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Evaluation of impulse response functions for convolution integrals of aerodynamic forces by optimization with a penalty function / Kilje Jung in Journal of engineering mechanics, Vol. 138 N° 5 (Mai 2012) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 138 N° 5 (Mai 2012) . - pp.519-529 Titre : Evaluation of impulse response functions for convolution integrals of aerodynamic forces by optimization with a penalty function Type de document : texte imprimé Auteurs : Kilje Jung, Auteur ; Kim, Ho-Kyung, Auteur ; Hae Sung Lee, Auteur Année de publication : 2012 Article en page(s) : pp.519-529 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Impulse  response  function  Transfer  function  Aeroelastic  analysis  Convolution  integral  Penalty  function  Causality  condition  Flutter  derivative  Optimization  Bridge Résumé : This paper presents a new algorithm for evaluating impulse response functions for the convolution integrals of the aerodynamic forces of bridge decks. The impulse response functions formed by measured flutter derivatives are modified to satisfy causality conditions through optimization. The error function in the object function is defined as the least square errors between the measured and the modified transfer function, and the causality condition is imposed as a penalty function. The modified transfer functions are interpolated with the cubic spline. The selection of the optimal penalty number is presented for obtaining a balanced solution between the effects of the error function and the penalty function. The proposed method is verified using two numerical examples. Time-domain aeroelastic analyses are performed with the proposed method for a thin rectangular section and a bluff H-type section, and the results are compared to values obtained by the rational function approximation (RFA) and the analytical particular solution of the equation of motion. The proposed method yields accurate and stable solutions for both types of sections, whereas the rational function approximation results in erroneous solutions for a bluff H-type section. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000355 [article] Evaluation of impulse response functions for convolution integrals of aerodynamic forces by optimization with a penalty function [texte imprimé] / Kilje Jung, Auteur ; Kim, Ho-Kyung, Auteur ; Hae Sung Lee, Auteur . - 2012 . - pp.519-529. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 138 N° 5 (Mai 2012) . - pp.519-529 Mots-clés : Impulse  response  function  Transfer  function  Aeroelastic  analysis  Convolution  integral  Penalty  function  Causality  condition  Flutter  derivative  Optimization  Bridge Résumé : This paper presents a new algorithm for evaluating impulse response functions for the convolution integrals of the aerodynamic forces of bridge decks. The impulse response functions formed by measured flutter derivatives are modified to satisfy causality conditions through optimization. The error function in the object function is defined as the least square errors between the measured and the modified transfer function, and the causality condition is imposed as a penalty function. The modified transfer functions are interpolated with the cubic spline. The selection of the optimal penalty number is presented for obtaining a balanced solution between the effects of the error function and the penalty function. The proposed method is verified using two numerical examples. Time-domain aeroelastic analyses are performed with the proposed method for a thin rectangular section and a bluff H-type section, and the results are compared to values obtained by the rational function approximation (RFA) and the analytical particular solution of the equation of motion. The proposed method yields accurate and stable solutions for both types of sections, whereas the rational function approximation results in erroneous solutions for a bluff H-type section. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000355