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This paper proposes an electromechanical impedance measurement (EIM)-based solution for monitoring concrete maturity that refers to concrete strength development at the early stage. A smart aggregate (SMA) that consists of a waterproofed piezoelectric patch is developed. The working principle is explained based on the impedance theory of an electromechanically coupled system. A finite element (FE) model of the EIM-SMA unit is established. The stiffness of the applied spring foundation is varied to emulate the concrete hardening process. The simulation results reveal that a peak located between 60 and 70 kHz in the impedance plot could be used as an indication to reflect the stiffness variation of the spring foundation. A 3D-printed mold is designed for rapid production of the EIM-SMA units. In the experiment, two sample EIM-SMA units are used to monitor fresh concrete maturity in the first 6 h after casting. The results of the two sample EIM-SMA units agreed well. The experimental results matched the simulation prediction. Compared to a bar-dropping test that is widely adopted at construction sites, the impedance evolution of an EIM-SMA unit is much smoother and has better monotonicity. In general, the proposed method has been proven to be a reliable solution to monitor the maturity development of concrete. © The Author(s) 2024.

© 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., Self-awareness has been successfully utilized to create adaptive behaviors in wireless sensor nodes. However, its adoption can be daunting in scenarios, such as structural health monitoring, where the monitored environment is too complex for it to be accurately modeled by a sensor node. This article addresses this challenge by proposing a novel and lightweight anomaly-aware monitoring method for structural health monitoring that can be directly executed by a sensor node. Instead of modeling the complete structure, the proposed anomaly-aware monitoring method uses the vibration measurements of the sensor node to identify local deviations in the dynamic response of the monitored structure. The self-awareness module can then use this information to guide the dynamic behavior of the sensor node, replacing more resource-intensive structural models. We use data from multiple public benchmark structures to evaluate different features and propose an unsupervised feature selection method. Additionally, we evaluate different anomaly detection algorithms comparing their ability to detect local structural damages, also taking into account their memory and energy cost. The proposed method has been implemented in a commercial sensor node, and deployed in a scaled structure where various damage scenarios were simulated to validate the proposed method, where it was able to successfully detect the presence of damages in over 88% of the cases. Finally, we showcase how the proposed method can enhance self-awareness through the use of a simulation, where the proposed monitoring method was able to extend the battery life of the sensor node by over 59%, without impacting the node’s ability to swiftly detect damages in the structure., This work was supported in part by the Industrial Doctorate Plan of the Department of Research and Universities of the Generalitat de Catalunya. The work of David Arnaiz was supported by Agència de Gestió d’Ajuts Universitaris de Recerca under Grant AGAUR 2019 DI 075., Peer Reviewed, Postprint (published version)

Wind loading is an essential aspect in the design and assessment of long-span bridges, but it is often not well-known and cannot be measured directly. Most structural health monitoring systems can easily measure structural responses at discrete locations using accelerometers. This data can be combined with reduced-order modal models in Kalman filter-based algorithms for an inverse estimation of wind loads and system states. As a further development, this work investigates the incorporation of Gaussian process latent force models (GP-LFMs), which can characterize the evolution of the wind loading. The Hardanger Bridge, a 1310 m long suspension bridge instrumented with a monitoring system for wind and vibrations, is used as a case study. It is shown how the LFMs can be enriched with physical information about the stochastic wind loads using monitoring anemometer data and aerodynamic coefficients from wind tunnel tests. It is found that the estimates of the modal wind loads and modal states obtained from a Kalman filter and Rauch–Tung–Striebel smoother are stable for acceleration output only, thus avoiding the accumulation of errors. The proposed approach demonstrates how physical or environmental data can be injected as valuable information for global monitoring strategies and virtual sensing in bridges., Dynamics of Structures, Offshore Engineering

Wind loading is an essential aspect in the design and assessment of long-span bridges, but it is often not well-known and cannot be measured directly. Most structural health monitoring systems can easily measure structural responses at discrete locations using accelerometers. This data can be combined with reduced-order modal models in Kalman filter-based algorithms for an inverse estimation of wind loads and system states. As a further development, this work investigates the incorporation of Gaussian process latent force models (GP-LFMs), which can characterize the evolution of the wind loading. The Hardanger Bridge, a 1310 m long suspension bridge instrumented with a monitoring system for wind and vibrations, is used as a case study. It is shown how the LFMs can be enriched with physical information about the stochastic wind loads using monitoring anemometer data and aerodynamic coefficients from wind tunnel tests. It is found that the estimates of the modal wind loads and modal states obtained from a Kalman filter and Rauch–Tung–Striebel smoother are stable for acceleration output only, thus avoiding the accumulation of errors. The proposed approach demonstrates how physical or environmental data can be injected as valuable information for global monitoring strategies and virtual sensing in bridges., Dynamics of Structures, Offshore Engineering

Soil movement may be induced by a wide variety of natural and anthropogenic causes, which are detectable in the local scale, but may influence the movement of the soil over vast geographical expanses. Space borne interferometric synthetic aperture radar (InSAR) measurements of ground movement provide a method for the remote sensing of soil settlement and uplift over wide geographic areas. Based on this settlement and uplift evaluation, the assessment of the potential damage to architectural heritage structures is possible. In this paper an interdisciplinary monitoring and analysis method is presented that processes satellite, cadastral, patrimonial and building geometry data, used for the calculation of settlement and uplift damage to architectural heritage structures in Belgium. It uses processed InSAR data for the determination of the soil movement profile around each case study, of which the typology is determined from patrimonial information databases and the geometry is calculated from digital elevation models. The impact on the historic structures is calculated from the determined soil movement profile based on various soil-structure interaction models for buildings. The Declercqresulting damage is presented in terms of a numerical index illustrating its severity according to different criteria. In this way the potential soil movement damage is quantified in a large number of buildings in an easily interpretable and user-friendly fashion. The processing of InSAR data collected over the previous 3 decades allows the determination of the progress of settlement- and uplift-induced damage in this time period. With the integration of newly acquired and more accurate data, the methodology will continue to produce results in the coming years, both for the evaluation of soil settlement and uplift in Belgium as for introducing related damage risk data for existing architectural heritage buildings. Results of the analysis chain are presented in terms of potential curren, The authors wish to acknowledge the funding received by BRAIN.be, BelSPO in support of the GEPATAR research project (“GEotechnical and Patrimonial Archives Toolbox for ARchitectural conservation in Belgium” BR/132/A6/Gepatar), Peer Reviewed, Postprint (published version)

The article proposes a methodology for assessing the development of damage in building structures, subjected to differential settlement and uplift, using the analysis of Interferometry Synthetic Aperture Radar (InSAR) data. The proposed methodology is targeted towards general applicability, capable of providing assessment results for measurements over wide geographic areas and for varying structural typologies. The methodology is not limited to ground movement measurements linked to tunnelling, as is the common case. Instead it extends to the monitoring of arbitrary movement in buildings, for example, due to ground consolidation, water table changes or excavation. The methodology is designed for use alongside patrimonial building databases, from which data on individual building geometry and typology are extracted on a region or country scale. Ground movement monitoring data are used for the calculation of the building deformation, expressed in different types of deformation parameters. The combined use of this data with analytical models for settlement damage classification in building structures enables the assessment in patrimonial building structures, at a country scale. The methodology is elaborated and applied on the patrimonial inventory of Belgium for the evaluation of potential settlement and uplift damage on buildings over a period of nearly three decades. The analysis results are compared to on-site observations., The authors would like to acknowledge the funding received by BRAIN.be, BelSPO in support of the GEPATAR research project (“GEotechnical and Patrimonial Archives Toolbox for ARchitectural conservation in Belgium” BR/132/A6/Gepatar)., Peer Reviewed, Postprint (published version)

[ES] Los elementos de hormigón armado presentan con frecuencia la patología de corrososión de las armaduras, que al hincharse producen una fisuración que puede llegar a producir el desprendimiento del recubrimiento. Para evaluar el estado de la seguridad de la construcción se ha realizado la monitorización en tiempo real de la variación de la deformación unitaria de las armaduras, así como de la temperatura y aceleración., [EN] The reinforced concrete elements frequently present the corrosion pathology of the reinforcements, which when swollen produce a cracking that can lead to the release of the coating. In order to evaluate the state of the security of the construction, real-time monitoring of the variation of the unit deformation of the reinforcements, as well as the temperature and acceleration, has been carried out.

[ES] Los elementos de hormigón armado presentan con frecuencia la patología de corrososión de las armaduras, que al hincharse producen una fisuración que puede llegar a producir el desprendimiento del recubrimiento. Para evaluar el estado de la seguridad de la construcción se ha realizado la monitorización en tiempo real de la variación de la deformación unitaria de las armaduras, así como de la temperatura y aceleración., [EN] The reinforced concrete elements frequently present the corrosion pathology of the reinforcements, which when swollen produce a cracking that can lead to the release of the coating. In order to evaluate the state of the security of the construction, real-time monitoring of the variation of the unit deformation of the reinforcements, as well as the temperature and acceleration, has been carried out.

[ES] Los elementos de hormigón armado presentan con frecuencia la patología de corrososión de las armaduras, que al hincharse producen una fisuración que puede llegar a producir el desprendimiento del recubrimiento. Para evaluar el estado de la seguridad de la construcción se ha realizado la monitorización en tiempo real de la variación de la deformación unitaria de las armaduras, así como de la temperatura y aceleración., [EN] The reinforced concrete elements frequently present the corrosion pathology of the reinforcements, which when swollen produce a cracking that can lead to the release of the coating. In order to evaluate the state of the security of the construction, real-time monitoring of the variation of the unit deformation of the reinforcements, as well as the temperature and acceleration, has been carried out.

[ES] Los elementos de hormigón armado presentan con frecuencia la patología de corrososión de las armaduras, que al hincharse producen una fisuración que puede llegar a producir el desprendimiento del recubrimiento. Para evaluar el estado de la seguridad de la construcción se ha realizado la monitorización en tiempo real de la variación de la deformación unitaria de las armaduras, así como de la temperatura y aceleración., [EN] The reinforced concrete elements frequently present the corrosion pathology of the reinforcements, which when swollen produce a cracking that can lead to the release of the coating. In order to evaluate the state of the security of the construction, real-time monitoring of the variation of the unit deformation of the reinforcements, as well as the temperature and acceleration, has been carried out.

The traditional wind load assessment for long-span bridges relies on assumed models for the wind field and aerodynamic coefficients from wind tunnel tests, which usually introduce some uncertainties. Recent studies have shown that large deviations can exist between the predicted and observed wind-induced dynamic response of suspension bridges. In studies of the dynamical behavior of bridges, inverse force identification methods can therefore be an interesting tool in the assessment of possible uncertainties involved in the modeling of wind loads. This paper presents a novel case study of the identification of the dynamic wind loads on the 1310 ​m long Hardanger bridge, a suspension bridge equipped with a monitoring system for wind and vibrations. The modal wind loads are identified from acceleration data using an algorithm for model-based joint input and state estimation. Several data sets with different wind conditions are presented. The wind loads are studied in the time and frequency domains and are compared to the mean velocity and turbulence characteristics of the wind., Offshore Engineering, Dynamics of Structures

Fiber Bragg grating (FBG) based sensors are widely used in very diverse fields ranging from health structural monitoring in civil and aerospace areas to more recent medical applications in the field of diagnosis in different specialities such as cardiology and biomechanics, among others. Their intrinsic properties of strain and temperature sensitivity and their ease of use make FBGs high potential sensors for research purpose. The proposed study aims to evaluate and assess the temperature increase due to heating at the tip of an electrosurgical knife subject to current at high voltage and high frequency in different conditions and verify the feasibility of using FBGs as temperature sensor in this application. For this purpose, an electrosurgical knife composed of a metal conductor and a plastic shaft on top of which 3 FBGs are placed is used. The latter ones are situated and fixed on the circumference of the shaft equally distributed at 120° from each other. To avoid strain interference in the measurements of the shift in Bragg wavelength, the metal conductor is kept fixed. After calibrating the FBGs, different experiments are conducted where the knife is used to heat a specific biological material using a high voltage generator and a thermal camera for measurements verification. The tests showed promising results which demonstrate that FBGs are easy to calibrate in temperature and robust to measure variation of temperature in the surrounding of an electrosurgical knife. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only., info:eu-repo/semantics/published

The traditional wind load assessment for long-span bridges relies on assumed models for the wind field and aerodynamic coefficients from wind tunnel tests, which usually introduce some uncertainties. Recent studies have shown that large deviations can exist between the predicted and observed wind-induced dynamic response of suspension bridges. In studies of the dynamical behavior of bridges, inverse force identification methods can therefore be an interesting tool in the assessment of possible uncertainties involved in the modeling of wind loads. This paper presents a novel case study of the identification of the dynamic wind loads on the 1310 ​m long Hardanger bridge, a suspension bridge equipped with a monitoring system for wind and vibrations. The modal wind loads are identified from acceleration data using an algorithm for model-based joint input and state estimation. Several data sets with different wind conditions are presented. The wind loads are studied in the time and frequency domains and are compared to the mean velocity and turbulence characteristics of the wind., Offshore Engineering, Dynamics of Structures

The traditional wind load assessment for long-span bridges rely on assumed models for the wind field and aerodynamic coefficients from wind tunnel tests, which usually introduces some uncertainties. It is therefore desired to develop tools that can utilize full-scale vibration response data from existing bridges in order to study the wind loading in detail for in-situ conditions. This paper presents a novel case study of inverse identification of dynamic wind loads on the 1310 m long Hardanger bridge, a suspension bridge equipped with a network of accelerometers. The identification method used is an extented Kalman-type filter for joint input, state, and parameter estimation. A system model considering the still-air modes in addition to a quasi-steady submodel for the self-excited forces of the bridge is presente. The coefficients for self-excited lift and pitching moment are considered unknown and are jointly estimated with the buffeting forces., Dynamics of Structures, Offshore Engineering

The dynamic behaviour of long-span bridges is governed by stochastic loads from typically ambient excitation sources. In real life, these loads cannot be measured directly at full scale. However, inverse methods can be utilised to identify these unknown forces using response measurements together with a numerical model of the relevant structure. This paper presents a case study of full-scale identification of the wave forces on the Bgsøysund bridge, a long-span pontoon bridge that has been monitored since 2013. First, a numerical model of the structure is formed, resulting in a reduced-order state-space model that takes into account the frequency-dependent hydrodynamic mass and damping from the fluid, based on fitting of rational transfer functions. Using acceleration data of the structure measured during several events of moderate and strong seas, the wave forces are identified using stochastic-deterministic methods for combined state and input estimation. In addition, a separate frequency-domain assessment of the wave forces is performed, in which the spectral density of the first-order wave forces is constructed from an estimated directional wave field model driven by wave elevation data. When compared in the frequency domain, the force estimates from the two approaches are of comparable magnitude. However, uncertainties in the assumptions and models behind the force estimates from the two approaches still play a significant role., Dynamics of Structures

The traditional wind load assessment for long-span bridges rely on assumed models for the wind field and aerodynamic coefficients from wind tunnel tests, which usually introduces some uncertainties. It is therefore desired to develop tools that can utilize full-scale vibration response data from existing bridges in order to study the wind loading in detail for in-situ conditions. This paper presents a novel case study of inverse identification of dynamic wind loads on the 1310 m long Hardanger bridge, a suspension bridge equipped with a network of accelerometers. The identification method used is an extented Kalman-type filter for joint input, state, and parameter estimation. A system model considering the still-air modes in addition to a quasi-steady submodel for the self-excited forces of the bridge is presente. The coefficients for self-excited lift and pitching moment are considered unknown and are jointly estimated with the buffeting forces., Dynamics of Structures, Offshore Engineering

The dynamic behaviour of long-span bridges is governed by stochastic loads from typically ambient excitation sources. In real life, these loads cannot be measured directly at full scale. However, inverse methods can be utilised to identify these unknown forces using response measurements together with a numerical model of the relevant structure. This paper presents a case study of full-scale identification of the wave forces on the Bgsøysund bridge, a long-span pontoon bridge that has been monitored since 2013. First, a numerical model of the structure is formed, resulting in a reduced-order state-space model that takes into account the frequency-dependent hydrodynamic mass and damping from the fluid, based on fitting of rational transfer functions. Using acceleration data of the structure measured during several events of moderate and strong seas, the wave forces are identified using stochastic-deterministic methods for combined state and input estimation. In addition, a separate frequency-domain assessment of the wave forces is performed, in which the spectral density of the first-order wave forces is constructed from an estimated directional wave field model driven by wave elevation data. When compared in the frequency domain, the force estimates from the two approaches are of comparable magnitude. However, uncertainties in the assumptions and models behind the force estimates from the two approaches still play a significant role., Dynamics of Structures

The Sacred Heart church of Vistabella (La Secuita, Tarragona) was designed by Josep Maria Jujol, one of the masters of Catalan Modernism, and built in the early twenties of the XX century. The structure of the steeple consists of four inclined T-shaped masonry ribs, crowned by a cross. Two intermediate levels sustained in short and shallow masonry arches, act as a bracing systems. At the end of 1934, the upper spire crumbled away, being rebuilt and reinforced with a pair of steel passive bars per rib. After some numerical approaches, it became clear that the lightness of such a masonry construction along with the feebleness of the connections between the structural members were at the basis of the problem. In order to provide additional vertical load without substantively modifying the structural scheme, a solution based on external prestressed bars, has been implemented. They replace the existing passive bars, which have proven to be totally useless. The active system proposed allows to eliminate the masonry’s tensile stresses. Hence, eight steel bars (ties) have been placed where previously the steel passive bars were. By prestressing them, a permanent vertical loading will be introduced in the structure, improving its structural behaviour in front of the horizontal loads (wind action). The additional loading to be applied varies depending on the level (three levels in total). Therefore, it has been necessary to design a procedure able to introduce independent tensions at the different levels throughout the same tie. Moreover, the prestressing process had to balance two different requirements: on one hand, the need to add load to the structure, and on the other - due to the slenderness of the masonry ribs - do not exceed the allowable compression of the material. For this reason, 24 strain gages - 8 per level - have been placed along the steel bars, to individually control the stresses at any bar and level, by means of monitoring these. The ties have been prestres, Peer Reviewed, Postprint (published version)

Numerical predictions of the dynamic response of complex structures are often uncertain due to uncertainties inherited from the assumed load effects. Inverse methods can estimate the true dynamic response of a structure through system inversion, combining measured acceleration data with a system model. This article presents a case study of full-field dynamic response estimation of a long-span floating bridge: the Bergøysund Bridge in Norway. This bridge is instrumented with a network of 14 triaxial accelerometers. The system model consists of 27 vibration modes with natural frequencies below 2 Hz, obtained from a tuned finite element model that takes the fluid-structure interaction with the surrounding water into account. Two methods, a joint input-state estimation algorithm and a dual Kalman filter, are applied to estimate the full-field response of the bridge. The results demonstrate that the displacements and the accelerations can be estimated at unmeasured locations with reasonable accuracy when the wave loads are the dominant source of excitation., Offshore Engineering

Structural health monitoring (SHM) seeks to assess the condition or behaviour of the structure from measurement data, which for long-span bridges typically are wind velocities and/or structural vibrations. However, in the assessment of the wind-induced response effects, models for the actual loads must be adopted, which introduces uncertainties. An alternative is to apply model-based inverse methods that consider the input forces unknown, and estimate these forces jointly together with the system states using limited vibration data. This article presents a case study of implementing Kalman-type inverse methods to a long-span suspension bridge in complex terrain, with the objective of estimating the full-field response. Previous studies have shown the local wind field is complicated, leading to uncertain load effects. We discuss the key challenges faced in the use of the methodology for the long-span bridges and present the results for a six hour storm event. The analysis show that the dynamic response contribution from the 14 lowermost bridge modes (up to 3 rad/s or 0.5 Hz) can be reconstructed with decent accuracy. The estimated response magnitude differs from the predicted response from design specifications, pointing to initial load model uncertainties that can be reduced to give greater confidence in the assessment of wind-induced fatigue, wind-resistant performance or other response effects., Offshore Engineering

Numerical predictions of the dynamic response of complex structures are often uncertain due to uncertainties inherited from the assumed load effects. Inverse methods can estimate the true dynamic response of a structure through system inversion, combining measured acceleration data with a system model. This article presents a case study of full-field dynamic response estimation of a long-span floating bridge: the Bergøysund Bridge in Norway. This bridge is instrumented with a network of 14 triaxial accelerometers. The system model consists of 27 vibration modes with natural frequencies below 2 Hz, obtained from a tuned finite element model that takes the fluid-structure interaction with the surrounding water into account. Two methods, a joint input-state estimation algorithm and a dual Kalman filter, are applied to estimate the full-field response of the bridge. The results demonstrate that the displacements and the accelerations can be estimated at unmeasured locations with reasonable accuracy when the wave loads are the dominant source of excitation., Offshore Engineering

Structural health monitoring (SHM) seeks to assess the condition or behaviour of the structure from measurement data, which for long-span bridges typically are wind velocities and/or structural vibrations. However, in the assessment of the wind-induced response effects, models for the actual loads must be adopted, which introduces uncertainties. An alternative is to apply model-based inverse methods that consider the input forces unknown, and estimate these forces jointly together with the system states using limited vibration data. This article presents a case study of implementing Kalman-type inverse methods to a long-span suspension bridge in complex terrain, with the objective of estimating the full-field response. Previous studies have shown the local wind field is complicated, leading to uncertain load effects. We discuss the key challenges faced in the use of the methodology for the long-span bridges and present the results for a six hour storm event. The analysis show that the dynamic response contribution from the 14 lowermost bridge modes (up to 3 rad/s or 0.5 Hz) can be reconstructed with decent accuracy. The estimated response magnitude differs from the predicted response from design specifications, pointing to initial load model uncertainties that can be reduced to give greater confidence in the assessment of wind-induced fatigue, wind-resistant performance or other response effects., Offshore Engineering

The evaluation of fatigue damage accumulation on wind turbine support structures under operational conditions is heavily influenced by a number of uncertainties. These uncertainties may, firstly, be attributed to the highly variable and complex environmental loads, and secondly, to the unavoidable modelling errors which mainly originate from the inherent randomness in both material properties and fatigue resistance of structural components. It is therefore essential that assessment of fatigue life is carried out within a probabilistic framework; one that accounts for the stochastic nature of the phenomenon. The present study proposes a strategy for real-time reliability prediction of accumulated fatigue damage on wind turbine support structures by taking into account the above-mentioned uncertainties. To this end, the availability of structural monitoring information for the identification of the global response on wind-turbine support structures is exploited in order to address the discrepancies between actual and predicted damage accumulation. This is carried through utilization of an augmented version of the Kalman filter, which is capable of jointly estimating the response and the unknown inputs of the structure while relying on a limited number of noisy observations and a presumably uncertain model of the real system. A fixed-lag smoother is further deployed for the attenuation of the estimation error in an on-line mode and the smoothed stochastic estimates of the response are propagated over the model at the level of stresses. The accumulated damage along with the corresponding reliability level is finally predicted using a stochastic nonstationary fatigue damage model. The proposed scheme is demonstrated via implementation on the NREL 5.0 MW wind turbine under different operational conditions, on the basis of dummy vibration data generated via the FAST software., Offshore Engineering

Suspension bridges with very long spans and slender designs are susceptible to large-amplitude dynamic excitation. Monitoring systems installed on bridges can provide measurement data (e.g. accelerations) and therewith valuable information on the true dynamic behaviour. This pilot study examines the possible use of recently developed methods for real-time response estimation at unmeasured locations. The methodology for response estimation is tested in a case study on the Hardanger Bridge, a 1310 m long suspension bridge in Norway, which has a network of twenty accelerometers. Two techniques, a joint input-state estimation algorithm (JIS) and a dual Kalman filter (DKF), are used to estimate the full-field dynamic response using data measured at the bridge and a reduced order structural model. The results show that the DKF is able to estimate accelerations fairly accurately. The JIS estimate, however, suffer from ill-conditioning and consequently show severe errors. Possible reasons for this ill-conditioning are briefly discussed., Offshore Engineering

Context: In the last sixty years urbanization processes have increased considerably. In many of them, the number of inhabitants of the so-called "slums" amounts to more than 50% of the population. In addition, they are located in areas at risk.Objective: To determine and evaluate the monthly progression of the Damage Index (ID, in Spanish) of a group of houses located in a hillside area in the “Altos de la Estancia” sector in Bogotá, Colombia, during a period of four months.Method: The houses were classified according to their structural system in six groups: confined masonry (group A); structural masonry (group B); unreinforced masonry (group C); provisional materials (group D); reinforced concrete porches (group E); and prefabricated houses (group F). And we applied the methodology proposed by the Fund for the Prevention and Attention of Emergencies (FOPAE).Results: There was a constant increase in the ID of all groups. However, group C presented the highest values in the last sampling (2.6% of the households had high ID and 0.87% very high). In the other groups the observed ID was lower and no houses were found with records classified as very high.Conclusions: According to the results, dwellings built in unreinforced masonry show a greater degree of deterioration in short periods of time compared to those constructed with other structural systems., Contexto: En los últimos sesenta años los procesos de urbanización se han incrementado considerablemente. En gran parte de ellos, el número de habitantes de los denominados tugurios asciende a más del 50 % de la población y, adicionalmente, se encuentran localizados en zonas de riesgo.Objetivo: Determinar y evaluar la progresión mensual del índice de daño (ID) durante un periodo de cuatro meses a un grupo de viviendas ubicado en zona de ladera en el sector Altos de la Estancia en Bogotá, Colombia.Método: Las viviendas fueron clasificadas de acuerdo con su sistema estructural en seis grupos: mampostería confinada (grupo A), mampostería estructural (grupo B), mampostería no reforzada (grupo C), materiales provisionales (grupo D), pórticos en concreto reforzado (grupo E) y viviendas prefabricadas (grupo F) y se les aplicó la metodología propuesta por el Fondo para la Prevención y Atención de Emergencias (FOPAE).Resultados: En todos los grupos se observó un incremento constante en el ID; sin embargo, el grupo C presentó los valores más altos en el último muestreo: 2,6 % de las viviendas (ID alto) y 0,87 % (ID muy alto). En los demás grupos el ID observado fue menor y no se encontraron viviendas con registros clasificados como muy altos.Conclusiones: De acuerdo con los resultados, las viviendas construidas en mampostería no reforzada presentan un mayor grado de deterioro en periodos cortos de tiempo en comparación a aquellas construidas con otros sistemas estructurales.

Context: In the last sixty years urbanization processes have increased considerably. In many of them, the number of inhabitants of the so-called "slums" amounts to more than 50% of the population. In addition, they are located in areas at risk.Objective: To determine and evaluate the monthly progression of the Damage Index (ID, in Spanish) of a group of houses located in a hillside area in the “Altos de la Estancia” sector in Bogotá, Colombia, during a period of four months.Method: The houses were classified according to their structural system in six groups: confined masonry (group A); structural masonry (group B); unreinforced masonry (group C); provisional materials (group D); reinforced concrete porches (group E); and prefabricated houses (group F). And we applied the methodology proposed by the Fund for the Prevention and Attention of Emergencies (FOPAE).Results: There was a constant increase in the ID of all groups. However, group C presented the highest values in the last sampling (2.6% of the households had high ID and 0.87% very high). In the other groups the observed ID was lower and no houses were found with records classified as very high.Conclusions: According to the results, dwellings built in unreinforced masonry show a greater degree of deterioration in short periods of time compared to those constructed with other structural systems., Contexto: En los últimos sesenta años los procesos de urbanización se han incrementado considerablemente. En gran parte de ellos, el número de habitantes de los denominados tugurios asciende a más del 50 % de la población y, adicionalmente, se encuentran localizados en zonas de riesgo.Objetivo: Determinar y evaluar la progresión mensual del índice de daño (ID) durante un periodo de cuatro meses a un grupo de viviendas ubicado en zona de ladera en el sector Altos de la Estancia en Bogotá, Colombia.Método: Las viviendas fueron clasificadas de acuerdo con su sistema estructural en seis grupos: mampostería confinada (grupo A), mampostería estructural (grupo B), mampostería no reforzada (grupo C), materiales provisionales (grupo D), pórticos en concreto reforzado (grupo E) y viviendas prefabricadas (grupo F) y se les aplicó la metodología propuesta por el Fondo para la Prevención y Atención de Emergencias (FOPAE).Resultados: En todos los grupos se observó un incremento constante en el ID; sin embargo, el grupo C presentó los valores más altos en el último muestreo: 2,6 % de las viviendas (ID alto) y 0,87 % (ID muy alto). En los demás grupos el ID observado fue menor y no se encontraron viviendas con registros clasificados como muy altos.Conclusiones: De acuerdo con los resultados, las viviendas construidas en mampostería no reforzada presentan un mayor grado de deterioro en periodos cortos de tiempo en comparación a aquellas construidas con otros sistemas estructurales.

Suspension bridges with very long spans and slender designs are susceptible to large-amplitude dynamic excitation. Monitoring systems installed on bridges can provide measurement data (e.g. accelerations) and therewith valuable information on the true dynamic behaviour. This pilot study examines the possible use of recently developed methods for real-time response estimation at unmeasured locations. The methodology for response estimation is tested in a case study on the Hardanger Bridge, a 1310 m long suspension bridge in Norway, which has a network of twenty accelerometers. Two techniques, a joint input-state estimation algorithm (JIS) and a dual Kalman filter (DKF), are used to estimate the full-field dynamic response using data measured at the bridge and a reduced order structural model. The results show that the DKF is able to estimate accelerations fairly accurately. The JIS estimate, however, suffer from ill-conditioning and consequently show severe errors. Possible reasons for this ill-conditioning are briefly discussed., Offshore Engineering

The evaluation of fatigue damage accumulation on wind turbine support structures under operational conditions is heavily influenced by a number of uncertainties. These uncertainties may, firstly, be attributed to the highly variable and complex environmental loads, and secondly, to the unavoidable modelling errors which mainly originate from the inherent randomness in both material properties and fatigue resistance of structural components. It is therefore essential that assessment of fatigue life is carried out within a probabilistic framework; one that accounts for the stochastic nature of the phenomenon. The present study proposes a strategy for real-time reliability prediction of accumulated fatigue damage on wind turbine support structures by taking into account the above-mentioned uncertainties. To this end, the availability of structural monitoring information for the identification of the global response on wind-turbine support structures is exploited in order to address the discrepancies between actual and predicted damage accumulation. This is carried through utilization of an augmented version of the Kalman filter, which is capable of jointly estimating the response and the unknown inputs of the structure while relying on a limited number of noisy observations and a presumably uncertain model of the real system. A fixed-lag smoother is further deployed for the attenuation of the estimation error in an on-line mode and the smoothed stochastic estimates of the response are propagated over the model at the level of stresses. The accumulated damage along with the corresponding reliability level is finally predicted using a stochastic nonstationary fatigue damage model. The proposed scheme is demonstrated via implementation on the NREL 5.0 MW wind turbine under different operational conditions, on the basis of dummy vibration data generated via the FAST software., Offshore Engineering

The railroad network in the united states is one of the best in the world, handling around 40 percent of all US freight movement. To maintain the serviceability and cost-effective operation of the railway infrastructure, regular monitoring is essential. Bridges are a critical part of the railway infrastructure and their timely maintenance and repair are important. Measuring transverse bridge displacement under train loading can assist to determine the bridge condition. The traditional methods available for transverse displacement measurement include Linear Variable Differential Transducers (LVDT). However, irregular terrain, remote and inaccessible locations, and the height of railroad bridges make implementation of these sensors for transverse displacement measurement either inadequate, or risky and time-consuming, and sometimes not possible altogether. Alternatively, railroads can monitor transverse bridge displacement using non-contact sensing with instruments such as robotic total station (RTS) and high-speed cameras. In recent years, the use of Laser Doppler Vibrometers (LDV) has started to draw some attention in the field of non-contact transverse bridge displacement measurement. However, in these applications, the instruments are generally placed on a fixed reference close to the bridge. It is not always possible to find this fixed reference point, especially when a bridge is spanning over a large opening, like a water body. In addition, a fixed reference point would require calibration of the measurement for every different bridge individually. Researchers use Unmanned Aerial Systems (UAS) to acquire aerial images for Structural Health Monitoring (SHM). However, this approach requires extensive image post-processing, and in general, complex algorithms development. More importantly, current systems are not capable of measuring dynamic transverse displacements. This MS Thesis presents a novel approach to measure transverse bridge dynamic displacements using

Large wooden structures of cultural value, such as the Vasa ship, suffer from increasing deformation over time, caused by creep in the wood members, time-dependent deformation of joints and damage accumulation. In this paper, we discuss the suitability of the different available measurement techniques to monitor the increasing deformation and the structural health of wooden structures. In particular, a monitoring system needs to be able to measure the exact same point at different times to measure displacements. For large wooden objects with limited surface texture, the best accuracy for displacement measurements is currently achieved by monitoring well-defined targets with laser-assisted total stations. Furthermore, we emphasize the relation between displacements and deformation and advocate translating the raw displacement data into more meaningful average strain fields. A straightforward method to compute the in-plane average strain field is presented, and illustrated for the Vasa ship. The strain fields can indicate areas with localized strain, caused e.g. by weak zones in the structure with increased creep, damage or cracking. Such zones can then be more closely inspected and considered for improved support.

AE-based structural integrity monitoring of composite structures potentially offers the means to gain knowledge on in-service damage accumulation, as well as mitigation of some of the risks associated with in-service damage. However, validation of any identified classes of AE events with regard to their underlying source mechanics is generally limited to data-centred metrics in existing literature. The approach in this project applies a mechanics-informed perspective on AE event classification by using the fatigue cycle phase as hit labels and validating this labelling with the stiffness degradation measured using DIC. A promising correlation is found between this labelling and the coupon stiffness degradation., Aerospace Engineering, Aerospace Structures and Materials

A review of the concrete dam’s structural performance is a complex issue comprised of many dimensions. This article proposes a method to assist in monitoring the displacements of structures and foundations of dams, considering the action of environmental conditions. Multivariate techniques are used to analyze the data pendulums, extensometer bases and multiple rods extensometer, along with environmental variables of the concrete surface temperature, ambient temperature and the reservoir water level. Specifically applies to Canonical Correlation Analysis to evaluate the influence of environmental variables in the displacement of structures and foundations. Factor Analysis identifies the factors inherent to the variability of the data. This technique makes it possible to order the variables considering the action of factors. This applies also to Cluster Analysis on the data of dates of measurements, according to the similarities present in the observations. Then, Discriminant Analysis evaluates the formed groups for uniformity. The results demonstrate that the method can distinguish the dam responses and identify the effects of variations in environmental conditions over the displacements of structures and foundations.

A review of the concrete dam’s structural performance is a complex issue comprised of many dimensions. This article proposes a method to assist in monitoring the displacements of structures and foundations of dams, considering the action of environmental conditions. Multivariate techniques are used to analyze the data pendulums, extensometer bases and multiple rods extensometer, along with environmental variables of the concrete surface temperature, ambient temperature and the reservoir water level. Specifically applies to Canonical Correlation Analysis to evaluate the influence of environmental variables in the displacement of structures and foundations. Factor Analysis identifies the factors inherent to the variability of the data. This technique makes it possible to order the variables considering the action of factors. This applies also to Cluster Analysis on the data of dates of measurements, according to the similarities present in the observations. Then, Discriminant Analysis evaluates the formed groups for uniformity. The results demonstrate that the method can distinguish the dam responses and identify the effects of variations in environmental conditions over the displacements of structures and foundations.

A review of the concrete dam’s structural performance is a complex issue comprised of many dimensions. This article proposes a method to assist in monitoring the displacements of structures and foundations of dams, considering the action of environmental conditions. Multivariate techniques are used to analyze the data pendulums, extensometer bases and multiple rods extensometer, along with environmental variables of the concrete surface temperature, ambient temperature and the reservoir water level. Specifically applies to Canonical Correlation Analysis to evaluate the influence of environmental variables in the displacement of structures and foundations. Factor Analysis identifies the factors inherent to the variability of the data. This technique makes it possible to order the variables considering the action of factors. This applies also to Cluster Analysis on the data of dates of measurements, according to the similarities present in the observations. Then, Discriminant Analysis evaluates the formed groups for uniformity. The results demonstrate that the method can distinguish the dam responses and identify the effects of variations in environmental conditions over the displacements of structures and foundations.

A review of the concrete dam’s structural performance is a complex issue comprised of many dimensions. This article proposes a method to assist in monitoring the displacements of structures and foundations of dams, considering the action of environmental conditions. Multivariate techniques are used to analyze the data pendulums, extensometer bases and multiple rods extensometer, along with environmental variables of the concrete surface temperature, ambient temperature and the reservoir water level. Specifically applies to Canonical Correlation Analysis to evaluate the influence of environmental variables in the displacement of structures and foundations. Factor Analysis identifies the factors inherent to the variability of the data. This technique makes it possible to order the variables considering the action of factors. This applies also to Cluster Analysis on the data of dates of measurements, according to the similarities present in the observations. Then, Discriminant Analysis evaluates the formed groups for uniformity. The results demonstrate that the method can distinguish the dam responses and identify the effects of variations in environmental conditions over the displacements of structures and foundations.

A review of the concrete dam’s structural performance is a complex issue comprised of many dimensions. This article proposes a method to assist in monitoring the displacements of structures and foundations of dams, considering the action of environmental conditions. Multivariate techniques are used to analyze the data pendulums, extensometer bases and multiple rods extensometer, along with environmental variables of the concrete surface temperature, ambient temperature and the reservoir water level. Specifically applies to Canonical Correlation Analysis to evaluate the influence of environmental variables in the displacement of structures and foundations. Factor Analysis identifies the factors inherent to the variability of the data. This technique makes it possible to order the variables considering the action of factors. This applies also to Cluster Analysis on the data of dates of measurements, according to the similarities present in the observations. Then, Discriminant Analysis evaluates the formed groups for uniformity. The results demonstrate that the method can distinguish the dam responses and identify the effects of variations in environmental conditions over the displacements of structures and foundations.

A review of the concrete dam’s structural performance is a complex issue comprised of many dimensions. This article proposes a method to assist in monitoring the displacements of structures and foundations of dams, considering the action of environmental conditions. Multivariate techniques are used to analyze the data pendulums, extensometer bases and multiple rods extensometer, along with environmental variables of the concrete surface temperature, ambient temperature and the reservoir water level. Specifically applies to Canonical Correlation Analysis to evaluate the influence of environmental variables in the displacement of structures and foundations. Factor Analysis identifies the factors inherent to the variability of the data. This technique makes it possible to order the variables considering the action of factors. This applies also to Cluster Analysis on the data of dates of measurements, according to the similarities present in the observations. Then, Discriminant Analysis evaluates the formed groups for uniformity. The results demonstrate that the method can distinguish the dam responses and identify the effects of variations in environmental conditions over the displacements of structures and foundations.

AE-based structural integrity monitoring of composite structures potentially offers the means to gain knowledge on in-service damage accumulation, as well as mitigation of some of the risks associated with in-service damage. However, validation of any identified classes of AE events with regard to their underlying source mechanics is generally limited to data-centred metrics in existing literature. The approach in this project applies a mechanics-informed perspective on AE event classification by using the fatigue cycle phase as hit labels and validating this labelling with the stiffness degradation measured using DIC. A promising correlation is found between this labelling and the coupon stiffness degradation., Aerospace Engineering, Aerospace Structures and Materials

The number of high-rise buildings worldwide has increased rapidly and this trend is set to continue. As symbols of a city they often incorporate new materials, special designs or stretch the limits of technical capability. For the validation of a building’s design, ongoing safety and maintenance, structural health monitoring systems can be used. Structural health monitoring systems are designed to be structure-specific and help in gaining information about structural performance. The monitoring system development process is mainly governed by the information required by civil and structural engineers and can therefore be seen as an engineering task. An operation oriented approach focused on providing information instead of raw data is proposed in this research and the development process is generalised to allow the creation of user-centric structural health monitoring systems for any civil engineering structure. Data storage and management are at the heart of structural monitoring systems. However, the methods for storing and accessing data have never been optimised for large amounts of continuous time series data and dedicated management and processing tasks are unavailable. As such, the new TB-tree (temporally blurred tree) data structure has been developed to address data storage and management issues and three software applications have been developed to demonstrate its capabilities. By implementing the generalised development process and the evaluation of current sensor strategies, a prototype integrated structural health monitoring system to obtain the most structural information is developed. To bridge the gap between research and practice, an operation-oriented user-centric system with use of the building information modelling paradigm is proposed.

En este artículo se presentan la concepción y el diseño de un nuevo sistema de monitorización para la jarcia de veleros de competición. Los sensores desarrollados incluyen un sistema de procesamiento basado en la aplicación de redes neuronales (ANN, por sus siglas en inglés) que es capaz de evaluar la carga que actúa sobre un elemento e identificar la dirección de acción de esa fuerza. De esta forma es posible identificar las condiciones en las que opera la jarcia del yate en cada momento. Los datos requeridos para el entrenamiento de las ANN se han generado a partir de una campaña de análisis estructurales del dispositivo mediante el método de los elementos finitos (FEM, por sus siglas en inglés). Además, durante la fase de diseño del sistema se llevaron a cabo diferentes campañas experimentales. Estos experimentos fueron diseñados como prueba de concepto, así como para validar los diferentes procedimientos usados en el desarrollo y en la aplicación del sistema. El sistema de monitorización desarrollado es inalámbrico, poco intrusivo y fácilmente adaptable a cualquier tipo de velero. Además, en este trabajo se presenta la integración del sistema con un modelo de cálculo acoplado fluido-estructura de las velas, jarcia y arboladura del velero, configurando una eficiente herramienta de soporte a la decisión para evaluar el comportamiento y optimizar el ajuste de la jarcia del yate., In this paper, the conception and design of a new monitoring system for a racing yachts rig is presented. The sensors developed are able to process the measured strain data, by applying artificial neural networks (ANN) algorithms, and then evaluate the load acting on an element and identify the direction of the action of that force. This way, it is possible to identify the actual operating conditions of the yacht rig. The required data for ANN training is generated from the results obtained from different finite element method (FEM) computational models of the device. Furthermore, during the design phase of the system, different experimental campaigns were carried out. The experimental tests were designed to serve as proof of concept, as well as to validate the different procedures used in the system development and application. The developed monitoring system is wireless, low-intrusive and easily adaptable to any yacht configuration. This work also presents the integration of the monitoring system into a coupled fluid-structure computation model for the sails and rig of a boat. The resulting system is an efficient tool for evaluating performance and decision support in the adjustment of a sailboat rig., Postprint (published version)

[ES] Se ha analizado el comportamiento a altas temperaturas de los sensores de fibra óptica regenerados (RFBG) en base a la comparación de los resultados obtenidos por termopares y los resultados predichos por los modelos de cálculo numérico de análisis térmico y el comportamiento real de una viga de hormigón armado, sometida a altas temperaturas, con el comportamiento predicho por un software estructural de altas prestaciones (SOFISTIK) muy poco empleado en Ingeniería del Fuego., [EN] Analysis of high temperature performance of regenerated optical fiber sensors (RFBG) based on the comparison of the results obtained from thermocouples and the results predicted by numerical calculation models, and thermal analysis and actual performance of a beam of reinforced concrete subjected to high temperatures, with the behavior predicted by a high performance structural software (SOFiSTiK).

[ES] Se ha analizado el comportamiento a altas temperaturas de los sensores de fibra óptica regenerados (RFBG) en base a la comparación de los resultados obtenidos por termopares y los resultados predichos por los modelos de cálculo numérico de análisis térmico y el comportamiento real de una viga de hormigón armado, sometida a altas temperaturas, con el comportamiento predicho por un software estructural de altas prestaciones (SOFISTIK) muy poco empleado en Ingeniería del Fuego., [EN] Analysis of high temperature performance of regenerated optical fiber sensors (RFBG) based on the comparison of the results obtained from thermocouples and the results predicted by numerical calculation models, and thermal analysis and actual performance of a beam of reinforced concrete subjected to high temperatures, with the behavior predicted by a high performance structural software (SOFiSTiK).

This paper presents an overview of the US Coast Guard’s Fatigue Life Assessment Project (FLAP) and the application of the results in hull structure lifecycle management of the National Security Cutter class. One of the key measurements of the FLAP instrumentation included a radar based wave data measuring system. These measurements were used to determine the operational profile and wave statistics the Cutter encountered for the first five years of service. This information was compared to the design assumptions to understand the differences between design, actual operations, and impact on the long term fatigue damage forecasts. The influence of the operator is discussed. The model tests, dedicated trials and long term monitoring provided valuable insights into the limitations of analysis and predictions. A reliability based fatigue life prediction approach is discussed, along with how they may be used to evaluate options for life cycle management of fatigue and the Return on Investment (ROI) for considering fatigue early in the design. Finally, conclusions and recommendations are provided for the advancement of the spectral fatigue approaches for cost effectively managing fatigue in ship structure., Marine and Transport Technology, Mechanical, Maritime and Materials Engineering

This paper presents an overview of the US Coast Guard’s Fatigue Life Assessment Project (FLAP) and the application of the results in hull structure lifecycle management of the National Security Cutter class. One of the key measurements of the FLAP instrumentation included a radar based wave data measuring system. These measurements were used to determine the operational profile and wave statistics the Cutter encountered for the first five years of service. This information was compared to the design assumptions to understand the differences between design, actual operations, and impact on the long term fatigue damage forecasts. The influence of the operator is discussed. The model tests, dedicated trials and long term monitoring provided valuable insights into the limitations of analysis and predictions. A reliability based fatigue life prediction approach is discussed, along with how they may be used to evaluate options for life cycle management of fatigue and the Return on Investment (ROI) for considering fatigue early in the design. Finally, conclusions and recommendations are provided for the advancement of the spectral fatigue approaches for cost effectively managing fatigue in ship structure., Marine and Transport Technology, Mechanical, Maritime and Materials Engineering

Quality descriptions are parts of the key tasks of geodetic data processing. Systematic errors should be detected and avoided in order to insure the high quality standards required by structural monitoring. In this study, the iterative closest point (ICP) method was invested to detect systematic errors in two overlapping data sets. There are three steps to process the systematic errors: firstly, one of the data sets was transformed to a reference system by the introduction of the Gauss–Helmert (GH) model. Secondly, quadratic form estimation and segmentation methods are proposed to guarantee the overlapping data sets. Thirdly, the ICP method was employed for a finer registration and detecting the systematic errors. A case study was casted in which a dam surface in Germany was scanned by terrestrial laser scanning (TLS) technology. The results indicated that with the conjugation of ICP algorithm the accuracy of the data sets was improved approximately by 1.6 mm.

Development of communication technologies during last decade carried out possibility of application wireless sensor networks in many different areas. Recently frequently application of this technology in civil engineering is consequence of its economy and simplicity of installation, which provide possibility of monitoring of different parameters more flexible and possible at hard accessed locations. Paper deals with structure of wireless sensor network and in detail describe all components of those systems, as well as accompanying software and topology. Successful significant examples of applications in civil structure monitoring are presented, which illustrate po­ssibility of application in this, very important, area of civil engineering. Accelerated infrastructural development actualized research efforts in this area., Razvoj komunikacionih tehnologija poslednje decenije otvorio je mogućnosti primene bežičnih senzorskih mreža u najrazličitijim oblastima. Sve učestalija primena ove tehnologije u građevinarstvu posledica je njihove ekonomičnosti i jednostavnosti instalacije, a osmatranje različitih veličina čini fleksibilnijim i omogućava registrovanje na teško dostupnim lokacijama. Rad tretira strukturu mreža bežičnih senzora, detaljno prikazujući sve komponente ovakvih sistema, kao i pratećeg softvera i njihovu topologiju. Prikazani su značajni primeri realizacije u monitoringu građevinskih konstrukcija, čime se ilustruju mogućnosti za primenu u ovoj, sve značajnijoj, oblasti građevinske delatnosti. Ubrzan infrastrukturni razvoj aktuelizuje inteziviranje istraživanja u ovoj oblasti.

Development of communication technologies during last decade carried out possibility of application wireless sensor networks in many different areas. Recently frequently application of this technology in civil engineering is consequence of its economy and simplicity of installation, which provide possibility of monitoring of different parameters more flexible and possible at hard accessed locations. Paper deals with structure of wireless sensor network and in detail describe all components of those systems, as well as accompanying software and topology. Successful significant examples of applications in civil structure monitoring are presented, which illustrate po­ssibility of application in this, very important, area of civil engineering. Accelerated infrastructural development actualized research efforts in this area., Razvoj komunikacionih tehnologija poslednje decenije otvorio je mogućnosti primene bežičnih senzorskih mreža u najrazličitijim oblastima. Sve učestalija primena ove tehnologije u građevinarstvu posledica je njihove ekonomičnosti i jednostavnosti instalacije, a osmatranje različitih veličina čini fleksibilnijim i omogućava registrovanje na teško dostupnim lokacijama. Rad tretira strukturu mreža bežičnih senzora, detaljno prikazujući sve komponente ovakvih sistema, kao i pratećeg softvera i njihovu topologiju. Prikazani su značajni primeri realizacije u monitoringu građevinskih konstrukcija, čime se ilustruju mogućnosti za primenu u ovoj, sve značajnijoj, oblasti građevinske delatnosti. Ubrzan infrastrukturni razvoj aktuelizuje inteziviranje istraživanja u ovoj oblasti.

Development of communication technologies during last decade carried out possibility of application wireless sensor networks in many different areas. Recently frequently application of this technology in civil engineering is consequence of its economy and simplicity of installation, which provide possibility of monitoring of different parameters more flexible and possible at hard accessed locations. Paper deals with structure of wireless sensor network and in detail describe all components of those systems, as well as accompanying software and topology. Successful significant examples of applications in civil structure monitoring are presented, which illustrate po­ssibility of application in this, very important, area of civil engineering. Accelerated infrastructural development actualized research efforts in this area., Razvoj komunikacionih tehnologija poslednje decenije otvorio je mogućnosti primene bežičnih senzorskih mreža u najrazličitijim oblastima. Sve učestalija primena ove tehnologije u građevinarstvu posledica je njihove ekonomičnosti i jednostavnosti instalacije, a osmatranje različitih veličina čini fleksibilnijim i omogućava registrovanje na teško dostupnim lokacijama. Rad tretira strukturu mreža bežičnih senzora, detaljno prikazujući sve komponente ovakvih sistema, kao i pratećeg softvera i njihovu topologiju. Prikazani su značajni primeri realizacije u monitoringu građevinskih konstrukcija, čime se ilustruju mogućnosti za primenu u ovoj, sve značajnijoj, oblasti građevinske delatnosti. Ubrzan infrastrukturni razvoj aktuelizuje inteziviranje istraživanja u ovoj oblasti.

Paper presents application of long-term Structural Health Monitoring - SHM of the rebuilt TV tower 'Avala'. According the actual trends for improvement of maintenance serviceability, safety and durability, on this structure is applied modern designed system for observation stress and deformation structural response. In the introduction are briefly introduced basics of the modern trends for improvements of serviceability infrastructure and other structures by recently published guidelines and standard drafts. Applied system for structural monitoring of the rebuild TV tower on Avala is described in details. Explained are general concept, disposition, applied transducers and central acquisition unit for logging, analysis and storing recorded data. ., U radu je prikazana primena dugotrajnog monitoringa stanja konstrukcije obnovljenog TV tornja 'Avala'. U skladu sa savremenim tendencijama za unapređenje održavanja, eksploatacije, sigurnosti i trajnosti objekata, i na ovoj značajnoj konstrukciji primenjen je savremeni pristup osmatranja naponsko-deformacijskog stanja konstrukcije. U uvodnom delu prikazan je savremeni trend u unapređenju funkcionisanja postojećih infrastrukturnih i drugih objekata izražen kroz skorije publikovane preporuke za sprovođenje monitoringa stanja konstrukcija u savremenim uslovima. Detaljno je obrazložen primenjeni sistem konstrukcijskog monitoringa obnovljenog TV tornja na Avali. Prikazana je opšta koncepcija, dispozicija, primenjeni senzori i centralizovano registrovanje i analiza merenih veličina.

Paper presents application of long-term Structural Health Monitoring - SHM of the rebuilt TV tower 'Avala'. According the actual trends for improvement of maintenance serviceability, safety and durability, on this structure is applied modern designed system for observation stress and deformation structural response. In the introduction are briefly introduced basics of the modern trends for improvements of serviceability infrastructure and other structures by recently published guidelines and standard drafts. Applied system for structural monitoring of the rebuild TV tower on Avala is described in details. Explained are general concept, disposition, applied transducers and central acquisition unit for logging, analysis and storing recorded data. ., U radu je prikazana primena dugotrajnog monitoringa stanja konstrukcije obnovljenog TV tornja 'Avala'. U skladu sa savremenim tendencijama za unapređenje održavanja, eksploatacije, sigurnosti i trajnosti objekata, i na ovoj značajnoj konstrukciji primenjen je savremeni pristup osmatranja naponsko-deformacijskog stanja konstrukcije. U uvodnom delu prikazan je savremeni trend u unapređenju funkcionisanja postojećih infrastrukturnih i drugih objekata izražen kroz skorije publikovane preporuke za sprovođenje monitoringa stanja konstrukcija u savremenim uslovima. Detaljno je obrazložen primenjeni sistem konstrukcijskog monitoringa obnovljenog TV tornja na Avali. Prikazana je opšta koncepcija, dispozicija, primenjeni senzori i centralizovano registrovanje i analiza merenih veličina.