Process for manufacturing a variable stiffness line and associated element
AssigneesInstitut Francais du Petrole, Aerospatiale
InventorsCharles Sparks, Pierre Odru, Marcel Auberon, Guy Metivaud
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Abstract
A process for manufacturing a line of variable stiffness over part of the length thereof and the associated element which allows the line to have the variable stiffness thereof is disclosed. The element is integrated during the manufacturing of the line or deposited thereafter around the line; the element consists of composite material underlayers in which the directions of the fibers have at least one component making a zero or a low-value angle with the axis of the pipe, and the layers end in a graded way. The process has application to the manufacturing of a riser base.
Claims25
A process for achieving a line having a stiffness varying over at least part of a length of the line with the line having at least one variable stiffness element having composite and fiber underlayers comprising:
- winding a first underlayer of fiber composite in a helicord wound with a winding angle measured with respect to an axis of the line;
- winding a second underlayer of fiber composite in a helicoid in contact wound with the first underlayer of fiber composite with a winding angle measured with respect to the axis of the line with the winding angles of the fiber composites of the first and second underlayers being different;
- positioning a plurality of composite underlayers including a fiber over the second underlayer with longitudinal dimensions of each composite underlayer ending in a graded way;
- winding at least one additional underlayer over the plurality of composite underlayers with the at least one additional underlayer being of a type of either the first or second underlayer;
- and
- cross linking at least some of the underlayers.
A variable stiffness element having composite and fiber underlayers comprising:
- a first underlayer of fiber composite formed in a helicord with the first underlayer forming a winding angle measured with respect to an axis of the line;
- a second underlayer of fiber composite formed in a helicord over the second underlayer of fiber composite having a winding angle measured with respect to the axis of the line with the winding angles of the fiber composites of the first and second underlayers being different;
- a plurality of composite layers containing fiber positioned over the second underlayer with longitudinal dimensions of each composite underlayer ending in a graded way;
- at least one additional underlayer positioned over the plurality of composite underlayers being of a type of either the first or second underlayer;
- and wherein
- at least one of the underlayers is cross linked.
Dependencies are inferred from the claim text.