Structural Health Monitoring

This comprehensive review focuses on the integration of intelligent technologies, such as the Internet of Things (IoT), Artificial intelligence (AI), and Nondestructive Testing (NDT), in the Structural Health Monitoring (SHM) field of civil engineering. The article discusses intelligent technologies in SHM for residential, commercial, industrial, historical, and special buildings, such as nuclear power plants (NPPs). With the incorporation of intelligent technologies, there have been remarkable advancements in SHM, a crucial aspect of infrastructure safety, reliability, and durability. The combination of SHM and intelligent technologies provides a cost-effective and efficient building monitoring approach, significantly contributing to energy and resource conservation. This article explores using electronic instruments, such as sensors, microcontrollers, and embedded systems, to measure displacement, force, strain, and temperature, which are crucial for detecting structural damage. I...

In this article, the effect of earthquake frequency content and noise effects on damage detection is inspected. For this purpose, the damage was defined as nonlinear behavior of beams and columns, and several ground motion records were scaled so that some elements yield under the applied excitation. Consequently, the acceleration response data of each floor obtained through the nonlinear dynamic analysis. Using the discrete wavelet analysis, the occurrence and time of damage in a frame can be detected based on the spikes appearing in the wavelet details plots acquired from discrete wavelet decomposition. The mean period (Tm) was utilized to compute the frequency content of earthquakes. The implications of this parameter for the analyses with dissimilar ground motion records were investigated and the results indicates that the records with low Tm are more suitable for structural damage detection. In order to examine the effect of noise or measurement errors on damage detection proces...

Teknologi transportasi di Indonesia semakin berkembang, contohnya pada transportasi darat. Untuk mempermudah manusia dalam penyebrangan antar daratan atau dalam konteks wilayah geografis Indonesia yaitu antar pulau maka dibangun jembatan gantung. Jembatan gantung tentunya memiliki batas ketahanan yang sudah seharusnya dikontrol untuk menghindari terjadinya kerusakan secara dini, sehingga dapat mengurangi jumlah korban apabila terjadi kerusakan pada jembatan. Sensor getaran berbasis serat optik ini merekam getaran yang terjadi pada bandul matematis sebagai modelisasi sensor ketahanan jembatan gantung. Intensitas terukur dari pemantulan sempurna pada serat optik akan berkurang dikarenakan loss akibat pembengkokan serat optik tersebut, sehingga intensitasnya berkurang. Perubahan intensitas ini diterima oleh detektor fotodioda pada ujung fiber optik. Berdasarkan getaran yang mengakibatkan respon sinyal rugi-rugi, diteruskan ke function generator sehingga dapat diterjemahkan menjadi bent...

As worldwide infrastructure is aging, significant efforts have been paid to the development of strengthening techniques that will restore or increase the initial capacity of existing structures. Considering that it is expected that shear failure happens in a less ductile mode than that observed under bending actions, special attention has been devoted to shear-strengthening methods. These methods included externally bonded fiber-reinforced polymers (EB‐FRP), the near‐surface mounted (NSM‐FRP) method, and the embedded trough‐section (ETS) technique, among others. In this paper, the ETS method is used for the strengthening of the shear of a reinforced concrete railway bridge located in Finland. The ETS method consists of the embedment of FRP or steel bars through predrilled holes into the concrete core. The bars are bonded to the concrete using adhesives. The paper includes a brief review of recent advances in the use of ETS and a comparison with other available techniques, a description of the case study, instrumentation of the bars using fiber optic sensors (FOS) for strain monitoring, the procedure used for the installation of the bars in the field, and a preliminary analysis of the data collected.

In order to improve the knowledge of the real behaviour of existing structures, structural health monitoring (SHM) is usually carried out. Initial calculations of a buttress dam located in Norway has been carried out to evaluate dam safety against the design loads. From this analysis, it was concluded that most of the pillars do not satisfy the required sliding safety factor. Despite of this, the dams shows very few signs of damage or damage development. Because of this it was believed that by installing appropriate sensors at critical locations on the dam structure the more informed decisions on future management of the dam could be made, based on the longterm measurements. This paper describes the use of Digital Image Correlation (DIC) technique for displacement monitoring and cracking assessment of a concrete pillar. The SHM monitoring system deployed proved its capability to provide remotely near-real time measurements of displacement, and crack progression. It was shown that the displacements are clearly influenced by the seasonal water level and temperature variations. Despite its extended use in laboratory environment, the current project highlighted the high potential of the DIC method which can readily be deployed for extended use in outdoor environments.

The aim of the current project is to digitalize inspections and monitoring of structures’ health using drones in order to identify and allow for easier inspection of damages in transport infrastructure. The objectives set are to perform aerial photogrammetry to recreate the as-is condition to enable off-site inspection of difficult to reach areas in structures and identify damages–eg cracks, spalling, corrosion. The drone is controlled either autonomously or with the use of a remote control by a pilot from the ground. The drone can carry a wide range of imaging technologies including still, video and infrared sensors. The high flexibility and accessibility of drones in hard-to-reach or risk exposed areas makes the airborne photogrammetry a better alternative to the ground-based method. Given the potential of UAVs to help bridge inspectors performing inspections off-site, the Swedish Transport Administration developed a demonstration project to evaluate the effectiveness and future opportunities within inspection field. Five bridges of varying sizes and types were selected as demonstrators. Data collection including the 3D model creation has been performed by three different contractors while the model-based inspection for all bridges was performed by the same team. It has been shown that the 3D models could serve as a tool for bridge inspectors from which measurements could be extracted and certain damages identified. A full off-site inspection is currently not feasible as some areas of the bridges were difficult to capture. The models are only providing near-surface information, and therefore, in-depth inspection should not be overlooked. The difficulty of capturing local defects such as delaminations and narrow cracks also reduces versatility. The main conclusion from the study is that drones cannot be
used independently to conduct inspections. Currently, they can only be used as a complement to traditional inspections. The added value of a 3D model derives from the possibility of using it as a tool to better plan large inspections in the field and/or future maintenance work.

Structural Health Monitoring (SHM) is a crucial scope of work in civil engineering specifically on monitoring the in-service and ageing coastal bridge deck concrete structure serviceability and limit state status performance. One of the possible natural process that pose detrimental effects to such structure performance monitoring is the steel rebar pitting corrosion problem. Progressive pitting corrosion process on the certain steel rebar area in low quality of concrete cover due to chloride ingression will cause local premature damage the steel rebar which obviously affect the serviceability performance of the structural element, i.e. displacement. However, the available displacement monitoring methods become an issue when it comes to engineering practicality and costs considerations. Therefore, the purpose of this study is to monitor and analyze the vertical displacement of an undamaged and damage reinforced concrete beam using the digital signal processing technology, Digital Im...

Sistema de alimentación de energy Harvesting Este estudio se enfoca en el diseño de un sistema de alimentación para una red de sensores acelerómetros de tipo MEMS, destinados al monitoreo de la salud estructural, utilizando el concepto de captura de energía (Energy Harvesting). El diseño de la

Structural Health Monitoring (SHM) of composite structures leads to greater safety during operation and reduces the cost of regular inspections. Impact damage detection is an important SHM task. Since impact damage can significantly reduce the lifetime of composite structures, sensors for impact damage are of great interest. Carbon Fiber Sensors (CFSs) can be used to detect composite damage. CFSs are lightweight and compact, and they can be integrated during the manufacturing process. In our study, CFSs were manufactured from three types of carbon fiber tows and were integrated into different layers of the lay-up in order to investigate the influence on impact damage detection. The effect of mechanical loading and temperature change on the measured electrical resistance was investigated during cyclic flexural tests. It was revealed that, it is possible to distinguish between changes in measured signals due to impact and due mechanical loading. The change in the measured electrical s...

Structural health monitoring (SHM) involves the control and analysis of mechanical systems to monitor the variation of geometric features of engineering structures. Damage processing is one of the issues that can be addressed by using several techniques derived from image processing. There are two types of SHM: contact-based and non-contact methods. Sensors, cameras, and accelerometers are examples of contact-based SHM, whereas photogrammetry, infrared thermography, and laser imaging are non-contact SHM techniques. In this research, our focus centres on image processing algorithms to identify the crack and analyze its properties to detect occurred damages. Based on the literature review, several preprocessing approaches were employed including image enhancement, image filtering to remove the noise and blur, and dynamic response measurement to predict the crack propagation.

Structural health monitoring (SHM) consists in embedding sensors in a structure like aircraft fuselages, pipes or ship hulls in order to detect defects (for example cracks or corrosion in metallic materials or delamination in composite materials) before a serious fault occurs in the structure. Guided elastic waves emitted by a sensor and propagating to another one are often used as the physical way of detecting the defect. However, the implementation of SHM systems is restricted in many situations by the necessity to store or to harvest the electric energy necessary to emit the waves and also by the intrusiveness of the sensors. Guided wave tomography imaging is able to localize and quantify the severity of the defect when it comes to loss of thickness such as corrosion or erosion. However, it needs many sensors (generally piezoelectric - PZT - transducers) and it has a cost, particularly in terms of intrusiveness. The idea in this paper is to use less intrusive sensors such as fibe...

Corrosion presents a major challenge for various industries, especially for petrochemical and nuclear industry. Estimating accurate wall thickness maps of pipes or pressure vessels is of great importance for detecting corrosion damage in these structures and assessing its remaining lifetime. Guided wave tomography provides a solution for this problem in which pipe-like structures have a high diameter to thickness ratio, by sending guided waves through the region of interest, then using tomographic imaging [1, 2] to reconstruct the thickness map, significantly eliminating the need to take measurements at all points across the surface. The Structural Health Monitoring (SHM) process involves the observation of a structure over time by using measurements from sensors embedded in this structure in order to monitor its current state of health and hence taking at the right time corrective action to prevent further rupture or leakage. It is essential to use a small number of sensors to limi...

In guided wave structural health monitoring (GW-SHM), a strong need for reliable and fast simulation tools has been expressed throughout the literature to optimize SHM systems or demonstrate performance. Even though guided wave simulations can be conducted with most finite elements software packages, computational and hardware costs are always prohibitive for large simulation campaigns. A novel SHM module has been recently added to the civa software and relies on unassembled high-order finite elements to overcome these limitations. This article focuses on the thorough validation of civa for SHM to identify the limits of the models. After introducing the key elements of the civa SHM solution, a first validation is presented on a stainless steel pipe representative of the oil and gas industry. Second, validation is conducted on a composite panel with and without stiffener representative of some structures in the aerospace industry. Results show a good match between the experimental an...

Analyses of field ambient vibration were performed on 50 concrete bridge spans along Interstate highways I-5 and I-405 in Washington State. These 50 spans included 21 pretensioned concrete beam (PCB) spans, 19 reinforced concrete box-girder (CBOX) spans, and 10 reinforced concrete slab (CS) spans. Eight measurement transducers were used to record ambient bridge vibrations at three locations on each span: midspan, one-quarter point, and one support. These records of bridge motion versus time were each subjected to a fast Fourier transformation, and plots of amplitude versus frequency were generated for each record. The plots of amplitude versus frequency were used to determine the fundamental vertical and lateral frequencies for the bridge spans measured. These fundamental frequencies were used with the bridge design parameters to derive empirical formulas that will be used to estimate the fundamental vertical and lateral frequencies of other PCB, CBOX, and CS bridge spans along I-5,...