An Investigation of Compression Bearing Capacity of Concrete-Filled Rectangular Stainless Steel Tubular Columns under Axial Load and Eccentric Axial Load

Abstract

In order to study the compression bearing capacity of concrete-filled rectangular stainless steel tubular columns, the influence of the stainless steel tube thickness, relative eccentricity, and slenderness ratio on the compression bearing capacity is analyzed, and then the calculation formula of compression bearing capacity is proposed. The results show that the finite element model can effectively simulate the compression bearing capacity, the mean of finite element calculations Nufem to the test Nuexp is 0.985, and the variance is 0.000621. The slenderness ratio and relative eccentricity have a great influence on the load–displacement curves. The thickness of the stainless steel tube has little influence on the load–displacement curves. With the increase in slenderness ratio and relative eccentricity, the compression bearing capacity decreases. With the increase in the slenderness ratio, the failure model of the specimen gradually changes from plastic failure to elastoplastic failure and then elastic failure. When the slenderness ratio is the same, if the relative eccentricity is larger, increasing the thickness of the stainless steel tube will be more effective in improving the compression bearing capacity. When the relative eccentricity is the same, if the slenderness ratio is smaller, increasing the thickness of the stainless steel tube will be more effective for improving the compression bearing capacity. The slenderness ratio and relative eccentricity have a great influence on the longitudinal stress distribution in the cross-section. When the slenderness ratio and relative eccentricity are greater, the longitudinal compressive stress in parts of the cross-section gradually becomes longitudinal tensile stress. The proposed formula can effectively predict the compression bearing capacity of concrete-filled rectangular stainless steel tubular columns. The mean of theoretical calculations to the test and the finite element is 1.054, and the variance is 0.0247.