Nonlinear vibration analysis of functionally graded beams

Download
2022-8
Dedeköy, Demir
In this thesis, nonlinear forced vibrations of functionally graded (FG) Euler-Bernoulli Beams are studied. Two types of nonlinearities, large deformation nonlinearity and nonlinearities resulting from rotating beam dynamics, are considered. The Spectral Chebyshev Technique (SCT) is employed for solving governing equations of the spectral-temporal boundary value problems of beam vibrations, which do not always have closed-form analytical solutions. The SCT is combined with Galerkin’s method to obtain spatially discretized nonlinear differential equations of motion. Those equations of motion are then converted into nonlinear algebraic equations with the Harmonic Balance Method (HBM), which are solved with the help of Newton’s method with arc-length continuation. First, natural frequencies and mode shapes of the uniform and functionally graded beams are obtained with respect to different case scenarios of material distribution properties. A convergence analysis is performed to obtain the minimum number of Chebyshev polynomials required to obtain precise results. Afterward, frequency responses of the nonlinear beams subjected to different boundary conditions are studied.

Suggestions

Nonlinear Vibration Analysis of Uniform and Functionally Graded Beams with Spectral Chebyshev Technique and Harmonic Balance Method
Dedekoy, Demir; Ciğeroğlu, Ender; Bediz, Bekir (2023-01-01)
In this paper, nonlinear forced vibrations of uniform and functionally graded Euler-Bernoulli beams with large deformation are studied. Spectral and temporal boundary value problems of beam vibrations do not always have closed-form analytical solutions. As a result, many approximate methods are used to obtain the solution by discretizing the spatial problem. Spectral Chebyshev technique (SCT) utilizes the Chebyshev polynomials for spatial discretization and applies Galerkin's method to obtain boundary condi...
Nonlinear 3D Modeling and Vibration Analysis of Horizontal Drum Type Washing Machines
Baykal, Cem; Ciğeroğlu, Ender; Yazıcıoğlu, Yiğit (2020-01-01)
In this study, a nonlinear 3-D mathematical model for horizontal drum type washing machines is developed considering rotating unbalance type excitation. Nonlinear differential equations of motion are converted into a set of nonlinear algebraic equations by using Harmonic Balance Method (HBM). The resulting nonlinear algebraic equations are solved by using Newton’s method with arc-length continuation. Several case studies are performed in order to observe the effects of orientation angles of springs and damp...
Nonlinear Vibrations of a Beam with a Breathing Edge Crack
Batihan, Ali C.; Ciğeroğlu, Ender (2015-02-05)
In this paper, nonlinear transverse vibration analysis of a beam with a single edge crack is studied. In literature, edge cracks are generally modeled as open cracks, in which the beam is separated into two pieces at the crack location and these pieces are connected to each other with a rotational spring to represent the effect of crack. The open edge crack model is a widely used assumption; however, it does not consider the nonlinear behavior due to opening and closing of the crack region. In this paper, a...
Nonlinear Vibrations of a Beam with a Breathing Edge Crack Using Multiple Trial Functions
Batihan, Ali C.; Ciğeroğlu, Ender (2016-01-28)
In this paper, a beam like structure with a single edge crack is modeled and analyzed in order to study the nonlinear effects of breathing crack on transverse vibrations of a beam. In literature, edge cracks are generally modeled as open cracks, in which the beam is separated into two pieces at the crack location and these pieces are connected to each other with a rotational spring to represent the effect of crack. The open edge crack model is a widely used assumption; however, it does not consider the nonl...
Nonlinear Vibrations of a Functionally Graded Material Microbeam with Geometric Nonlinearity
Uz, Canan; Ciğeroğlu, Ender (2017-02-02)
In this paper, nonlinear vibration analysis of micro scale functionally graded material (FGM) beams with geometric nonlinearity due to large deflection is studied using modified couple stress theory (MCST). MCST is a nonlocal elasticity theory which includes a material length scale parameter since the size of an atomic microstructure becomes comparable to the length of the microbeam. Equations of motion of the micro scale FGM beam are obtained by using Hamilton's principle. Nonlinear free vibrations of the ...
Citation Formats
D. Dedeköy, “Nonlinear vibration analysis of functionally graded beams,” M.S. - Master of Science, Middle East Technical University, 2022.