Reserch On Axial Compression Test About Concrete Filled Stell Tube Of Round Tip Shape

Now in the high-speed development of the society, the development of the construction industry is also changing. And the new concrete filled steel tube component is also gradually developing. In steel tube concrete filled steel tube is waters the concrete composite structure, this combination with the structure of the steel and concrete properties of both, can give full play to the advantages of both. This paper mainly studies the round shape steel tube concrete, the so-called round shape make up by two period that the arc and two section of linear connection section. The round shape steel tube concrete has not only high bearing capacity, the plastic toughness, good fireproof performance is good, convenient construction, low cost advantages. Also has the following advantages:(1) the round shape steel tube concrete has a good external model, and can meet the requirement of architectural aesthetics(2) the round shape of concrete filled steel tube with his strong axis and the weak axis, The same section area of the round shape concrete filled steel tube compared with the circular concrete filled steel tube, The round shape steel tube concrete in strong axis anti-bending ability is more, So for single shaft bending of components, The round shape steel tube concrete can reduce the cost(3) the round shape of the concrete filled steel tube for circular arc than any other section of the form of concrete filled steel tubular more smooth, Can effectively resist running water or other liquid impact, For example in the river bridge across the river, The round shape steel tube concrete can reduce the impact of water load, Prolong the service life of the pier(4) the round shape steel tube concrete in strong axis has strong stability. In this paper, according to the lake bridge after the round shape steel tube concrete column launch test on the following work component research:(1) through the test methods and ansys modeling analysis method to the round shape steel tube concrete component launch axial compression stress mechanism analysis process, Analysis in the process of concrete filled steel tube bearing failure form, Analysis of the stress distribution law.(2) with the test method to analyze the round shape steel tube concrete axial pressure load the same section differences stress relationship and The analysis on the vertical axis different points of the section stress size relations and A comparative analysis of the ansys analysis modeling result.(3)Using the method of unified theory, deduce the axial compressive load calculation formula of the round shape steel tube concrete; use ring of stress theory compute the ratio of ring to stress on arc and linear. Draw the stress graphics of the ring to stress and contrast analysis the results.(4) by experimental method to determine the limit bearing capacity of the round shape steel tube concrete and contrast the result of theoretical calculation.This paper based on experiments, by theoretical calculation and finite element, carries on the analysis to the round shape steel tube concrete. Conclusions are as follows:(1) The round shape steel tube concrete depend on axial pressure load, the stress of The circular arc the outside of the longitudinal and ring to stress is bigger In the same section, The circular arc and linear contact point has less stress, Straight segment minimum.(2) The DBJ13-15-2003procedures in Fujian province in our country has the most close result about the calculation and experimental value to the theoretical calculation of The round shape steel tube concrete,EC4procedures has subaltern result. The United States steel structure association of the proposed design rules and AISC-LRFD AISC code calculated results and test results have large difference.(3)1use finite element analysis software ansys analyzing and modeling the round shape steel tube concrete, analyzing the strain curve of the load. Two curves are the same. Using finite element analysis software to simulate the round shape steel tube concrete component is feasible.(4)Using the principle of unfiled theory, the calculation formula deduced has the same results about the experimental data, for the engineering practice to have the certain reference function.