1,721,081 research outputs found
Aventa wind turbine in Winterthur (Switzerland)
No full textThe wind turbine’s rated power is 6.5kW, the rotor diameter is 12.9m and the hub height is 18m. The tower is a tubular steel-reinforced concrete structure, and the blades are made of glassfiber with a tubular steel main-spar. The turbine is regulated via a variable-speed and variable pitch control system.
The measurements/instrumentation setup, type and layout is provided in the pdf files.
Data available upon request, please contact:
Prof. Dr. Eleni Chatzi ([email protected])
Dr. Imad Abdallah ([email protected])
For further details or questions, please contact:
Prof. Dr. Eleni Chatzi
Chair of Structural Mechanics & Monitoring
ETH Zürich
http://www.chatzi.ibk.ethz.ch
Aventa AV-7 ETH Zurich Research Wind Turbine SCADA and high frequency Structural Health Monitoring (SHM) data
No full textGeneral description of wind turbine: The ETH owned wind turbine is Aventa AV-7, manufactured by Aventa AG in Switzerland and was commissioned in December 2002. The turbine is operated via a belt-driven generator and a frequency converter with a variable speed drive. The rated power of the Aventa AV-7 is 7 kW, beginning production at a wind speed of 2 m/s and having a cut-off speed of 14 m/s. The rotor diameter is 12.8 m with 3 rotor blades, and a hub height is 18m. The maximum rotational speed of the turbine is 63 rpm. The tower is a tubular steel-reinforced concrete structure, supported on concrete foundation, while the blades are made of glassfiber with a tubular steel main-spar. The turbine is regulated via a variable-speed and variable pitch control system.
Location of site: The wind turbine is located in Taggenberg, about 5 km from the city centre of Winterthur, Switzerland. This site is easily accessible by public transport and on foot with direct road access right next to the turbine. This prime location reduces the cost of site visits and allows for frequent personal monitoring of the site when test equipment is installed. The coordinates of the site are: 47°31'12.2"N 8°40'55.7"E.
Control and measurement systems and signals: The turbine is regulated via a variable-speed and collective variable pitch control system.
SHM Motivation: Designed and commissioned in 2002, the Aventa wind turbine in Winterthur is soon reaching its end of design lifetime. In order to assess the various techniques of predicting the remaining useful lifetime, a Structural Health Monitoring (SHM) campaign was implemented by ETH Zurich. The monitoring campaign started in 2020, and is still ongoing. In addition, the setup is used as a research platform on topics such as system identification, operational modal analysis, faults/damage detection and classification. We analyze the influence of operational and environmental conditions on the modal parameters and to further infer Performance Indicators (PIs) for assessing structural behavior in terms of deterioration processes.
Data Description: The tower and nacelle have been instrumented with 11 accelerometers distributed along the length of the tower, nacelle main frame, main bearing and generator. Two full bridge strain gauges are installed on the concrete tower based measuring fore-aft and side-side strain (and can be converted to bending moments) – all acceleration and strain signals sampled at 200Hz. Temperature and humidity are measured at the tower base – 1Hz data. In additional we are collecting operational performance data (SCADA), namely: wind speed, nacelle yaw orientation, rotor RPM, power output and turbine status – SCADA signals are sampled at 10Hz. See appendix for further details of the sensors layout.
The measurements/instrumentation setup, type and layout is provided in the pdf files.
The data: the data is provided in zip files corresponding to four use-cases as follows:
Normal operation data for system identification
Aerodynamic imbalance on one blade
Rotor icing event
Failure of the flexible coupling of the linear drive of the collective pitch system
The data for each of the four uses-cases is organized in zip files. The content of each zip file is as follows:
Time-series data in HDF5 format
Metadata:
Turbine specification (Aventa-AV-7.json and Aventa-AV-7.yaml)
Sensor specification (Aventa_sensors.json )
Unstructured description of the Aventa Turbine and the installed sensors (Aventa_Sensors_Specs.xlsx)
Semantic artifacts:
WindIO Wind Turbine YAML schema describing turbine specifications (IEAontology_schema.yaml)
Sensor specification JSON schema (sensors_schema.json)
Media: Pictures of leading edge roughness and a clip of wind turbine operation
Code: Jupyter notebook containing example code to load metadata from JSON and data from HDF5 files (example.ipynb)
Additional data is available upon request, please contact:
Prof. Dr. Eleni Chatzi ([email protected])
Dr. Imad Abdallah ([email protected] , [email protected])
For further details or questions, please contact:
Prof. Dr. Eleni Chatzi
Chair of Structural Mechanics & Monitoring
ETH Zürich
http://www.chatzi.ibk.ethz.ch
Aventa AV-7 ETH Zurich Research Wind Turbine SCADA and SHM
No full textGeneral description of wind turbine: The ETH owned wind turbine is Aventa AV-7, manufactured by Aventa AG in Switzerland and was commissioned in December 2002. The turbine is operated via a belt-driven generator and a frequency converter with a variable speed drive. The rated power of the Aventa AV-7 is 7 kW, beginning production at a wind speed of 2 m/s and having a cut-off speed of 14 m/s. The rotor diameter is 12.8 m with 3 rotor blades, and a hub height is 18m. The maximum rotational speed of the turbine is 63 rpm. The tower is a tubular steel-reinforced concrete structure, supported on concrete foundation, while the blades are made of glassfiber with a tubular steel main-spar. The turbine is regulated via a variable-speed and variable pitch control system.
Location of site: The wind turbine is located in Taggenberg, about 5 km from the city centre of Winterthur, Switzerland. This site is easily accessible by public transport and on foot with direct road access right next to the turbine. This prime location reduces the cost of site visits and allows for frequent personal monitoring of the site when test equipment is installed. The coordinates of the site are: 47°31'12.2"N 8°40'55.7"E.
Control and measurement systems and signals: The turbine is regulated via a variable-speed and collective variable pitch control system.
SHM Motivation: Designed and commissioned in 2002, the Aventa wind turbine in Winterthur is soon reaching its end of design lifetime. In order to assess the various techniques of predicting the remaining useful lifetime, a Structural Health Monitoring (SHM) campaign was implemented by ETH Zurich. The monitoring campaign started in 2020, and is still ongoing. In addition, the setup is used as a research platform on topics such as system identification, operational modal analysis, faults/damage detection and classification. We analyze the influence of operational and environmental conditions on the modal parameters and to further infer Performance Indicators (PIs) for assessing structural behavior in terms of deterioration processes.
Data Description: The tower and nacelle have been instrumented with 11 accelerometers distributed along the length of the tower, nacelle main frame, main bearing and generator. Two full bridge strain gauges are installed on the concrete tower based measuring fore-aft and side-side strain (and can be converted to bending moments) – all acceleration and strain signals sampled at 200Hz. Temperature and humidity are measured at the tower base – 1Hz data. In additional we are collecting operational performance data (SCADA), namely: wind speed, nacelle yaw orientation, rotor RPM, power output and turbine status – SCADA signals are sampled at 10Hz. See appendix for further details of the sensors layout.
The measurements/instrumentation setup, type and layout is provided in the pdf files.
The data: the data is provided in zip files corresponding to four use-cases as follows:
Normal operation data for system identification
Aerodynamic imbalance on one blade
Rotor icing event
Failure of the flexible coupling of the linear drive of the collective pitch system
The data for each of the four uses-cases is organized in zip files. The content of each zip file is as follows:
Time-series data in HDF5 format
Metadata:
Turbine specification (Aventa-AV-7.json and Aventa-AV-7.yaml)
Sensor specification (Aventa_sensors.json )
Unstructured description of the Aventa Turbine and the installed sensors (Aventa_Sensors_Specs.xlsx)
Semantic artifacts:
WindIO Wind Turbine YAML schema describing turbine specifications (IEAontology_schema.yaml)
Sensor specification JSON schema (sensors_schema.json)
Media: Pictures of leading edge roughness and a clip of wind turbine operation
Code: Jupyter notebook containing example code to load metadata from JSON and data from HDF5 files (example.ipynb)
Additional data is available upon request, please contact:
Prof. Dr. Eleni Chatzi ([email protected])
Dr. Imad Abdallah ([email protected] , [email protected])
For further details or questions, please contact:
Prof. Dr. Eleni Chatzi
Chair of Structural Mechanics & Monitoring
ETH Zürich
http://www.chatzi.ibk.ethz.ch
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
SiDMACIB: A Digital Tool for an Automated Structurally Informed Design of Interlocking Masonry Assemblages
No full textThis manuscript presents a new computational form-finding tool developed for a structurally informed design of masonry interlocking assemblages. Applying the concave contact model of limit analysis to corrugated joints, a novel static problem with seven options for the distribution of contact points on the interlocking joints is presented. To validate the static problem, an experimental investigation and a discrete element-based numerical test are carried out. Using these experimental and numerical tests, the torsion-shear capacity of the cohesive interface connecting a lock to the main body of an interlocking block is calculated and compared to torsion-shear capacities obtained by the seven options of the proposed concave contact model. Implementing the proposed static problem, a flexible computational setup is developed to model and analyze free-form single-layer interlocking assemblages with stacked or running bonds. Reformulating the static problem, a new parameter is introduced to quantify the infeasibility of the interlocking assemblages due to the violation of the sliding constraint. This infeasibility measurement method is finally implemented in a novel shape optimization procedure that minimizes the sliding infeasibility of the assemblage through adjustment of the interlocking joint shapes. The application of this digital tool to analyze and optimize the interlocking assemblages, is presented using some benchmarks
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A semi-supervised interpretable machine learning framework for sensor fault detection
No full textStructural Health Monitoring (SHM) of critical infrastructure comprises a major pillar of maintenance management, shielding public safety and economic sustainability. Although SHM is usually associated with data-driven metrics and thresholds, expert judgement is essential, especially in cases where erroneous predictions can bear casualties or substantial economic loss. Considering that visual inspections are time consuming and potentially subjective, artificial-intelligence tools may be leveraged in order to minimize the inspection effort and provide objective outcomes. In this context, timely detection of sensor malfunctioning is crucial in preventing inaccurate assessment and false alarms. The present work introduces a sensor-fault detection and interpretation framework, based on the well-established support-vector machine scheme for anomaly detection, combined with a coalitional game-theory approach. The proposed framework is implemented in two datasets, provided along the 1st International Project Competition for Structural Health Monitoring (IPC-SHM 2020), comprising acceleration and cable-load measurements from two real cable-stayed bridges. The results demonstrate good predictive performance and highlight the potential for seamless adaption of the algorithm to intrinsically different data domains. For the first time, the term “decision trajectories”, originating from the field of cognitive sciences, is introduced and applied in the context of SHM. This provides an intuitive and comprehensive illustration of the impact of individual features, along with an elaboration on feature dependencies that drive individual model predictions. Overall, the proposed framework provides an easy-to-train, application-agnostic and interpretable anomaly detector, which can be integrated into the preprocessing part of various SHM and condition-monitoring applications, offering a first screening of the sensor health prior to further analysis
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