Analysis of wave propagation in waveguides by FEM via eigenvalue problem /
Several important engineering problems are modelled by infinite waveguides, where a certain section may be inhomogeneous, may have irregular geometry or obstacles. In such sections the waves may partially reflect, but in the concatenated homogeneous part of the waveguide, which stretches to infinity...
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| Main Authors: | , |
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| Format: | Book Chapter |
| Jezik: | English |
| Teme: | |
| Sorodne knjige/članki: | Vsebovano v:
Computational methods and experimental measurements X |
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| Izvleček: | Several important engineering problems are modelled by infinite waveguides, where a certain section may be inhomogeneous, may have irregular geometry or obstacles. In such sections the waves may partially reflect, but in the concatenated homogeneous part of the waveguide, which stretches to infinity, the waves propagate only away from the source of excitation, yet some of them may be decaying standing waves. When solving the dynamics of the waveguide by FEM we have to introduce an artificial boundary, where radiation conditions have to be properly encountered for exact results. We are proposing a procedure, which solves the dynamics of the waveguide in the frequency domain exactly, but within the error immanent to discretization in FEM. In addition, this procedure yields a parametric study of wave propagation modes. The procedure is based on the decomposition of displacements and stresses into thepropagating and the standing decaying wave modes, which are altogether linearly independent. They are acquired as the solution to the eigenvalue problem of the dynamics of a "cell" element augmented to fictitious boundary. Only the waves satisfying radiation conditions on the fictitious boundary are then used to depict the excitation via transfer function from the fictive boundary to the site of excitation. In the paper, the basic theory for the presented procedure is described. The numerical intermediate and final resultsof the examples of anti-plane shear wave motion in a homogeneous and in-homogeneous elastic layer are presented in some detail, and the results compared to exact ones. |
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| Fizični opis: | Str. 915-923. |
| ISBN: | 1853128708 |