Session: 04-01-01 Flexible Pipes & Umbilicals I

Paper Number: 125209

125209 - Finite Element Modelling of Residual Stresses in Flexible Pipe Pressure Armor Z Profiles 

Title:

Finite element modelling of residual stresses in flexible pipe pressure armor Z profiles

 

Authors:

Rodrigo Provasi
Fernando Geremias Toni
Clóvis de Arruda Martins
Roberto Ramos Junior
George Carneiro Campello
Rodolfo Figueira de Souza
Tiago Brun Coser
 

Abstract:

In the manufacturing of flexible pipes, the pressure armor wires are submitted to successive folding and unfolding processes to achieve its final form. This process results in residual stresses that must be taken into account when calculating the total stresses they are subjected to in operational situations and in fatigue life calculations. After the manufacturing, the flexible pipe is submitted to the so-called Factory Acceptance Test (FAT), in which a huge internal pressure is applied and then removed. In this latter process, part of the residual stresses is alleviated, resulting in the residual stress field that must be considered in subsequent mechanical analysis. This paper presents finite elements analysis and the developed models that simulate all the folding and unfolding operations, besides the internal pressure application and removal during the Factory Acceptance Test for Z-shaped pressure armor profiles. This modelling contributes to a more representative manufacturing process, leading to a more assertive stress evaluation.

 

Keywords: 

Pressure armor layer, Z profiles, residual stresses, factory acceptance test, finite element method

Presenting Author: Rodrigo Provasi University of São Paulo

Presenting Author Biography: Rodrigo Provasi is currently an assistant professor in the department of Structural and Geotechnical Engineering in University of São Paulo. His background is from a graduation course in Mechatronics Engineering and PhD in Computational Mechanics, in which he focused on developing methods and tools for Offshore flexible pipes and umbilical cables analysis.
He is also part of the LMO - Offshore Mechanics Laboratory, which is well-known in the offshore industry with more than 30 years working as partner of the largest offshore players.

Authors:

Rodrigo Provasi University of São Paulo
Fernando Geremias Toni University of São Paulo
Clovis De Arruda Martins University of São Paulo
Roberto Ramos Junior University of São Paulo
George Carneiro Campello CENPES / Petrobras
Rodolfo Figueira Souza CENPES / Petrobras
Tiago Brun Coser CENPES / Petrobras