Installation Of Monitoring System Research Articles

Structural health monitoring of an onshore steel wind turbine

The study presents the development of a structural monitoring system installed in a 45-m-high steel wind tower located in Italy. The installed monitoring system was composed by 16 strain gauges placed in the tower wall, in a pattern of four Wheatstone bridges at 45°, together with thermal couples, at 21 m from the ground (half-height of the tower). Moreover, several accelerometers were placed along the tower height (with one of them located next to the strain gauges). The wind velocity and directions were obtained directly from the turbine own monitoring system. Such a monitoring system was designed because, due to the decrement of the total height from the original design, the tower suffers from resonance problems. In fact, the investigated tower was originally designed with 65 m of height but then, to comply with local regulations, the height was decreased to the actual size. Therefore, to allow safe operation and avoid excessive fatigue due to the increased displacements, the velocity of the rotor has been manually limited causing an important reduction in the energy production. The results of the study show the importance of monitoring the resonance issue. The differences between the damage indexes obtained with two different working conditions are discussed: tower working with limited operational capacity and tower working at its maximum capacity (in resonance).

Relationships of Water Quality Parameters for Hydroponic Production of Kale (Brassica oleracea) with In-Ground Passive Cooling System

Greenhouses in Philippines are encountering high ambient air temperature problem. Along with this, the water quality directly affects the growth, development and yield of hydroponically grown plants. This study was conceptualized through the principle of cooling the nutrient solution that will effectively regulate plant’s growth and yield with relatively low investment and easier management. One of the essential elements of a functional hydroponics system is water quality monitoring, hence this study utilized a monitoring system for water quality parameters. Nutrient solution was closely monitored to maintain and ensure that nutrient levels are not too low to inhibit growth and not too high to be potentially toxic. The study was conducted to develop a monitoring system for environmental and water quality parameters of in-ground passive cooling system for hydroponic production of kale. Specifically, the study aimed to determine the relationships of water quality parameters such as pH, EC, TDS, and temperature for kale production, compare the performance of an in-ground passive cooling system (IGPCS) and without cooling system (Control) on hydroponically grown kale, and to evaluate the water productivity of the in-ground passive cooling system. This study utilized both in-ground passive cooling system (IGPCS) and control (without cooling system) to compare its performance based on the growth and yield of the kale, and to determine the water productivity of utilizing IGPCS. In addition, water quality parameter such as pH, EC, TDS, and temperature were closely monitored using the installed monitoring system, and relationships of these water quality parameters were established. The gathered data were analyzed using trend analysis in Microsoft Excel, Analysis of variance (ANOVA) was computed in Completely Randomized Design (CRD) and comparison among means were compared using Least Significant Difference (LSD) Test at 5% level. Results revealed that EC and TDS of nutrient solution are inversely proportional to pH and temperature of nutrient solution, moreover EC and TDS are directly proportional, also with pH and temperature of nutrient solution. The performance of the IGPCS and without cooling system is comparable with growth and yield of kale in terms of leaf length, leaf width, number of leaves, weight and yield at harvest, but are significantly affected by the location of growing pipes where crops received less and ample amount of sunlight. Since the temperature of IGPCS was reduced up to 3°C, kale plants with cooling system uptake less water compared to without cooling system and results to higher productivity. Therefore, regulating one of the water quality parameters directly affects other water quality parameters, so relationships of these water quality parameters were established through close monitoring of water quality parameters using the monitoring system. Utilization of IGPCS reduced the temperature of the nutrient solution up to 3°C which gave higher yield (44.01 g/plant) than without cooling system (41.18 g/plant). Kale production in tropical areas can have higher yield using the in-ground passive cooling system that reduced water consumption, resulting to higher productivity.

Experience of operation monitoring system of the cat-bone bridge through the Petrovskaya Channel in the alignment of the Western Speed Diameter Highway in St. Petersburg

Aim: Analysis of the current monitoring system of the engineering structures of a cable-stayed bridge across the Petrovsky Canal in the alignment of the Western High-Speed ​​Diameter highway in St. Petersburg.
 Methods and Materials: Statistical data from the databases of the existing system of monitoring engineering structures is used to obtain the results. The tasks, set within the framework of the study, are accomplished by applying the theoretical methods of scientific knowledge: the analytical method, the mathematical statistics theory, induction.
 Results: Analysis of the current monitoring system of engineering structures is presented with a description of one of the main problems the impossibility of synchronizing readings from all sensors during considered period of time, which leads to the inability to correctly assess the stress-strain state of the bridge structure as a whole. Discovered problem solutions are proposed, further research prospect is determined in part of the imperfection of monitoring systems for long-span facilities.
 Conclusion: The obtained study results can be used in designing and installation of monitoring systems of the engineering structures for cable-stayed bridges, as well as for modernization and optimization of existing monitoring systems to improve the quality of assessing technical condition of structures assessment.

DETECT-AGING blind prediction contest: a benchmark for structural health monitoring of masonry buildings

The installation of monitoring systems on buildings allows analyzing variations in structural parameters over time, creating room for detection of damage. Structural Health Monitoring (SHM) systems have the potential to support pro-active risk management, where structural interventions are planned if specific thresholds related to target performance losses are achieved.DETECT-AGING is a research project of relevant national interest that was funded by the Italian Ministry of University and Research (MUR) through the PRIN 2017 programme. The project started in September 2019 and involves the universities of Bologna, Genova, Napoli Federico II, and Perugia. The main goal of the project is to develop a new analytical-instrumental approach aimed at the quantitative assessment of the effects of aging and material degradation on structural safety of cultural heritage, with special focus on masonry structures. Based on a combined use of structural models and health monitoring systems, indications and operational tools will be provided for the identification and quantification of structural damage, supporting the management of built cultural heritage. To this purpose, a two-storey masonry building, having a single room with a vault at the first floor and a timber roof, was built with the aim of being monitored and progressively and will be damaged during the project. It is equipped with a hybrid SHM system managed by the University of Perugia, which is based on both vibration and strain measurements. The present paper illustrates the main features of the case-study building and presents the results of the experimental program aimed at characterizing the mechanical properties of masonry the materials used. The final part of the paper presents a blind prediction contest based on prediction of modal features of the building in different damaged configurations.

Improved Resilience and Sustainable Reconstruction of Cultural Heritage Areas to cope with Climate Change and Other Hazards based on Innovative Algorithms and Modelling Tools

Our proposed framework aims to efficiently train a network of fellows on the field of the resilience of Cultural Heritage (CH) areas and historic cities against Climate Change (CC) and other types of hazards. Towards this direction, the proposed framework aims to introduce a research framework for downscaling the created climate and atmospheric composition as well as associated risk maps down to the 1x1 km (historic area) scale, and specific damage functions for CH ma-terials. Applying atmospheric modelling for specific CC scenarios at such refined spatial and time scales allows for an accurate quantitative and qualitative impact as-sessment of the estimated micro-climatic and atmospheric stressors. Our proposed framework will perform combined structural/geotechnical analysis of the CH sites and damage assessment under normal and changed conditions, based on the cli-matic zone, the micro-climate conditions, the petrographic and textural features of building materials, historic data for the structures, the effect of previous restoration processes and the environmental/physical characteristics of the surrounding envi-ronment. The data coming from installed monitoring system will be coupled with simulated data and will be further analysed through our data management system, while supporting communities’ participation and public awareness. The data from the monitoring system will feed the Decision- Support-System (DSS) so as to pro-vide proper adaptation and mitigation strategies. The produced vulnerability map will be used by the local authorities to assess the threats of CC (and other natural hazards), visualize the built heritage and cultural landscape under future climate scenarios, model the effects of different adaptation strategies, and ultimately prior-itize any rehabilitation actions to best allocate funds in both pre- and post-event en-vironments. To train the fellows, our approach will make use of extensive workshop and training sessions, as well organise summer schools.

Dynamic monitoring of a tunnel-like masonry structure using wireless sensor networks

The application of wireless sensor network technology for long-term monitoring of a historic tunnel-like masonry structure in Italy is described. The monitoring was performed within the activity of a research project aimed at providing a general framework to check the structural health of heritage structures and detect, in real time, any potential damage that may compromise their safety. The selected case study (a tunnel-like masonry structure) represented a challenging experiment, both in terms of the type of structure itself and the technical solution employed for installing the monitoring system. After a brief description of the installed monitoring system and the design of the sensor layout, the lessons learned after 1 year of monitoring are summarised.

Automatic anomaly detection and processing for long-term tension monitoring of stay cables based on vibration measurements

Abstract Stay cables are the crucial force-transmitting components of cable-stayed bridges. Consequently, effective cable tension monitoring is typically regarded as the most important issue in structural health monitoring for this type of bridge. In the long-term monitoring of structures, the occurrence of abnormal signals due to a variety of reasons such as sensor faults, a system malfunction, data loss in transmission, or the instability of power supply, are almost unavoidable and are highly likely to lead to a deterioration in the quality of subsequent analyses. The current paper presents the first phase of a project to develop an automatic monitoring system for cable tension based on ambient vibration signals for the Mao-Luo-Hsi Bridge. The results demonstrate that automatic anomaly detection and processing for cable vibration measurements can be achieved with a relatively simple algorithm using an appropriate threshold of maximum response value. In addition, the paper also reports the elimination of anomalies during testing of the monitoring system installation.

Easily installed monitoring system detects leaks in industrial facilities

Freudenberg Sealing Technologies (FST) has designed and developed a monitoring system based on an optical sensor that enables the early detection of leaks in industrial plants. The system is easy to install, and can be retrofitted to existing infrastructure. According to the company, simple installation and activation can be done easily – even by small and mid-level companies without their own IT specialists. Here we briefly look at how the technology works.

Ecological monitoring of air condition in smart cities according to conception of “Internet of Things”

The paper considers the current state of art in the ecological monitoring in the urban locality, existing problems and disadvantages of the installed monitoring systems of air conditions that are autonomous, stationary and ecological. The paper presents studies on the current state of monitoring systems in the city of St. Petersburg with a comparative analysis based on the results of field observations. Possible solutions proposed in this paper are based on the existing trend in the development of the Internet of Things and the requirements of regulatory documents.

Value of information of a pro-active SHM-based tool supported by advanced FE models and Bayesian statistics towards efficiency in bridge management

Bridges are critical components in the extensive European transportation network, most of them built as part of the post-World War II reconstruction effort. This means that society is facing the beginning of the end of their design life, showing the necessity of enhanced approaches, complementing visual inspections, to improve the efficiency in bridge management. Knowing in advance the Return on Investment (RoI), of such enhanced approaches, becomes appealing information for decision-makers. This work introduces a formulation for the quantification of the Value of Information (VoI, i.e. the RoI) of a pro-active Structural Health Monitoring (SHM) tool devoted to early damage detection. A comprehensive case study—the Lezíria Bridge—is used by benefiting from (i) an SHM system operating since construction, 2006, and an accurate FE model of the structure. The structural behaviour and sensors’ measurements for a set of likely damages are anticipated via the mentioned FE model. Based on this, it is shown that RoI can go up, approximately, between +11.7% and +13.1%. How these values were reached are explained from a pedagogical and comprehensive perspective, focussing on how to benefit effectively from the installed monitoring system in the future considering the inevitable ageing of the structure.

A probabilistic method for structural integrity assurance based on damage detection structural health monitoring data

The value of using permanently installed monitoring systems for managing the life of an engineering asset is determined by the confidence in its damage detection capabilities. A framework is proposed that integrates detection data from permanently installed monitoring systems with probabilistic structural integrity assessments. Probability of detection (POD) curves are used in combination with particle filtering methods to recursively update a distribution of postulated defect size given a series of negative results (i.e. no defects detected). The negative monitoring results continuously filter out possible cases of severe damage, which in turn updates the estimated probability of failure. An implementation of the particle filtering method that takes into account the effect of systematic uncertainty in the detection capabilities of a monitoring system is also proposed, addressing the problem of whether negative measurements are simply a consequence of defects occurring outside the sensors field of view. A simulated example of fatigue crack growth is used to demonstrate the proposed framework. The results demonstrate that permanently installed sensors with low susceptibility to systematic effects may be used to maintain confidence in fitness-for-service while relying on fewer inspections. The framework provides a method for using permanently installed sensors to achieve continuous assessments of fitness-for-service for improved integrity management.

Verification of Composite Steel and Concrete Bed Behaviour for Machine Tools

This paper focuses on the theoretical and experimental verification of a behaviour composite reinforced concrete bed for installation in high-precision machine tools. The design solution consists of coupling the steel shell and HPC concrete filling, which ensures the high rigidity of the bed. Studies in this article were aimed at describing, in detail, the behaviour of the bed, from production to setting into its final position. An integral part of the solution was implementing the measurement of the response of the real bed segment using the installed monitoring system as well as the numerical simulations performed on the assembled FEM model. Thanks to the modular design of the bed, it was possible to verify the behaviour of the simulated load during the operation of the machine tool on a smaller sample. The aim is to verify the functionality of the coupling and, based on the comparison of measured and theoretical data, to define the critical points of the composite and, thus, provide a basis for design optimisation in order to maximise the monitored parameters.

Groundwater Monitoring Systems to Understand Sea Water Intrusion Dynamics in the Mediterranean: The Neretva Valley and the Southern Venice Coastal Aquifers Case Studies

Sea water intrusion (SWI) has been widely recognized as a global problem, significantly influencing coastal aquifers, mostly through reduced water quality and agricultural production indicators. In this paper, we present the outcomes of the implementation of two independent real-time monitoring systems, planned and installed to get insights on groundwater dynamics within the adjacent coastal aquifer systems, one located in the Neretva Valley, southeastern Croatia, the other located south of the Venice lagoon, northeastern Italy. Both systems are presented with technical details and the capacity to observe, store, and transmit (Neretva site) observed values in real-time. Analysis of time series reveals the significant influence of the sea level oscillations onto the observed groundwater electrical conductivity (EC) and piezometric head values, while precipitation rate is detected as a driving mechanism for groundwater parameters in shallow geological units. The installed monitoring systems are shown to be of great importance to provide qualitative and quantitative information on the processes influencing groundwater and surface water dynamics within two coastal systems.

Design optimisation of permanently installed monitoring system for polycrystalline materials

This article presents a design procedure for structural health monitoring systems based on bulk wave ultrasonic sensors for structures fabricated from polycrystalline materials. When designing a monitoring system, maximum coverage per transducer is a general requirement in order for the system to be economic. For coarse-grained polycrystalline materials, monitoring is often made challenging by low signal-to-noise ratios caused by grain scattering. Therefore, when designing a monitoring system for these materials, in addition to the economic requirement, it needs to be ensured that an adequate signal-to-noise ratio can be obtained throughout the monitoring volume. This typically introduces a trade-off between volume coverage per transducer and sensitivity that must be investigated. In this article, this trade-off is studied and a methodology using signal-to-noise maps is presented to design the system, that is, choose the optimal transducer parameters and placement. First, a combined analytical and numerical approach is used to generate a signal-to-noise map. Then, the influence of various factors on signal-to-noise ratio is investigated. Finally, two representative examples, with different criteria, are given to illustrate the methodology. In one example, the full surface area of the testpiece is covered with transducers and the optimum gives the deepest coverage. The other one aims to achieve the minimum fractional surface area that has to be covered with transducers to monitor a narrow depth range far from the surface, which has a potential application in weld monitoring. Results show that the optimum is likely to be at much lower frequency than typically used in inspection, as tracking signals with time gives sensitivity gains. Experiments were carried out to illustrate that higher volume coverage can be obtained at lower frequencies.

BIM data model requirements for asset monitoring and the circular economy

Purpose The purpose of this paper is to review and provide recommendations to extend the current open standard data models for describing monitoring systems and circular economy precepts for built assets. Open standard data models enable robust and efficient data exchange which underpins the successful implementation of a circular economy. One of the largest opportunities to reduce the total life cycle cost of a built asset is to use the building information modelling (BIM) approach during the operational phase because it represents the largest share of the entire cost. BIM models that represent the actual conditions and performance of the constructed assets can boost the benefits of the installed monitoring systems and reduce maintenance and operational costs. Design/methodology/approach This paper presents a horizontal investigation of current BIM data models and their use for describing circular economy principles and performance monitoring of built assets. Based on the investigation, an extension to the industry foundation classes (IFC) specification, recommendations and guidelines are presented which enable to describe circular economy principles and asset monitoring using IFC. Findings Current open BIM data models are not sufficiently mature yet. This limits the interoperability of the BIM approach and the implementation of circular economy principles. An overarching approach to extend the current standards is necessary, which considers aspects related to not only modelling the monitoring system but also data management and analysis. Originality/value To the authors’ best knowledge, this is the first study that identifies requirements for data model standards in the context current linear economic model of making, using and disposing is growing unsustainably far beyond the finite limits of planet of a circular economy. The results of this study set the basis for the extension of current standards required to apply the circular economy precepts.

Vibration analysis in the process of operation of installations and machines from the oil industry

Vibrations are alternative movements made by the mechanical system in relation to the reference state, being caused by disruptive forces (excitations) whose sizes, directions or points of application vary over time. From the multitude of parameters that, by measuring, give an image of the operating state, the vibrations and noise produced by machines and machines have attracted the attention of researchers, designers, builders and specialists in operation in recent years. Also the vibration and noise offer a high sensitivity to the analysis, but also individuality to the concrete situations, only apparently repeated. The development of vibration and noise measurement techniques, as well as the development of signal processing techniques, have allowed important improvements in the control, monitoring and diagnostic systems. The vibration diagnostics of the state of operation of facilities, installations and machinery in the oil industry is based on the fact that in the energy transfer process, oriented towards the realization of a given function, different components, located on the route of the transfer, can be excited mechanically, and thus the vibration. Monitoring the operation of the installations and machines in operation by the specific parameters of the operating process, by vibration, temperature etc., is recognized as an important way to increase the reliability, operating efficiency, reduce production and operating costs. For use or installation of monitoring systems is to check normality operation, to detect deviations potential „problems” and to provide information, decision support and interventions to disconnect or shutdown and for diagnosis. The accumulation, classification, analysis of these results, gathered in diagnostic databases, with the help of advanced processing techniques, are capable of ensuring, first of all, the objectivity of the diagnosis.

Distributed fibre-optic sensing applications at the Semmering Base Tunnel, Austria

The Semmering Base Tunnel in Austria is currently one of the largest tunnel construction sites in Central Europe. Two tunnel tubes, each 27.3 km long, are being built from the portal and three intermediate construction sites. Each access point poses specific challenges, and structural monitoring is a crucial element to ensure both economic and safe construction. In this paper, the authors describe one of the most comprehensive distributed fibre-optic sensing installations on a tunnel construction site worldwide. At the Semmering Base Tunnel, fibre-optic sensing is used at every construction location to monitor tunnel linings, shafts, reinforced earth structures and pipelines. The authors also discuss the challenges posed by the installations and the results of long-term monitoring programmes. The installed monitoring systems will, furthermore, be used throughout the expected 150-year operational lifetime of the tunnel. Unlike conventional sensors, fibre-optic sensors do not comprise electric or moveable components at the measurement location. A longer lifetime can, therefore, be expected for fibre-optic sensors, which makes them promising candidates for condition-based maintenance of civil infrastructure.

Probabilistic rainfall thresholds in Chibo, India: estimation and validation using monitoring system

The Himalayan region has been severely affected by landslides especially during the monsoons. In particular, Kalimpong region in Darjeeling Himalayas has recorded several landslides and has caused significant loss of life, property and agricultural land. The study region, Chibo has experienced several landslides in the past which were mainly debris and earth slide. Globally, several types of rainfall thresholds have been used to determine rainfall-induced landslide incidents. In this paper, probabilistic thresholds have been defined as it would provide a better understanding compared to deterministic thresholds which provide binary results, i.e., either landslide or no landslide for a particular rainfall event. Not much research has been carried out towards validation of rainfall thresholds using an effective and robust monitoring system. The thresholds are then validated using a reliable system utilizing Microelectromechanical Systems (MEMS) tilt sensor and volumetric water content sensor installed in the region. The system measures the tilt of the instrument which is installed at shallow depths and is ideal for an early warning system for shallow landslides. The change in observed tilt angles due to rainfall would give an understanding of the applicability of the probabilistic model. The probabilities determined using Bayes’ theorem have been calculated using the rainfall parameters and landslide data in 2010–2016. The rainfall values were collected from an automatic rain gauge setup near the Chibo region. The probabilities were validated using the MEMS based monitoring system setup in Chibo for the monsoon season of 2017. This is the first attempt to determine probabilities and validate it with a robust and effective monitoring system in Darjeeling Himalayas. This study would help in developing an early warning system for regions where the installation of monitoring systems may not be feasible.

Evaluating the use of rate-based monitoring for improved fatigue remnant life predictions

The ability to perform accurate remnant life predictions is crucial to ensure the integrity of engineering components that experience fatigue loading during operation. This is conventionally achieved with periodic inspections, where results from non-destructive evaluation and estimation of the operating conditions are obtained to perform remnant life predictions using empirical crack growth laws. However, remnant life predictions made with this approach are very sensitive to their input parameters; uncertainty in each parameter would aggregate and result in great uncertainty in the final prediction. With the increasing viability of permanently-installed systems, it is proposed that the rate of damage growth can be used to more accurately and confidently gauge the integrity of an engineering component and perform remnant life predictions using the Failure Forecast Method. A statistical analysis of an example fatigue crack growth test was performed to compare the uncertainties of the remnant life predictions made using the conventional inspection approach and the proposed rate-based monitoring approach. It is shown that the Failure Forecast Method produces significantly more accurate and confident predictions compared to the inspection approach. The use of the Failure Forecast Method under non-constant amplitude loading conditions was also investigated. An equivalent cycles method is introduced to accommodate step changes in operating conditions. The effect of load interactions was also studied through a fatigue test with isolated overloads and a random variable amplitude loading test. Overall, the study has shown that the frequent data obtained from permanently installed monitoring systems provides new opportunities in remnant life estimates and potentially opens the way to increasing the intervals between outages and safely reducing conservatism in life predictions.

Continuous dynamic monitoring of an onshore wind turbine

Current utility-scale wind turbines are highly dynamic systems excited by a large variety of loading sources. The proper operation of wind turbines thus requires a complete knowledge of the actual dynamic behavior of the system, in order to ensure the expected longevity of their main structural elements. In that context, this paper describes the monitoring project developed for a 2.0 MW wind turbine, the description of the installed monitoring system, as well as the main steps included in the methodology developed for the continuous processing of the collected data. The main results achieved during one year of monitoring are shown in detail. They allowed to accurately characterize the variability of the dynamic properties of the wind turbine, with special emphasis on the natural frequencies and damping ratios of the most important vibration modes, throughout normal operating conditions of the turbine. In addition, several shutdown events were identified and used to estimate the modal damping of the wind turbine through the analysis of free-decay responses of the structure. This monitoring project contributes to improve the knowledge on the dynamic behavior of onshore wind turbines under normal operating conditions.