Vibration Problems in Machines,
2nd Edition by Arthur W. Lees
Complete Chapter Solutions Manual
are included (Ch 1 to 9)
** Immediate Download
** Swift Response
** All Chapters included
,CONTENTS
A Note on Solution Methods and Software Used 2
Chapter 2: Data Presentation - Problems and Solutions 3
Chapter 3: Modelling and Analysis - Problems and Solutions 15
Chapter 4: Faults in Machines (1) - Problems and Solutions 22
Chapter 5: Faults in Machines (2) - Problems and Solutions 29
Chapter 6: Rotor-Stator Interaction - Problems and Solutions 36
Chapter 7: Machine Identification - Problems and Solutions 42
Chapter 8: Some Further Analysis Methods - Problems and Solutions 49
Chapter 9: Case Studies - Problems and Solutions 54
1
,A Note on Solution Methods and Software Used
Chapters 2 to 9 of this book have sets of problems on the topics of each chapter as an
aid to understanding of the material presented. Most of the problems can be
approached in a number of ways but in many instances the most convenient method
of solution will involve some computation. Throughout the book MATLAB has
been used, often applying the modelling software toolbox constructed as part of
Friswell et al. (2010). This toolbox is freely available at www.rotordynamics.info.
In addition, some extensions to this toolbox have been constructed for the current
work and these may be found at
https://www.crcpress.com/product/isbn/9781498726764.
This website also has the MATLAB scripts for each of the appropriate problems.
Reference
Friswell, M.I., Penny, J.E.T., Garvey, S.D. and Lees, A.W., 2010, Dynamics of
Rotating Machines, Cambridge University Press.
2
, Chapter 2
DATA PRESENTATION
Problem 2.1
Explain what is meant by ‘order tracking’ and why it is an important concept for the
monitoring of rotating machines.
On shutdown a large boiler feed pump runs down from 6000rpm at an initial rate of
120rpm/sec. The response up to four times shaft speed is required.
i) How would you sample to obtain maximum resolution, describing block size
and sampling rate.
ii) What is the resulting frequency resolution?
Solution
a) Order tracking is the process of resolving vibration into contributions at shaft speed
and multiples thereof. For modest slew rates the Short Time Fourier Transform is a
suitable technique. An alternative for rapid transients is the Vold-Kalman approach
which is explained in Chapter 8.
b) For an exponential speed decay, use Equation 2.16 to calculate the optimum
number of revs.
(2.16)
i) Using this value we see that, if the sampling time is T, then
(2.17)
From the question we infer that
3
2nd Edition by Arthur W. Lees
Complete Chapter Solutions Manual
are included (Ch 1 to 9)
** Immediate Download
** Swift Response
** All Chapters included
,CONTENTS
A Note on Solution Methods and Software Used 2
Chapter 2: Data Presentation - Problems and Solutions 3
Chapter 3: Modelling and Analysis - Problems and Solutions 15
Chapter 4: Faults in Machines (1) - Problems and Solutions 22
Chapter 5: Faults in Machines (2) - Problems and Solutions 29
Chapter 6: Rotor-Stator Interaction - Problems and Solutions 36
Chapter 7: Machine Identification - Problems and Solutions 42
Chapter 8: Some Further Analysis Methods - Problems and Solutions 49
Chapter 9: Case Studies - Problems and Solutions 54
1
,A Note on Solution Methods and Software Used
Chapters 2 to 9 of this book have sets of problems on the topics of each chapter as an
aid to understanding of the material presented. Most of the problems can be
approached in a number of ways but in many instances the most convenient method
of solution will involve some computation. Throughout the book MATLAB has
been used, often applying the modelling software toolbox constructed as part of
Friswell et al. (2010). This toolbox is freely available at www.rotordynamics.info.
In addition, some extensions to this toolbox have been constructed for the current
work and these may be found at
https://www.crcpress.com/product/isbn/9781498726764.
This website also has the MATLAB scripts for each of the appropriate problems.
Reference
Friswell, M.I., Penny, J.E.T., Garvey, S.D. and Lees, A.W., 2010, Dynamics of
Rotating Machines, Cambridge University Press.
2
, Chapter 2
DATA PRESENTATION
Problem 2.1
Explain what is meant by ‘order tracking’ and why it is an important concept for the
monitoring of rotating machines.
On shutdown a large boiler feed pump runs down from 6000rpm at an initial rate of
120rpm/sec. The response up to four times shaft speed is required.
i) How would you sample to obtain maximum resolution, describing block size
and sampling rate.
ii) What is the resulting frequency resolution?
Solution
a) Order tracking is the process of resolving vibration into contributions at shaft speed
and multiples thereof. For modest slew rates the Short Time Fourier Transform is a
suitable technique. An alternative for rapid transients is the Vold-Kalman approach
which is explained in Chapter 8.
b) For an exponential speed decay, use Equation 2.16 to calculate the optimum
number of revs.
(2.16)
i) Using this value we see that, if the sampling time is T, then
(2.17)
From the question we infer that
3
