1st Edition

Principles of Aeroelasticity

By Rama B. Bhat Copyright 2016
    186 Pages 69 B/W Illustrations
    by CRC Press

    Introductory Guide on the Design of Aerospace Structures

    Developed from a course taught at Concordia University for more than 20 years, Principles of Aeroelasticity utilizes the author’s extensive teaching experience to immerse undergraduate and first-year graduate students into this very specialized subject. Ideal for coursework or self-study, this detailed examination introduces the concepts of aeroelasticity, describes how aircraft lift structures behave when subjected to aerodynamic loads, and finds its application in aerospace, civil, and mechanical engineering.

    The book begins with a discussion on static behavior, and moves on to static instability and divergence, dynamic behavior leading up to flutter, and fluid structure interaction problems. It covers classical approaches based on low-order aerodynamic models and provides a rationale for adopting certain aeroelastic models. The author describes the formulation of discrete models as well as continuous structural models. He also provides approximate methods for solving divergence, flutter, response and stability of structures, and addresses non-aeroelastic problems in other areas that are similar to aeroelastic problems.

    Topics covered include:

    • The fundamentals of vibration theory
    • Vibration of single degree of freedom and two degrees of freedom systems
    • Elasticity in the form of an idealized spring element
    • Repetitive motion
    • Flutter phenomenon
    • Classical methods, Rayleigh-Ritz techniques, Galerkin’s technique, influential coefficient methods, and finite element methods
    • Unsteady aerodynamics, and more


    Elementary Aerodynamics

    General Concepts
    The Joukowski Transformation for Airfoils
    Dimensional Analysis of Force Experienced by a Solid Body in a Flow

    Static Aeroelasticity

    Determination of Shear Center in a Thin-Walled Section

    Divergence of a Lifting Surface


    Divergence of a Typical Section with a Control Surface

    Control Surface Reversal

    Dynamic Aeroelasticity

    Vibration Theory
    Damped Single DOF System
    Energy Method
    Sinusoidal Excitation
    Periodic Force
    Arbitrary Force
    Two DOF System
    Equations of Motion of a Two DOF Model of an Aircraft Wing
    Quasi-Steady Aerodynamic Theory
    Can Flutter Be Seen If Only Torsional Motion Is Considered?
    Dynamics of Airfoil
    Random Motion

    One-Dimensional Aeroelastic Model of Airfoils

    Simple Torsion of a Bar
    General Approximations for Aerodynamic Theory
    Eigenvalue and Eigenfunction Approaches

    Rolling of a Straight Wing

    Determination of Aerodynamic Influence Functions

    Flutter of a Cantilever Wing

    Simple Bending of Beams
    Stability of the Motion

    Approximate Techniques of Modeling Continuous Systems

    Influence Coefficient Method
    Galerkin’s Method
    Rayleigh-Ritz Method
    Finite Element Method
    Assembly of Finite Elements
    Finite Element Representation of the Response and Flutter Problems
    Elastic Foundation
    Eigenfunctions and Eigenvalues
    Nonairfoil Physical Problems
    Stall Flutter
    Flutter and Buffeting of Bridges
    Aeroelasticity of Turbomachinery Blades

    Nonlinear Aeroelasticity

    Generic Nonlinear Aeroelastic Behavior
    One Degree of Freedom Nonlinear System: Divergence
    One Degree of Freedom System: Dynamic Effects
    Two Degrees of Freedom System: Dynamic Effects

    Unsteady Aerodynamics

    Theodorsen’s Unsteady Thin-Airfoil Theory
    Flutter Prediction via Assumed Modes



    Rama Bhat is a professor of mechanical and industrial engineering at Concordia University, Montreal, Canada. His research areas include dynamics of structures, vibration of continuous systems, rotor dynamics, sound transmission into aircraft fuselage, dynamics of micro-electro-mechanical systems, ride dynamics and biodynamics. He has published widely and taught courses in the above areas. In particular, he has been teaching a course on the principles of aeroelasticity for over two decades. He was awarded the NASA Award for his contribution as a member of the team that developed the "PROSSS-Programming Structured Synthesis System" and is a Fellow of several technical societies.