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Spiral Bevel Pinion Crack Detection in a Helicopter Gearbox

Spiral Bevel Pinion Crack Detection in a Helicopter Gearbox PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

Book Description
The vibration resulting from a cracked spiral bevel pinion was recorded and analyzed using existing Health and Usage Monitoring System (HUMS) techniques. A tooth on the input pinion to a Bell OH-58 main rotor gearbox was notched and run for an extended period at severe over-torque condition to facilitate a tooth fracture. Thirteen vibration-based diagnostic metrics were calculated throughout the run. After 101.41 hours of run time, some of the metrics indicated damage. At that point a visual inspection did not reveal any damage. The pinion was then run for another 12 minutes until a proximity probe indicated that a tooth had fractured. This paper discusses the damage detection effectiveness of the different metrics and a comparison of effects of the different accelerometer locations.

Spiral Bevel Pinion Crack Detection in a Helicopter Gearbox

Spiral Bevel Pinion Crack Detection in a Helicopter Gearbox PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

Book Description
The vibration resulting from a cracked spiral bevel pinion was recorded and analyzed using existing Health and Usage Monitoring System (HUMS) techniques. A tooth on the input pinion to a Bell OH-58 main rotor gearbox was notched and run for an extended period at severe over-torque condition to facilitate a tooth fracture. Thirteen vibration-based diagnostic metrics were calculated throughout the run. After 101.41 hours of run time, some of the metrics indicated damage. At that point a visual inspection did not reveal any damage. The pinion was then run for another 12 minutes until a proximity probe indicated that a tooth had fractured. This paper discusses the damage detection effectiveness of the different metrics and a comparison of effects of the different accelerometer locations.

Analysis of the vibration of the input bevel pinion in RAN Wessex helicopter main rotor gearbox WAK143 prior to failure

Analysis of the vibration of the input bevel pinion in RAN Wessex helicopter main rotor gearbox WAK143 prior to failure PDF Author: P. D. McFadden
Publisher:
ISBN:
Category :
Languages : en
Pages : 54

Book Description
Following the crash of an RAN Wessex helicopter caused by the catastrophic fatigue failure of the input spiral bevel pinion in the main rotor gearbox, routine recordings of the gearbox vibration have been analyzed by ARL. It has been shown that conventional spectral analysis of the vibration is unable to give adequate indication of the presence of the fatigue crack but that an alternative technique of vibration analysis called signal averaging can give warning of the crack 42 hours before failure. Enhancement of the signal average using a computer enables detection of the crack as early as 103 hours before failure.

Gear Crack Detection for a Helicopter Gearbox

Gear Crack Detection for a Helicopter Gearbox PDF Author: Harry J. Decker
Publisher:
ISBN:
Category : Gearing
Languages : en
Pages : 122

Book Description


Cyclostationarity: Theory and Methods III

Cyclostationarity: Theory and Methods III PDF Author: Fakher Chaari
Publisher: Springer
ISBN: 3319514458
Category : Technology & Engineering
Languages : en
Pages : 257

Book Description
This book gathers contributions presented at the 9th Workshop on Cyclostationary Systems and Their Applications, held in Gródek nad Dunajcem, Poland in February 2016. It includes both theory-oriented and practice-oriented chapters. The former focus on heavy-tailed time series and processes, PAR models, rational spectra for PARMA processes, covariance invariant analysis, change point problems, and subsampling for time series, as well as the fraction-of-time approach, GARMA models and weak dependence. In turn, the latter report on case studies of various mechanical systems, and on stochastic and statistical methods, especially in the context of damage detection. The book provides students, researchers and professionals with a timely guide to cyclostationary systems, nonstationary processes and relevant engineering applications.

Prognostics and Health Management of Electronics

Prognostics and Health Management of Electronics PDF Author: Michael G. Pecht
Publisher: John Wiley & Sons
ISBN: 0470385839
Category : Technology & Engineering
Languages : en
Pages : 335

Book Description
The first book on Prognostics and Health Management of Electronics Recently, the field of prognostics for electronic products has received increased attention due to the potential to provide early warning of system failures, forecast maintenance as needed, and reduce life cycle costs. In response to the subject's growing interest among industry, government, and academic professionals, this book provides a road map to the current challenges and opportunities for research and development in Prognostics and Health Management (PHM). The book begins with a review of PHM and the techniques being developed to enable a prognostics approach for electronic products and systems. building on this foundation, the book then presents the state of the art in sensor systems for in-situ health and usage monitoring. Next, it discusses the various models and algorithms that can be utilized in PHM. Finally, it concludes with a discussion of the opportunities in future research. Readers can use the information in this book to: Detect and isolate faults Reduce the occurrence of No Fault Found (NFF) Provide advanced warning of system failures Enable condition-based (predictive) maintenance Obtain knowledge of load history for future design, qualification, and root cause analysis Increase system availability through an extension of maintenance cycles and/or timely repair actions Subtract life cycle costs of equipment from reduction in inspection costs, down time, and inventory Prognostics and Health Management of Electronics is an indispensable reference for electrical engineers in manufacturing, systems maintenance, and management, as well as design engineers in all areas of electronics.

Simulating Fatigue Crack Growth in Spiral Bevel Gears

Simulating Fatigue Crack Growth in Spiral Bevel Gears PDF Author: Lisa Eron Spievak
Publisher:
ISBN:
Category : Boundary element methods
Languages : en
Pages : 122

Book Description
The majority of helicopter transmission systems utilize spiral bevel gears to convert the horizontal power from the engine into vertical power for the rotor. Due to the cyclical loading on a gear's tooth, fatigue crack propagation can occur. In rotor craft applications, a crack's trajectory determines whether the gear failure will be benign or catastrophic for the aircraft. As a result, the capability to predict crack growth in gears is significant. A spiral bevel gear's complex shape requires a three dimensional model of the geometry and cracks. The boundary element method in conjunction with linear elastic fracture mechanics theories is used to predict arbitrarily shaped three dimensional fatigue crack trajectories in a spiral bevel pinion under moving load conditions. The predictions are validated by comparison to experimental results. The sensitivity of the predictions to variations in loading conditions and crack growth rate model parameters is explored. Critical areas that must be understood in greater detail prior to predicting more accurate crack trajectories and crack growth rates in three dimensions are identified.

Advances in Forming, Machining and Automation

Advances in Forming, Machining and Automation PDF Author: Uday S. Dixit
Publisher: Springer Nature
ISBN: 9811938660
Category : Technology & Engineering
Languages : en
Pages : 655

Book Description
This book presents selected proceedings of the 8th International and 29th All India Manufacturing Technology, Design and Research Conference (AIMTDR 2021). It covers the recent developments in the areas of metal forming and machining techniques, incremental forming, microforming, nesting algorithms, process simulation, parameter analysis, tools and tooling, tool wear, condition monitoring, cyber physical systems, robotics, machine vision, intelligent manufacturing, enterprise manufacturing intelligence, etc. The contents of this book will be useful for students, researchers as well as industry professionals in the various fields of mechanical engineering.

Testing of Face-Milled Spiral Bevel Gears at High-Speed and Load

Testing of Face-Milled Spiral Bevel Gears at High-Speed and Load PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14

Book Description
Spiral bevel gears are an important drive system components of rotorcraft (helicopters) currently in use. In this application the spiral bevel gears are required to transmit very high torque at high rotational speed. Available experimental data on the operational characteristics for thermal and structural behavior is relatively small in comparison to that found for parallel axis gears. An ongoing test program has been in place at NASA Glenn Research Center over the last ten years to investigate their operational behavior at operating conditions found in aerospace applications. This paper will summarize the results of the tests conducted on face-milled spiral bevel gears. The data from the pinion member (temperature and stress) were taken at conditions from slow-roll to 14400 rpm and up to 537 kW (720 hp). The results have shown that operating temperature is affected by the location of the lubricating jet with respect to the point it is injected and the operating conditions that are imposed. Also the stress measured from slow-roll to very high rotational speed, at various torque levels, indicated little dynamic affect over the rotational speeds tested.

Advances in Rotor Dynamics, Control, and Structural Health Monitoring

Advances in Rotor Dynamics, Control, and Structural Health Monitoring PDF Author: Subashisa Dutta
Publisher: Springer Nature
ISBN: 9811556938
Category : Technology & Engineering
Languages : en
Pages : 625

Book Description
This book consists of selected and peer-reviewed papers presented at the 13th International Conference on Vibration Problems (ICOVP 2017). The topics covered in this book are broadly related to the fields of structural health monitoring, vibration control and rotor dynamics. In the structural health monitoring section studies on nonlinear dynamic analysis, damage identification, viscoelastic model of concrete, and seismic damage assessment are thoroughly discussed with analytical and numerical techniques. The vibration control part includes topics such as multi-storeyed stacked tuned mass dampers, vibration isolation with elastomeric mounts, and nonlinear active vibration absorber. This book will be useful for beginners, researchers and professionals interested in the field of vibration control, structural health monitoring and rotor dynamics.

International Journal of Prognostics and Health Management Volume 2 (color)

International Journal of Prognostics and Health Management Volume 2 (color) PDF Author: PHM Society
Publisher: Lulu.com
ISBN: 1936263114
Category : Technology & Engineering
Languages : en
Pages : 151

Book Description
International Journal of Prognostics and Health Management (IJPHM) was established in 2009 to facilitate archival publication of peer-reviewed results from research and development in the area of PHM. As a journal solely dedicated to the emerging field of PHM IJPHM is the first of its kind and has been a focal point for dissemination of peer-reviewed PHM knowledge. While for the first few years the journal maintained only an online presence, the printed volumes will now be available and can be obtained upon request. IJPHM is dedicated to all aspects of PHM: technical, management, economic, and social. In addition to regular periodic volumes IJPHM also publishes special issues with quality papers dedicated to focused topics.