substrate (polyethylene terephthalate (PET), glass, silicon, so on) for production limits its...

To deal with the uncertainties in modeling offshore wind turbines, we propose a parameter inversion method for pile–soil interaction model based on structural health monitoring results and numerical model. The proposed has model, an objective function selected using both identified results, inverse optimization random search algorithm assumed space. minimum are as situ parameter. is confirmed to converge after some number of iterations, depending what initial values are. However, different...

Digital twin aims to create a virtual model for physical structure by combining measurement data in structural health monitoring. The most important feature is achieve the structure-monitoring synchronization. For this purpose, physics-data hybrid framework develop bridge digital monitoring proposed paper. base firstly formed finite element of representation that can fully incorporate both geometry and state. then built all monitored bridge. By defining context common base, mirror...

Short/mid-span bridges are the most commonly used infrastructure in highways, railways, and other transportation projects. With service time increasing, local damage performance degradation of short/mid-span inevitable. Therefore, assessment bridge condition is essential to ensure its safe operation. However, existing methods mostly assume region as a uniform reduction stiffness, which not consistent with actual bridge. Consequently, those can hardly achieve evaluation damage. To address...

Mixed-dimensional nanomaterials composed of one-dimensional (1D) and two-dimensional (2D) nanomaterials, such as graphene-silver nanowire (AgNW) composite sandwiched structures, are promising candidates building blocks for multifunctional structures materials. However, their mechanical behavior failure mechanism have not yet been fully understood. In this work, we performed integrated experimental, theoretical, numerical studies to explore the performance modes graphene-AgNW under tensile...

This study aims to explore bond capacity between monolayer graphene and cementitious composites for the first time through a pullout test. The low-pressure chemical vapor deposition method was used synthesize on copper substrate be embedded in mortar made by briquette mold. them higher than tensile strength of sheet with as-grown surface since all specimens failed fracture embedment length more 30 mm. enhanced stress normalized energy during test as width increased. short communication...

Bridge deformation consists of cross-section rotation and deflection, which are crucial parameters for bridge capacity evaluation damage detection. The maximum value deflection usually happens at mid-span while it two-ends. Therefore, compared with is more convenient in-situ measurement since the pier can be reference point. In this study, a high-precision inclinometer was conceptualized, designed, validated. proposed converted small section into an elastomer. Strain gauges were then...

In this study, a corrosion threshold-controllable sensing system of long period fiber gratings (LPFG) is developed and validated for life-cycle monitoring steel bars in corrosive environments. Three Fe-C coated LPFG sensors with two bare LP06 LP07 modes strain temperature compensation were multiplexed deployed inside three miniature, coaxial tubes to measure (long-term years) critical mass losses through the penetration tube walls their corresponding (short-term hours) rates life span bars....