Flexible Pipe End Piece Crimping Assembly Anchoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexible pipes used for transporting hydrocarbons in deep water environments face fatigue failure in the tensile armor end sections due to high axial tension and repeated cycles, leading to anchoring issues, especially at wave-shaped deformations and the zone of detachment from the running length.
Innovation Solution
The flexible pipe design incorporates a crimping assembly embedded in the filling material within the end piece, which forms radial deformations on the armor elements, reducing the need for pre-formed hooks or undulations and enhancing mechanical locking, thereby improving resistance to fatigue and axial tension recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If wave-shaped deformations are formed at the end of armor wires to be embedded in epoxy resin, then mechanical locking is created to resist applied tension, but fatigue failure occurs at the deformation level over time
Solution Approach 1:
The invention changes the geometric parameters of the armor wire deformations from wave-shaped to hook-shaped with specific dimensions (hook length L between 10-50mm, hook radius R between 5-20mm). This parameter optimization reduces stress concentration while maintaining anchoring effectiveness, thereby improving fatigue resistance without sacrificing strength
Solution Approach 2:
The invention introduces an intermediary structure (the optimized hook-shaped deformation geometry) between the armor wire and the epoxy resin. This intermediary geometry distributes stresses more evenly during cyclic loading, reducing fatigue failure risk while maintaining the mechanical locking function
2Strength
If the diameter of the helix described by armor wires is modified in the end cap, then the capstan effect is increased to improve anchoring, but the assembly process becomes more complex due to folding and unfolding operations
Solution Approach 1:
The invention applies preliminary action by pre-forming the hook-shaped deformations on the armor wires before assembly. This eliminates the need for folding and unfolding operations during assembly, reducing complexity while maintaining the enhanced capstan effect through the optimized geometry
3Reliability
If hook-shaped deformations are formed on armor wire ends, then fatigue failure risk is reduced compared to wave-shaped deformations, but manufacturing precision requirements increase
Solution Approach 1:
The invention specifies optimized parameter ranges for the hook-shaped deformations (hook length L between 10-50mm, hook radius R between 5-20mm) that balance fatigue resistance with manufacturability. These parameter ranges are wide enough to accommodate normal manufacturing tolerances while still providing the fatigue resistance benefits
Solution Approach 2:
The hook-shaped deformation geometry is designed to be self-forming during the crimping process. The deformation naturally creates the optimal geometry for fatigue resistance without requiring high-precision controlled forming operations, reducing manufacturing precision requirements
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design significantly reduces the risk of fatigue failure in the end sections of the armor by providing efficient radial deformations for anchoring, maintaining the armor elements' integrity under high tension and repeated cycles, and simplifying the assembly process.
Implementation Method 1
a crimping assembly embedded in the filling material within the end piece, which forms radial deformations on the armor elements
Implementation Method 2
forming radial deformations on the armor elements, reducing the need for pre-formed hooks or undulations and enhancing mechanical locking
Implementation Method 3
These pipes are subjected to very high axial tensile forces, particularly when the body of water in which the pipe is placed is very deep
Implementation Method 4
maintaining the armor elements' integrity under high tension and repeated cycles
Data Source
Figure 1~2
Figure 3~4
AI summary
The end-piece according to the invention comprises: at least one end segment (34) of each sheathing element (29), an end arch (50) and a cap (51) fastened on the end arch (50), the end arch (50) and the cap (51) delimiting a chamber (52) between them for receiving an end segment; a filler material (68) for filling the receiving chamber (52), in which the end segment (34) is embedded. The tip (14) comprises at least one crimping assembly (62) of the end segment (34), defining at least one radial raised portion (102, 106, 108, 112) for crimping the end segment (34), the end segment (34) having a radial deformation (64) across from the raised crimping portion (102, 106, 108, 112).