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An accurate strength amplification factor for the design of SDOF systems with P –Δ effects
Author(s) -
Amara Fabio,
Bosco Melina,
Marino Edoardo M.,
Rossi Pier Paolo
Publication year - 2013
Publication title -
earthquake engineering and structural dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.218
H-Index - 127
eISSN - 1096-9845
pISSN - 0098-8847
DOI - 10.1002/eqe.2361
Subject(s) - amplification factor , structural engineering , ground motion , ductility (earth science) , seismic analysis , displacement (psychology) , range (aeronautics) , vibration , sensitivity (control systems) , geotechnical engineering , engineering , physics , acoustics , telecommunications , psychology , amplifier , creep , bandwidth (computing) , electronic engineering , psychotherapist , thermodynamics , aerospace engineering
SUMMARY The response of structures subjected to seismic actions is always influenced by P –Δ effects. The importance of this effect is generally modest for structures experiencing an elastic response but often relevant for structures responding well within the inelastic range of behaviour. Seismic codes indicate that P –Δ effects may be counterbalanced through an increase in the structural strength required by a first order analysis. This increase is calculated by means of a strength amplification factor. The expressions suggested in codes for this factor are simplistic and often criticized by researchers. In this paper, the effectiveness of some of the provisions reported in the literature or suggested in seismic codes is evaluated on single degree of freedom systems with different periods of vibration. As suggested by past studies, attention is focused on the influence of the interstorey drift sensitivity coefficient, significant duration of the ground motion, class of the site soil, displacement ductility and equivalent viscous damping ratio of the system. Finally, an accurate expression of the strength amplification factor is proposed. Copyright © 2013 John Wiley & Sons, Ltd.