Download or read book Gearbox Condition Monitoring and Early Damage Diagnosis by Two and Three Dimensional Vibration Signal Analysis written by W. J. Wang and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rotating Machinery Structural Health Monitoring Shock and Vibration Volume 5 written by Tom Proulx and published by Springer. This book was released on 2011-03-22 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotating Machinery, Structural Health Monitoring, Shock and Vibration, Volume 5 Proceedings of the 29th IMAC, A Conference and Exposition on Structural Dynamics, 2011, the fifth volume of six from the Conference, brings together 35 contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Rotating Machinery, Structural Health Monitoring, as well as Shock and Vibration, along with other structural engineering areas.

Download or read book Condition Monitoring of Gear Systems Using Vibration Analysis written by Salem Al-Arbi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is often impractical to measure vibrations directly at /or close to their sources when condition monitoring gearbox systems. It is common to measure the vibration distant from the source due to limited access to the component which is to be monitored. In addition, operating the gearbox under different loads and speeds also produces vibration signals within different components. Vibration measured in this way may be significantly distorted by the effect of signal transmission paths and interference from other sources. Therefore, suppression of distortions is a key issue for remote measurement based condition monitoring. In this research work, the influences of transducer locations and operating conditions on the vibration signal have been investigated on a typical gearbox transmission system for the detection of faults induced within the gearbox. Vibration signals corresponding to a healthy (baseline) and faulty conditions on two-stage helical gearbox at various load and speed levels were recorded. The baseline vibration data were examined using conventional methods in the time, frequency and the joint time-frequency domains, and are referenced for comparison with more advanced methods. Several parameters have been proposed for monitoring gear condition locally (gearbox casing) including time, frequency, and joint time-frequency domain representation. The results show that traditional signal processing techniques were insufficient for revealing fault detection information due to the low signal to noise ratio (SNR). This research also presents a mathematical model for the simulation of vibration signals in order to further understand the source of the vibration. The model represents a two stage gear system using a suitable stiffness function to represent the forces acting between each pair of gears. Rotational stiffness and damping are also used to simulate the angular motion of the gears and shafts. Results show that the frequency spectrum of acceleration outputs from the model take the expected form with peaks at the meshing frequency and associated harmonics. Furthermore, if the stiffness function between the first pair of gears is simulated with a broken tooth, and various degrees of damage, outputs from the simulation have similar sideband effects to the signals produced in the experimental investigation. In addition, the model also demonstrates that variation of load and speed produces a corresponding effect to that seen in the experiments. Consequently, although relatively simple, the mathematical model can be used to explain vibration mechanisms in real gearbox systems used in condition monitoring. Time synchronous averaging (TSA) has been applied to the vibration signals from the gearbox to remove random noise combined with the raw signal. The angular domain signal, the order spectrum and the order-frequency presentation were used to characterise gearbox vibration in these new domains in more detail. Results obtained following TSA were compared with those obtained through conventional analysis from waveform characteristics, spectrum patterns and corresponding feature parameters under different operating loads and fault conditions. In addition, continuous wavelet transform (CWT) of TSA was also compared with the conventional CWT results of raw signals to further characterise vibrations. As part of this research study, the vibration transmission path has been estimated using the frequency response function (FRF) technique. A response based estimation method has been developed to revise the base path and adapted to operating conditions for more accurate fault estimation. Both theoretical analysis and test results showed that improved diagnosis when the path information was included in vibration signal processing and feature selection. Finally, the vibration data recorded from the two accelerometers located on the gearbox casing and motor flange were analyzed using different signal processing methods to investigate the effect of path transmission (transducer location) on the detection and diagnosis of the seeded gear tooth faults. Results from the angular domain, the order spectrum and the order-frequency analysis are presented to demonstrate use of these techniques for fault detection in gearboxes and that the effect of path transmissions can be observed on the vibration signals. Results showed that CWT of the TSA signal could be used to detect and indicate the severity of the gear damage effectively even if vibration signals originated from a remote motor flange.

Download or read book Vibration based Condition Monitoring written by Robert Bond Randall and published by John Wiley & Sons. This book was released on 2011-03-25 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Without doubt the best modern and up-to-date text on the topic, wirtten by one of the world leading experts in the field. Should be on the desk of any practitioner or researcher involved in the field of Machine Condition Monitoring" Simon Braun, Israel Institute of Technology Explaining complex ideas in an easy to understand way, Vibration-based Condition Monitoring provides a comprehensive survey of the application of vibration analysis to the condition monitoring of machines. Reflecting the natural progression of these systems by presenting the fundamental material and then moving onto detection, diagnosis and prognosis, Randall presents classic and state-of-the-art research results that cover vibration signals from rotating and reciprocating machines; basic signal processing techniques; fault detection; diagnostic techniques, and prognostics. Developed out of notes for a course in machine condition monitoring given by Robert Bond Randall over ten years at the University of New South Wales, Vibration-based Condition Monitoring: Industrial, Aerospace and Automotive Applications is essential reading for graduate and postgraduate students/ researchers in machine condition monitoring and diagnostics as well as condition monitoring practitioners and machine manufacturers who want to include a machine monitoring service with their product. Includes a number of exercises for each chapter, many based on Matlab, to illustrate basic points as well as to facilitate the use of the book as a textbook for courses in the topic. Accompanied by a website www.wiley.com/go/randall housing exercises along with data sets and implementation code in Matlab for some of the methods as well as other pedagogical aids. Authored by an internationally recognised authority in the area of condition monitoring.

Download or read book Health Monitoring of Aerospace Structures written by Wieslaw Staszewski and published by John Wiley & Sons. This book was released on 2004-04-02 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing quality research for the reader, this title encompasses all the recent developments in smart sensor technology for health monitoring in aerospace structures, providing a valuable introduction to damage detection techniques. Focussing on engineering applications, all chapters are written by smart structures and materials experts from aerospace manufacturers and research/academic institutions. This key reference: Discusses the most important aspects related to smart technologies for damage detection; this includes not only monitoring techniques but also aspects related to specifications, design parameters, assessment and qualification routes. Presents real case studies and applications; this includes in-flight tests; the work presented goes far beyond academic research applications. Displays a balance between theoretical developments and engineering applications

Download or read book Development of Effective Gearbox Fault Diagnosis Methodologies Utilising Various Levels of Prior Knowledge written by Stephan Schmidt and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effective fault diagnosis techniques are important to ensure that expensive assets such as wind turbines can operate reliably. Vibration condition monitoring data are rich with information pertaining to the dynamics of the rotating machines and are therefore popular for rotating machine diagnostics. However, vibration data do not only contain diagnostic information, but operating condition information as well. The performance of many conventional fault diagnosis techniques is impeded by inherent varying operating conditions encountered in machines such as wind turbines and draglines. Hence, it is not only important to utilise fault diagnosis techniques that are sensitive to faults, but the techniques should also be robust to changes in operating conditions. Much research has been conducted to address the many facets of gearbox fault diagnosis e.g. understanding the interactions of the components, the characteristics of the vibration signals and the development of good vibration analysis techniques. The aforementioned knowledge, as well as the availability of historical data, are regarded as prior knowledge (i.e. information that is available before inferring the condition of the machine) in this thesis. The available prior knowledge can be utilised to ensure that e ective gearbox fault diagnosis techniques are designed. Therefore, methodologies are proposed in this work which can utilise the available prior knowledge to e ectively perform fault diagnosis, i.e. detection, localisation and trending, under varying operating conditions. It is necessary to design di erent methodologies to accommodate the di erent kinds of historical data (e.g. healthy historical data or historical fault data) that can be encountered and the di erent signal analysis techniques that can be used. More speci cally, a methodology is developed to automatically detect localised gear damage under varying operating conditions without any historical data being available. The success of the methodology is attributed to the fact that the interaction between gear teeth in a similar condition results in data being generated which are statistically similar and this prior knowledge may be utilised. Therefore, a dissimilarity measure between the probability density functions of two teeth can be used to detect a gear tooth with localised gear damage. Three methodologies are also developed to utilise the available historical data from a healthy machine for gearbox fault diagnosis. Firstly, discrepancy analysis, a powerful novelty detection technique which has been used for gear diagnostics under varying operating conditions, is extended for bearing diagnostics under varying operating conditions. The suitability of time-frequency analysis techniques and di erent models are compared for discrepancy analysis as well. Secondly, a methodology is developed where the spectral coherence, a powerful second-order cyclostationary technique, is supplemented with healthy historical data for fault detection, localisation and trending. Lastly, a methodology is proposed which utilises narrowband feature extraction methods such as the kurtogram to extract a signal rich with novel information from a vibration signal. This is performed by attenuating the historical information in the signal. Sophisticated signal analysis techniques such as the squared envelope spectrum and the spectral coherence are also used on the novel signal to highlight the bene ts of utilising the novel signal as opposed to raw vibration signal for fault diagnosis. Even though a healthy state is the desired operating condition of rotating machines, fault data will become available during the operational life of the machine. Therefore, a methodology, centred around discrepancy analysis, is developed to utilise the available historical fault data and to accommodate fault data becoming available during the operation of the machine. In this investigation, it is recognised that the machine condition monitoring problem is in fact an open set recognition problem with continuous transitions between the healthy machine condition and the failure conditions. This is explicitly incorporated into the methodology and used to infer the condition of the gearbox in an open set recognition framework. This methodology uses a di erent approach to the conventional supervised machine learning techniques found in the literature. The methodologies are investigated on numerical and experimental datasets generated under varying operating conditions. The results indicate the bene ts of incorporating prior knowledge into the fault diagnosis process: the fault diagnosis techniques can be more robust to varying operating conditions, more sensitive to damage and easier to interpret by a non-expert. In summary, fault diagnosis techniques are more e ective when prior knowledge is utilised.

Download or read book Multiphysics Modelling and Simulation for Systems Design and Monitoring written by Mohamed Haddar and published by Springer. This book was released on 2016-10-08 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on the state of the art in the field of multiphysics systems. It consists of accurately reviewed contributions to the MMSSD’2014 conference, which was held from December 17 to 19, 2004 in Hammamet, Tunisia. The different chapters, covering new theories, methods and a number of case studies, provide readers with an up-to-date picture of multiphysics modeling and simulation. They highlight the role played by high-performance computing and newly available software in promoting the study of multiphysics coupling effects, and show how these technologies can be practically implemented to bring about significant improvements in the field of design, control and monitoring of machines. In addition to providing a detailed description of the methods and their applications, the book also identifies new research issues, challenges and opportunities, thus providing researchers and practitioners with both technical information to support their daily work and a new source of inspiration for their future research.

Download or read book International Journal of Prognostics and Health Management Volume 3 color written by PHM Society and published by Lulu.com. This book was released on 2013-09-24 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: PHM Society established International Journal of Prognostics and Health Management (IJPHM) 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.

Download or read book Second International Conference on Gearbox Noise Vibration and Diagnostics written by and published by Wiley-Blackwell. This book was released on 1995 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: These are the transactions of the Second International Conference on Gearbox Noise, Vibration and Diagnostics. The conference was held on the 16th and 17th of November 1995 and was organized by the Aerospace, Automobile and Railway divisions of the Institution of Mechanical Engineers.

Download or read book A Comprehensive Study on the Gearbox Fault Diagnosis Based on Vibration Analysis Development of a Condition Monitoring System written by Catalin Dascaliuc and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Condition Monitoring of Gearboxes Using Acoustic Emission written by Babak Eftekharnejad and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic emission (AE) is one of many technologies for health monitoring and diagnosis of rotating machines such as gearboxes. Although significant research has been undertaken in understanding the potential of AE in monitoring gearboxes this has been solely applied to spur gears and slow speed roller bearings. This research presents an experimental investigation that assesses the effectiveness of both AE and vibration technologies in identifying various types of defects on in a helical gearbox; the first known attempt. Furthermore, the application of advanced signals processing techniques such as Spectral kurtosis (SK) and wavelet analysis were studied on AE and vibration signatures. It is shown that the application of advanced signal processing methods is particularly necessary for monitoring helical gears. The application of SK and wavelet analysis was found to be effective in denoising the acquired signals. The first chapter of this thesis is an introduction to this research and briefly explains motivation and theoretical background supporting this research. The second chapter summaries the relevant literature to establish the current level of the knowledge in this field. The third chapter describes methodologies and experimental arrangement utilized for this investigation. Chapter 4 discusses helical gear diagnosis for both natural and seeded surface defect. Chapter 5 reports on an experimental investigation in which several technologies such as AE, vibration and motor current signature analysis, were applied to identify the presence of a naturally fatigued pinion shaft in an operating gearbox. Chapter 6 details an investigation which compared the applicability of AE and vibration technologies in monitoring a naturally degraded roller bearing. It has been concluded that AE is a strong diagnostic tool for early diagnosis of bearings faults. However, the application of condition monitoring for helical gear diagnosis was fraught with some degree of complexity as compared to spur gears. This implies that condition monitoring of the gears using AET can be challenging. On the contrary, the applicability of AET for bearing diagnosis was promising and it offered an absolute advantage over the conventional vibrationdiagnosis. Furthermore, the application advanced signals processing methods such as Spectral Kurtosis and wavelet was found to be promising in denoise the recorded AE signals. It was also concluded that the use of different signal processing methods is often necessary to achieve meaningful diagnostic information from the signals.

Download or read book The Shock and Vibration Digest written by and published by . This book was released on 1986 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vibration based Condition Monitoring written by Robert Bond Randall and published by Wiley. This book was released on 2011-02-14 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Without doubt the best modern and up-to-date text on the topic, wirtten by one of the world leading experts in the field. Should be on the desk of any practitioner or researcher involved in the field of Machine Condition Monitoring" Simon Braun, Israel Institute of Technology Explaining complex ideas in an easy to understand way, Vibration-based Condition Monitoring provides a comprehensive survey of the application of vibration analysis to the condition monitoring of machines. Reflecting the natural progression of these systems by presenting the fundamental material and then moving onto detection, diagnosis and prognosis, Randall presents classic and state-of-the-art research results that cover vibration signals from rotating and reciprocating machines; basic signal processing techniques; fault detection; diagnostic techniques, and prognostics. Developed out of notes for a course in machine condition monitoring given by Robert Bond Randall over ten years at the University of New South Wales, Vibration-based Condition Monitoring: Industrial, Aerospace and Automotive Applications is essential reading for graduate and postgraduate students/ researchers in machine condition monitoring and diagnostics as well as condition monitoring practitioners and machine manufacturers who want to include a machine monitoring service with their product. Includes a number of exercises for each chapter, many based on Matlab, to illustrate basic points as well as to facilitate the use of the book as a textbook for courses in the topic. Accompanied by a website www.wiley.com/go/randall housing exercises along with data sets and implementation code in Matlab for some of the methods as well as other pedagogical aids. Authored by an internationally recognised authority in the area of condition monitoring.

Download or read book Vehicle Gearbox Noise and Vibration written by Jiri Tuma and published by John Wiley & Sons. This book was released on 2014-02-20 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in methods of gear design and the possibility of predicting the sound pressure level and life time of gearboxes and perfect instrumentation of test stands allows for the production of a new generation of quiet transmission units. Current literature on gearbox noise and vibration is usually focused on a particular problem such as gearbox design without a detailed description of measurement methods for noise and vibration testing. Vehicle Gearbox Noise and Vibration: Measurement, Signal Analysis, Signal Processing and Noise Reduction Measures addresses this need and comprehensively covers the sources of noise and vibration in gearboxes and describes various methods of signal processing. It also covers gearing design, precision manufacturing, measuring the gear train transmission error, noise test on testing stands and also during vehicle pass-by tests. The analysis tools for gearbox inspection are based on the frequency and time domain methods, including envelope and average toothmesh analysis. To keep the radiated noise under control, the effect of load, the gear contact ratio and the tooth surface modification on noise and vibration are illustrated by measurement examples giving an idea how to reduce transmission noise. Key features: Covers methods of processing noise and vibration signals Takes a practical approach to the subject and includes a case study covering how to successfully reduce transmission noise Describes the procedure for the measurement and calculation of the angular vibrations of gears during rotation Considers various signal processing methods including order analysis, synchronous averaging, Vold-Kalman order tracking filtration and measuring the angular vibration Vehicle Gearbox Noise and Vibration: Measurement, Signal Analysis, Signal Processing and Noise Reduction Measures is a comprehensive reference for designers of gearing systems and test engineers in the automotive industry and is also a useful source of information for graduate students in automotive and noise engineering.

Download or read book International Journal of Prognostics and Health Management Volume 2 color written by PHM Society and published by Lulu.com. This book was released on 2013-09-24 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Dynamics guided Vibration Signal Analysis for Fixed axis Gearbox Fault Diagnosis written by Xingkai Yang and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gearboxes are key components commonly employed to transfer torque and power and adjust speed in mechatronic systems, such as wind turbines, automobiles, and mining machines. Due to the harsh working environment, various faults may occur in gearboxes. Tooth cracks account for a large proportion of gearbox faults. Detection and severity assessment of early tooth cracks is of vital significance to prevent gearbox failures since it enables efficient condition-based maintenance activities, which not only improves system reliability but also reduces operation and maintenance costs. Vibration analysis has been widely utilized for gear tooth crack detection and severity assessment. In industrial applications, gearboxes may work under either constant or time-varying operating conditions. Besides, gearboxes may suffer from either one single tooth crack or multiple tooth cracks depending on their working environment. All these factors render it challenging to get a good understanding of vibration characteristics of gearboxes with tooth cracks owing to their complexity, which undermines the effectiveness of vibration analysis for tooth crack detection and severity assessment. This thesis aims to procure some insights into vibration characteristics of fixed-axis spur gearboxes with tooth cracks through dynamic simulation, and the obtained insights are further adopted to guide the development of effective vibration signal analysis methods for tooth crack detection and severity assessment. To this end, the overarching objective of this thesis consists of four sub-objectives, which aim to address four issues related to tooth crack detection and severity assessment for fixed-axis spur gearboxes. Firstly, inspired by the observation that the Crack Induced Impulses (CII) contain more information on tooth crack growth, two novel condition indicators are developed by a proposed method which conducts a thorough analysis on the CII and are adopted for early tooth crack severity assessment. Secondly, to effectively track tooth crack severity progression under time-varying operating conditions, a comprehensive study on how time-varying operating conditions affect vibration signals of a fixed-axis spur gearbox with a tooth crack is conducted. A linear dependence of the Amplitude Modulation (AM) of the CII on the time-varying operating conditions is identified, through which a new condition indicator is proposed to track tooth crack severity progression under time-varying operating conditions. In addition, inspired by the finding that the AM of the CII is resulted from operating condition variations, a normalization method is proposed to remove the speed variation-induced AM of the CII and a normalized CII is obtained. The normalized CII preserve information on tooth crack growth and are free from gearbox speed fluctuations, which are used to track tooth crack severity progression under variable speed conditions. Lastly, insights into vibration characteristics of a fixed-axis spur gearbox with multiple tooth cracks are obtained using dynamic simulation and are further experimentally validated. Besides, inspired by the observation that the CII can well reflect tooth cracks, a method focusing on the CII is proposed to detect the number and locations of multiple tooth cracks in fixed-axis spur gearboxes. The research work conducted in this thesis enables us to procure a good understanding of vibration characteristics of fixed-axis spur gearboxes with tooth cracks working under both constant and time-varying operating conditions and provides effective vibration signal analysis methods for tooth crack detection and severity assessment of fixed-axis spur gearboxes. Future work will explore the effects of tooth lubrication and bearing faults on gearbox vibration characteristics.

Download or read book Crack Detection for Aerospace Quality Spur Gears written by and published by . This book was released on 2002 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Health and Usage Monitoring System research and development involves analysis of the vibration signals produced by a gearbox throughout its life. There are two major advantages of knowing the actual lifetime of a gearbox component: safety and cost. In this report, a technique is proposed to help extract the critical data and present it in a manner that can be easy to understand. The key feature of the technique is to make it independent of speed, torque and prior history for localized, single tooth damage such as gear cracks. This extraction technique is demonstrated on two sets of digitized vibration data from cracked spur gears. Standard vibration diagnostic parameters are calculated and presented for comparison. Several new detection algorithms are also presented. The results of this study indicate that crack detection methods examined are not robust or repeatable. The proposed techniques provide a limited improvement to existing diagnostic parameters. Current techniques show that the cracks progressed at a much faster rate than anticipated which reduced available time for detection.