Bending effects on instabilities of internally pressurised tubes modelled by a nonlocal membrane theory

摘要

For a closed - end elastic- plastic tube under internal pressure the development of tensile instabilities in the tube wall is analysed numerically. A nonlocal enhanced membrane analysis is used to account for 3D effects in the context of a 2D analysis. The first instability is seen as the development of an axisymmetric bulge on the tube, and a secondary instability involves the development of necking on one side of the bulge. The effect of realistic end conditions on the development of the instabilities is studied.