This work describes an approach for combining local and global non-destructive techniques for the structural characterization and conservation assessment of cultural heritage buildings. An experimental investigation program was conducted on the south vault of St. Mark's Basilica in Venice, involving historical investigations, a damage survey, sonic tests, and ambient vibration measurements. Recorded

Measurement systems using different sensors are currently well established for the safe use of structures in principal infrastructures, such as cable-stayed bridges. However, existing practical technologies that assess structural states by analyzing monitored data are underutilized. Although technologies to identify potential damage using advanced sensors or algorithms are continuously being developed

Magnetorheological (MR) damper is one of the most promising smart devices for dissipating seismic energy and reducing structural vibrations. The MR dampers with multiple coils are widely adopted to enhance the output damping forces and seismic performance. In order to study the dynamic characteristics of multicoil MR dampers from a micro to macro viewpoint, a three-coil MR damper was designed and manufactured

A nonlinear energy sink is designed to control the oscillations of a 2 degrees-of-freedom pendulum under the following types of excitations: horizontal and vertical base displacements and initial energy. Coupled nonlinear governing system equations are treated with the multiple-scale methods with different assumptions depending on applied loads. Fast and slow system dynamics are revealed leading to

Wind, wave and seismic loading induced excessive vibration of offshore wind turbines (OWTs) impairs the wind turbine energy output and escalates its fatigue damage. The present study proposes a three-dimensional adaptive pendulum tuned mass damper (3D-APTMD) to control the bidirectional dynamic responses of monopile OWTs exposed to combined wind, wave, seismic loading, and time-varying structural properties

This paper deals with the identification of the weight of a train in motion, based on the measurement of the time history of strains at the foot of the rail. The direct problem is initially considered, modelling the rail as a one-dimensional infinite Euler–Bernoulli beam, resting on a viscoelastic soil and subjected to a Dirac delta load travelling at constant speed. A closed-form solution is used

The real-time hybrid simulation (RTHS), which combines experiment with numerical simulation, is an effective method to study the dynamic characteristic of high-speed railway train–bridge coupling vibration. In this paper, a simplified virtual RTHS platform of train–bridge coupling vibration is developed to illustrate the test logic and the feasibility of carrying out the physical test of moving train

Tensegrity domes are reticulated prestressed structures composed of bars in compression and cables in tension. These structures are flexible lightweight systems with low structural damping, and thus, they are sensitive to vibrations induced by strong wind and earthquakes. The present work deals with the robust multimodal control of a large-scale tensegrity dome of Geiger's type. Assuming random excitations

In Tatsis et al,1 the link to repository “Sonkyo-Benchmark GitHub” was mistakenly omitted in the published article. The correct link is provided below. https://github.com/ETH-WindMil/Sonkyo-Benchmark The online version has been corrected.

No abstract is available for this article.

Damage and failure of rubberized self-compacting concrete (RSCC) under uniaxial tension are investigated by acoustic emission (AE) and digital image correlation (DIC) techniques. Four RSCC mixtures containing fine rubber particles with 0%, 5%, 10%, and 15% volume fractions are tested. The effect of rubber content on the macroscopic mechanical behavior, the AE parameters, the strain fields, and the

The analysis of the dynamic behavior of wind turbines is a complex task. These structures present diverse configurations, dependent on the wind conditions. Consequently, the dynamic behavior is highly dependent on their operating conditions. This paper analyzes the dynamic behavior of a 2.0 MW wind turbine during 1 year of operation. In that sense, post-processing tools aiming to decompose the measured

The tuned mass damper inerter (TMDI) is a linear passive dynamic vibration absorber widely considered in the literature to mitigate the motion of dynamically excited primary structures. Previous studies focused on optimal TMDI tuning approaches and connectivity arrangements to improve motion control efficiency for some given primary structure. This paper investigates the influence of the elastic and

Recent advances in visual sensing technology and unmanned aerial vehicle (UAV) provide an effective tool to capture the as-is conditions of infrastructure and thus have gained their popularity in infrastructure inspection and documentation. To facilitate this process, several recent studies have proposed automated methods for detecting concrete cracks from UAV-based images. This study is aimed at proposing

Civil building structures equipped with active or semi-active control devices help mitigate structural damages in the presence of any seismic excitation. These advanced mitigation systems require additional devices such as sensors, actuators, and communication systems that increase issues related to energy consumption, measurement errors, and costs of implementation. In this work, we propose a methodology

Each operational modal analysis (OMA) technique may produce significant errors during the identification procedure due to the applied methodology, environmental/operational conditions, and instrumentation. Consequently, those errors can adversely affect the quality of identified parameters. In this context, this study aims at providing a comprehensive discussion on the propagation of predictions errors

In the context of detecting changes in structural systems, several vibration-based damage detection methods have been proposed and successfully applied to both mechanical and civil structures over the past years. These methods involve computing data-based features, which are then evaluated in statistical tests to detect damages. While being sensitive to damages, the data-based features are affected

Knowledge of the camera motion is important in the applications of structural dynamic response measurement using a vision-based approach because in most of the field measurements, such motion can be non-trivial and the accuracy of dynamic response measurements is strongly affected by the camera motion. This paper presents a new framework for camera motion estimation and vision-based displacement measurement

Although the effectiveness of discrete wavelet transform (DWT) for analyzing time-varying measurements has been studied for mechanical and civil engineering applications, a few fundamental questions still need to be answered, such as how to choose an optimal decomposition level (DL) for a specific task. Selection of the optimal DL still remains a question that has not been adequately explored and not

Inerter-augmented tuned mass dampers (TMDI) demonstrated considerable performance robustness. A tuned liquid column damper (TLCD) offers reduced mass ratio than a TMD for identical efficiency. TLCD provides additional dissipation by flow through orifice. Motivated by these attributes, this study employs an inerter in conjunction with a TLCD. The compliance for installation of an inerter is availed

Crack detection provides valuable information concerning the location, extent, type, and severity for structural health monitoring of civil infrastructures. Due to the influence of uneven lighting and imaging noise, as well as the debris, various textures, and materials of the different civil structure, detecting cracks in the surface images of civil infrastructures remains challenging in that there

Within civil engineering, the inclusion of control strategies is confined to limited application areas due to the practical overhead and an alleged conservatism. This paper presents a simple yet flexible framework for experimental testing of closed-loop structural systems. Compared to alternative existing solutions, the proposed framework requires limited programming knowledge, which heavily simplifies

During the operating lifecycle of civil structures, cracks will occur inevitably, which may pose great threat to the safety of the structures without timely maintenance. Digital image processing techniques have great potential in automatically detecting cracks, which can replace the labor-intensive and highly subjective traditional manual on-site inspections. Therefore, this paper presents a crack

To determine the degree of fire damage in reinforced concrete (RC) T-beams, a damage identification method based on an improved support vector machine and firefly algorithm (FA-SVM) is proposed herein. First, based on the fire test of 10 simply supported beams, a refined finite element model of simply supported T-beams was established. A modal analysis of the simply supported beams was performed to

The precision error of the Brillouin optical time domain reflectometry (BOTDR)-based distributed fiber optic strain measurement is normally evaluated based on strain change from the initial zero strain state. In many structural health monitoring applications, however, there is initial strain caused by the installation process of a fiber optic sensor cable to a structure. Engineers are interested in

Bridge influence surface is an important tool to study the bridge responses under the moving loads, which contains tremendous structural information. The structural deterioration during the service life would induce the variation of the bridge influence surface, which makes it essential to identify the influence surface exactly from the field measured data under moving vehicle loads. This paper firstly

Finite element (FE) model updating in multi-objective framework helps for better understanding of overall performance in updating (under various variations of weightages assigned to basic components of the objective function) along with providing scope for better judgmental selection. A FE model updating in multi-objective framework is proposed with no requirement of repeated eigen-solution along with

Real-time hybrid simulation (RTHS) is a novel structural seismic test method that has good application prospects. The applicability of RTHS for large-scale space frame structures is further investigated in this study based on high-strength steel composite Y-eccentrically braced frames (Y-HSS-EBFs). First, an RTHS system was established, which included OpenSees, OpenFresco, an xPC-Target, and an electrohydraulic

A data-driven approach for modeling bridge buffeting in the time domain is proposed based on the structural health monitoring (SHM) system. The long short-term memory (LSTM) network is applied to model the bridge aerodynamic system with the potential fluid memory effect which is characterized by an uncertain time lag between inflow wind and the structural response. SHM is incorporated into this data-driven

This study addresses a key issue that prevents the wide application of the novel predominant natural frequency (PNF)-based method for bridge scour monitoring, which is also applicable to the frequency-based health monitoring of other structures with soil–structure interaction. This issue is that no theory or method is currently available to guide the prediction of scour depths based on measured PNFs

The objective of the present study is to investigate a new energy dissipation system that combines the positive stiffness of the resetting passive stiffness damper (RPSD) with the negative stiffness of a passive negative stiffness device (PNSD). The displacement-based adjustable stiffness and energy dissipation (D-BASED) system can be designed to have independent damper stiffness and energy dissipation

This paper studies the use of a new nonlinear damper, the hysteretic friction tuned inerter damper (HFTID), for seismic control of engineering structures. The HFTID consists of a tuned inerter damper (TID) in parallel with a hysteresis spring friction element. The analytical expressions for the force and displacement transmissibility of a SDOF system with HFTID are derived via the method of harmonic

Automatic visual inspection of cracks on concrete surface has become increasingly important for the health diagnosis of subway tunnel structures to prevent catastrophic failures. This paper designs an on-board image acquisition system using multiple line scan cameras to capture the full-section images of tunnel surface and proposes a robust automatic crack detection method for noisy and complicated

Many building structures in our life are mainly composed of concrete. Thus, monitoring of the failure of concrete structures is of great significance. We built an experimental system to monitor the magnetic field change upon concrete damage, based on which the magnetic field signal of the concrete failure process was tested. And then the relationships between magnetic induction intensity and load,

The mathematical monitoring models that are currently used for the displacement of arch dams are mostly established for a single monitoring point, without considering the spatial association of the displacements at multiple monitoring points. The main purpose of this paper is to develop and verify a mixed-coefficient panel model for dam displacements of multiple monitoring points. To maintain the largest

This work aims at radar sensors in the frequency band from 57 to 64 GHz that can be embedded in wind turbine blades during manufacturing, enabling non-destructive quality inspection directly after production and structural health monitoring (SHM) during the complete service life of the blade. In this paper, we show the fundamental damage detection capability of this sensor technology during fatigue

Deep learning-based approach has emerged as a promising solution to handle big machinery data from multi-sensor suites in complex physical assets and predict their remaining useful life (RUL). However, most recent deep learning-based approaches deliver a single-point estimate of RUL as these models represent the weights of a neural network as a deterministic value and hence cannot convey uncertainty

Estimating temperature-induced strain is of critical importance for structural safety assessment. Most previous studies estimated the temperature-induced strain by statistical analysis, resulting in the unexplainable physical meaning of the obtained model coefficients. In this paper, an analytical formula for the temperature-induced strain of supertall structures is derived based on the simulated temperature

The robust design of a tuned mass damper (TMD) with hybrid aleatory and epistemic uncertainties is proposed in this study. In this method, the aleatory uncertainty involved in the external excitation is represented with the white noise in stochastic theory. The epistemic uncertainties derived from fragmentary statistical data and incomplete preknowledge of structural model and site condition are fully

In this paper, a methodology for the detection and localization of damages in composite pultruded members is proposed. This is particularly relevant to thin-walled pultruded members, which are typically characterized by orthotropic behavior, anisotropic along the fibers and isotropic in the cross section. Hence, a method to detect and localize damage, and the influence these might have on the performance

This study presents a novel digital control algorithm with state estimator technique for semi-active control of structures with magneto-rheological (MR) damper. The proposed control strategy is based on servomechanism (popularly known as command-following or tracking system), where the measured output of a system pursues the command of reference input. This is achieved through a hybrid proportional–integral

In this paper, an innovative controllable negative stiffness system (CNSS) integrating adaptive negative stiffness and controllable damping characteristics is proposed to realise desirable vibration protection and improve adaptability, hence being effective to various earthquakes. The force-displacement relationship of the CNSS is derived as the forward model to describe its nonlinear properties. Three

Developing a smart civil structure, in which the structure instantaneously identifies damages during vibration and makes decisions to compensate or reduce them, is one of the new issues in the seismic control of structures. One of the most important challenges in asymmetric buildings is the torsion due to the damage occurrence in the structure during severe excitation. The aim of this study is to try

Beam-end fractures of steel frame building structures cause the degradation of story stiffness, which may lead to the tilt or collapse of the whole structure. However, it is difficult to recognize this kind of local damage using conventional building damage detection methods. Generally, the beam-end fracture can be recognized directly from the pulse of the waveform which is generated by the shock due

This paper proposes a novel approach for improving the identifiability of structural damage by using higher order responses and singular spectrum analysis (SSA)-based phase space topology (PST) technique. SSA is employed to decompose the structural dynamic acceleration response into several low-dimensional components. Then, the change of PST (CPST) reconstructed from the decomposed component with higher

The three-point bending fracture tests of steel slag pervious concrete (SSPC) with different aggregate size and initial notch to depth ratio were done. Meanwhile, acoustic emission (AE) technique was used during the fracture test. In this paper, the relationship between fracture mechanics properties of SSPC and cumulative AE energy was explored; both b-value and cluster analysis between rise angle

No abstract is available for this article.

This study focused on the incorporation of pitch-based short carbon fibers in the self-compacting concrete (SCC) to obtain electrically conductive carbon fiber-based SCC (CFBSCC) composite. The dispersion of carbon fiber in the SCC was done utilizing a low-speed mechanical churner along with a surfactant. The ultimate goal was to impart the smart properties of carbon fiber into SCC to form electrically

Past research has shown that negative stiffness may be used to good effect in mitigating the response of seismically excited structures. This has led to the emergence of several new negative stiffness devices of varying sizes, complexity, effectiveness, and practicality. In this study, a passive negative stiffness device composed of curved leaf springs using geometric nonlinearity is presented. The

Supplemental damping devices present an attractive means to improve the structural system. Typically, dampers are designed after the structural system is selected, and they are added to increase structural damping and effectively reduce the dynamic response. On the other hand, topology optimization offers a possibility to obtain an efficient structural system but not the damper placement. Therefore

This paper presents an overview of the structural performance monitoring system for a butterfly-shaped arch footbridge located at The Hong Kong Polytechnic University. The system is the product of a multidisciplinary academic collaboration of the pooling expertise of four academic departments, namely, structural engineering, traffic engineering, surveying, and optical communication engineering. This

Controlled deployment of a foldable tensegrity-membrane system is investigated in this article. A membrane folding technique referred to as the spiral folding pattern is applied to the attached membrane to achieve compact folded shapes for the system. The foldable tensegrity-membrane system experiences transitions between two system configurations (i.e., the tensegrity configuration and the tensegrity-membrane

Harvesting cable vibration energy via electromagnetic dampers has been demonstrated as potential power supplies for wireless sensor networks or semi-active control devices. However, how the inerter enhances the energy harvesting performance of the electromagnetic damper when applied to a bridge stay cable remains largely unknown. This paper presents a full-scale experimental study on harvesting the

As an essential part of the steel structure, looseness of bolted joint greatly affects the integrity of the structure; however, there is a lack of technologies to detect the multibolt-loosening condition in practical applications. This study proposes an automatic method based on mask and region-based convolutional neural network to detect bolt looseness by labeling the defect to each pixel in an image

Ancient architectures have a lot of distinctive patterns on their component surfaces. But due to the wind and the Sun, the patterns will present extensive deficiencies, which are not conducive to the routine inspections and the subsequent repair work. To overcome these limits, an automatic deep learning-based method of segmentation, inpainting, and classification for defective patterns on ancient architecture

In this study, acoustic emission (AE) was used to monitor the whole process of tensile and fracture of the self-compacting rubber concrete (SCRC) under four-point bending. The AE activities of SCRC during the stretching and fracture process were analyzed by statistical methods to correlate the process of crack propagation with changes in mechanical properties. And by comparing the tensile and fracture

Connection failure between precast components greatly increases the risk of collapse of a precast concrete (PC) frame during earthquakes. In this study, a PC frame structure system with sector lead-viscoelastic damper (SLVD) is proposed, in which the SLVD not only protects the wet connection but also absorbs input energy in earthquakes. Two two-storey two-bay PC frame were constructed, one without

Advances in smart infrastructure produces a natural demand of system identification techniques for structural health and performance monitoring that can be scaled to regions and large asset inventories. Conventional approaches require sensors to be installed, often in long-term deployments, on the monitored infrastructure systems, which is a costly undertaking when thousands of systems (e.g., bridges)

Many damage detection strategies have been developed within the field of structural health monitoring, showing promising results in real-world applications. Most of them rely on the use of modal parameters to locate damage in structures. However, they are highly dependent on the process of extracting such characteristics, which contains uncertainties and needs to be adapted specifically for each structure

Rapid crack assessment is widely thought to be critical for monitoring and maintaining roads in appropriate conditions. In this paper, a novel crack-affected risk-informed assessment framework is proposed for the monitoring and maintenance of roads. The framework includes five steps: data collection, crack detection, crack location extraction, crack real-size calculation, and risk-level assessment