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Citation |
Souza Pippi A, Junior JK, Silva Pinheiro MA. Procedia Eng. 2017; 199: 122-127. |
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Copyright |
(Copyright © 2017, Elsevier Publishing) |
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DOI |
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PMID |
unavailable |
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Abstract |
This paper presents a numerical dynamic analysis of a self-supporting transmission line (TL) latticed steel tower, for the purpose of compare the results with those obtained in an experimental dynamic analysis of a full-scale tower. The main objective of this work is to calibrate the structural damping (c) in the numerical model until the damping ratio (ζ) results the same that in the experimental analysis, since the damping is a fundamental parameter in numerical analysis, which can change significantly the response of the structure, especially in terms of dynamic amplification. It should be noted that in this type of structure is crucial perform a structural analysis most accurate possible, given the fact that in a TL are built hundreds of identical towers and the collapse of one can lead to a cascading failure. The dynamic characteristics, such as the frequencies and normal modes were evaluated in a modal analysis, using the ANSYS© program v. 15.0, and also through the direct numerical integration method, using an explicit approach (central finite differences). The experimental tower was tested using impulsive loads, which were reproduced in the numerical model to allow comparison with the experimental results. In the modal analysis were employed models commonly used in actual designs, that is, with space truss and space frame members. For the direct integration method, was used a program developed in FORTRAN, in which only space truss elements are allowed, necessitating the adoption of the fictitious bars to eliminate internal instabilities. The consideration of the damping in the direct integration method was taken in a simplest form, that is, proportional to the mass. Finally, the numerical values found were very close to the experimental response, setting the value of structural damping for use in such projects of this type of tower. Language: en |
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Keywords |
Direct integration method; Dynamic analysis; Latticed steel towers; Structural damping; Transmission line towers |