为计算和分析一种新型的钢-混凝土组合结构——钢箱-混凝土组合构件,研究钢箱-混凝土组合构件中钢箱与钢筋共同约束下的混凝土本构关系模型,进行了一组钢箱-混凝土组合压弯构件试验,分析了在不对称约束条件下各部分混凝土的约束效应,根据各部分约束效应,将混凝土分成了强约束区、弱约束区及无约束区。对约束混凝土采用非均匀材料的直接均匀化理论,提出了析钢箱-混凝土组合构件中约束混凝土的匀质化材料本构模型,使用试验实测数据确定了本构模型中的参数。采用该本构模型的纤维模型法全过程分析结果表明,应用该本构关系计算所得的M-N曲线及荷载-应变曲线的分析结果与试验实测结果吻合良好。 In order to calculate and analyze a new type of steel-concrete composite structure-steel box-concrete composite component, the constitutive model of concrete under the steel box and steel bar in steel-concrete composite component was studied. A set of steel box The test of concrete combined bending and bending members shows that the confinement effect of each part of concrete under the asymmetrical restraint condition is analyzed. According to the restraint effect of each part, the concrete is divided into strong restraint zone, weak restraint zone and unconstrained zone. Aiming at the theory of direct homogenization of confined concrete with inhomogeneous material, a homogeneous material constitutive model of confined concrete in steel box-concrete composite is presented. Parameters of the constitutive model are determined by experimental data. The whole process of the fiber model method using this constitutive model shows that the M-N curve and the load-strain curve obtained by applying the constitutive equation are in good agreement with the experimental results.