7R6. Analysis and Optimization of Prismatic and Axisymmetric Shell Structures: Theory, Practice, and Software. - Edited by E Hinton (Dept of Civil Eng, Univ of Wales Swansea, Singleton Park, Swansea SA2 8PP UK), J Sienz (Dept of Mech Eng, Univ of Wales Swansea, Singleton Park, Swansea SA2 8PP UK), and M Ozakca (Dept of Civil Eng, Faculty of Eng, Univ of Gaziantep, Gaziantep 77310, Turkey). Springer-Verlag London Ltd, Surrey UK. 2003. 496 pp. ISBN 1-85233-421-5. $159.00.
Reviewed by CH Yoo (Civil Eng Dept, Auburn Univ, 238 Harbert Eng Center, Auburn AL 36849-5333).
This is a very useful reference book on analysis and optimization of prismatic and axisymmetric shell structures. Optimization presented in this book is based on mini-/maximizing objective functions dealing with structural shapes, weight, buckling strengths, and/or natural frequencies of structures like many other books written on the subject of structural optimization. Optimum structural design in a general sense encompassing many intangible variables including minimum overall cost, maintenance, long term performance (fatigue, corrosion), aesthetics, and owner’s satisfaction, is perhaps beyond the realm of mathematical tools.
The book is divided into five parts. Part I: Introduction (Chs 1–3), Part II: Static Analysis and Optimization (Chs 4–6), Part III: Free Vibration Analysis and Optimization (Chs 7–9), Part IV: Dynamic and Buckling Analysis and Optimization (Chs 10–11), and Part V: CD-ROM.
Chapter 1 lays down the foundation of the book including the main objective of the book, review of previous work, limitations and scope of the work, basic definition of terminology, and layout of the book. Chapter 2 deals with structural shape definition and automatic mesh generation. Chapter 3 presents structural optimization methods and algorithms dealing with classification of problems treated, overview of optimization algorithms, and sensitivity analysis.
Chapter 4 verifies the validity of the basic finite element formulation for shells of revolution by comparing the solutions with a few benchmark examples. Chapter 5 presents the basic finite strip formulation for prismatic shells. The analysis is carried out using Mindlin-Reissner finite strips. Using a single cell and multi-cell curved box-girder bridge examples to test the developed method appears to be ill-advised as the procedures and dimensions presented in the book are far from those used in practice. Most concrete box-girders, if not all, are post-tensioned. As a consequence, thicknesses of concrete boxes are frequently determined to accommodate the pre-stressing forces. In the case of steel-concrete composite box-girders, the dimensions of the steel box are frequently determined considering it as a semi- or completely open cross section (tub-girder) under the construction loads. Chapter 6 deals with structural optimization of shells of revolution and prismatic shells. Because of the simple objective functions (weight minimization or strain energy minimization) employed, very interesting (impractical) optimal thickness variations of a cylindrical tank or a square plate emerge.
Chapters 7 and 8 are devoted to the basic finite element formulation for vibrating axisymmetric shells and the finite strip formulation for vibrating prismatic shells, respectively. Mindlin-Reissner theory is used for the analysis. Chapter 9 is concerned with structural shape and thickness optimization of vibrating axisymmetric and prismatic plates and shells. The objective function to be maximized is the fundamental frequency.
Buckling analysis and optimization of prismatic and axisymmetric plate and shell structures are presented in Chapter 10. Chapter 11 considers additional approach to the analysis of axisymmetric and prismatic shells. Included in this chapter are some very interesting comparisons of numerical solutions obtained using the developed computer program and known closed form solutions.
A salient feature of Analysis and Optimization of Prismatic and Axisymmetric Shell Structures: Theory, Practice, and Software is the inclusion of the computer program written in Fortran77 along with a free Gnu Fortran compiler g77 and Gnu PostScript interpreter under the Gnu Public License. This is a tremendous contribution to practicing engineers who do not have a ready access to high power computing facilities along with rich software libraries. Although Gnu programs are free, it is not easy for a novice to extract what he needs from the tangle of the website. In all current main programs and subroutines, the authors utilize the PARAMETER statement, thereby achieving semi-dynamic storage allocations. Despite the authors claim, documentation included in the Tools section of the CD-ROM is choppy and brief. Some commands in Tools simply did not work. There are too many abbreviations used in the text. For example, SAM is meant for semi analytical method instead of surface to air missile. Users are forced to read from the beginning to understand SAM. The nature of the book being a reference, this is a bothersome shortcoming.
There are several impractical optimums structural shapes presented in the book. Perhaps introducing constraints, ie, higher order continuity, in the structural shapes, could alleviate these problems. Despite shortcomings, the book is highly recommended for engineering offices and libraries.