Deep Water Cable Strength Member Termination with Resin Hardness Gradient
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Solution Overview
Problem
Existing cable termination methods using epoxy resin for fibre rod armouring result in rigid connections prone to fatigue, leading to potential slippage and unsecure terminations over time, especially in subsea cables.
Innovation Solution
A method and device for terminating cables with strength members using a polymer resin with varying Shore hardness and an anchoring sleeve to reduce slippage, where the resin hardness decreases towards the cable inlet and an anchoring sleeve secures the fibre ends, providing a more flexible and durable connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If epoxy resin is used as a potting material to secure fibre rod armouring, then the termination connection achieves high strength and rigidity, but the rigid connection leads to fatigue and slippage of fibre rods under alternating tension and bending
Solution Approach 1:
The patent applies parameter changes by varying the Shore hardness of the polymer resin along the longitudinal direction of the strength member. The resin hardness decreases in a stepwise or continuous manner from the end section towards the cable inlet, creating a gradient structure that allows the termination chamber to provide both strong anchoring at the fibre end and flexible stress distribution towards the cable body, thereby preventing fatigue and slippage while maintaining connection strength
Solution Approach 2:
The patent implements local quality by creating different resin hardness zones within the termination chamber. The end section of the termination chamber contains harder resin for strong fibre anchoring, while the region towards the cable inlet contains softer resin for flexible stress distribution. This local differentiation allows each region to perform its specific function optimally, resolving the contradiction between strength and reliability
2Stability of the object's composition
If a rigid potting material is used to secure strength members, then the termination achieves initial structural stability, but alternating tension and bending cause fatigue and eventual slippage over time
Solution Approach 1:
The patent uses parameter changes by implementing a gradient in resin Shore hardness along the longitudinal direction. The harder resin at the end section provides initial structural stability for anchoring, while the progressively softer resin towards the cable inlet absorbs and distributes cyclic stresses, preventing fatigue accumulation and extending the termination lifespan over 25 years
Solution Approach 2:
The patent applies beforehand cushioning by placing softer resin material in the region towards the cable inlet before the strength member is fully installed. This softer resin acts as a cushion that absorbs and distributes alternating tensions and bending stresses before they can cause fatigue damage to the fibre rods, thereby extending the duration of action
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
The method and device enhance the lifespan of cable terminations by minimizing slippage and fatigue, ensuring a secure and durable connection between the strength members and the cable, reducing the risk of fibre rod slippage due to alternating tension and bending.
Implementation Method 1
fastening the end section by curing a polymer resin in the termination chamber
Data Source
Figure 1a~1b
Figure 2a~2d
Figure 3~4
AI summary
The present invention provides a method for terminating a cable (6) comprising at least one strength member (7), the method comprises the steps of providing a cable termination comprising at least one termination chamber (2) for accommodating an end section of the strength member (7); arranging and fastening an anchoring sleeve (12) around at least parts of the end section; introducing the end section into the termination chamber (2); and fastening the end section by curing a polymer resin in the termination chamber (2), as well as a termination suitable for said method.