Course detail

Dynamics

FAST-CD05Acad. year: 2013/2014

Assessment of civil engineering structures subjected to dynamic loads. Vibration theory fundamentals. Free vibration of single degree of freedom systems (SDOF). Experimental determination of fundamental natural frequency and damping factor. Response of SDOF systems to harmonic excitation. Response of SDOF systems to special forms of excitation and to general dynamic excitation. Frequency domain analysis. DFT, FFT. Mathematical models of continuous systems - axial and transverse vibration of elastic beams. Vibration of thin flat plate. Mathematical models of multi degree of freedoms (MDOF) systems. Application of Newton’s Laws to lumped-parameter models. Hamilton’s principle. Lagrange’s equations. Application of Lagrange’s equations to continuous systems. Free vibration of MDOF systems. Dynamic response by mode superposition method. The eigenvalue problem and numerical evaluation of modes and frequencies of MDOF systems. Dynamic analysis by finite element method (FEM). Element stiffness, damping, mass matrices and element force vector. Assembly of system Matrices. Vibration analysis employing FEM models. Direct integration methods for dynamic response. Response of systems to seismic excitation.

Language of instruction

Czech

Number of ECTS credits

Mode of study

Not applicable.

Guarantor

doc. Ing. Vlastislav Salajka, CSc.

Department

Institute of Structural Mechanics (STM)

Learning outcomes of the course unit

The course output is knowledge in the theory of structure vibration area. Student knows necessary technical and became acquainted with option of computational models useful for dynamic analyses of the structure. The skills are possible to apply in solving of dynamic response of the structure. Obtained knowledge and acquirements are the basis for practical design and appreciation of dynamically loaded structures. The theoretic knowledge is instrumental towards to understanding of single type of dynamic analyses implemented in modern computational programs based on FEM.

Prerequisites

Diagrams of internal forces on a beam, the meaning of the quantities: stress, strain and displacement, Hook’s law, equilibrium conditions for a beam, physical and geometrical equations for a beam, foundations of higher mathematics, variational principles, theory of plates, theory of FEM,.

Co-requisites

Not applicable.

Planned learning activities and teaching methods

During lectures, standard model of theory explanation using the projector and blackboard is used. In the training course, students themselves solve tasks on a paper.

Assesment methods and criteria linked to learning outcomes

Conditions to get credit are active presence in training course (two absences are allowed) and successful evaluated of two tests. Tests are consists of both theoretical questions and practical tasks.

Course curriculum

1.Examination of civil engineering structures loaded by dynamic effects.
2.Bases of the theory of civil engineering structures vibration. Single degree of freedom model.
3.Modal analysis. SDOF response on special action. Damping models.
4.Eigenvalue frequencies measurement. Response on general type of action.
5.Numerical analysis of SDOF response. Frequency analysis. FFT.
6.Continuous computational models – bended beam. Modal analysis. Vibration of plates.
7.Newton law application. Hamilton principle. Rayleigh method.
8.Models with finite degree of freedom. Lagrange equation.
9.Discrete and continuous models. Two degree of freedom model modal analysis.
10.Response solution using mode superposition. Rayleigh method.
11.Eigen frequency and eigen vectors characteristics. Rayleigh-Ritz method. Eigenvalues tasks – introduction.
12.Usage of FEM in dynamic analysis. Element matrix. Modal analysis.
13.Mode superposition method. Direct integration of motion equations.

Work placements

Not applicable.

Aims

To get knowledge from the structure vibration theory, acquire appropriate terminology, recognize advantages of the alternatives to the dynamic analysis models, utilize up-to-date solving methods. Skills can be used as a basis for the real design of dynamically loaded structures; the theoretical knowledge helps to understand dynamic analyses implemented in modern computational programs based on FEM.

Specification of controlled education, way of implementation and compensation for absences

Extent and forms are specified by guarantor’s regulation updated for every academic year.

Recommended optional programme components

Extended theoretical knowledge of nonlinear mechanics including its applications in analysis of structures should be gained on a voluntary specialized seminar.

Prerequisites and corequisites

Not applicable.

Basic literature

Craig, R. R., Jr.: Structural Dynamics. John Wiley & Sons, Inc., 1981. (EN)
Inman, J.D.: Enginnering Vibration. Prentice-Hall International, 1994. (EN)

Recommended reading

Baťa, M., Plachý, V.: Vyšetřování dynamických účinků na stavební konstrukce. SNTL – Nakladatelství technické literatury, Praha, 1978. (CS)
Bittnar, Z., Šejnoha, J.: Numerické metody mechaniky. Vydavatelství ČVUT, Praha, 1992. (CS)
Koloušek, V.: Dynamika stavebních konstrukcí I. SNTL - Nakladatelství technické literatury, Praha, 1967. (CS)

Classification of course in study plans

  • Programme N-K-C-SI Master's

    branch K , 1 year of study, winter semester, compulsory

  • Programme N-P-C-SI Master's

    branch K , 1 year of study, winter semester, compulsory

  • Programme N-P-E-SI Master's

    branch K , 1 year of study, winter semester, compulsory

Type of course unit

 

Lecture

26 hod., optionally

Teacher / Lecturer

doc. Ing. Vlastislav Salajka, CSc.

Syllabus

1. Assessment of civil engineering structures subjected by dynamic loads.
2. Foundations the theory vibration of civil engineering structures. Models with single degree of freedom system (SDOF).
3. Free Vibration. Response SDOF systems to specials form of excitation. Damping models.
4. Measurement of frequencies and damping. Response of SDOF to general type of action.
5. Numerical analysis of SDOF response. Frequency analysis. FFT.
6. Continuous computational models – tension and bending of beam. Modal analysis. Vibration of plates.
7. Newton law application. Hamilton principle.
8. Multi degree of freedom models. Lagrange equations.
9. Discrete and continuous models. Modal analysis of two degree of freedom models.
10. Response solution using mode superposition method. Rayleigh method.
11. Natural frequency and eigenvalue vectors characteristics. Rayleigh-Ritz method. General eigenvalues problem.
12. Dynamic analysis by finite element method (FEM). Element matrices. The global system of equations Systems matrices. Modal analysis. Direct integration equations of motion.
13. Response solution structures on seismic loads.

Exercise

26 hod., compulsory

Teacher / Lecturer

doc. Ing. Vlastislav Salajka, CSc.

Syllabus

1. Calculation of equivalent stiffness and mass of models with single degree of freedom system (SDOF)
2. Derivation of equation of motion of SDOF systems
3. Free vibration of undamped SDOF system – calculation of natural frequencies
4. Free vibration of undamped SDOF system – calculation of damping parameters
5. Response of SDOF system to harmonic excitation
6. Response of SDOF system to various type excitations (impulse, constant force etc.)
7. Calculation of frequencies and modes of vibrations of continuous systems – rods and plates
8. Derivation of equation of motion system with 2DOF (translational and rotational motion)
9. Assembly equation of 2DOF systems to calculate the frequencies and modes of vibrations and their solution
10. Assembly modal matrices. Using procedures for normalizing mode of vibration and plotting modes.
11. Solution by mode-superposition method of the 2DOF system to harmonic excitation.
12. Tuning dampers for vibration reduction simple systems.
13. Derive elastic response spectra for solutions to seismic excitation.