对套管构件中承受轴向压力的内核,提出了它与柔性套筒之间线接触屈曲的模型,研究了内核与套筒线接触的后续变形过程。利用小挠度二阶平衡微分方程推导了线接触屈曲后内核挠度、弯矩、剪力、接触力等物理量的计算公式。应用算例表明:(1)当内核与套筒刚度比值足够小时,内核在经历与套筒点接触、线接触的变形过程后,会发生线接触屈曲,最终演变成同侧两点接触变形;(2)当内核与套筒刚度比值足够大时,内核只经历与套筒点接触、线接触的变形过程,不发生线接触屈曲,最终内核与套筒一起发生失稳破坏。该模型也能应用于模拟内核与刚性套筒线接触的屈曲。
A buckling model of the line-contact segment between the axially compressed inner core and the flexible sleeve in a sleeved column is proposed and the deformation process of the inner core after the line contact between the inner core and the sleeve is studied. Expressions of the deflection, moment, shear and contact forces of the inner core after the buckling of the line-contact segment are derived according to the second order differential equilibrium equations for small deflection. The following rules can be obtained through the numerical examples: (1) If the ratio of the inner-core stiffness to the sleeve stiffness is small enough, buckling of line-contact segment takes place after the inner core undergoes sequential deformations characterized by a single point contact and a line contact with the sleeve, and eventually the inner core undergoes deformation characterized by two points contact with the sleeve having a buckled segment between them; (2) If the ratio of the inner-core stiffness to the sleeve stiffness is large enough, the inner core fails together with the sleeve during the line-contact phase as a result of large deflection without buckling of line.contact segment. This proposed model can also be applied to simulate the buckling of the line-contact segment between the inner core and the rigid sleeve.