Equating incremental dynamic analysis with static

Authors: Asghar Bahramirad Mohsen Tehranizadeh Amir Moshref

Publish Date: 2015/09/08

Volume: 14, Issue: 3, Pages: 465-476

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Abstract

In an incremental dynamic analysis IDA using a set of ground motion records nonlinear time history analysis needs to be performed on structures It is well recognized that IDA calls for high computational efforts and the results are highly sensitive to selected ground motions As a result alternative static methods are needed This study aims to introduce a new doublestage N1 N2 static method to estimate capacity curves of MR frames The technique is regulated to resemble IDA results with specific emphasis on nearfield ground motions Using an ensemble of 56 nearfield earthquake records required IDAs have been carried out for SACLos Angeles 3 9 and 20story buildings and an additional 15story building The results of the proposed static method are compared with those from IDA displacementbased adaptive procedure DAP and multimodal procedure MMP The results indicate that in addition to enhanced accuracy very little time is required in the case of N1N2 method Thus for the 3story structure the time required is less than 1 minute The proposed N1N2 method shows the best accuracy in terms of lateral mechanisms for the 15story frame while for the other cases the first mode load pattern leads to the best accuracy

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