Elements of Structural Optimization — Second revised edition. HaftkaR.T.. et al.. Kluwer Academic Publishers, Dordrecht. 1990. 369 pp. Illustrated. £69.00.

There are many textbooks on modern optimisation techniques, and a few specialising in applications of these techniques to optimal design, usually for minimum weight with constraints imposed on stress, displacement, or geometrical configuration limited. Most of these texts are aimed either at the research community or the industrial practitioners using (say) commercial optimisation codes. This text book is intended to form the basis of a postgraduate teaching course in engineering, not mathematics. Thus it has to aim to cover all the fundamentals, demonstrate all the strategies on a variety of structural optimisation problems, and provide simple worked-through examples, together with problem exercises, for the student. This is a nontrivial task and by and large the authors have succeded. The fundamental methods are certainly all covered: classical variational methods, linear mathematical programming including duality, unconstrained optimisation by search — especially QuasiNewton-methods, and constrained optimisation with various gradient search and penalty function methods. Sensitivity analysis is given a thorough treatment, as is dual and optimality criteria. All of the techniques are illustrated by example which means inevitably a certain amount of repetition. The optimum design of a 3-bar truss can never have been attempted so many times before. The optimum design of tapered beams and struts has fair coverage also. However the gap between simple example and real-life design exercises is a big one. A finite element description of a real aircraft structure will contain many design variables such as local thickness or other section properties and occasionally shape parameters also. The authors here tend to discuss stragegies and cite the references for the interested reader to pursue. This is a reasonable compromise for a text being only 400 pages. There is one chapter which covers one topic quite thoroughly — laminated composite materials. Here the design variables are layer laminar thicknesses and fibre orientation. The authors manage to cover buckling of stiffened plates and aeroelastic tailoring in enough detail for the novice. For anyone wanting a general introductin to the topic, backed by enough examples to put the strategies into context, this book is a first, and a brave attempt. PROFESSOR G. A. O. DAVIES, CEng, FRAeS