Analysis On Optimization Of Seismic Performance Based On A Frame.Shear Wall Structure In High.rise Building

Frame-shear wall structure has not only frame structure characteristics of large inne r space, flexible arrangement and good ductility, but also shear wall characteristics of ra re stiffness and bearing capacity. So it is widely used in high.rise buildings in recent ye ars. This article studied on seismic performance of the structure mainly from-shear wall thickness and opening rate. This article got dynamic response of the structure by using SAP2000 and we got some conclusions for reference.This paper did modal analysis, response spectrum analysis and dynamic time history by using SAP2000 based on related references which study on the seismic performance of frame-shear wall structure. The seismic performance comparison under static analysis and dynamic analysis is observed by changing the thickness and opening rate of the shear wall. The main research content includes:(1)Introduced the main analysis methods of structure performance, especially the bais principles and analysis progress of the dynamic time history analysis method.(2)This paper mainly investigates the natural frequency, cycle, structural modal participation factor in the modal analysis.(3) In response spectrum analysis, we mainly investigate anisotropic displacement of structure under seismic action value. (4)In analysis of dynamic time history, this paper mainly investigates comparison between relative displacement of reference points and displacement comparison in three directions. (5)Moreover, this paper introduced some characteristics of the earthquake waves, including selecting method, amplitude modulation method, definition of strong motion duration and response spectrum.The main content and conclusions are as follows:1.Got the the natural period of vibration, vibration mode and some other structural dynamic characteristics in the modal analysis.(1)From the vibration mode diagram, it can be seen in the X direction of the rotation direction is much stronger than Y. The stiffness is greater while period is smaller. The characteristic periodunder is not changing, so earthquake effect increased.(2)Structure based on translation in the first two order vibration mode. In the last two modes based on intorsion.(3)In case 3 and case 6 (shear wall thickness is 300 mm), fourth modes of X to the reverse occurs. The reason is that the shear wall thickness of X direction and Y directionstiffness is not uniform, resulting in the reverse. Thus blindly increase the thickness of shear wall is not desirable, but also in the impact on the overall stiffness of the shear wall isthe equilibrium volume is too large, resulting in economic waste of resources, reachoptimization purposes.(4)In 6 cases of contrast, it can be found the increase of shear wall with opening rate,decreasing wall thickness. It increase the natural period of vibration, thus the seismic influence coefficient decreases, the seismic performance of structure is improved to some extent.(5)Through the analysis of the dynamic characteristics of the structure of higher modes, it can be found that for the entire structure, get the lateral stiffness of the structure and the seismic response of structure lateral displacement is nonlinear. Comparing the economic situation(shear wall with small volume), the stiffness of the structure should meet and close to the maximum allowable deformation structure.2.Got the displacement of each layer and layer displacement in two directions by doing earthquake response analysis through response spectrum method.(1)Structure under earthquake force is larger than that of X direction in the Y direction of the upper displacement, average Y direction X direction displacement between layers is 39.4%, because the structure of X direction stiffness is greater than that of Y direction.(2)The maximum lateral displacement of the top structure is 39.2361 mm. In all cases ofcontrast can be found, along with the thickness of shear wall with opening rate increased. Structure interlayer displacement angle showed a downward trend.(3)Using the control variable method, shear wall thickness, were compared for case 1 and case 4, case 2 and case 5, case 3 and case 6. Visible wall thickness influence on the force of the earthquake is opening rate is bigger. So the need to consider the effect of shear wall structure with two lateral stiffness and seismic response of the shear wall and wall thicknessof the hole rate when choosing.(4)From the analysis results, we can clearly see the various working conditions, the inter storey displacement angle position in the centre, the structural design process we need toappropriately increase the middle lower part of the structure stiffness, practical engineeringcan be considered small shear wall with opening the middle lower part is not even a hole,the other part can the normal opening, thus to increase slightly in the shear wall under thepremise of the volume is good to improve the structure of lateral resistant performance,can optimize the structure performance and economic balance of the.3.Got the comparison between relative displacement of reference points and displacement comparison in three directions through the analysis of dynamic time history of the structure model.(1)By comparing the 139 node displacement under seismic wave with 144 nodes in three directions, relative to the X direction displacement of node layout of shear wall is very small,is significantly smaller than the remaining 2 directions;(2)Comparing on various conditions in the 4 node displacement under seismic wave value and relative displacement. That is to say, in the capacity of the circumstances, the larger the shear wall with opening rate is favorable for the lateral seismic, and the thickness of shear wall and not blindly increase or decrease can play a good damping effect.(3)Through the analysis of the plastic hinge under rare earthquake can be found in. thedevelopment process. In the process of seismic shear wall acts as the first line of defense,the framework for the second line of defense.4.The earthquake waves are important factor in dynamic time history analysis.(1)It is important to choose appropriate earthquake waves and do range adjustment and get the duration of strong earthquake and get energy accumulative curve and response spectrum by integral method.(2)This paper adopted 90% relative duration time. It can objectively tell the duration time of engering and reduce calculation effectively.