Abstract: The use of thin steel plates in rectangular concrete-filled steel stub columns will give rise to the local buckling that would reduce the strength，stiffness and ductility performance of the rectangular concrete-filled steel stub columns. The changes of local critical buckling stress (σcr) of the rectangular concrete-filled steel stub column under the eccentric loading are analyzed. Thus，the eccentricity is described by adopting the stress gradient coefficient φ and the formula for calculating the critical local buckling stress σcrof the rectangular concrete-filled steel stub columns is deduced by Galerkin method. From the formula，it is known that the local critical buckling stress (σcr) of steel plates of rectangular concrete-filled steel columns decreases with the increase of stress gradient coefficient φ. In addition，the axial force is disadvantageous to the local buckling of the rectangular concrete-filled steel stub columns.

Key words: rectangular concrete-filled steel columns, local buckling, eccentricity, stress gradient coefficients, Galerkin method, critical local buckling stress

摘要： 在矩形钢管混凝土柱中采用薄壁钢板将引起局部屈曲，局部屈曲会降低钢管混凝土柱的强度、延性和抗弯刚 度。主要分析在偏心荷载作用下，矩形钢管混凝土柱局部临界屈曲应力σcr 的变化情况。因此，通过引入应力梯度 系数φ来描述偏心距，并应用伽辽金法推导出了矩形钢管混凝土柱局部屈曲的临界应力公式。从公式可知，随着 应力梯度系数φ的增加，矩形钢管混凝土柱中外包钢板的局部屈曲应力会减小。另外，完全的轴心压力对矩形钢 管混凝土柱的局部屈曲是不利的。

关键词: 矩形钢管混凝土柱, 局部屈曲, 偏心荷载, 应力梯度系数, 伽辽金法, 临界屈曲应力