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Dimensional analysis of the earthquake-induced pounding between adjacent structures / Dimitrakopoulos, Elias in Earthquake engineering structural dynamics, Vol. 38 N° 7 (Juin 2009) 

Public ISBD [article]  in Earthquake engineering structural dynamics > Vol. 38 N° 7 (Juin 2009) . - pp. 867-886 Titre : Dimensional analysis of the earthquake-induced pounding between adjacent structures Type de document : texte imprimé Auteurs : Dimitrakopoulos, Elias, Auteur ; Nicos Makris, Auteur ; Kappos, Andreas J., Auteur Article en page(s) : pp. 867-886 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Pounding;  unilateral  contact;  Dimensional  analysis;  Earthquake  engineering;  Pounding  of  adjacent  structures Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : In this paper the dynamic response of two and three pounding oscillators subjected to pulse-type excitations is revisited with dimensional analysis. Using Buckingham's -theorem the number of variables that govern the response of the system is reduced by three. When the response is presented in the dimensionless -terms remarkable order emerges. It is shown that regardless of the acceleration level and duration of the pulse all response spectra become self-similar and follow a single master curve. This is true despite the realization of finite duration contacts with increasing durations as the excitation level increases. All physically realizable contacts (impacts, continuous contacts, and detachments) are captured via a linear complementarity approach. The study confirms the existence of three spectral regions. The response of the most flexible among the two oscillators amplifies in the low range of the frequency spectrum (flexible structures); whereas, the response of the most stiff among the two oscillators amplifies at the upper range of the frequency spectrum (stiff structures). Most importantly, the study shows that pounding structures such as colliding buildings or interacting bridge segments may be most vulnerable for excitations with frequencies very different from their natural eigenfrequencies. Finally, by applying the concept of intermediate asymptotics, the study unveils that the dimensionless response of two pounding oscillators follows a scaling law with respect to the mass ratio, or in mathematical terms, that the response exhibits an incomplete self-similarity or self-similarity of the second kind with respect to the mass ratio. ISSN : 0098-8847 En ligne : http://www3.interscience.wiley.com/journal/121517591/abstract [article] Dimensional analysis of the earthquake-induced pounding between adjacent structures [texte imprimé] / Dimitrakopoulos, Elias, Auteur ; Nicos Makris, Auteur ; Kappos, Andreas J., Auteur . - pp. 867-886. Génie Civil Langues : Anglais (eng) in Earthquake engineering structural dynamics > Vol. 38 N° 7 (Juin 2009) . - pp. 867-886 Mots-clés : Pounding;  unilateral  contact;  Dimensional  analysis;  Earthquake  engineering;  Pounding  of  adjacent  structures Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : In this paper the dynamic response of two and three pounding oscillators subjected to pulse-type excitations is revisited with dimensional analysis. Using Buckingham's -theorem the number of variables that govern the response of the system is reduced by three. When the response is presented in the dimensionless -terms remarkable order emerges. It is shown that regardless of the acceleration level and duration of the pulse all response spectra become self-similar and follow a single master curve. This is true despite the realization of finite duration contacts with increasing durations as the excitation level increases. All physically realizable contacts (impacts, continuous contacts, and detachments) are captured via a linear complementarity approach. The study confirms the existence of three spectral regions. The response of the most flexible among the two oscillators amplifies in the low range of the frequency spectrum (flexible structures); whereas, the response of the most stiff among the two oscillators amplifies at the upper range of the frequency spectrum (stiff structures). Most importantly, the study shows that pounding structures such as colliding buildings or interacting bridge segments may be most vulnerable for excitations with frequencies very different from their natural eigenfrequencies. Finally, by applying the concept of intermediate asymptotics, the study unveils that the dimensionless response of two pounding oscillators follows a scaling law with respect to the mass ratio, or in mathematical terms, that the response exhibits an incomplete self-similarity or self-similarity of the second kind with respect to the mass ratio. ISSN : 0098-8847 En ligne : http://www3.interscience.wiley.com/journal/121517591/abstract

Dimensional analysis of the earthquake response of a pounding oscillator / Dimitrakopoulos, Elias in Journal of engineering mechanics, Vol. 136 N° 3 (Mars 2010) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 136 N° 3 (Mars 2010) . - pp. 299-310 Titre : Dimensional analysis of the earthquake response of a pounding oscillator Type de document : texte imprimé Auteurs : Dimitrakopoulos, Elias, Auteur ; Nicos Makris, Auteur ; Kappos, Andreas J., Auteur Article en page(s) : pp. 299-310 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Dimensional  analysis  Earthquake  engineering  Oscillations. Résumé : In this paper, the dynamic response of a pounding oscillator subjected to pulse type excitations is revisited with dimensional analysis. The study adopts the concept of the energetic length scale which is a measure of the persistence of the distinguishable pulse of strong ground motions and subsequently presents the dimensionless Pi products that govern the response of the pounding oscillator. The introduction of Buckingham's Pi theorem reduces the number of variables that govern the response of the system from 7 to 5. The proposed dimensionless Pi products are liberated from the response of an oscillator without impact and most importantly reveal remarkable order in the response. It is shown that, regardless the acceleration level and duration of the pulse, all response spectra become self-similar and, when expressed in the dimensionless Pi products, follow a single master curve. This is true despite the realization of contacts with increasing durations as the excitation level increases. All physically realizable contacts (impacts, continuous contacts, and detachment) are captured via a linear complementarity approach. The proposed analysis stresses the appreciable differences in the response due to the directivity of the excitation (toward or away the stationary wall) and confirms the existence of three spectral regions where the response of the pounding oscillator amplifies, deamplifies, and equals the response of the oscillator without pounding. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...] [article] Dimensional analysis of the earthquake response of a pounding oscillator [texte imprimé] / Dimitrakopoulos, Elias, Auteur ; Nicos Makris, Auteur ; Kappos, Andreas J., Auteur . - pp. 299-310. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 136 N° 3 (Mars 2010) . - pp. 299-310 Mots-clés : Dimensional  analysis  Earthquake  engineering  Oscillations. Résumé : In this paper, the dynamic response of a pounding oscillator subjected to pulse type excitations is revisited with dimensional analysis. The study adopts the concept of the energetic length scale which is a measure of the persistence of the distinguishable pulse of strong ground motions and subsequently presents the dimensionless Pi products that govern the response of the pounding oscillator. The introduction of Buckingham's Pi theorem reduces the number of variables that govern the response of the system from 7 to 5. The proposed dimensionless Pi products are liberated from the response of an oscillator without impact and most importantly reveal remarkable order in the response. It is shown that, regardless the acceleration level and duration of the pulse, all response spectra become self-similar and, when expressed in the dimensionless Pi products, follow a single master curve. This is true despite the realization of contacts with increasing durations as the excitation level increases. All physically realizable contacts (impacts, continuous contacts, and detachment) are captured via a linear complementarity approach. The proposed analysis stresses the appreciable differences in the response due to the directivity of the excitation (toward or away the stationary wall) and confirms the existence of three spectral regions where the response of the pounding oscillator amplifies, deamplifies, and equals the response of the oscillator without pounding. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000 [...]