| As the end of the Second World War, countries gradually tend to be more peaceful and stable development, but some of the terrorists are still rampant activities. They are devoid of human nature to make terrorist attacks around the world, and the bombing is one of their tricks. So it is important to study the function of buildings under the blast load effect.Many buildings will be in the destruction and collapse during the explosion. This phenomenon is due to the effect of violent of the explosion load. For a building, its main force component is column. When the explosion load is acting on the building, security of the whole structure often depends on the security of column.Special-shaped concrete-filled steel tube column is a new type of composite column based on reinforced concrete special-shaped column, concrete filled steel tube, concrete-filled steel tube compound. It has three kinds of forms, cross-shaped, T-shaped and L-shaped. Due to the addition of concrete filled steel tube, special-shaped concrete-filled steel tube column makes up for the lack of bearing capacity of special-shaped reinforced concrete column. It broadens the application of special-shaped columns, especially in the application of the high-rise, super-high-rise, high-rise and large span structure systems. At present there are many researches on the mechanical properties of the special-shaped concrete-filled steel tube columns under quasi-static load. However, there are few investigations considering accidental load function such as explosion, impact or penetration. But we must pay attention to that the special-shaped concrete-filled steel tube column is usually used in the long-span and heavy load for high-rise and super-high-rise buildings and it will lead to greater casualties when this kind of structure subjected to sudden explosion caused severe damage. In order to get more time for people escape in time of danger, It is important to study on the dynamic performance of the special-shaped concrete-filled steel tube column under blast Loads and improve its antiknock ability.This paper adopts theoretical analysis and numerical simulation to study dynamic response of T-shaped concrete-filled steel tube column under surface burst blast load. The T-shaped concrete-filled steel tube column is composed of out concrete, steel tube, core concrete, longitudinal reinforcement, stirrup etc. It belongs to the typical inhomogeneous material member. Because of the inherent large stiffness of the steel pipes and the distinctive interaction mechanisms with concrete in T-shaped concrete-filled steel tube column members, the study of their response characteristics and failure modes under blast loading is difficult for us.First of all this paper introduces the application of the special-shaped concrete filled steel tube column, the basic principle of explosive effect, the strain rate effect of the materials, and the functions and features of the software ABAQUS. In this paper we get the dynamic response results of T-shaped concrete-filled steel tube column under three typical explosions. At the same time, we get the differ from of the response characteristics and failure modes between the T-shaped concrete-filled steel tube column normal reinforced concrete columns. At last, some factors which decide the blast-resistant performance of the T-shaped concrete-filled steel tube column such as the diameter of the steel tube, the thickness of steel tube, the ratio of reinforcement, the strength of concrete, the slenderness ratio of the column and the ration of axis force compression on the column are analyzed. All of these can provide a basis for the explosion resistance design of this kind of structure. |
