非均匀受压矩形钢管混凝土局部弹性屈曲分析

Local Elastic Buckling Analysis of Rectangular Concrete-filled Steel Tube Under Non-uniform Compression

应用不同的特征函数描述了矩形板在非均匀压力作用下的屈曲形态,解决了采用三角级数为屈曲函数模拟非均匀受压荷载作用下单侧表面约束矩形板件屈曲模态的不对称问题;通过伽辽金法建立屈曲控制方程组,分析了非均匀荷载作用对矩形钢管混凝土构件局部弹性屈曲性能的影响。结果表明:钢管屈曲系数随着不均匀荷载梯度α增加而增大,纯弯作用下(α=2)的板件弹性屈曲荷载特征值约为轴压作用下的6倍;钢板的宽厚比限值随不均匀加载梯度α的增大而增加;非均匀荷载作用下非加载边固支约束板件的屈曲系数明显大于简支约束的板件。

The buckling modes of rectangular plates under non-uniform compression were described by using different characteristic functions, and the trigonometric series as buckling function to simulate the surface of the unilateral constraints under non-uniform compression load were solved, which rectangular plate buckling mode was asymmetric. The buckling governing equations by Galerkin method were built, then the effect of local elastic buckling under nonuniform load on rectangular concrete-filled steel tube （CFST） was analyzed. The results show that the steel tube buckling coefficient increases with non-uniform loading gradient a, uniform bending （a=2） plate under elastic buckling load characteristic value is about 6 times than axial compression. The limit values of width-thickness ratio of steel increase with non-uniform loading gradient a. The buckling coefficient of fixed constraint plate with unloaded edges under nonuniform load is greater than that of simply supported plate.