Mechanical modeling of helical structures accounting for translational invariance. Part 2: Guided wave propagation under axial loads

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:50

Article

Treyssede, Fabien¹  Frikha, Ahmed¹  Cartraud, Patrice² 

[1] LUNAM Univ, IFSTTAR, MACS, F-44344 Bouguenais, France

[2] LUNAM Univ, GeM, UMR CNRS 6183, Ecole Cent Nantes, F-44321 Nantes 3, France

关键词: Waveguide;    Prestress;    Helical coordinates;    Finite element;    Strands;    Springs;   

DOI  :  10.1016/j.ijsolstr.2013.01.006

来源: Elsevier

【 摘 要 】

This paper corresponds to the second part of a study that aims at modeling helical structures accounting for translational invariance. In the Part I of this paper, the static behavior has been addressed using a helical homogenization approach which provides the stress state corresponding to axial loads. The latter is considered as a prestressed state, for elastic wave propagation analysis in helical waveguides, which is the subject of the Part 2 of this paper. Non destructive testing of springs and multi-wire strands is a potential application of the proposed model. Accounting for translational invariance, the elastodynamic equations of prestressed helical structures yield a 2D problem posed on the cross-section, corresponding to a so-called semi-analytical finite element (SAFE) formulation. For helical springs, the numerical model is validated with an analytical solution corresponding to a Timoshenko beam approximation. It is shown that the influence of the prestressed state is significant at low frequencies. Finally, a seven-wire strand subjected to axial loads is considered. The computed dispersion curves are compared to experimental data. Good agreement is obtained for the first compressional-like modes and their veering central frequency. (C) 2013 Elsevier Ltd. All rights reserved.

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