Application Of Low-frequency Artificial Waves In Seismic Analysis Of Typicallong-period Structures

The low-frequency component of the ground motion would damage structures oflong-period exceedingly.In this paper, Clough-Penzien seismic random model isselectedto generate artificial seismic waves, which is suitable for long-period buildings.Then the artificial seismic wavesare applied in analysis oftwo kinds of typicallong-period buildings: base-isolated structures and superhigh-rise structures.The seismic response of the combined base-isolated structures use friction pendulumbearings and lead-rubber bearings underdifferent bearings layout schemes considerbilateral horizontal ground motions is investigated in this paper.The results show that, theenergy dissipation ratio of the combined base-isolated system is greater and theprotection of superstructure is better under soft sites. The decentralized bearingdistributions are better than concentrated cases, and it will increase the energy dissipationratio of the base-isolated system and give a better protection for superstructure.The resultshows that the response oflong-periodstructures by artificial waves is stronger than that ofnatural waves.For superhigh-risestructure, a frame-core tubesuper high-rise structure, the finiteelement model of an international financial center, was established in ABAQUS software.With the secondary development function of ABAQUS, constitutive relation ofreinforced concrete members was established by explicit subroutine VUMAT. Take theaccumulation of damage into consideration, the elastic-plastic mechanical behavior ofreinforced concrete members, which is appointed by users, consistent with the realsituation well. Then, the elasto-plastic time-history analysis under frequent, basic and rareearthquakes of intensity7were carried out to get the structural deformations, memberforces and damage distributions．Lastly, failure progress of the super high-rise structuredue to extremely strong earthquake was simulated.Analysis shows that the location ofabrupt change in stiffness is the weak link of the structure, which can be reference foranalysis and design for such kinds of super high-rise buildings.The result also shows thatthe response oflong-periodstructures byartificial waves is stronger than that of natural waves.