Panagiotis Amarianos

Diploma Thesis, February 2014


This work investigates the structural behaviour and integrity of underwater pipelines. These pipelines are subjected primarily to external pressure loading, and may fail in the form of collapse because of the phenomenon of buckling propagation. The work is numerical and uses nonlinear finite element simulations in ABAQUS.

In this work, the effects of initial imperfections are examined in terms of the pipeline resistance to external pressure. Imperfections may be mainly in the form of out-of-roundness of the cross-section due to manufacturing or because of external interference. Imperfections may also be in the form of material anisotropy, or the variation of pipe wall thickness. Subsequently, the phenomenon of buckling propagation, and its arrest with the use of appropriate buckle arrestors is examined.



Figure 1: pipe cross-section collapses;
contact between opposite points on the inner pipe wall.


Figure 2: buckle propagation develops.


Figure 3: “integral” buckled arrestor stop
buckling propagation.



Figure 4: buckle “crosses over” the arrestor
at an increased level of pressure.

Spyros A. Karamanos, PhD

Department of Mechanical Engineering | University of Thessaly | Pedion Areos, Volos 38334, Greece
Phone: +30 - 24210 74086, 74360 | Fax : +30 - 24210 74360 | Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Go to top