Book Reviews
CONTACT MECHANICS AND FRICTION: PHYSICAL
PRINCIPLES AND APPLICATIONS
V L Popov, 2010, 362 pp., 1
st
English Edition; Springer,
Berlin, Heidelberg (hardback) ISBN: 978-3-642-
10802-0
Everybody who deals with the problem of the contact
mechanics between wheel and rail sooner or later has
to deal with two books. One of these books is
Johnson’s book on contact mechanics (K. L.
Johnson: Contact Mechanics, Cambridge University
Press, 1985; 6. Edition 2001) and the other is
Kalker’s monograph (J. J. Kalker: Three Dimensional
Elastic Bodies in Rolling Contact, Kluwer Academic
Publishers, Dordrecht, 1990). Both books go beyond
the rolling contact mechanics of wheel-on-rail con-
tact. With Kalker, the problem revolves around
numerical treatment of contact problems for elastic
bodies. Everybody who wants to deal with contact
mechanical problems for real wheel-rail systems,
including wear, cannot ignore the work of Kalker. In
Johnson’s book a broad variety of contact mechanical
problems are considered, not only in the field of
theory of elasticity. Johnson always uses analytical,
semi-analytical, or graphical solutions.
Now, as announced in the title, there is an addi-
tional book in this field at Springer publishing
house, initially for the German-speaking world and
now as an English edition. One naturally asks, if
another book in this field is justified, given that two
monographs on the subject already exist. The answer
is definitely: Yes. The reason for this answer becomes
clear from the title: Contact Mechanics and Friction
go hand in hand. The subtitle makes it clear that the
book is not limited to a purely mechanical problem,
but rather it reaches back to physical fundamentals.
The reviewer agrees with the author of this book in
that (even with apparently ‘‘pure’’ technical pro-
blems such as the wheel-rail contact) it is impossible
to avoid physical considerations, if one is required to
tackle previously unsolved or unsatisfactorily solved
aspects. The book by Popov allows new problems to
be considered more easily than before.
Popov primarily writes not for academic collea-
gues, but for students and engineers in the field of
contact mechanics. Valentin Popov believes that the
essential aspects of contact mechanics and friction
are much simpler than they often appear to be. The
author has succeeded in presenting very complicated
situations in the simplest possible way. Thereby,
he exposes himself to criticism from colleagues in
the field of physics for oversimplifying matters.
Obviously, he does not stop short of this criticism,
for he first wants to help the beginner to overcome
his psychological inhibitions.
Already by perusing the table of contents, a broader
aspect becomes clear. Chapters 2 and 3 deal with a
qualitative approach whereas Chapters 5 and 6 with a
‘‘rigorous’’ approach. Above all, it is essential to the
author to gain fundamental insights with a qualitative
approach; only then does the author draw near to a
more stringent procedure for the exact solution.
However, even there he still limits himself (for
instance with Hertzian contact problems) to the sim-
plest case (sphere on a half-space) for the generalized
cases, once again he provides an approximation.
It is important to the author to convey basic
insights into general problems: adhesive contact,
roughness, frictionally induced oscillations, thermal
effects, viscoelastic properties, wear, and influence of
high frequency vibrations. Compared with the
German edition one can find an additional chapter
entitled ‘‘Earthquake and Friction’’. Of course, this
chapter is not necessary for rolling contact problems;
however it indicates how the author tackles comple-
tely new problems.
The focal point, above all regarding the wheel-rail
contact, is composed of the rolling contact problem
and Coulomb’s law of friction. At this the Prandtl-
Tomlinson model of dry friction is considered in
detail.
In Chapter 19 of Popov’s book, numerical simula-
tion methods for contact mechanics and friction are
covered. Of main interest is a procedure in which a
three-dimensional contact problem is consistently
represented as a one-dimensional problem. A certain
proximity to Kalker’s simplified theory is unmistak-
able. Popov, however, goes further when he applies
his simulation method, which he calls reduction
method, to the contact of rough surfaces. Different
from Kalker (FASTSIM), the transition to arbitrary
contact surfaces is (still) not possible.
The reader of this book should not expect a univer-
sal remedy. The fact that understanding is linked to
some amount of effort will become very clear, at least,
341
Proc. IMechE Vol. 225 Part F: J. Rail and Rapid Transit
when one attempts to tackle the numerous exercises.
However, one who puts in the effort will be rewarded
with a fundamental understanding of contact
mechanics and friction.
Klaus Knothe
TU Berlin, retired
THE V/S SIC GUIDE TO BRITISH GAUGING
PRACTICE
D M Johnson, Rail Safety and Standards Board
(RSSB), 2010, RSSB Research Contract T926, London
This guide was written to introduce the subject of
British gauging practices, covering a wide scope
from simple vehicle gauges and gauging methods to
the latest computer based software methods cur-
rently employed for the gauging process in Britain.
The guide begins with a brief introduction to the
background history of gauging in Britain which
includes a useful glossary of terms. It follows with a
chapter on vehicle gauges offering insightful informa-
tion on an area which can be quite confusing for those
unfamiliar with the techniques used. A good example
is the description of the peculiarities of network
gauging in Britain especially for freight vehicles. The
author explains for example that although a W8
freight gauge is widely known to be able to accom-
modate 8’ 6’’ (2.59 m) high containers, this is only the
case when the container is loaded onto suitable
wagons with the correct deck height. It also highlights
that the British freight gauges are not all nested within
one another. Passenger vehicle, locomotive and track
maintenance vehicle gauges are also covered includ-
ing the effects of loading and tilting trains.
Further sections cover gauging methods such as
comparative gauging, absolute gauging and hybrid
gauging. Comparative gauging is a process of demon-
strating that new rolling stock can operate on a route
by comparing its dynamic swept envelope with an
existing comparator vehicle already approved to run
on that route. In absolute gauging, the actual space
required to run a vehicle along a route is compared
with the actual size of structures and adjacent tracks
on the route. The guide also explains hybrid gauging
which is a combination of gauging techniques used to
clear a vehicle for a route where comparative gauging
and absolute gauging techniques are applied to dif-
ferent parts of the vehicle. How structure clearances,
track fixity, tolerances and electrification influences
gauging are covered in the guide. There is also a brief
mention of the International Union of Railways (UIC)
method of gauging which is adopted in Europe.
The chapter on platform gauging explains the rela-
tionship between vehicles and platforms highlighting
the problem of achieving a balance between passen-
ger accessibility and sufficient clearances for passing
trains. A section on heritage rolling stock and steam
locomotives describe the possible conflicts that may
arise in running these vehicles on today’s network
due to the possibility that modifications have been
carried out to the track alignment. The suitability of
European style double decked trains is also briefly
debated by the author. This is followed by a chapter
on the surveying techniques employed in gauging
which covers methods from the rudimentary pole
and tape to laser profiling.
A flowchart attached in the appendix of the guide
manages to clearly illustrate the route to gauging
acceptance in an easy to understand manner.
However it would also be helpful to include a diagram
to show the various important points on a vehicle
body such as the cant-rail and solebar. There is a
recommended reading list and useful contacts for
readers needing further information.
In conclusion, this is a comprehensive document
covering all aspects related to gauging in Britain.
Although some areas of the guide only skim the sur-
face of a topic, it should be sufficient to kick-start the
process of gaining a greater understanding of gauging
practices in Britain to those new to the subject. Those
wanting to run trains in Britain or involved in gauging
processes may also find this guide useful to assist
them in achieving their objectives.
S L Tan
Rail Technology Unit, Manchester Metropolitan
University, Manchester, UK
WHEEL-RAIL BEST PRACTICE HANDBOOK
F Schmid (Ed.), 2010, University of Birmingham
Press, Birmingham, ISBN: 978-0-952-9997-3-7
The ‘Wheel-Rail Best Practice Handbook’ is pub-
lished by the University of Birmingham and was com-
missioned by the UK rail industry Vehicle/Track
System Interface Committee (V/T SIC). It is the
latest collection of theoretical and practical knowl-
edge on issues relating to the wheel-rail interface
and in the broader sense, railway operations. Wheel
and rail maintenance and replacement are two major
cost drivers of the railway industry. From a physical
342 Book Reviews
Proc. IMechE Vol. 225 Part F: J. Rail and Rapid Transit
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