Vibration based damage detection of rotor blades in a gas turbine engine
TL;DR: In this article, the authors describe the problems concerning turbine rotor blade vibration that seriously impact the structural integrity of a developmental aero gas turbine, where the blades are fabricated from nickel base super alloy through directionally solidified investment casting process.
About: This article is published in Engineering Failure Analysis.The article was published on 2014-11-01. It has received 89 citations till now. The article focuses on the topics: Turbine blade & Rotor (electric).
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TL;DR: In this paper, a systematic review of recently developed engine performance monitoring, diagnostic and prognostic techniques is presented, which provides experts, students or novice researchers and decision-makers working in the area of gas turbine engines with the state of the art for performance-based condition monitoring.
271 citations
Cites background from "Vibration based damage detection of..."
...2014 [24] Vibration-based damage detection of rotor blades Faults in auxiliary subsystems Pennacchi and Vania 2008 [25] Diagnostics of a crack in load coupling...
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...…misalignment, imbalance, crack and eccentricity Walker et al. 2012 [23] Localizing unbalancy looking at stationary and rotating vibration phenomena Madhavan et al. 2014 [24] Vibration-based damage detection of rotor blades Faults in auxiliary subsystems Pennacchi and Vania 2008 [25] Diagnostics…...
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TL;DR: In this article, a synchronous resonance vibration measurement method of blade based on tip-timing is presented, which requires no once-per-revolution sensor which makes it more generally applicable in the condition where this sensor is difficult to install, especially for the high-pressure rotors of dual-rotor engines.
73 citations
TL;DR: The main failure modes of turbines are reported, and the existing monitoring techniques for these components, with their own particular advantages and disadvantages, are summarised in this review.
Abstract: The need for non-destructive testing/structural health monitoring (SHM) is becoming increasingly important for gas turbine manufacturers. Incipient cracks have to be detected before catastrophic events occur. With respect to condition-based maintenance, the complex and expensive parts should be used as long as their performance or integrity is not compromised. In this study, the main failure modes of turbines are reported. In particular, we focus on the turbine blades, turbine vanes and the transition ducts of the combustion chambers. The existing monitoring techniques for these components, with their own particular advantages and disadvantages, are summarised in this review. In addition to the vibrational approach, tip timing technology is the most used technique for blade monitoring. Several sensor types are appropriate for the extreme conditions in a gas turbine, but besides tip timing, other technologies are also very promising for future NDT/SHM applications. For static parts, like turbine vanes and the transition ducts of the combustion chambers, different monitoring possibilities are identified and discussed.
56 citations
TL;DR: An iterative reweighted L1-norm based parameter identification method is applied to obtain the vibration parameters from the highly undersampled BTT data with better amplitude reconstruction accuracy.
54 citations
TL;DR: In this article, a case study is presented in order to detect failure mode and locate cracks on a 30 MW first stage gas turbine blade made of nickel based super alloy IN738LC, which has failed after rendering a useful life of 72000 h.
Abstract: Structure frequency response testing “modal analysis” is an integral part of the development and testing of structures such as pistons, turbine blades, compressor blades, crankshafts, and connecting rods. The usefulness of this technique lies in the fact that the energy in an impulse input is distributed continuously in the frequency domain. Thus, an impulse force will excite all resonances within given frequency range. To detect a fault in the structure, one may require frequency response functions (FRFs) of structures in both conditions, before (healthy structure) and after (failed structure) fault occurs. Now by extracting modal properties from collected FRFs and by comparing modal properties, one can detect and locate the structural faults. A case study is presented in order to detect failure mode and locate cracks on a 30 MW first stage gas turbine blade made of nickel based super alloy IN738LC, which has failed after rendering a useful life of 72000 h. The root causes of failure are detected by comparing the failed blade experimental model with the failed blade computational model. It is observed that the frequencies of the real failed blade experimental model are lesser than the computational model of the failed turbine blade. This is due to the metallurgical defects, which result in loosening of stiffness at the leading and trailing edges of the blade. Further, the stress concentration areas noticed on leading and trailing edges in computational model of the failed blade at the sixth mode are well corroborated with the cracked zone seen on leading and trailing edges of a real case failed turbine blade, collected from the site. It is concluded that the blade has failed due to that the resonance at sixth modal frequency. Scanning electron microscope (SEM) images reveal the presence of corrosion pits on the surfaces of the turbine blade that lead to surface degradation, which results in crack initiation and its propagation with high-cycle fatigue. It is concluded that the failure of turbine blade occurs due to high cycle fatigue.
43 citations
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TL;DR: The largest single cause of component failures in modern military aircraft gas turbine engines is high cycle fatigue (HCF), exceeding the number attributed to low cycle fatigue, corrosion, overstress, manufacturing processes, mechanical damage, and materials.
Abstract: The largest single cause of component failures in modern military aircraft gas turbine engines is high cycle fatigue (HCF), exceeding the number attributed to low cycle fatigue, corrosion, overstress, manufacturing processes, mechanical damage, and materials. The HCF problem is a pervasive one, affecting all engine sections and a wide range of materials. In addition to the impact on engine component reliability, HCF problems cause significant economic impacts through field inspection and maintenance actions, and reduced readiness reliability.
358 citations
TL;DR: In this article, the authors present an in-depth study of blade vibration problems that seriously impact development of advanced gas turbine configurations, and they conclude that structural integrity of power plants is the dominant factor that influences the quality, reliability, and marketability of the product.
Abstract: This paper presents an in-depth study of blade vibration problems that seriously impact development of advanced gas turbine configurations. The motivation for this study arises from the author's conviction that structural integrity of power plants is the dominant factor that influences the quality, reliability, and marketability of the product. Implications of this study in the context of potential R&D challenges and opportunities of interest to industry, governments, and academia are discussed.
313 citations
TL;DR: In this article, a series of mechanical analyses were performed to identify the possible causes of the failures by examining anomalies in the mechanical behaviour of the turbine blade, and the steady-state stresses and dynamic characteristics of the blade were evaluated and synthesized in order to determine the cause of blade failures.
194 citations
TL;DR: In this paper, the results of experimental vibration tests of the helicopter turbo-engine compressor blades were presented for selected undamaged blades, without existence of preliminary cracks or corrosion pits.
100 citations
TL;DR: In this article, the failure mechanism of Ti6Al4V compressor blades of an industrial gas turbine was analyzed by means of both experimental characterisations and numerical simulation techniques Several premature failures occurred in the high pressure section of the compressor due to the fracture of the blade roots.
92 citations