基于总应变裂缝本构的矩形钢管-钢管混凝土组合桁架静力性能分析

Static Performance Analysis on Combined Truss with Steel Tube and Concrete-filled Steel Tube Based on Total Strain Crack Constitutive Model

基于约束混凝土的总应变裂缝本构模型,利用大型通用有限元程序MIDAS/FEA建立了空钢管桁架、钢管-钢管混凝土组合桁架和钢管混凝土桁架的有限元模型,进行约束混凝土本构模型的有效性验证及试验桁架静力性能分析。结果表明,文中有限元模型能较好地反映钢管-钢管混凝土组合桁架的静力性能,可以对影响组合桁架静力性能的各种参数进行分析。桁架破坏均发生在节点部位,但节点失效模式不同,主管内填混凝土改变了节点的失效模式。桁架的极限承载力均受到节点控制,主管内填混凝土能够有效提高桁架节点的强度和刚度,从而提高桁架的承载能力,减小桁架的整体变形。

Based on the total strain crack constitutive model,finite element model on three trusses was established by the finite element procedure MIDAS/FEA and the analysis was executed in order to verify the validity of constitutive model and study the static performance of combined truss.The results show that the finite element model based on total strain crack constitutive can reflect the static performance of combined truss and can execute the affective parameters analysis,which can offer the theory evidence for its engineering application.The failure of three trusses is due to the joint failure,however,the failure modes were different and were changed by the concrete filled in chord.The bearing capacity of three trusses were controlled by the joints and the strength and stiffness of joints were increased by the concrete filled in the chord.