Study on axial compression performance of concrete-encased t-shaped steel special-shaped column

A T-shaped column with thin concrete covered with section steel was proposed, and the axial compression test and finite element simulation were carried out on it. The static axial compression test of 7 specimens was studied, and the ABAQUS finite element parameter analysis was carried out, and the load-displacement curve, mechanical property index, stress-strain curve and failure mode of the specimens were obtained, and the influence of parameters such as the thickness of the steel flange and web, stirrup spacing, stirrup diameter, concrete protective layer thickness, and whether to add fireproof board on the static properties were obtained. The results show that all specimens have strength failure. When the steel content of the special-shaped column cross-section is the same, increasing the web thickness is more obvious than increasing the flange thickness to improve the bearing capacity of the specimen. Increasing the clamping ratio makes the bearing capacity of the specimen decrease and slow down after reaching the ultimate load. When the specimen is unstable along the strong axis, the bearing capacity is greater, and the curve descends more slowly and has better ductility after reaching the ultimate bearing capacity. The calculation of the compressive bearing capacity of the positive section is corrected, and the calculation formula of the stability coefficient of the strong and weak axes and the slenderness ratio is proposed and the effectiveness is verified.