The Study Of Seismic Behavior For The Mega-frame Tube Composite Structure

The maga-frame tube combination structure is a kind of new huge structuralsystem belonging to high-rise building or super high–rise build- ing.This structurecombined with the main level structure and the second- dary structure.It hasadvantages as below:clear force transmission,well done integral performance,quicklygoing construction,less spending materials. The study on dynamic characteristics andseismic performance of this kind of structure is seldom at present.The specific matterssuch as structural structural modal, seismic performance of the main and secondaryframe the location of weak layer and weak point of the structure and structurestiffness degradation have not been settled.There are no specific data and designmethod on those matters.So,the study on dynamic characteristics and seismicperformance of this kind of structure is meaningful.According to finite element theory,together with the basic knowledge ofearthquake and structural system,this article gets a maga-frame tube structuremodel.Using MIDAS/Gen,this article checks some characteristic of the tube-in-tubestructure such as the natural vibration,seismic performance under common andseldom earthquake and yielding mechanism under seldom earthquake.Those works have been done as follows:(1)The study model of mega-frame tube composite structure was proposed, andtheoretical method for study was summarized;(2)Model analysis towards mega-frame tube composite structure was carriedout, and then its natural vibration characteristics were checked;( 3 ) By comparing mega-frame tube composite structure with commonframe-tube composite structure, the similarities and differences of natural vibrationcharacteristics and mechanical behavior under earthquake between the two kinds ofstructures were obtained;(4)Elastic time-history analysis for mega-frame tube composite structure wascompleted, so the seismic behavior under frequent earthquake was checked;(5)Through nonlinear static analysis towards mega-frame tube compositestructure, its seismic behavior and yield mechanism under rare earthquake werechecked.