Biaxial eccentric behavior of improved multi-cell T-shaped concrete-filled steel tubes
Year: 2024
Type: article
Abstract: The special-shaped concrete-filled steel tube (CFST) structure has attracted considerable scholarly interest in recent years. However, limited attention has been given to research on multi-cell T-shaped CFST (MT-CFST) column, resulting in a lack of uniformity in calculation methods. This paper presents an improved MT-CFST column composed of three rectangular steel tubes, a steel plate, and concrete. This design ensures that welds avoid cold bending zones in steel tubes, thereby enhancing quality of welds. In practical engineering applications , columns often experience biaxial eccentric loads . A biaxial eccentric compression test was conducted on fifteen MT-CFST specimens. This study investigated the influence of eccentricity, eccentric angle, and web height on performance of MT-CFST column. The experimental results revealed a similar failure mode among specimens: prior to peak load, minor bending deformation was observed. For specimens T56.6–60-45° and T40–90-180°, the smaller width-to-thickness ratio of steel plates on compressed side prevented local buckling. For other specimens, slight local buckling on compressed side near mid-span section was observed. After peak load, local buckling progressively intensified, primarily due to substantial bending deformation . The failure of specimens was attributed to local buckling and overall bending deformation. For eccentricity greater than 20 mm, the bearing capacity and elastic-plastic stiffness of specimens exhibited an increasing trend followed by a decreasing trend with the increase in eccentric angle at the same eccentricity, with the peaks occurring at around 90°. Specimens with the compressed side located at flange demonstrated higher bearing capacity and elastic-plastic stiffness. Additionally, FE models have been established to simulate the bidirectional eccentric behavior. A simplified method for calculating flexural capacity was developed, grounded in stress analysis of section at ultimate conditions. In accordance with ANSI/AISC 360, a method was established for predicting uniaxial eccentric capacity. By conducting a parametric analysis of M x / M ux,n - M y / M uy,n curves, a simplified method for determining M x / M ux,n - M y / M uy,n curves was proposed, with calculation results in good agreement with FE results.
Authors: Chao Hu, Rui Cheng, Yuhang Wang, Meilan Gong, Jichun Liu
Institution: Chongqing University
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,180
Award: G3156810425
OpenAlex ID: W4404066089