Yazar "Oguz, Ali D." seçeneğine göre listele

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    Condition monitoring of wind turbine blades and tower via an automated laser scanning system
    (Elsevier Sci Ltd, 2019) Dilek, Ahmet U.; Oguz, Ali D.; Satis, Furkan; Gokdel, Yigit D.; Ozbek, Muammer
    During its service life, a wind turbine has to withstand very challenging loads and severe environmental factors which can cause some deteriorations and cracks on structural components. Yearly periodic controls may not be sufficient to diagnose a fault at early stages. Therefore, wind turbines are very important systems which have to be monitored continuously. This work aims at developing an automated scanning system for IR (Infrared) laser vibrometers to conduct the tests and measurements, which are required for condition monitoring, in a more accurate and efficient manner. Unlike visible green or red lasers, IR laser is reflected by most surfaces (especially by blade material) with a very high intensity without needing a preparation or surface enhancement on the target. However, IR laser cannot be guided by refracting/reflecting the beam by lenses and mirrors used by conventional laser scanners. This work proposes a new methodology which is based on mounting the laser source on a motorized platform and then rotating the platform rather than guiding the laser beam by optical systems. The tests performed by using wind turbine models show that the proposed system is capable of guiding the laser to the desired measurement points with very high precision and efficiency. The results of the analyses also show that some important dynamic characteristics of the system such as Eigenfrequencies and mode shapes can be extracted very accurately.
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    Development of Automated Laser Scanning System for Structural Health Monitoring of Wind Turbines
    (IEEE, 2017) Dilek, A. Ugur; Oguz, Ali D.; Gokdel, Y. Daghan; Ozbek, Muammer
    In recent years, the growing interest and demand in wind energy requires developing new wind turbines with larger size and capacity. However, this situation also causes some new and challenging problems which have not been encountered before in design, operation and maintenance. Strong winds and severe environmental factors can cause cracks and damage on several turbine components such as blades and tower. Determination of the location and extent of this damage at early stages is essential to ensure safe and efficient operation of the turbine. This work aims at developing a new motorized laser Doppler scanning system which can rotate about two axes freely. This new device will enable structural dynamics of the turbine to be monitored remotely by using optical measurement techniques. The developed laser system will be used to take vibration measurements on the structure regularly. The acquired measurements will be compared with the reference measurements taken on the undamaged structure and be used to detect possible damage on the turbine while turbine is parked.