| In the general structure analysis and design, designers usually keep the floor as amember of in-plane infinite stiffness to participate in the structure calculation, which canreduce the amount of unknowns in the equations and greatly simplify the calculation ofthe model. But as the plane form becomes more complicated and various, partial openinghole of the floor or plane irregularity will cause in-plane floor deformation, and it can’tmeet the assumption of infinite stiffness. If rigid floor assumption is still considered inthe analysis, authenticity and reliability of the calculation results can’t be assured. So forthe frame-shear structure, the influence of floor deformation on its mechanicalcharacteristics can’t be ignored because of the large difference of stiffness between framecolumns and shear walls.This thesis establishes two types of analysis model: one for the rigid floorassumption that in-plane stiffness is infinite, the other for the elastic floor assumptionconsidering in-plane deformation. Through modal analysis and response spectrumanalysis, the influence of different floor assumption on dynamic characteristics,displacement behavior and inner force variation is investigated, and it reveals thevariation regularity of influence on mechanical characteristics of frame-shear structureconsidering floor deformation.The study shows that: compared with rigid floor assumption, elastic floorassumption reduces the stiffness of overall structure and the natural vibration period islonger. The proportion of modal participation factor of high order codes can’t be ignored.The story displacement and story drift increase with elastic floor assumption and at thesame story the displacement change of frame columns is larger than shear walls’. Shearforce of columns around the opening hole or plane notch may be several times larger thantheirs with rigid floor assumption and stress concentration phenomenon is also seriousaround these parts. |
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