On the Collapse of Inelastic Thick-Walled Tubes Under External Pressure

Abstract

The collapse of long thick-walled tubes under external pressure is studied both experimentally and analytically. A two-dimensional nonlinear formulation of the problem is presented. The formulation is general enough to include initial geometric imperfections of the tube cross section such as initial ovality and wall thickness variation. In addition the effects of residual stresses and of initial inelastic anisotropy are considered. Experiments on tubes with D/t values between 10 and 40 were carried out. Good agreement between experiments and theory is shown to occur provided all parameters are modeled correctly. A study of the effect of the various parameters of the problem on the collapse pressure is also presented.