The static axial compression of tall hollow cylinders with high interfacial friction

Hollow cylinders of initial height to diameter ratios between 1:1 and 2:1, with central holes of various diameters, were compressed axially under dry, quasi-static conditions. In the initial phase of compression three modes of flow could be identified, distinguished by single (I), double (II) or triple (III) barrels on the free surface.During continued compression, mode III degenerated into an unstable process similar to the collapse of thin-walled cans, whilst specimens initially displaying mode II changed to mode I or retained their initial form. Those cylinders that initially displayed mode I were found to retain this form throughout their subsequent compression.The deformation characteristics outlined above are shown to be dependent on the initial height to diameter ratio and the size of the bore.A preliminary axi-symmetric upper bound analysis is presented, but the simple models used are shown to be insufficient to represent accurately the complex phenomena observed. It is suggested that finite-element elastic-plastic analysis may be more appropriate.