The Analysis Of The Shear Capacity Of The Specially Shaped Column Joints And The Damage Of The Global Structure In The Earthquake

Because of their series of advantages, R/C structures with specially shaped columns became more and more popular duing recent years. However, these structures have had some problems unsettled while they were used in high seismic region, especially, how to provide sufficient shear bearing capacity of beam-and-column joints under earthquake resistance behavior is prominent.This dissertation briefly introduce the background of study on the structures with specially shaped columns, and the situation of our country and overseas are presented for the Study on the seismic performance of beam-column joints. Some basic theories about reinforced concrete joints and finite element method analysis were related.In order to improve the shear bearing capacity of beam-and-column joints, this dissertation proposed a new method that uses the X-shaped cross reinforcing bar in the core area of joints. On the basis of previous theories, this paper adopts the software ABAQUS with finite element method to establish a 6-story frame structural with十-shaped columns which is situated in near earthquake seismic regions of intensity 8,a regular beam-and-column joints model and a joints model using X-shaped cross reinforcing bar are respectively analyzed.Carring out the nonlinear analysis of joints of different measures, stress-strain diagrams of all loading stages were obtained. The linear and nonlinear performance of joints can be deduced by these diagrams, and the failure behavior of concrete members can be gained by changing the tension-stiffing factor. By comparing it was draw that using the X-shaped cross reinforcing bar can't significantly improve the shear bearing capacity of beam-and-column joints.In addition,the paper adopts the software ABAQUS with beam element to analyze an example of R/C structures with specially shaped columns and compare with the damage characteristics of the structure in the Wenchuan earthquake.It is showed that adopting the software ABAQUS with beam element can reasonable similate and analyze the R/C structures with specially shaped columns.Finally, by contacting the problems came across in research, the direction for the follow-up research was provided.