Many engineers will be familiar with the books and papers on various aspects of structural behaviour written by Professor Heyman. They are always concise, clear and well written, and often include an approach to the particular subject from the viewpoint of plastic analysis. They also include useful insights into the behaviour of structures, which are valuable for all of those involved in structural engineering. Readers will not be disappointed by this volume, which maintains his extremely high standards and is – in Professor Heyman's own words – ‘written against the advances made in structural theory in the last 50 years notably by the introduction of the so-called plastic theory'.
It is a relatively small volume of five chapters and three appendices, which sets out to introduce the basic equations of the theory of structures.
Following the first chapter which details the assumptions made in structural analysis the second chapter is mainly concerned with the use of plastic theory to calculate collapse loads of structures. By the use of relatively simple models Professor Heyman is able to demonstrate that the introduction of built-in forces, for example owing to lack of fit, in a redundant structure has no effect on the collapse load of the structure. Also included is a section on the use of plastic analysis for masonry structures – an application which still surprises many engineers in view of the brittle nature of masonry.
Chapters 3 and 4 deal with basic elastic theory, including the reciprocal theorems and influence lines derived elegantly using virtual work, in order that the stiffness and hence displacements of the structure can be determined. While accepting that the actual stress distribution under working loads is likely to be significantly different to those calculated by elastic theory, it is still necessary to use the theory to ascertain displacements. The point is also made that these results can be used as an equilibrium solution to produce safe, although possibly not the most economic, designs by invoking the lower bound theorem of plasticity. An introduction to some of the methods of elastic analysis is also given, which is particularly useful for checking computer analyses.
Chapter 5 initially covers elastic instability of perfect struts, subsequently extended to include imperfections and plastic behaviour. There is a discussion about the inclusion of imperfections which, together with the content of Appendix 3, gives the background to many code design approaches including an interesting discussion about factors of safety.
The other two appendices cover virtual work and the plastic theorems.
This is an excellent book and should be read by all students studying structural engineering and practising structural engineers – and certainly those teaching structures! There is much more than described above. In the preface Professor Heyman indicates that his objective is to present the basics of structural theory rather than a plethora of methods. This objective has been admirably achieved.
