The inextensional collapse of grooved thin-walled cylinders of PVC under axial loading

Abstract

An inextensional collapse mechanism is considered for the crumpling of thin-walled, grooved tubes and tubes without any discontinuities (non-grooved), when subject to axial load. Shortening of the tube (or shell) height is achieved by folding in a non-aximmetric diamond mode about stationary circumferential and inclined plastic hinges; collapse is initiated at the thinnest section of the tube (groove) and spreads along the various rings and grooves of which the tube consists, by passage as a travelling hinge. Expressions for the mean collapse load when the shell material is rigid-perfectly plastic are developed. Predicted loads based on the collapse modes encountered, when compared with those obtained experimentally, using rigid PVC tubes of constant axial length and groove dimensions (depth and length), are found to be in good agreement.