Review of Bridge Aeroelasticity: Sensitivity Analysis and Optimal Design by J. A. Jurado, S. Hernandez, F. Nieto, and A. Mosquera

The book focuses on aeroelastic flutter analysis of suspension and cable-stayed bridges, along with design sensitivity analysis and optimization of response. The book is indeed comprehensive, containing descriptions of various types of bridges in the world with color illustrations, discussion of various failures with a technical and historical perspective, development of equations for flutter analysis, computational algorithms and applications to various bridges, construction considerations, experimental approaches, and design optimization. Until now, information on this subject has only appeared scattered across various journal and conference publications. Thus, the book’s appearance is timely. Further, the equations and solution procedures presented have been verified by actual implementation into computer software along with experimental corroboration. The authors have published in this area for more than a decade with university–industry cooperation.

The book is comprised of 12 chapters. Each chapter in the book contains information that diverse readers will find valuable. Chapter 1 gives an overview of all of the topics covered. Chapter 2 begins with a detailed discussion of the Tacoma Narrows bridge and its collapse. Subsequently, suspension and cable-stayed bridges across the world are illustrated along with details, which include lengthwise and cross-sectional dimensions and wind speeds considered in design. Chapters 3–5 focus on dynamic and flutter analysis while Chapters 6–10 focus on design sensitivity analysis (i.e., derivatives of response to design parameters). Chapters 11–12 focus on optimal design.

Chapter 3 begins with a discussion of scaled-down models used in wind-tunnel testing and the types of wind tunnels used in bridge engineering, which will be of great value to the student or engineer. Beginning with the basic principles of aeroelasticity in aeronautics, a system of equations governing the dynamic behavior of bridge decks is derived with finite element implementation. Use of modal analysis and a subsequent solution of the resulting nonlinear eigenvalue problem is explained with great clarity. Here an algorithm, a detailed flowchart, and illustrative plots are used. Second-order effects, which account for the cable forces, are also treated. The chapter then explains how to examine the resulting complex eigenvalues to generate flutter speeds and understanding stability. In Chapter 4, the methods developed in Chapter 3 are applied to bridges during the construction phase. This is relevant, as bridges do not have their complete design rigidity until completion. Plots of flutter speed versus percent completed are generated for several bridges. In Chapter 5, four completed bridges are analyzed, starting with the Great Belt bridge in Denmark. The effect of modes included in the expansion on flutter speed are discussed as are the physical modes that are critical. The reader can understand, through analysis how bridges can fail or have failed from aeroelastic instability, and what to look for in redesigning the structures.

Chapters 6–8 contains a clear discussion on how to carry out analytical design sensitivity analysis of eigenvalue–eigenvector, vibration, and flutter problems. It begins by considering the linear eigenvalue problem as occurs in undamped vibration or buckling; Nelson’s method is explained in detail. A rare-to-find adjoint technique is also discussed. Then, eigenvalue problems with damping are considered. These methods are applied to determining sensitivity coefficients of free-vibration bridge problems in Chapter 7. Worthy of mention is the treatment of design sensitivity analysis with a nonlinear geometric stiffness matrix. The authors discuss a code, ADISNOL3D, that they have developed for dynamic analysis and analytical design sensitivity analysis. A code with such capability is not available commercially. The results have been validated using divided differences. The authors have design data for various bridges, which enable them to produce the results. Chapter 8 treats the analytical design sensitivity analysis of flutter speeds. This derivation is not readily available in the literature and will be of great value for engineers working in dynamics and aeroelasticity. The details of finite elements and implementation that are presented will be of considerable value to scientists and professors as well. The derived expressions are then applied to bridges undergoing construction (Chapter 9) and completed bridges (Chapter 10).

Chapters 11 and 12 deal with optimal design, which is relatively new in bridge engineering. The design approach is applied to a practical bridge design problem in which weight is minimized subject to constraints on maximum vertical deflection of the deck and on minimum flutter critical wind speed. The cross-sectional dimensions of the bridge are treated as design variables and reduction of up to 33% of the deck material has been achieved.

The book has a few grammatical errors, and it is hoped that they can be corrected in subsequent printings. However, these do not distract the reader. The book can also be improved upon with the inclusion of an index. In summary, the book is an excellent resource for diverse readers, be they engineers, researchers, professors, or graduate students, in civil or aerospace engineering. Each chapter is accompanied by an extensive bibliography for further study. The excellent color illustrations add to the readability of the book.