The Tracing Analysis Of The Normal Section During Whole Loading Procedure Of T-shaped Columns Of Concrete-filled Steel Tubes

With the rapid development of society and economy,the needs of living environment and space have been increasing.Compared with the general reinforced concrete frame structure,special-shaped column frame structure has been widely used in design of multi-story and high-rise buildings,and has better using function,lower cost and higher flexibility.It is generally considered that the seismic performance of specialshaped column is not as good as that of reinforced concrete frame structure because of the relatively larger section height.Further research is needed to ensure its seismic performance future application.This paper summarized the current research accumulations and the existing problems of reinforced concrete special-shaped column structure from domestic to overseas.Based on the assumption of strain plane distribution,the formula for calculating the relationship between bending moment and curvaturing of the cross section is obtained and the iterative solution software is programmed by MATLAB.Results show that because of the arrangement of the steel pipe in the column section and under the condition of moderate sectional steel ratio(3%),compared with the ultimate moment of section of rectangle type specially shaped concrete filled steel tube column,that of Tshaped column has been enhanced by about 200%,while the ultimate curvature was reduced by about 50%.It is also shown that increasing strength grade of concrete has visible effect on improving the ultimate curvature,however,the benefit of raising yield strength of steel pipe isn’t so obvious on ultimate curvature.Area of steel pipes have notable efficiency on both enhancing ultimate moment and decreasing ultimate curvature.With moment-curvature beam element in Adina,a model for a single storey reinforced concrete special-shaped column structure was established.Results show that the increase of concrete strength is beneficial to improve the load bearing capacity.The effect of changing the strength grade of the steel pipe to improve it is not obvious while the section area of the steel pipe has a significant effect on improving it.The analysis results were proved with enough accuracy compared with those of elastic calculations...