TY - BOOK AU - Humar,J.L TI - Dynamics of structures SN - 9780415620864 AV - TA654 .H79 2012 PY - 2012///] CY - Boca Raton, FL PB - CRC Press - Taylor and Francis Croup KW - Structural dynamics N1 - "A Balkema Book."; Includes bibliographical references and index; Contents; Preface ; Preface to Second Edition ; List of symbols ; 1. Introduction ; 1.1. Objectives of the study of structural dynamics ; 1.2. Importance of vibration analysis ; 1.3. Nature of exciting forces ; 1.3.1. Dynamic forces caused by rotating machinery ; 1.3.2. Wind loads ; 1.3.3. Blast loads ; 1.3.4. Dynamic forces caused by earthquakes ; 1.3.5. Periodic and nonperiodic loads ; 1.3.6. Deterministic and nondeterministic loads ; 1.4. Mathematical modeling of dynamic systems ; 1.5. Systems of units ; 1.6. Organization of the text ; PART 1 ; 2. Formulation of the equations of motion: Single-degree-of-freedom systems ; 2.1. Introduction ; 2.2. Inertia forces ; 2.3. Resultants of inertia forces on a rigid body ; 2.4. Spring forces ; 2.5. Damping forces ; 2.6. Principle of virtual displacement ; 2.7. Formulation of the equations of motion ; 2.7.1. Systems with localized mass and localized stiffness ; 2.7.2. Systems with localized mass but distributed stiffness ; 2.7.3. Systems with distributed mass but localized stiffness ; 2.7.4. Systems with distributed stiffness and distributed mass ; 2.8. Modeling of multi-degree-of-freedom discrete parameter system ; 2.9. Effect of gravity load ; 2.10. Axial force effect ; 2.11. Effect of support motion ; Selected readings ; Problems ; 3. Formulation of the equations of motion: Multi-degree-of-freedom systems ; 3.1. Introduction ; 3.2. Principal forces in multi-degree-of-freedom dynamic system ; 3.2.1. Inertia forces ; 3.2.2. Forces arising due to elasticity ; 3.2.3. Damping forces ; 3.2.4. Axial force effects ; 3.3. Formulation of the equations of motion ; 3.3.1. Systems with localized mass and localized stiffness ; 3.3.2. Systems with localized mass but distributed stiffness ; 3.3.3. Systems with distributed mass but localized stiffness ; 3.3.4. Systems with distributed mass and distributed stiffness ; 3.4. Transformation of coordinates ; 3.5. Static condensation of stiffness matrix ; 3.6. Application of Ritz method to discrete systems ; Selected readings ; Problems ; 4. Principles of analytical mechanics ; 4.1. Introduction ; 4.2. Generalized coordinates ; 4.3. Constraints ; 4.4. Virtual work ; 4.5. Generalized forces ; 4.6. Conservative forces and potential energy ; 4.7. Work function ; 4.8. Lagrangian multipliers ; 4.9. Virtual work equation for dynamical systems ; 4.10. Hamilton's equation ; 4.11. Lagrange's equation ; 4.12. Constraint conditions and Lagrangian multipliers ; 4.13. Lagrange's equations for multi-degree-of-freedom systems ; 4.14. Rayleigh's dissipation function ; Selected readings ; Problems ; PART 2 ; 5. Free vibration response: Single-degree-of-freedom system ; 5.1. Introduction ; 5.2. Undamped free vibration ; 5.2.1. Phase plane diagram ; 5.3. Free vibrations with viscous damping ; 5.3.1. Critically damped system ; 5.3.2. Overdamped system ; 5.3.3. Underdamped system ; 5.3.4. Phase plane diagram ; 5.3.5. Logarithmic decrement ; 5.4. Damped free vibration with hysteretic damping ; 5.5. Damped free vibration with coulomb damping ; 5.5.1. Phase plane representation of vibrations under Coulomb damping ; Selected readings ; Problems ; 6. Forced harmonic vibrations: Single-degree-of-freedom system ; 6.1. Introduction ; 6.2. Procedures for the solution of the forced vibration equation ; 6.3. Undamped harmonic vibration ; 6.4. Resonant response of an undamped system ; 6.5. Damped harmonic vibration ; 6.6. Complex frequency response ; 6.7. Resonant response of a damped system ; 6.8. Rotating unbalanced force ; 6.9. Transmitted motion due to support movement ; 6.10. Transmissibility and vibration isolation ; 6.11. Vibration measuring instruments ; 6.11.1. Measurement of support acceleration ; 6.11.2. Measurement of support displacement ; 6.12. Energy dissipated in viscous damping ; 6.13. Hysteretic damping ; 6.14. Complex stiffness ; 6.15. Coulomb damping ; 6.16. Measurement of damping ; 6.16.1. Free vibration decay ; 6.16.2. Forced-vibration response ; Selected readings ; Problems ; 7. Response to general dynamic loading and transient response ; 7.1. Introduction ; 7.2. Response to an Impulsive Force ; 7.3. Response to general dynamic loading ; 7.4. Response to a step function load ; 7.5. Response to a ramp function load ; 7.6. Response to a step function load with rise time ; 7.7. Response to shock loading ; 7.7.1. Rectangular pulse ; 7.7.2. Triangular pulse ; 7.7.3. Sinusoidal pulse ; 7.7.4. Effect of viscous damping ; 7.7.5. Approximate response analysis for short-duration pulses ; 7.8. Response to ground motion ; 7.8.1. Response to a short-duration ground motion pulse ; 7.9. Analysis of response by the phase plane diagram ; Selected readings ; Problems ; 8. Analysis of single-degree-of-freedom systems: Approximate and numerical methods ; 8.1. Introduction ; 8.2. Conservation of energy ; 8.3. Application of Rayleigh method to multi-degree-of-freedom systems ; 8.3.1. Flexural vibrations of a beam ; 8.4. Improved Rayleigh method ; 8.5. Selection of an appropriate vibration shape ; 8.6. Systems with distributed mass and stiffness: analysis of internal forces ; 8.7. Numerical evaluation of Duhamel's integral ; 8.7.1. Rectangular summation ; 8.7.2. Trapezoidal method ; 8.7.3. Simpson's method ; 8.8. Direct integration of the equations of motion ; 8.9. Integration based on piece-wise linear representation of the excitation ; 8.10. Derivation of general formulas ; 8.11. Constant-acceleration method ; 8.12. Newmark's β method ; 8.12.1. Average acceleration method ; 8.12.2. Linear acceleration method ; 8.13. Wilson-method ; 8.14. Methods based on difference expressions ; 8.14.1. Central difference method ; 8.14.2. Houbolt's method ; 8.15. Errors involved in numerical integration ; 8.16. Stability of the integration method ; 8.16.1. Newmark's β method ; 8.16.2. Wilson-method ; 8.16.3. Central difference method ; 8.16.4. Houbolt's method ; 8.17. Selection of a numerical integration method ; 8.18. Selection of time step ; Selected readings ; Problems ; 9. Analysis of response in the frequency domain ; 9.1. Transform methods of analysis ; 9.2. Fourier series representation of a periodic function ; 9.3. Response to a periodically applied load ; 9.4. Exponential form of Fourier series ; 9.5. Complex frequency response function ; 9.6. Fourier integral representation of a nonperiodic load ; 9.7. Response to a nonperiodic load ; 9.8. Convolution integral and convolution theorem ; 9.9. Discrete Fourier transform ; 9.10. Discrete convolution and discrete convolution theorem ; 9.11. Comparison of continuous and discrete fourier transforms ; 9.12. Application of discrete inverse transform ; 9.13. Comparison between continuous and discrete convolution ; 9.14. Discrete convolution of an infinite- and a finite-duration waveform ; 9.15. Corrective response superposition methods ; 9.15.1. Corrective transient response based on initial conditions ; 9.15.2. Corrective periodic response based on initial conditions ; 9.15.3. Corrective responses obtained from a pair of force pulses ; 9.16. Exponential window method ; 9.17. The fast Fourier transform ; 9.18. Theoretical background to fast Fourier transform ; 9.19. Computing speed of FFT convolution ; Selected readings ; Problems ; PART 3 ; 10. Free vibration response: Multi-degree-of-freedom system ; 10.1. Introduction ; 10.2. Standard eigenvalue problem ; 10.3. Linearized eigenvalue problem and its properties ; 10.4. Expansion theorem ; 10.5. Rayleigh quotient ; 10.6. Solution of the undamped free vibration problem ; 10.7. Mode superposition analysis of free-vibration response ; 10.8. Solution of the damped free-vibration problem ; 10.9. Additional orthogonality conditions ; 10.10. Damping orthogonality ; Selected readings ; Problems ; 11. Numerical solution of the eigenproblem ; 11.1. Introduction ; 11.2. Properties of standard eigenvalues and eigenvectors ; 11.3. Transformation of a linearized eigenvalue; problem to the standard form ; 11.4. Transformation methods ; 11.4.1. Jacobi diagonalization ; 11.4.2. Householder's transformation ; 11.4.3. QR transformation ; 11.5. Iteration methods ; 11.5.1. Vector iteration ; 11.5.2. Inverse vector iteration ; 11.5.3. Vector iteration with shifts ; 11.5.4. Subspace iteration ; 11.5.5. Lanczos iteration ; 11.6. Determinant search method ; 11.7. Numerical solution of complex eigenvalue problem ; 11.7.1. Eigenvalue problem and the orthogonality relationship ; 11.7.2. Matrix iteration for determining the complex eigenvalues ; 11.8. Semidefinite or unrestrained systems ; 11.8.1. Characteristics of an unrestrained system ; 11.8.2. Eigenvalue solution of a semidefinite system ; 11.9. Selection of a method for the determination of eigenvalues ; Selected readings ; Problems ; 12. Forced dynamic response: Multi-degree-of-freedom systems ; 12.1. Introduction ; 12.2. Normal coordinate transformation ; 12.3. Summary of mode superposition method ; 12.4. Complex frequency response ; 12.5. Vibration absorbers ; 12.6. Effect of support excitation ; 12.7. Forced vibration of unrestrained system ; Selected readings ; Problems ; 13. Analysis of multi-degree-of-freedom systems: Approximate and numerical methods ; 13.1. Introduction ; 13.2. Rayleigh-Ritz method ; 13.3. Application of Ritz method to forced vibration response ; 13.3.1. Mode superposition method ; 13.3.2. Mode acceleration method ; 13.3.3. Static condensation and Guyan's reduction ; 13.3.4. Load-dependent Ritz vectors ; 13.3.5. Application of lanczos vectors in the transformation of the equations of motion ; 13.4. Direct integration of the equations of motion ; 13.4.1. Explicit integration schemes ; 13.4.2. Implicit integration schemes ; 13.4.3. Mixed methods in direct integration ; 13.5. Analysis in the frequency domain ; 13.5.1. Frequency analysis of systems with classical mode shapes ; 13.5.2. Frequency analysis of systems without classical mode shapes ; Selected readings ; Problems ; PART 4 ; 14. Formulation of the equations of motion: Continuous systems ; 14.1. Introduction ; 14.2. Transverse vibrations of a beam ; 14.3. Transverse vibrations of a beam: variational formulation ; 14.4. Effect of damping resistance on transverse vibrations of a beam ; 14.5. Effect of shear deformation and rotatory inertia on the flexural vibrations of a beam ; 14.6. Axial vibrations of a bar ; 14.7. Torsional vibrations of a bar ; 14.8. Transverse vibrations of a string ; 14.9. Transverse vibrations of a shear beam ; 14.10. Transverse vibrations of a beam excited by support motion ; 14.11. Effect of axial force on transverse vibrations of a beam ; Selected readings ; Problems ; 15. Continuous systems: Free vibration response ; 15.1. Introduction ; 15.2. Eigenvalue problem for the transverse vibrations of a beam ; 15.3. General eigenvalue problem for a continuous system ; 15.3.1. Definition of the eigenvalue problem ; 15.3.2. Self-adjointness of operators in the eigenvalue problem ; 15.3.3. Orthogonality of eigenfunctions ; 15.3.4. Positive and positive definite operators ; 15.4. Expansion theorem ; 15.5. Frequencies and mode shapes for lateral vibrations of a beam ; 15.5.1. Simply supported beam ; 15.5.2. Uniform cantilever beam ; 15.5.3. Uniform beam clamped at both ends ; 15.5.4. Uniform beam with both ends free ; 15.6. Effect of shear deformation and rotatory inertia on the frequencies of flexural vibrations ; 15.7. Frequencies and mode shapes for the axial vibrations of a bar ; 15.7.1. Axial vibrations of a clamped-free bar ; 15.7.2. Axial vibrations of a free-free bar ; 15.8. Frequencies and mode shapes for the transverse vibration of a string ; 15.8.1. Vibrations of a string tied at both ends ; 15.9. Boundary conditions containing the eigenvalue ; 15.10. Free-vibration response of a continuous system ; 15.11. Undamped free transverse vibrations of a beam ; 15.12. Damped free transverse vibrations of a beam ; Selected readings ; Problems ; 16. Continuous systems: Forced-vibration response ; 16.1. Introduction ; 16.2. Normal coordinate transformation: general case of an undamped system ; 16.3. Forced lateral vibration of a beam ; 16.4. Transverse vibrations of a beam under traveling load ; 16.5. Forced axial vibrations of a uniform bar ; 16.6. Normal coordinate transformation, damped case ; Selected readings ; Problems ; 17. Wave propagation analysis ; 17.1. Introduction ; 17.2. The Phenomenon of wave propagation ; 17.3. Harmonic waves ; 17.4. One dimensional wave equation and its solution ; 17.5. Propagation of waves in systems of finite extent ; 17.6. Reflection and refraction of waves at a discontinuity in the system properties ; 17.7. Characteristics of the wave equation ; 17.8. Wave dispersion ; Selected readings ; Problems ; PART 5 ; 18. Finite element method ; 18.1. Introduction ; 18.2. Formulation of the finite element equations ; 18.3. Selection of shape functions ; 18.4. Advantages of the finite element method ; 18.5. Element Shapes ; 18.5.1. One-dimensional elements ; 18.5.2. Two-dimensional elements ; 18.6. One-dimensional bar element ; 18.7. Flexural vibrations of a beam ; 18.7.1. Stiffness matrix of a beam element ; 18.7.2. Mass matrix of a beam element ; 18.7.3. Nodal applied force vector for a beam element ; 18.7.4. Geometric stiffness matrix for a beam element ; 18.7.5. Simultaneous axial and lateral vibrations ; 18.8. Stress-strain relationships for a continuum ; 18.8.1. Plane stress ; 18.8.2. Plane strain ; 18.9. Triangular element in plane stress and plane strain ; 18.10. Natural coordinates ; 18.10.1. Natural coordinate formulation for a uniaxial bar element ; 18.10.2. Natural coordinate formulation for a constant strain triangle ; 18.10.3. Natural coordinate formulation for a linear strain triangle ; Selected readings ; Problems ; 19. Component mode synthesis ; 19.1. Introduction ; 19.2. Fixed interface methods ; 19.2.1. Fixed interface normal modes ; 19.2.2. Constraint modes ; 19.2.3. Transformation of coordinates ; 19.2.4. Illustrative example ; 19.3. Free interface method ; 19.3.1. Free interface normal modes ; 19.3.2. Attachment modes ; 19.3.3. Inertia relief attachment modes ; 19.3.4. Residual flexibility attachment modes ; 19.3.5. Transformation of coordinates ; 19.3.6. Illustrative example ; 19.4. Hybrid method ; 19.4.1. Experimental determination of modal parameters ; 19.4.2. Experimental determination of the static constraint modes ; 19.4.3. Component modes and transformation of component matrices ; 19.4.4. Illustrative example ; Selected readings ; Problems ; 20. Analysis of nonlinear response ; 20.1. Introduction ; 20.2. Single-degree-of freedom system ; 20.2.1. Central difference method ; 20.2.2. Newmark's β Method ; 20.3. Errors involved in numerical integration of nonlinear systems ; 20.4. Multiple degree-of-freedom system ; 20.4.1. Explicit integration ; 20.4.2. Implicit integration ; 20.4.3. Iterations within a time step ; Selected readings ; Problems ; Answers to selected problems ; Index ER -