EFFECTS OF END CONSTRAINTS ON DYNAMIC RESPONSE OF STEEL REINFORCED CONCRETE FILLED WITH STEEL TUBE CONCRETE COLUMN UNDER BLAST LOAD

A steel reinforced concrete filled with steel tube concrete column is the main bearing member of building structures, under the explosive load, the stress characteristic and reaction process of the member are obviously different from those under the static load. The dynamic response on a steel reinforced concrete filled with steel tube concrete column in the condition of different end constraints under a blast load were simulated with the finite element analysis software ABAQUS. Concrete uses a concrete-damaged-plasticity model, considering the damage effect and strain rate effect, reinforced steels uses a classic-metal-plasticity model. The results show that the steel reinforced concrete filled with steel tube concrete column with a free constraint top has worse explosion resisting capacity, and cannot compete that of a steel reinforced concrete filled with steel tube concrete column with a fixed top or a hinged top, and the steel reinforced concrete filled with steel tube concrete column with a fix top or a hinged one has almost identical explosion resisting capacity.