On the Determination of the Propagation Pressure of Long Circular Tubes

A propagating buckle can be initiated in tubes under external pressure from localized imperfections. Once initiated a buckle will propagate with the result of flattening the tube behind it. The lowest pressure at which it can propagate is known as the propagation pressure, and it represents a characteristic pressure of the tube. The paper attempts to model quasistatic steady-state propagation through a plane strain large deflection, inelastic analysis of the collapse of a circular ring. An energy balance type of argument is used to obtain a lower-bound estimate of the propagation pressure from the ring response. The results are compared with experimental results obtained from stainless steel and aluminum tubes having diameter-to-thickness ratios ranging between 100 and 10. It was found that for these two materials the estimated value for the propagation pressure was in good agreement with experimental results for D/t > 20.