An investigation on flexible pipes birdcaging triggering

Author(s)

Rabelo, Marcos A. ^[1] ; Pesce, Celso P. ^[1] ; Santos, Caio C. P. ^[1] ; Junior, Roberto Ramos ^[1] ; Franzini, Guilherme R. ^[1] ; Neto, Alfredo Gay ^[1]

Affiliation

^[1] Univ Sao Paulo, Escola Politecn, Offshore Mech Lab, LMO, BR-05508030 Sao Paulo - Brazil

• Document type: Journal article
• Source: MARINE STRUCTURES; v. 40, p. 159-182, JAN 2015.
• Web of Science Citations: 7

Abstract

An investigation on triggering mechanism g for the birdcaging failure mode of flexible pipes, used in offshore oil and gas production, is carried out. From previous experimental observations, a conjecture is made: the local axisymmetric instability of the external plastic layer, caused by the high radial loading which is internally applied due to the helical armor wires tendency to expand when the pipe is subjected to compression, would be this trigger. A simple instability onset criterion for the external plastic layer, namely, the polymer intrinsic yielding limit stress, is proposed and assessed, analytically, numerically and experimentally for HDPE tubes. Then, previous birdcaging experimental observations are investigated further, focusing on the flexible pipe external plastic layer, to assess the proposed criterion. Strong evidences of validity are obtained. (C) 2014 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 12/10274-8 - Experimental investigation of the instability of high density polyethylene (HDPE) tubes under axial compression and internal pressurization
• Grantee: Celso Pupo Pesce
• Support Opportunities: Regular Research Grants