【摘要】 通过引入纤维梁截面的正应变平截面假定和剪应变线性分布假定,根据美国学者Hsu提出的转角软化桁架模型中的混凝土材料二维本构关系,从基本的材料力学原理出发,推导了可考虑扭转作用的钢管混凝土纤维梁单元的本构关系求解流程。基于大型通用有限元程序ABAQUS提供的用户自定义子程序UEL,采用FORTRAN语言开发了可考虑扭转作用的钢管混凝土纤维梁模型,能够模拟钢管混凝土柱在轴力-弯矩-扭矩复合受力下的全过程力学行为,并可考虑任意加载路径。该文所开发的纤维梁模型具有较高的精度和求解效率。更多还原

【Abstract】 Based on the assumption of plane section distribution for normal strain and linear distribution for shear strain on the fiber beam section,the solution flow of a fiber beam-column model for a concrete filled steel tube considering torsion effect is proposed.The two dimensional constitutive law of concrete in the rotation soften truss model proposed by Hsu is used for this fiber beam-column model.Based on the user defined subprogram UEL provided by general finite element program ABAQUS,the fiber beam-column model for concrete filled steel tube considering torsion effect is developed using FORTRAN language.The whole mechanical process of a concrete-filled steel tube under combined action of an axial force,a bending moment and a torque could be predicted by the fiber beam-column model;arbitrary loading path could be considered.High solution precision and efficiency are obtained when analyzing concrete filled steel tube under a combined action when use the fiber beam-column model.更多还原