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Attenuation and damping of multireflected transient elastic waves in a pile / Yih-Hsing Pao in Journal of engineering mechanics, Vol. 137 N° 8 (Août 2011) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 137 N° 8 (Août 2011) . - pp.571-579 Titre : Attenuation and damping of multireflected transient elastic waves in a pile Type de document : texte imprimé Auteurs : Yih-Hsing Pao, Auteur ; Yun-Yan Yu, Auteur Année de publication : 2011 Article en page(s) : pp.571-579 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Impact  loading  on  a  pile  Damped  wave  equation  Reverberation-ray  matrix  analysis  Attenuation  and  damping  of  waves  Ultrasonic  inspection  of  piles Résumé : Early time transient waves multireflected in a finite pile, governed by a damped wave equation, are analyzed by a reverberation-ray matrix. The pile is surrounded by compacted soil, and the composite is modeled by elastic springs and viscous dampers distributed along the length and at the tip of an elastic rod. Steady-state waves with complex frequencies and wave numbers that are generated by a source of harmonic time function at the top and reverberated between the top and bottom surface of the pile are sorted in matrix form into ray-groups, arriving at a receiver in successive orders of reflections from the bottom. The steady-state ray groups are synthesized into a series of nonsingular Fourier integrals that can be evaluated accurately with a fast Fourier-transform algorithm. The first integral (zeroth-order) has also been reduced by complex contour integration to the well-known closed-form solution in Bessel functions for a semi-infinite pile. Detailed time records of velocity response received at the top after three reflections are calculated to illustrate attenuation and damping; arrival times and amplitude-phase change on each reflection for various lateral and base supports. The calculated records resemble ultrasonic nondestructive testing data. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i8/p571_s1?isAuthorized=no [article] Attenuation and damping of multireflected transient elastic waves in a pile [texte imprimé] / Yih-Hsing Pao, Auteur ; Yun-Yan Yu, Auteur . - 2011 . - pp.571-579. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 137 N° 8 (Août 2011) . - pp.571-579 Mots-clés : Impact  loading  on  a  pile  Damped  wave  equation  Reverberation-ray  matrix  analysis  Attenuation  and  damping  of  waves  Ultrasonic  inspection  of  piles Résumé : Early time transient waves multireflected in a finite pile, governed by a damped wave equation, are analyzed by a reverberation-ray matrix. The pile is surrounded by compacted soil, and the composite is modeled by elastic springs and viscous dampers distributed along the length and at the tip of an elastic rod. Steady-state waves with complex frequencies and wave numbers that are generated by a source of harmonic time function at the top and reverberated between the top and bottom surface of the pile are sorted in matrix form into ray-groups, arriving at a receiver in successive orders of reflections from the bottom. The steady-state ray groups are synthesized into a series of nonsingular Fourier integrals that can be evaluated accurately with a fast Fourier-transform algorithm. The first integral (zeroth-order) has also been reduced by complex contour integration to the well-known closed-form solution in Bessel functions for a semi-infinite pile. Detailed time records of velocity response received at the top after three reflections are calculated to illustrate attenuation and damping; arrival times and amplitude-phase change on each reflection for various lateral and base supports. The calculated records resemble ultrasonic nondestructive testing data. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.org/emo/resource/1/jenmdt/v137/i8/p571_s1?isAuthorized=no