scholarly journals Damping of Torsional Beam Vibrations by Control of Warping Displacement

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Jan Høgsberg ◽  
David Hoffmeyer ◽  
Christian Ejlersen
Keyword(s):  
Eigenvalue Problem ◽  
Boundary Conditions ◽  
Vibration Mode ◽  
Supplemental Damping ◽  
Torsional Beam ◽  
Warping Displacement ◽  
Viscous Boundary ◽  
Viscous Boundary Conditions

Supplemental damping of torsional beam vibrations is considered by viscous bimoments acting on the axial warping displacement at the beam supports. The concept is illustrated by solving the governing eigenvalue problem for various support configurations with the applied bimoments represented as viscous boundary conditions. It is demonstrated that properly calibrated viscous bimoments introduce a significant level of supplemental damping to the targeted vibration mode and that the attainable damping can be accurately estimated from the two undamped problems associated with vanishing and infinite viscous parameters, respectively.

Stability and Natural Characteristics of a Supported Beam

2011 ◽  
Vol 338 ◽  
pp. 467-472 ◽  
Author(s):  
Ji Duo Jin ◽  
Xiao Dong Yang ◽  
Yu Fei Zhang
Keyword(s):  
Eigenvalue Problem ◽  
Boundary Conditions ◽  
Axial Force ◽  
Critical Values ◽  
Rotational Spring ◽  
Analytical Expression ◽  
The Stability ◽  
Spring Constants ◽  
Critical Axial Force ◽  
Natural Characteristics

The stability, natural characteristics and critical axial force of a supported beam are analyzed. The both ends of the beam are held by the pinned supports with rotational spring constraints. The eigenvalue problem of the beam with these boundary conditions is investigated firstly, and then, the stability of the beam is analyzed using the derived eigenfuntions. According to the analytical expression obtained, the effect of the spring constants on the critical values of the axial force is discussed.

Transparent boundary conditions for discretized non-Hermitian eigenvalue problems

2021 ◽  
pp. 2150138
Author(s):  
Jonathan Heinz ◽  
Miroslav Kolesik
Keyword(s):  
Quantum Mechanics ◽  
Eigenvalue Problem ◽  
Boundary Conditions ◽  
Eigenvalue Problems ◽  
Complex Scaling ◽  
Transparent Boundary Conditions ◽  
Drastic Reduction ◽  
Optical Cavities ◽  
Energy Dependent ◽  
Lossy Waveguides

A method is presented for transparent, energy-dependent boundary conditions for open, non-Hermitian systems, and is illustrated on an example of Stark resonances in a single-particle quantum system. The approach provides an alternative to external complex scaling, and is applicable when asymptotic solutions can be characterized at large distances from the origin. Its main benefit consists in a drastic reduction of the dimesnionality of the underlying eigenvalue problem. Besides application to quantum mechanics, the method can be used in other contexts such as in systems involving unstable optical cavities and lossy waveguides.

scholarly journals On the numerical solution for nonlinear elliptic equations with variable weight coefficients in an integral boundary conditions

2021 ◽  
Vol 26 (4) ◽  
pp. 738-758
Author(s):  
Regimantas Čiupaila ◽  
Kristina Pupalaigė ◽  
Mifodijus Sapagovas
Keyword(s):  
Eigenvalue Problem ◽  
Boundary Conditions ◽  
Sufficient Conditions ◽  
Integral Boundary Conditions ◽  
Nonlinear Elliptic Equations ◽  
Integral Boundary ◽  
Nonlinear Elliptic ◽  
Variable Weight ◽  
The Difference ◽  
Convergence Of Iterative Method

In the paper the two-dimensional elliptic equation with integral boundary conditions is solved by finite difference method. The main aim of the paper is to investigate the conditions for the convergence of the iterative methods for the solution of system of nonlinear difference equations. With this purpose, we investigated the structure of the spectrum of the difference eigenvalue problem. Some sufficient conditions are proposed such that the real parts of all eigenvalues of the corresponding difference eigenvalue problem are positive. The proof of convergence of iterative method is based on the properties of the M-matrices not requiring the symmetry or diagonal dominance of the matrices. The theoretical statements are supported by the results of the numerical experiment.

scholarly journals Lower bounds for Orlicz eigenvalues

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Ariel Salort
Keyword(s):  
Eigenvalue Problem ◽  
Boundary Conditions ◽  
Lower Bounds ◽  
Dirichlet Boundary ◽  
Nonlinear Eigenvalue Problem ◽  
Dirichlet Boundary Conditions ◽  
Young Functions ◽  
New Strategies ◽  
Nonlinear Eigenvalue

<p style='text-indent:20px;'>In this article we consider the following weighted nonlinear eigenvalue problem for the <inline-formula><tex-math id="M1">\begin{document}$ g- $\end{document}</tex-math></inline-formula>Laplacian</p><p style='text-indent:20px;'><disp-formula> <label/> <tex-math id="FE1"> \begin{document}$ -{\text{ div}}\left( g(|\nabla u|)\frac{\nabla u}{|\nabla u|}\right) = \lambda w(x) h(|u|)\frac{u}{|u|} \quad \text{ in }\Omega\subset \mathbb R^n, n\geq 1 $\end{document} </tex-math></disp-formula></p><p style='text-indent:20px;'>with Dirichlet boundary conditions. Here <inline-formula><tex-math id="M2">\begin{document}$ w $\end{document}</tex-math></inline-formula> is a suitable weight and <inline-formula><tex-math id="M3">\begin{document}$ g = G' $\end{document}</tex-math></inline-formula> and <inline-formula><tex-math id="M4">\begin{document}$ h = H' $\end{document}</tex-math></inline-formula> are appropriated Young functions satisfying the so called <inline-formula><tex-math id="M5">\begin{document}$ \Delta' $\end{document}</tex-math></inline-formula> condition, which includes for instance logarithmic perturbation of powers and different power behaviors near zero and infinity. We prove several properties on its spectrum, being our main goal to obtain lower bounds of eigenvalues in terms of <inline-formula><tex-math id="M6">\begin{document}$ G $\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id="M7">\begin{document}$ H $\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id="M8">\begin{document}$ w $\end{document}</tex-math></inline-formula> and the normalization <inline-formula><tex-math id="M9">\begin{document}$ \mu $\end{document}</tex-math></inline-formula> of the corresponding eigenfunctions.</p><p style='text-indent:20px;'>We introduce some new strategies to obtain results that generalize several inequalities from the literature of <inline-formula><tex-math id="M10">\begin{document}$ p- $\end{document}</tex-math></inline-formula>Laplacian type eigenvalues.</p>

scholarly journals Entire functions, PT-symmetry and Voros’s quantization scheme

2020 ◽  
Vol 54 (2) ◽  
pp. 203-210
Author(s):  
A.E. Eremenko
Keyword(s):  
Eigenvalue Problem ◽  
Boundary Conditions ◽  
Entire Functions ◽  
Pt Symmetry ◽  
Quantization Scheme ◽  
Principal Branch

In this paper, A. Avila's theoremon convergence of the exact quantization scheme of A.~Vo\-rosis related to the reality proofs of eigenvalues of certain $PT$-symmetricboundary value problems.As a result, a special caseof a conjecture of C. Bender, S. Boettcherand P. Meisinger on reality of eigenvalues is proved.In particular the following Theorem~2 is proved:{\sl Consider the eigenvalue problem$$-w''+(-1)^\ell(iz)^mw=\lambda w,$$where $m\geq 2$ is real, and $(iz)^m$ is the principal branch,$(iz)^m>0$ when $z$ is on the negative imaginary ray,with boundary conditions $w(te^{i\beta})\to 0,\ t\to\infty,$where$ \beta=\pi/2\pm\frac{\ell+1}{m+2}\pi.$If $\ell=2$, and $m\geq 4$, then all eigenvalues are positive.}\

scholarly journals On the spectrum of one dimensional p-Laplacian for an eigenvalue problem with Neumann boundary conditions

2013 ◽  
Vol 33 (1) ◽  
pp. 9
Author(s):  
Ahmed Dakkak ◽  
Siham El Habib ◽  
Najib Tsouli
Keyword(s):  
Eigenvalue Problem ◽  
Boundary Conditions ◽  
Neumann Boundary ◽  
Neumann Boundary Conditions ◽  
Laplacian Operator ◽  
Strict Monotonicity ◽  
Indefinite Weight ◽  
One Dimensional ◽  
Weight One

This work deals with an indefinite weight one dimensional eigenvalue problem of the p-Laplacian operator subject to Neumann boundary conditions. We are interested in some properties of the spectrum like simplicity, monotonicity and strict monotonicity with respect to the weight. We also aim the study of zeros points of eigenfunctions.

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