套管构件中轴压内核本构关系的分析

套管构件是一种新型的承压设计构件。它由内核与套筒组成，且两者之间有间隙，套筒为受压内核提供侧向约束，使得内核可以发生高阶屈曲模态，极大提高了内核的受压承载力。在对比分析已有的内核本构关系模型的基础上，提出了当套筒刚度为有限时内核的轴力-轴向位移简化曲线，该曲线考虑了内核处于与套筒未接触、与套筒一阶模态点接触、与套筒一阶模态线接触这一系列变形过程，并通过算例分析，验证了该简化本构关系的合理性。

Analysis of relation between the axial compression and the axial displacement for the inner core in a sleeved column

The sleeved column that is new-fashioned member bearing axial compression is composed of inner core and sleeve with gap between them. The bearing capacity of the inner core under compression is superior to that of traditional member because the inner core is laterally confined from buckling by the sleeve. The current constitutive relations of the member are analyzed. The simplified curve of the axial compression and the axial displacement of the inner core with the sleeve having finite stiffness is proposed and is validated by two cases. The deformation process of non-contact, one point contact and one line contact between the inner core and the sleeve is considered in the curve.