5R9. Introduction to Structural Dynamics and Aeroelasticity. - DH Hodges and GA Pierce (Sch of Aerospace Eng, Georgia Inst of Tech, Atlanta GA). Cambridge UP, Cambridge, UK. 2002. 170 pp. ISBN 0-521-80698-4. $55.00.
Reviewed by MA Cutchins (Dept of Aerospace Eng, Auburn Univ, 211 Aerospace Eng Bldg, Auburn AL 36849-5338).
This textbook would be excellent for its targeted audience—“to provide an introduction to the field of structural dynamics and aeroelasticity (SD & A),…a semester-length, senior-level, undergraduate course or a first-year graduate course in which the emphasis is placed on conventional aircraft.” There is sufficient material for a separate course on aeroelasticity alone. The figures are excellent.
This reviewer really likes the quote from da Vinci as the subheading of Chapter 2, “O students, study mathematics, and do not build without foundations.” The book then proceeds with the subject at hand using differential equations, partial differential equations, various principles such as orthogonality, separation of variables, Lagrange’s equations (with an eight-page appendix on this very important subject), various energy concepts, virtual work, and a number of approximate solution techniques. These are indeed, along with good modeling techniques, the “foundations” of SD & A!
Intentionally absent are the popular, but less enlightening digital techniques. There are, however, several problems on which the student is asked to use either , MATLAB®, or Mathematica® as the means to solve the problem. And the concept of stiffness and mass matrices is utilized in the excellent treatment of approximate solution techniques. Some instructors might consider this absence (see above) a shortcoming of the book, but exposure to digital modeling usually occurs in other courses, and this type of material can be easily supplemented. (See for example the chapter on elastic and aeroelastic instabilities in An Analysis of Aircraft Structures, An Introduction, by Bruce K. Donaldson, 1993.) The references and the index are limited (1.5 and 3.5 pages, respectively).
Most of the models in the structural dynamic chapter are uniform string models and uniform beam models, as they should be for an introductory course.
There are numerous aeroelastic models scattered throughout Chapters 3 and 4 that make up the material on this topic. They include a rigid wing section mounted on: a torsional elastic support, a flexible sting, and two struts, and the “typical section” mounted on pitch and plunge springs. In addition, there is a flapped, 2D wing section, a uniform, unswept cantilevered lifting surface, and a swept wing. Chapter 2 on Structural Dynamics, Chapter 3 on Static Aeroelasticity, and Chapter 4 on Aeroelastic Flutter, each end with an ample number of thoughtful problems (55 of them) for assignment to students. Answers are given below the problems for a number of them. An adequate number of examples are strategically placed throughout the text.
This reviewer would have liked to see references to some of the current web sites on aeroelasticity where there are videos and simulations that are quite helpful. Two locations, for the Auburn and Texas A & M sites, are http://www.eng.auburn.edu/∼drmac/ae605hp.html and http://aerounix.tamu.edu/aeroel/.
Introduction to Structural Dynamics and Aeroelasticity is highly recommended for individuals and libraries. The field was in dire need for an up-to-date, error-free book that addresses the fundamentals and treats the very important problems of divergence, aileron reversal, dynamic response, and flutter and related problems. That need is fulfilled in this book.