Study On Seismic Behavior Of Plane Irregular Frame Shear Wall Structures

In practical engineering,the irregular plane structure looms to view one after the other for reasons such as the needs of architectural appearance and the limit of certain site’s shape.The previous earthquake disasters show that the irregular plane structure will be easily destroyed under earthquake due to torsion,what’s worse,it will lead to the collapse of structure which brings great threat and hidden danger to people’s life and property.However,The chinese code JGJ 3-2010 and GB 50011-2010 mainly focus on the control of period ratio and displacement ratio.As the main structural form of civil and residential building,frame-shear wall structure is widely used in engineering practice because of its many advantages.However,considering this kind of structure,whose period ratio is easy to surpass the limit of the code,we have to face the problem of how to reduce period ratio effective ly.In this paper,the linear and nonlinear analysis of planar irregular frame-shear structures is carried out by finite element software,namely SAP2000.The general connection of the torsion effect,the ratio of plane protrusion size,eccentricity ratio and period ratio is analyzed through 7 examples of planar irregular structures(frame structure and frame-shear structure).Then two finite element models are established based on the engineering project,one period ratio exceeding the limit,and the other reduce the period ratio by adjusting the layout of the component which cause the eccentricity increased.The main content of research are as follows:(1)We select the software SAP2000 as the research tool,choosing 3 seismic waves which meet the requirements,and then analyze two models by time-history analysis.Also,we compares the index of two models when the structure sustain different seismic waves,such as the horizontal displacement of the top floor,the inter-story drift and the story shear force,and find the weakness floor.Lastly,their seismic performance can be easily evaluated.(2)A nonlinear static model in SAP2000 is established,also,proper model units and load-pushing conditions is selected,Then we push the models from two directions respectively(X and Y).Lastly,the performance points of two models under frequent earthquakes and rare earthquake s are determined based on the capacity-spectrum method.(3)Analyzing the results of the pushover of the model and comparing the indexes of two models under frequent earthquakes and rare earthquakes,such as inter-story drift and inter-story torsion angle.Then we can estimate the faulted condition of the structure under the rare earthquakes and the performance that the structure step into nonlinear work state through the development of the plastic hinge and the distribution of the stress of the shear wall.Lastly,drawing the conclusion.