On thin rings and short tubes subjected to centrally opposed concentrated loads

The deformation behaviour of mild steel rings and short tubes of various diameters, thicknesses and lengths loaded centrally by opposed conically-headed cylindrical punches is examined. The test equipment and procedure are briefly described and typical histories of deformation, punch load—displacement diagrams and the increase in the horizontal ring or tube radius for increasing punch travel are presented. A comparison is made between the latter and those predicted by use of a simple expression based on the assumption of rigid-plastic material deformation. Good correlation is obtained with rings of different diameter to thickness ratio.