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structural integrity of the umbili- conditions,” Dhaigude said. The

SubseaEyebrow cal system by using the 3DUST program being used to accomplish umbilical simulation program. this analysis scheme is called

This method models the instal-

Helica, an umbilical analysis tool lation of the umbilical system by whose calculation effciency is simulating loads that occur dur- due to analytical calculation of ing the installation process These helix bending stresses assum- loads include bend radius, con- ing loxodromic helix geometry. tact force, tension, and squeeze

Helica is capable of being applied loads from caterpillar tracks and to umbilicals and fexible risers tube internal pressure. while featuring a load sharing

An umbilical cross-section.

Photo: FMC Technologies.

analysis for combined loading.

Assessing fatigue life

Additionally, Helica can calculate

The US DOE’s Los Alamos National Laboratory in New Mexico.

Photo: Los Alamos National Laboratory.

of fexibles and umbilicals cross sectional stiffness proper-

DNV GL’s Mayuresh Dhaigude ties, consistent fatigue stresses presented progress highlighted in the armors and steel tubes. In the presenta- on the umbilicals, capacity curves for an

OTC paper “developments in computa- tion, Dhalgude and Sharma outlined an umbilical cross section in compliance tional methods for assessing fatigue life effcient fatigue analysis scheme involv- with applicable design codes, and both of fexibles and umbilicals,” written by ing cross-sectional analysis techniques long- and short-term fatigue life expec-

Dhaigude and P.P. Sharma. “Flexible risers required for fatigue stress calculations tancy. As factors such as installation, and dynamic umbilicals are being used in helix elements subjected to bending, power effciency, and simulation tech- increasingly in harsh environments which tensile and pressure loading, with special niques are continually being developed to require reliable prediction of fatigue life,” attention given to the effects of friction address and predict the various challenges

Dhaiguda said. While it is extremely stresses caused by the stick/slip behavior facing the successful operation of subsea important to be able to predict fatigue of helix elements in bending. umbilical systems, it will be extremely life to ensure continuous and effcient “This analysis scheme will enable interesting to observe how the offshore oil operation, these predictions are extremely operators to establish fatigue damage and and gas industry adopts and applies these diffcult due to layered construction fatigue life by considering corresponding new technologies to reach new production and helical components such as tensile probability of occurrence for short term and exploration depths.

PROVIDING THE

VITAL CONNECTION

More HV power and control for reliable remote access to a global subsea industry that is stepping out and going deeper.

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