部分包覆双肢拼合冷弯型钢-混凝土组合短柱轴压性能研究OA

To investigate the mechanical behavior of partially encased composite back-to-back built-up cold-formed steel-concrete short columns(PECCF)under axial loading,a finite element model of the PECCF short column was established using the finite element software ABAQUS,and the accuracy of the model was verified.Parametric studies were conducted to analyze the effects of lip length,rear lip length,lip ratio,and width-to-thickness ratio on the bearing capacity and ductility of the column.The results indicate that the primary failure mode of PECCF short columns are the crushing of concrete and the outward buckling of the flange and lip under compression in the column mid-height.Under the same steel ratio,it is recommended to prioritize increasing the length of the lip.The ratio of rear lip length to flange length should be greater than 0.2 and not more than 0.6,while the ratio of lip length to rear lip length should be no less than 2.Reducing the width-to-thickness ratio of flange significantly improves both bearing capacity and ductility,and it is advised that this ratio should not exceed 100 in design.Additionally,a fitted curve was established between the ratio of lip length to thickness and the strength index coefficient,leading to a proposed formula for calculating the axial bearing capacity of PECCF short columns.The calculated results show good agreement with the finite element simulation results.