000019603 001__ 19603
000019603 005__ 20170118182328.0
000019603 04107 $$aeng
000019603 046__ $$k2017-01-09
000019603 100__ $$aGunay, Selim
000019603 24500 $$aAcceleration Response Spectrum: Revisited for Higher Mode Effects

000019603 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000019603 260__ $$b
000019603 506__ $$arestricted
000019603 520__ $$2eng$$aAcceleration response spectrum (ARS) is a tool that has conveniently been used in earthquake engineering in the last 75 years. One of the common uses of the response spectrum concept is the identification of higher mode contribution to the structural response. If the spectral acceleration (SA) corresponding to a higher mode (generally the second or third mode) is significantly larger than that of the first mode, the ground motion is accepted to induce higher mode response. However, in general, this interpretation is not necessarily correct because the structural response is usually inelastic and the ARS is obtained from linear elastic single degree of freedom (SDOF) response. ARS for constant base shear capacity coefficient has been developed to consider the inelastic response. However, such spectrum is not useful for higher mode effects identification since the SA for all the periods are bound by the base shear capacity coefficient and it is likely that the SA values corresponding to all the sought modes are the same. A modified ARS concept is introduced in this paper for a specific base shear coefficient at a desired period. In this modified ARS, a linear elastic SDOF system with a selected period (which generally corresponds to the first mode period) is analyzed with time history analysis. The time of the ground motion at which inelastic response initiates (i.e., the time when the restoring force first exceeds the base shear capacity) is determined from this analysis and the ground motion is redefined as the original ground motion truncated to this time defined by the initiation of inelastic response. Subsequently, the original ARS procedure is followed using the ground motion with truncated duration to obtain the modified ARS, namely the MARS. A theoretical background information is provided in the first part of the paper to explain why the proposed MARS is expected to produce a better indicator, compared to ARS, for the identification of ground motions leading to higher mode response. Subsequently, the outline for developing MARS is presented and the superiority of MARS in identifying the ground motions with higher mode effect is demonstrated using the results from nonlinear time history analyses conducted on a 35-story tall building.

000019603 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000019603 653__ $$aacceleration response spectrum, base shear coefficient, higher mode effects, nonlinear time history analysis, tall building.

000019603 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000019603 720__ $$aGunay, Selim$$iMosalam, Khalid
000019603 8560_ $$ffischerc@itam.cas.cz
000019603 8564_ $$s450852$$uhttps://invenio.itam.cas.cz/record/19603/files/3988.pdf$$yOriginal version of the author's contribution as presented on USB, paper 3988.
000019603 962__ $$r16048
000019603 980__ $$aPAPER