Stability of confined thin-walled steel cylinders under external pressure

A Full 3D Finite Element Model for Buckling Analysis of Stiffened Steel Liners in Hydroelectric Pressure Tunnels

“…Comparisons with experimental data, as well as with nonlinear finite-element results [10,11] have shown that Glock's formula can predict quite accurately the buckling pressure of tightly fitted elastic cylinders in a rigid cavity.…”

“…It has been assumed that there is no friction between the steel liner and the surrounding concrete. Vasilikis and Karamanos [11] in demonstrates that in very soft confinement medium, the consideration of friction results in a small increase of the ultimate capacity and in the case of rigid confinement, this effect has been found to be negligible. Beam-type elements have been used for modeling the stiffeners.…”

“…Hence, the first yield point would represent the critical buckling load if the liner were not restricted (i.e., linear elastic buckling). However, this is an inelastic buckling case: the elastic yield point is reached [11,21].…”

“…Vasilikis and Karamanos [11] developed a plastic hinge mechanism and achieved a closed-form solution to illustrate the post-buckling of the liner. They also defined a slenderness parameter λ, which shows that buckling occurs in the inelastic range when D/t ranges from 100 up to 400…”

“…Another type of failure may occur when the steel elastic yield stress is reached, which may lead to inelastic buckling [11].…”