Instability of Sleeve Member with High and Ordinary Strength Steel

Ultimate instability of sleeve member with Q460 inner pipe and Q235 outer pipe was analyzed. Numerical models of one-ring and three-ring sleeve members were established and calculated by ANSYS. By analyzing relationship between ultimate load and stiffness ratio & slenderness ratio of sleeve members, the influence of stiffness ratio and slenderness ratio on the stability capacity was studied. Instability capacity of one-ring sleeve member was also compared with that of three-ring sleeve member. The results show that sleeve member can make good use of the high strength of inner tube, and the effectiveness is improved by increase of the slenderness ratio.