加肋薄壁钢管混凝土柱局部屈曲与承载力分析

采用能量法分析加肋薄壁方形钢管局部屈曲，探讨加劲肋的数量和刚度对屈曲系数的影响，以及加肋薄壁钢管混凝土柱的承载力；同时，在考虑构件屈曲作用及管壁对核心混凝土承载力提高的基础上，提出带肋薄壁方钢管混凝土轴压短柱的极限承载力公式，并用试验数据验证其合理性。研究表明:在薄壁钢管中设置加劲肋，使钢管的局部屈曲系数变大、核心混凝土约束增强，构件极限承载力也相应得到增加；钢管局部屈曲系数随着加劲肋的刚度和数量的增加而增大，合理设置加劲肋可防止构件提早屈曲，提高构件承载力；提出的极限承载力公式和试验结果有较好的吻合度，与实际受力情况更符合。

Analysis of Local Buckling and Bearing Capacity of Concrete Filled Stiffened Thin Walled Steel Tubular Columns

The energy approach is used to analyze the local buckling of the stiffened thin walled square steel tubular columns,the influence of the number and stiffness of stiffener on the buckling coefficient, and the bearing capacity of stiffened thin walled concrete filled steel tube.At the same time,based on the consideration of the buckling effect of the member and the improvement of the bearing capacity of the core concrete by tubular wall,a ultimate bearing capacity formula of the short column with stiffened thin walled square steel tube under axial compression is proposed,with feasibility verification by relevant test data.The results show that the local buckling coefficient of the thin walled steel tube increases with the increase of the stiffness and number of stiffeners,so that the ultimate bearing capacity of the member is also increasedthe local buckling coefficient of the steel tube increases with the increase of the stiffness and number of stiffeners,and proper setting of stiffeners can prevent early buckling of members and improve their bearing capacity.The formula is in good agreement with the experimental results and better consistence with the actual stress bearing state.