Structures characterized by eccentricity in plan between the centre of mass and the centre of stiffness, under seismic excitations, develop coupled lateral-torsional response which may increase the deformation level of the structural elements which are more distant from the centre of stiffness. In this paper, first, the fundamental linear-elastic parameters and the additional non-linear parameters which govern the torsional response of one-storey asymmetric systems have been clearly identified. Second, the basic findings are briefly recalled of previous research works by the authors which have led to the identification of a synthetic structural parameter (called a) capable of capturing the essence of the torsional behaviour of linear-elastic systems and allowing effective maximum rotational response estimations. Third, preliminary non-linear dynamic simulations are carried out to investigate the rotational trends of asymmetric systems characterised by non-linear behaviour under seismic excitation. The results indicate that (i) the ratio of the maximum rotation over the maximum displacement for non-linear systems is generally inferior to the corresponding ratio for linear-elastic systems, and that (ii) the estimations of the maximum rotation obtained using the a parameter are generally on the safe side, thus providing useful upper bounds for the actual rotation of non-linear systems.

On the non-linear rotational response of one-storey asymmetric structures

SILVESTRI, STEFANO;TROMBETTI, TOMASO;GASPARINI, GIADA
2008

Abstract

Structures characterized by eccentricity in plan between the centre of mass and the centre of stiffness, under seismic excitations, develop coupled lateral-torsional response which may increase the deformation level of the structural elements which are more distant from the centre of stiffness. In this paper, first, the fundamental linear-elastic parameters and the additional non-linear parameters which govern the torsional response of one-storey asymmetric systems have been clearly identified. Second, the basic findings are briefly recalled of previous research works by the authors which have led to the identification of a synthetic structural parameter (called a) capable of capturing the essence of the torsional behaviour of linear-elastic systems and allowing effective maximum rotational response estimations. Third, preliminary non-linear dynamic simulations are carried out to investigate the rotational trends of asymmetric systems characterised by non-linear behaviour under seismic excitation. The results indicate that (i) the ratio of the maximum rotation over the maximum displacement for non-linear systems is generally inferior to the corresponding ratio for linear-elastic systems, and that (ii) the estimations of the maximum rotation obtained using the a parameter are generally on the safe side, thus providing useful upper bounds for the actual rotation of non-linear systems.
Atti del Convegno "Valutazione e riduzione della vulnerabilità sismica di edifici esistenti in cemento armato"
238
246
Silvestri S.; Trombetti T.; Gasparini G.
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11585/70639
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact