Download Mechanical Analysis and Design of Ocean Flexible Pipes

Mechanical analysis and design of ocean flexible pipes
Dr. Jun Yan, Lecturer , Department of Engineering Mechanics, and State Key Lab of
Structural Analysis of Industrial Equipment, Dalian University of Technology, Dalian,
116024, P. R.China. E-mail: [email protected]
Pipelines are widely used in oil and gas industry not only on land but also offshores.
Normally, the pipelines are made by steel, but in many cases the steel pipe could not
resist large deformation exerted by severe environmental forms. Recently flexible
pipelines made by composite material are extensively used for a variety of
applications in the ocean petroleum industry due to many merits, such as the excellent
properties in flexibility, corrosion resistance, thermal insulating simple laying method,
and building block design, etc.
In recent years, oil exploitations have reached deep water areas, which need pipelines
be not only more flexible but also strong enough. There is a need to develop a rational
design method for the flexible pipe.
In order to make conception design, we need to know its basic mechanical behavior
and the typical failure modes of the flexible pipes in laying and working conditions.
In 2007, a research group for flexible pipes was set up in Dalian University of
Technology. The essential objective of this group is to investigate the mechanical
behaviors and design the ocean flexible pipes properly based on the laboratory tests
and numerical simulations. Then some useful advices on the rationality, economical
efficiency, reliability and durability for design and application of existing flexible
patterns can be proposed. Moreover, a further target is to demonstrate the feasibility in
deep-sea application and develop its corresponding design criteria in some extreme
serving conditions of flexible pipes.
In 2009 REU program, the student will investigate mechanical behavior of flexible
pipes by analytical and FE methods, and then rationally design flexible pipe under
actual static loads.
Tasks:
(1) Learn basic knowledge of Flexible pipes, such as composition, application
and failure modes.
(2) Simplify global analysis model under laying and working load case, such as
tension, pressure, bending and torsion.
(3) Based on theoretical analysis and simplified analytical model, establish the
geometric and physical models on ANSYS. Compare the simulation results
with the laboratory tests data and validate the numerical model.
(4) Carry out the numerical tests under classic/extreme loads based on (2).
Change the parameters of the pipe, such as layers, angle, thickness, etc.
Reveal the distribution of the force and transmission mechanism between the
layers. At last rationally design flexible pipe.
(5)
References
1. Feret, JJ and Bournazel, CL (1987).Calculation of Stresses and Slip in Structural Layers of
Unbonded Flexible Pipes, Journal of Offshore Mechanics and Artic Engineering, No 109, pp
263-269.
2. Witz, JA (1996). A Case Study in the Cross-section Analysis of Flexible Risers, Marine
Structures, pp. 885-904.
3. Ramos, R, Pesce, CP (2002). A Consistent Analytical Model to Predict the Structural Behavior
of Flexible Risers Subjected to Combined Loads, Proceedings of the 21st OMAE, No 28081, Oslo.
4. Elton J. B. Ribeiro(2003), On the Tension-Compression Behaviour of Flexible Risers,
Proceedings of The Thirteenth ISOPE,pp105-112
5. Y Zhang, B Chen, L Qiu, T Hill, M Case Halliburton Wellstream. State of the art analytical
tools improve optimization of unbonded flexible pipes for deepwater environments, Offshore
technology Conference, OTC 15169, Houston, Texas, U.S.A.,5–8 May 2003.