Download or read book Fundamentals for Remote Structural Health Monitoring of Wind Turbine Blades a Pre project Annex A Cost benefit for Embedded Sensors in Large Wind Turbine Blades written by Lars Gottlieb Hansen and published by . This book was released on 2002 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals for Remote Structural Health Monitoring of Wind Turbine Blades a Preproject Annex A written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Health Monitoring of Civil Infrastructure Systems written by Vistasp M. Karbhari and published by Elsevier. This book was released on 2009-08-25 with total page 553 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural health monitoring is an extremely important methodology in evaluating the 'health' of a structure by assessing the level of deterioration and remaining service life of civil infrastructure systems. This book reviews key developments in research, technologies and applications in this area of civil engineering. It discusses ways of obtaining and analysing data, sensor technologies and methods of sensing changes in structural performance characteristics. It also discusses data transmission and the application of both individual technologies and entire systems to bridges and buildings.With its distinguished editors and international team of contributors, Structural health monitoring of civil infrastructure systems is a valuable reference for students in civil and structural engineering programs as well as those studying sensors, data analysis and transmission at universities. It will also be an important source for practicing civil engineers and designers, engineers and researchers developing sensors, network systems and methods of data transmission and analysis, policy makers, inspectors and those responsible for the safety and service life of civil infrastructure. - Reviews key developments in research, technologies and applications - Discusses systems used to obtain and analyse data and sensor technologies - Assesses methods of sensing changes in structural performance

Download or read book Fundamentals for Remote Structural Health Monitoring of Wind Turbine Blades a Preproject Annex E written by Ole J. D. Kristensen and published by . This book was released on 2002 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals for Remote Structural Health Monitoring of Wind Turbine Blades a Pre project Annex B Sensors and Non destructive Testing Methods for Damage Detection in Wind Turbine Blades written by L. Lading and published by . This book was released on 2002 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals for Remote Structural Health Monitoring of Wind Turbine Blades a Pre project written by B. F. Sørensen and published by . This book was released on 2002 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals for Remote Structural Health Monitoring of Wind Turbine Blades a Preproject Annex C written by Peter Sendrup and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals for Remote Structural Health Monitoring of Wind Turbine Blades a Preproject written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Embedded Sensors for Structural Health Monitiroing of Wind Turbine Blades written by Edward Charles Meehan and published by . This book was released on 2012 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monitoring a structure's response to various loading conditions is essential to being able to predict catastrophic failure of the part. There are many types of sensors that have been developed to be able to accurately measure these important quantities. However, as the structure becomes thicker, it is important to monitor in more places than just the surface of the material. Composite materials, such as those used in the wind turbine industry, are typically built in layers, which lend themselves to having sensors embedded in the structure. Previous research had focused on how these embedded sensors affected the mechanical properties of the material, and this research continues on by utilizing the gages to monitor the strains developed in the material. An important aspect of the research was to be able to separate the mechanical strain from the thermal strains developed in the substrate. This was achieved by using advanced circuitry, and was confirmed by performing tensile and heating tests on both surface mounted and embedded sensors. From the data collected, it was shown that it was possible to separate out the mechanical and thermal strains.

Download or read book Structural Health Monitoring of Wind Turbine Blades written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ACME Wind Turbine Corporation has contacted our dynamic analysis firm regarding structural health monitoring of their wind turbine blades. ACME has had several failures in previous years. Examples are shown in Figure 1. These failures have resulted in economic loss for the company due to down time of the turbines (lost revenue) and repair costs. Blade failures can occur in several modes, which may depend on the type of construction and load history. Cracking and delamination are some typical modes of blade failure. ACME warranties its turbines and wishes to decrease the number of blade failures they have to repair and replace. The company wishes to implement a real time structural health monitoring system in order to better understand when blade replacement is necessary. Because of warranty costs incurred to date, ACME is interested in either changing the warranty period for the blades in question or predicting imminent failure before it occurs. ACME's current practice is to increase the number of physical inspections when blades are approaching the end of their fatigue lives. Implementation of an in situ monitoring system would eliminate or greatly reduce the need for such physical inspections. Another benefit of such a monitoring system is that the life of any given component could be extended since real conditions would be monitored. The SHM system designed for ACME must be able to operate while the wind turbine is in service. This means that wireless communication options will likely be implemented. Because blade failures occur due to cyclic stresses in the blade material, the sensing system will focus on monitoring strain at various points.

Download or read book Structural Health Monitoring of Wind Turbine Blades written by and published by . This book was released on 2008 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Health Monitoring of Wind Turbine Blades Using Guided Wave NDT Technique written by Kenneth C. Burnham and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind energy is an increasingly important contributor of power within the renewable energy sector. In the year to 2012, wind generation within the United Kingdom (UK) increased 40% meeting 6% of the UK's national electricity demand. The UK is committed to providing 15% of its energy from renewable resources by 2020. Currently, the UK has approximately 40% of Europe's entire wind resource with significant potential for development of both on and offshore wind. In recent years, the number of reports on defective blades contributing towards turbine failure has grown. Blade manufacturers have privately reported a recurring problem with the spar cap - a critical strengthening component - which when weakened by damage, hastens the onset of operational failure. The contents of this thesis consider composite materials used within the blade and the detection techniques appropriate for in-field implementation. Application of Guided Waves, in particular Lamb waves, suits the typical dimensions of the blade composite structure. Experiments were conducted to understand the characteristics of Lamb wave modes within glass fibre reinforced plastic (GFRP) to assess attenuation levels; modal propagation; and dispersion with respect to fibre orientation. Finite Element Analysis (FEA) was used to observe material characteristics and discern possible modes of wave propagation. To exploit the directional qualities of GFRP, directional Macro Fibre Composite (MFC) sensors were applied to a wind turbine blade providing low-profile, light-weight, durability and conformability with sufficient sensitivity to detect elastic disturbance over large areas. Parametric monitoring of GFRP samples under loading identified tensile stress from defect onset. Cross correlation and sliding-window correlation signal processing techniques on recorded data from the applied sparse array identified the onset of fibre damage using Guided wave modes. This technique was able to identify modal changes to specific defects providing the prospect for in-situ blade monitoring.

Download or read book Polycrystalline Silicon Capacitive MEMS Strain Sensor for Structural Health Monitoring of Wind Turbines written by Maziar Moradi and published by . This book was released on 2016 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind energy is a fast-growing sustainable energy technology and driven by the need for more efficient energy harvesting, size of the wind turbines has increased over the years for both off-shore and land-based installations. Therefore, structural health monitoring and maintenance of such turbine structures have become critical and challenging. In order to keep the number of physical inspections to minimum without increasing the risk of structural failure, a precise and reliable remote monitoring system for damage identification is necessary. Condition-based maintenance which significantly improves safety compared to periodic visual inspections, necessitates a method to determine the condition of machines while in operation and involves the observation of the system by sampling dynamic response measurements from a group of sensors and the analysis of the data to determine the current state of system health. This goal is being pursued in this thesis through the development of reliable sensors, and reliable damage detection algorithms. Blade strain is the most important quantities to judge the health of wind turbine structure. Sensing high stress fields or early detection of cracks in blades bring safety and saving in rehabilitation costs. Therefore, high performance strain measurement system, consisting of sensors and interface electronics, is highly desirable and the best choice. It has been revealed that the conventional strain gauge techniques exhibit significant errors and uncertainties when applied to composite materials of wind turbine blades. Micro-electro-mechanical system (MEMS) based sensors are very attractive among other sensing techniques owing to high sensitivity, low noise, better scaling characteristics, low cost and higher potential for integration with low power CMOS circuits. MEMS sensors that are fabricated on a chip can be either bonded to the surface of wind turbine blade or embedded into the fiber reinforced composite. Therefore, MEMS technology is selected to fabricate the strain sensor in this work. Two new sensor structures that can be used for strain measurement are designed. While the proposed sensors focus on high sensitivity, they are based on simple operating principle of comb-drive differential variable capacitances and chevron displacement amplification. Device performances are validated both by analytical solutions and finite element method simulations. The transmission of strain fields in adhesively bonded strain sensors is also studied. In strain sensors that are attached to host structures using adhesive layers such as epoxy, complete strain transfer to the sensor is hindered due to the influence of the adhesive layer on the transfer. An analytical model, validated by finite element method simulation, to provide insight and accurate formulation for strain transfer mechanism for bonded sensors is developed. The model is capable of predicting the strain transmission ratio through a sensor gauge factor, and it clearly establishes the effects of the flexibility, length, and thickness of the adhesive layer and sensor substrate. Several fabrication steps were required to realize the MEMS capacitive strain sensor in our lab. Polycrystalline silicon is selected as the structural layer and silicon nitride as the sacrificial layer. Polysilicon is deposited using LPCVD and SiN is deposited by PECVD in our lab. A comprehensive material study of silicon nitride and polycrystalline silicon layers is therefore performed. The whole fabrication process involves deposition, etching, and photolithography of five material layers. Although this process is developed to realize the MEMS strain sensors, it is also able to fabricate other designs of surface micromachining structures as well. The fabricated MEMS capacitive strain sensors are tested on a test fixture setup. The measurement setup is created under the probe station by using a cantilever beam fixed on one side and free on other side where a micrometer applies accurate displacement. The displacement creates bending stress on the beam which transfers to the MEMS sensor through the adhesive bond. Measurement results are in a good match with the simulation results. Finally, a real-time non-destructive health monitoring technique based on multi-sensor data fusion is proposed. The objective is to evaluate the feasibility of the proposed method to identify and localize damages in wind turbine blades. The structural properties of turbine blade before and after damage are investigated and based on the obtained results, it is shown that information from smart sensors, measuring strains and vibrations, distributed over the turbine blades can be used to assist in more accurate damage detection and overall understanding of the health condition of blades. Data fusion technique is proposed to combine the diagnostic tools to improve the detection system with providing a more robust reading and fewer false alarms.

Download or read book Experimental Results of Structural Health Monitoring of Wind Turbine Blades written by and published by . This book was released on 2008 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Remote Monitoring of the Structural Health of Hydrokinetic Composite Turbine Blades written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A health monitoring approach is investigated for hydrokinetic turbine blade applications. In-service monitoring is critical due to the difficult environment for blade inspection and the cost of inspection downtime. Composite blade designs have advantages that include long life in marine environments and great control over mechanical properties. Experimental strain characteristics are determined for static loads and free-vibration loads. These experiments are designed to simulate the dynamic characteristics of hydrokinetic turbine blades. Carbon/epoxy symmetric composite laminates are manufactured using an autoclave process. Four-layer composite beams, eight-layer composite beams, and two-dimensional eight-layer composite blades are instrumented for strain. Experimental results for strain measurements from electrical resistance gages are validated with theoretical characteristics obtained from in-house finite-element analysis for all sample cases. These preliminary tests on the composite samples show good correlation between experimental and finite-element strain results. A health monitoring system is proposed in which damage to a composite structure, e.g. delamination and fiber breakage, causes changes in the strain signature behavior. The system is based on embedded strain sensors and embedded motes in which strain information is demodulated for wireless transmission. In-service monitoring is critical due to the difficult environment for blade inspection and the cost of inspection downtime. Composite blade designs provide a medium for embedding sensors into the blades for in-situ health monitoring. The major challenge with in-situ health monitoring is transmission of sensor signals from the remote rotating reference frame of the blade to the system monitoring station. In the presented work, a novel system for relaying in-situ blade health measurements in hydrokinetic systems is described and demonstrated. An ultrasonic communication system is used to transmit sensor data underwater from the rotating frame of the blade to a fixed relay station. Data are then broadcast via radio waves to a remote monitoring station. Results indicate that the assembled system can transmit simulated sensor data with an accuracy of ±5% at a maximum sampling rate of 500 samples/sec. A power investigation of the transmitter within the blade shows that continuous max-sampling operation is only possible for short durations (d̃ays), and is limited due to the capacity of the battery power source. However, intermittent sampling, with long periods between samples, allows for the system to last for very long durations (ỹears). Finally, because the data transmission system can operate at a high sampling rate for short durations or at a lower sampling rate/higher duty cycle for long durations, it is well-suited for short-term prototype and environmental testing, as well as long-term commercially-deployed hydrokinetic machines.

Download or read book Structural Health Monitoring Static Test of a Wind Turbine Blade August 1999 written by Mannur J. Sundaresan and published by . This book was released on 2002 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Smart Sensor System for Structural Condition Monitoring of Wind Turbines written by M. J. Schulz and published by . This book was released on 2006 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the efforts of the University of Cincinnati, North Carolina A & T State University, and NREL to develop a structural neural system for structural health monitoring of wind turbine blades.