2nd Edition

Vibration Problems in Machines Diagnosis and Resolution

By Arthur W. Lees Copyright 2020
    380 Pages 126 B/W Illustrations
    by CRC Press

    380 Pages 126 B/W Illustrations
    by CRC Press

    Vibration Problems in Machines explains how to infer information about the internal operations of rotating machines from external measurements through methods used to resolve practical plant problems. Second edition includes summary of instrumentation, methods for establishing machine rundown data, relationship between the rundown curves and the ideal frequency response function. The section on balancing has been expanded and examples are given on the strategies for balancing a rotor with a bend, with new section on instabilities. It includes case studies with real plant data, MATLABĀ® scripts and functions for the modelling and analysis of rotating machines.

    1. Introduction
    1.1 Monitoring and Diagnosis
    1.2 Instrumentation
    1.3 Mathematical Models
    1.4 Machine Classification
    1.5 Considerations for a Monitoring Scheme
    1.6 Outline of the Text
    1.7 Software
    1.8 References

    2 Data presentation
    2.1 Introduction
    2.2 Presentation Formats
    2.3 Comparison with Calculations
    2.4 Detection and Diagnosis Process
    2.5 Concluding Remarks

    3 Modeling and Analysis
    3.1 Introduction
    3.2 Need for Models
    3.3 Modeling Approaches
    3.4 Analysis Methods
    3.5 Further Modeling Considerations
    3.6 Summary

    4 Faults in Machines (1)
    4.1 Introduction
    4.2 Definitions: Rigid and Flexible Rotors
    4.3 Mass Imbalance
    4.4 Rotor Bends
    4.5 Concluding Remarks

    5 Faults in Machines (2)
    5.1 Introduction
    5.2 Misalignment
    5.3 Cracked Rotors
    5.4 Torsional Excitation
    5.5 Nonlinearity
    5.6 Instability
    5.7 Interactions and Diagnostics
    5.8 Closing Remarks
    6.  Rotor-Stator Interaction
    6.1 Introduction
    6.2 Interaction through Bearings
    6.3 Interaction via Working Fluid
    6.4 Direct Stator Contact
    6.5 The Morton Effect
    6.6 Harmonics on Contact
    6.7 Concluding Remarks

    7. Machine Identification
    7.1 Introduction
    7.2 Current State of Modelling
    7.3 Primary Components
    7.4 Sources of Error/Uncertainty
    7.5 Model Improvement
    7.6 Application to Foundations
    7.7 Imbalance Identification
    7.8 Extension to Alignment
    7.9 Future Options
    7.10 Concluding remarks

    8. Some Further Analysis Methods
    8.1 Introduction
    8.2 Standard Approaches
    8.3 Artificial Neural Networks
    8.4 Merging ANNs with Physics-Based Models
    8.5 Singular Value Decomposition
    8.6 Other Useful Techniques
    8.7 Concluding Remarks

    9.   Case Studies
    9.1 Introduction
    9.2 A Crack in a Large Alternator Rotor
    9.3 Workshop Modal Testing of a Cracked Rotor
    9.4 Gearbox Problems on a Boiler Feed Pump
    9.5 Vibration of Large Centrifugal Fans
    9.6 Low-Pressure Turbine Instabilities
    9.7 Concluding Remarks

    10. Overview and Outlook
    10.1 Progress in Instrumentation
    10.2 Progress in Data Analysis and Handling
    10.3 Progress in Modeling
    10.4 Expert Systems
    10.5 Future Prospects
    10.6 Summary

    Solutions to Problems



    Professor Arthur W. Lees graduated in Physics and remained Manchester University for three years research. After completing his PhD , he joined the Central Electricity Generating Board, initially developing Finite Element codes then later resolving plant problems. After a sequence of positions he was appointed head of the Turbine Group for Nuclear Electric Plc. He moved to Swansea University in 1995 and has been active in both research and teaching. He is a regular reviewer of many technical journals and was, until his recent retirement, on the editorial boards of the Journal of Sound & Vibration and Communications on Numerical Methods in Engineering. His research interests include structural dynamics, rotor dynamics, inverse problems and heat transfer. Professor Lees is a Fellow of the Institution of Mechanical Engineers and a Fellow of the Institute of Physics, a Chartered Engineer and a Chartered Physicist. He was a member of Council of the Institute of Physics, 2001-5. He is now Professor Emeritus at Swansea University, but remains an active researcher.