Numerical Analysis On Seismic Performance Of T-Section Concrete-filled Steel Tubular Columns

Concrete-filled steel tube structure refers to the steel pipe filled with concrete to form a new type of composite structure. Because of the restraining action of the pipe to the role of the core concrete, the concrete is under complex stress state, so that the strength of concrete will be increased and the plasticity and toughness improvement in performance. At the same time, due to the existence of concrete, especially in Concrete-filled steel tube structure with a large slenderness ratio, can be effective to postpone or avoid the local buckling of the steel premature, which can guarantee the performance of its materials into full play. In addition, in the construction of concrete-filled steel tube structure, the steel also can be used as the template of the core concrete during pouring, Compared with reinforced concrete , it can save the speeding of the template and speed up the construction.Base on the seismic behavior by the low cyclic loading test to six T-shaped concrete-filled steel tube column sample, and combined with the use of large finite element software ANSYS to make the finite element simulation analysis for the six sample, the article get the following conclusions:1. The specimen with the largest steel lateral load increases with increasing thickness; the core strength of the concrete impact on the lateral bearing capacity is not very clear, high strength of concrete specimens with low concrete strength than the specimen cross-cutting capacity is slightly higher ; axial compression ratio of the horizontal bearing capacity of the law is not clear; section of the form of horizontal bearing capacity of specimens and little influence of maximum stress, the wall thickness of the same specimen, C cut-off pieces of the displacement of the interview slightly lower than the A cut-off interview displacement of large parts; 6 samples is no less than the maximum Mises stress in the 250Mp around the specimen thickness, slightly larger than the number of maximum stress.2. The form of the same cross-section specimen, specimen stiffness and the horizontal bearing capacity of the largest steel pipe with wall thickness are increased; for the same wall thickness of test piece, high strength of concrete core samples than the overall stiffness of the core concrete samples with low intensity high axial compression ratio, cross-section form of the specimen did not significantly affect the performance of the law.3. Calculated from six specimens of the hysteresis curve of the overall comparison, the smaller wall thickness, the lower strength of concrete specimen hysteretic behavior of some relatively full, cross-section form of the hysteretic behavior was not obvious; sample consumption can not factor in the difference between the 1.5-2.0; pipe wall thickness under the same circumstances, A cross-section of sample C slightly lower than the energy of the specimen cross-section the form of good; Although the sample has a certain energy, but its energy consumption are not very satisfactory.4. The whole changes in hysteresis loop shape by test and calculated has litter different, the overall stiffness of the sample, the largest carrying capacity are same, stiffness also has the same downward trend, the only difference is that hysteresis curves from trial has a obvious bearing declining phase, and the results from calculated hasn't. the test results has a larger limited displacement than the calculated.5. Compared the test results and finite element method, we can see the results in test and finite element coincided well, It's said that using ANSYS finite element simulation analysis with rational parameter setting and the reasonable finite element model, the results show that is feasible and credible, at the same time also shows that simulation using finite element method to study such problems, the results show that is feasible and credible.