中文摘要：

采用塑性铰方法模拟钢管混凝土结构的弹塑性工作性能时,常需要定义钢管混凝土柱截面的塑性屈服面。纤维模型法虽然可以较好的应用于钢管混凝土截面的塑性屈服面分析,但从实际应用的角度考虑,数值方法还是显得较为复杂,不便于工程应用。因此文中在已有方钢管混凝土（concrete-filled square steel tubular,CFST）构件试验研究和理论研究的基础上,首先给出弹性单元参数的确定方法;然后通过理论分析和大量的参数分析,提出了一种方钢管混凝土柱截面轴力-弯矩相关塑性屈服面的快速确定方法。并对纤维模型法与文中建议方法的计算结果进行比较,两者吻合较好,验证了文中方法的正确性。

英文摘要：

When the plastic hinge method is used to simulate the elasto-plastic properties of concrete-filled steel tubular structures,the plastic interactive yield surfaces of concrete-filled steel tubular column sections need to be defined. Although the fiber model approach can be well applied to the yield surface analysis,the numerical method is still complicated for the real applications. Therefore based on the experimental and theoretical researches on concrete-filled square steel tubular （CFST） members,this paper develops one method to determine the elastic element parameters. Then a simplified approach to quickly define the axial force-moment interactive plastic yield surface of concrete-filled square steel tubular columns is developed through theoretical analysis and a large number of parametric analyses. Finally,the fiber model method is adopted to verify the feasibility and validity of the proposed method. Results of the two methods are in good agreement,which indicates that the proposed method is reliable.