A gradually changing armored layer dynamic submarine cable based on axial force partition

Abstract

The application provides a kind of based on axial force partition's gradual change type armoring layer dynamic submarine cable, and relates to cable technical field, including submarine cable main body, the armoring layer being arranged in the outer side of submarine cable main body and the outer sheath being covered in the outer side of armoring layer;The armoring layer is divided into a plurality of stress regions along the axial direction of dynamic submarine cable, each stress region sets corresponding armoring structure parameters according to the load distribution characteristics of dynamic submarine cable along the axial direction;Gradual transition zone is arranged between adjacent two stress regions, and the gradual transition zone is used to make the armoring structure parameters between adjacent stress regions change continuously along the axial direction;The stress region specifically includes first stress zone, second stress zone, third stress zone and fourth stress zone arranged in sequence along the axial direction of dynamic submarine cable;The armoring structure parameters include armoring steel wire pitch, armoring steel wire spiral angle and armoring steel wire arrangement density, so that the structure parameters of the armoring layer are matched with the stress state of different axial regions of dynamic submarine cable.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and in particular to a dynamic submarine cable with a gradually changing armor layer based on axial stress partitioning. Background Technology

[0002] With the rapid development of the new energy industry, floating wind power technology has gradually become an important direction for deep-sea wind energy development. Because floating wind power platforms are constantly moving with waves, currents, and wind loads, the dynamic submarine cables connecting them to the offshore power transmission system need to withstand complex cyclic loads over long periods. To ensure the mechanical reliability of these dynamic submarine cables during long-term service, armored steel wire reinforcement structures are commonly used. The armor layer improves the overall tensile strength, bending strength, and fatigue resistance of the cable.

[0003] As floating wind power expands into deep-sea areas, the service environment of dynamic submarine cables becomes more complex, placing higher demands on their long-term reliability and fatigue life. During actual operation, dynamic submarine cables are affected by platform movement, waves, ocean currents, and their own weight, resulting in significant differences in axial tensile, bending, and torsional loads at different locations along the axial direction. Specifically, the suspension end area typically bears substantial axial tension, the buoyancy module transition area exhibits significant bending deformation and stiffness changes, and the seabed contact area is subjected to contact pressure and friction loads. Therefore, structural optimization design is necessary to address the actual stress characteristics of different areas of the dynamic submarine cable, enabling the armor layer to adapt to load variations in different regions and improving the overall mechanical performance and long-term operational reliability of the dynamic submarine cable.

[0004] However, existing dynamic submarine cable armor layers typically employ a uniform structural parameter design, making it impossible to tailor adjustments based on the stress states of different regions along the cable's axial direction. When a dynamic submarine cable undergoes cyclic bending motion, uneven stress distribution on the armor wires due to load differences between regions can easily lead to significant wire contact pressure and relative slippage between wires. This can result in problems such as localized wear, stress concentration, and fatigue damage, reducing the cable's service life. Simultaneously, using a uniform reinforcement structure in areas with lower stress levels creates redundancy in the armor structure, increasing material costs and reducing the overall cable flexibility, making it difficult to meet the differentiated stress requirements of different regions in complex marine environments. Summary of the Invention

[0005] To address the technical problems of existing dynamic submarine cables that use uniform armor structure parameters and cannot adapt to differentiated loads along the axial direction, resulting in high contact pressure and significant relative slippage in local areas of the steel wires, which easily leads to wear, stress concentration and fatigue damage, while structural redundancy exists in low-stress areas, reducing the cable's flexibility and economy, and making it difficult to meet the long-term reliable operation requirements of dynamic submarine cables in complex marine environments, this invention provides a dynamic submarine cable with a gradually changing armor layer based on axial stress zoning.

[0006] The technical solutions provided by the embodiments of the present invention are as follows: The present invention provides a dynamic submarine cable with a gradually changing armor layer based on axial stress partitioning, comprising: a submarine cable body, an armor layer disposed on the outside of the submarine cable body, and an outer sheath covering the outside of the armor layer; The armor layer is divided into multiple stress-bearing regions along the axial direction of the dynamic submarine cable, and each stress-bearing region is configured with corresponding armor structure parameters according to the load distribution characteristics of the dynamic submarine cable along the axial direction. A gradual transition zone is provided between two adjacent stress-bearing areas. The gradual transition zone is used to make the armor structure parameters between adjacent stress-bearing areas change continuously along the axial direction. The stress-bearing areas specifically include a first stress-bearing area, a second stress-bearing area, a third stress-bearing area, and a fourth stress-bearing area arranged sequentially along the axis of the dynamic submarine cable; The armor structure parameters include the armor wire pitch, armor wire helix angle, and armor wire arrangement density, so that the structural parameters of the armor layer match the stress state of different axial regions of the dynamic submarine cable.

[0007] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: In this embodiment of the invention, the armor layer is designed with stress zoning based on the load distribution characteristics of different regions along the axial direction of the dynamic submarine cable. Different structural parameters such as armor wire pitch, helix angle, and arrangement density are set for each stress region. At the same time, a gradual transition zone is set between adjacent stress regions, so that the armor structural parameters change continuously along the axial direction. This makes the local stiffness and load-bearing capacity of the armor layer match the stress state of different positions of the dynamic submarine cable, avoiding stress concentration and excessive contact pressure between steel wires caused by abrupt changes in stiffness in traditional uniform armor structures. This reduces relative slippage and wear of armor steel wires, improves the fatigue resistance and long-term service reliability of the dynamic submarine cable, and reduces structural redundancy in low-stress areas, thereby improving the overall flexibility of the submarine cable. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of a dynamic submarine cable with a gradually changing armor layer based on axial stress partitioning, provided as an embodiment of the present invention.

[0010] Figure 2 This is a dynamic stress zoning diagram of a submarine cable provided in an embodiment of the present invention.

[0011] Figure 3 This is a schematic diagram of a gradient steel wire armor with variable pitch provided in an embodiment of the present invention.

[0012] Figure 4 This is a schematic diagram illustrating the working principle of a dynamic submarine cable with a gradually changing armor layer based on axial stress partitioning, provided as an embodiment of the present invention.

[0013] Reference numerals: 1. Main body of submarine cable; 2. Armor layer; 3. Outer sheath; 21. First stress zone; 22. Second stress zone; 23. Third stress zone; 24. Fourth stress zone; 25. Gradual transition zone.

[0014] As shown in the figure, specific structures and devices are labeled in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0015] The technical solutions of the present invention will now be described with reference to the accompanying drawings. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies. Furthermore, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0016] like Figures 1 to 4 As shown, an embodiment of the present invention provides a dynamic submarine cable with a gradually changing armor layer based on axial stress partitioning, comprising: The submarine cable body 1, the armor layer 2 disposed on the outside of the submarine cable body 1, and the outer sheath 3 covering the outside of the armor layer 2.

[0017] Armor layer 2 is divided into multiple stress zones along the axial direction of the dynamic submarine cable. Each stress zone is configured with corresponding armor structure parameters based on the load distribution characteristics of the dynamic submarine cable along the axial direction.

[0018] A gradual transition zone 25 is provided between two adjacent stress-bearing areas. The gradual transition zone 25 is used to make the armor structure parameters between adjacent stress-bearing areas change continuously along the axial direction.

[0019] The stress-bearing areas specifically include a first stress-bearing area 21, a second stress-bearing area 22, a third stress-bearing area 23, and a fourth stress-bearing area 24, which are arranged sequentially along the axis of the dynamic submarine cable.

[0020] The armor structure parameters include the armor wire pitch, armor wire helix angle, and armor wire arrangement density, so that the structural parameters of armor layer 2 match the stress state of different axial regions of the dynamic submarine cable.

[0021] In one possible implementation, the armor layer 2 includes a plurality of armor steel wires spirally wound around the outer periphery of the coastal cable body 1, and the armor steel wires are arranged circumferentially at intervals along the coastal cable body 1 to form an armor structure.

[0022] It should be noted that by setting multiple spirally wound armored steel wires around the outer periphery of the submarine cable body, the armor layer forms a continuous reinforcement structure, which improves the overall tensile, bending and torsional resistance of the submarine cable. At the same time, the circumferentially spaced armored steel wires help to ensure uniform stress on the armor layer, reduce local stress concentration, and improve the structural stability of the dynamic submarine cable during long-term operation.

[0023] In one possible implementation, the surface of the armored steel wire is provided with a wear-resistant layer, an anti-corrosion layer, or a surface structure that reduces the coefficient of friction.

[0024] In this embodiment of the invention, by providing a wear-resistant layer, an anti-corrosion layer, or a surface structure that reduces the coefficient of friction on the surface of the armored steel wire, the corrosion resistance and wear resistance of the armored steel wire in complex marine environments can be effectively improved, frictional damage caused by relative movement between steel wires can be reduced, the service life of the armor layer can be extended, and the reliability of long-term cyclic operation of dynamic submarine cables can be improved.

[0025] In one possible implementation, the armor layer 2 is specifically a single-layer armor structure, a double-layer armor structure, or a multi-layer armor structure.

[0026] Each layer of armor structure has gradually varying structural parameters based on the axial stress distribution of the dynamic submarine cable.

[0027] It should be noted that by adopting single-layer, double-layer, or multi-layer armored structures, and by gradually designing the parameters of each layer of armored structure according to the stress distribution in different regions along the axial direction of the dynamic submarine cable, the multi-layer armored structure can adapt to different load conditions, improve the load-bearing capacity and structural adaptability of the armored layers, and enhance the fatigue resistance of the dynamic submarine cable in complex marine environments.

[0028] Specifically, the gradient structure of armor layer 2 can be achieved by adjusting the process parameters during the armor manufacturing process.

[0029] The continuous variation of the armor wire pitch can be achieved by adjusting the matching relationship between the rotation speed of the armoring machine and the traction speed of the submarine cable. When the traction speed of the submarine cable remains constant, the number of wire turns per unit axial length can be changed by altering the rotation speed of the armoring machine, thereby achieving continuous adjustment of the armor pitch along the axial direction.

[0030] The change of helix angle can be achieved by synchronously adjusting the rotation speed of the armoring machine, the traction speed of the submarine cable, and the wire laying angle, so that the armoring steel wire has different winding angles at different axial positions, thereby meeting the stiffness requirements of different stress areas.

[0031] The gradual change in wire arrangement density is achieved by adjusting the relative spacing of the armor wires in the circumferential direction. While keeping the winding pitch and helix angle of the armor wires basically unchanged, the circumferential spacing between adjacent wires is changed, causing the wire coverage ratio within a unit circumference to vary along the axial direction, thereby achieving a gradual change in the local arrangement density of the armor layer.

[0032] The above-mentioned structural parameter adjustment methods can be used individually or in combination according to the actual stress conditions of the dynamic submarine cable, so that the structural parameters of the armor layer match the axial stress distribution of the dynamic submarine cable.

[0033] In one possible implementation, the first stress zone 21 is located in the area of ​​the dynamic submarine cable suspension end.

[0034] The second stress zone 22 is located in the bending transition area between the suspension end and the buoyancy module.

[0035] The third stress zone 23 is located in the area where the buoyancy module functions.

[0036] The fourth stress zone 24 is set in the free suspension area or the seabed contact area.

[0037] It should be noted that by dividing the dynamic submarine cable along its axial direction into a suspension end area, a bending transition area, a buoyancy module area, and a free suspension or seabed contact area, the armor layer can be designed differently for the load characteristics of different locations. This improves the matching degree between the armor structure of each area and the actual stress state, reduces the risk of local damage, and improves the overall operational reliability of the submarine cable.

[0038] In one possible implementation, the structural parameters of the armor layer of the first stress-bearing region 21 are set as follows: The pitch of the armored steel wire is smaller than the pitch of the adjacent stress area, and the wire arrangement density is greater than the arrangement density of the adjacent stress area.

[0039] The armor structure parameters of the second stress zone 22 are set according to the characteristics of cyclic bending load, and the armor wire pitch or helix angle of the second stress zone 22 gradually changes along the axis of the dynamic submarine cable.

[0040] The armor structure parameters of the third stress zone 23 are set according to the bending moment change and dynamic swing load of the buoyancy module area. The third stress zone 23 adopts a medium armor steel wire pitch and a helix angle that is adapted to the stress state of the area.

[0041] The fourth stress zone 24 sets the armor structure parameters according to the load characteristics of the free suspension area and the seabed contact area.

[0042] It should be noted that by setting corresponding armor structure parameters for different stress areas, the high axial load area has a high load-bearing capacity, the cyclic bending area has good flexibility, and the buoyancy module area and seabed contact area meet the corresponding load requirements, thereby reducing uneven stress on the steel wire, contact wear and fatigue damage, and improving the service life of the dynamic submarine cable.

[0043] Specifically, the first stress zone 21 corresponds to the cable suspension end area. Because this area bears significant axial tensile and bending loads, a smaller armor pitch and a higher wire density are used to improve the local load-bearing capacity and bending resistance of the armor layer. The second stress zone 22 corresponds to the bending transition area, where the stress state gradually transitions from a high-stiffness load-bearing state to a flexible motion state. Therefore, the structural parameters of the armor layer gradually change along the axial direction to reduce the stiffness difference between adjacent areas. The third stress zone 23 corresponds to the buoyancy module area, which is mainly affected by buoyancy changes and dynamic oscillations. A medium pitch and an appropriate helix angle are used to improve the overall flexibility of the cable. The fourth stress zone 24 corresponds to the free suspension section and seabed contact area. Appropriate armor parameters are set according to the actual stress characteristics to meet the requirements of long-term cyclic bending and contact wear conditions.

[0044] The structural parameters of the armor layer 2 include the armor wire pitch, helix angle, and wire arrangement density, with at least one structural parameter differing in each stress zone. A gradual transition zone 25 is provided between adjacent stress zones to achieve continuous conversion between armor structural parameters in different stress zones.

[0045] In one possible implementation, the starting end of the gradual transition zone 25 adopts the armor structure parameters corresponding to the previous stress area, and the ending end adopts the armor structure parameters corresponding to the next stress area.

[0046] It should be noted that by making the starting end of the gradual transition zone consistent with the parameters of the previous stress area and the ending end consistent with the parameters of the next stress area, the continuous and smooth change of the armor structure parameters of adjacent areas is achieved, avoiding stiffness abrupt changes and stress concentration caused by abrupt changes in structural parameters, reducing the contact pressure and relative slippage between armor steel wires, and improving the fatigue resistance of dynamic submarine cables.

[0047] In one possible implementation, the armored wire pitch of the first stress zone 21 is smaller than that of the armored wire pitch of the second stress zone 22, the third stress zone 23 and the fourth stress zone 24, and the armored wire arrangement density of the first stress zone 21 is greater than that of the other stress zones.

[0048] It should be noted that by setting the first stress zone to have a smaller armor wire pitch and a larger arrangement density, the high axial load area at the suspension end has a higher armor reinforcement capacity, which improves the tensile strength and load-bearing capacity of the submarine cable end. At the same time, it avoids the waste of materials caused by using excessively high reinforcement structures in other low stress areas, thus achieving a reasonable optimization of the armor structure.

[0049] In one possible implementation, the pitch of the armored steel wire in the gradual transition zone 25 is adjusted by linear gradual change, curved gradual change, or segmented continuous gradual change.

[0050] The armor wire pitch is achieved by changing the number of wire turns per unit axial length.

[0051] It should be noted that by adjusting the pitch of the armored steel wires in the gradual transition zone using linear, curved, or segmented continuous gradual methods, the armored steel wire winding structure can achieve a smooth transition according to changes in axial force, thereby reducing the stiffness difference between adjacent areas, reducing local stress concentration during cyclic bending, and improving the fatigue life of dynamic submarine cables.

[0052] Specifically, the axial length of the gradual transition zone 25 is determined based on the differences in structural parameters between adjacent stress zones and the actual stress changes of the dynamic submarine cable. Its length can be adjusted according to the submarine cable specifications, operating water depth, operating environment, and fatigue design requirements. The starting end of the gradual transition zone 25 maintains the same structural parameters as the previous stress zone, and the ending end maintains the same structural parameters as the next stress zone, enabling the armor structure parameters to change continuously during the transition process.

[0053] The armored wire pitch within the gradual transition zone 25 is adjusted using a continuous gradual change method. Specifically, by changing the number of wire turns per unit axial length, the armored pitch gradually changes from the pitch corresponding to the previous stress zone to the pitch corresponding to the next stress zone. The pitch change method can adopt linear change, curvilinear change, or segmented continuous change to adapt to the dynamic characteristics of the submarine cable's axial load variation.

[0054] In one possible implementation, the helix angle of the armored steel wire in the gradient transition zone 25 is achieved by adjusting the winding angle of the armored steel wire relative to the axis of the submarine cable.

[0055] In areas with high bending loads, compliance can be improved by reducing local bending stiffness.

[0056] In areas with high axial load requirements, the axial load capacity can be improved by adjusting the helix angle.

[0057] In this embodiment of the invention, by adjusting the helix angle of the armor steel wire relative to the axis of the submarine cable in the gradual transition zone, the bending stiffness and axial load-bearing capacity of the armor layer can be adjusted to vary along the axial direction of the submarine cable. This improves flexibility in areas with large bending loads and enhances load-bearing capacity in areas with high axial load requirements, thereby achieving an effective match between the performance of the armor structure and the dynamic stress state of the submarine cable.

[0058] Specifically, the helix angle within the gradual transition zone 25 is continuously adjusted. By changing the winding angle of the armor steel wires relative to the cable axis, the stiffness and flexibility of the armor layer transition smoothly along the axial direction. In areas subjected to large bending loads, the local bending resistance can be reduced by adjusting the helix angle. In areas with high axial load requirements, the axial load capacity can be increased by adjusting the helix angle. Through this gradual transition method, the structural parameters of the armor layer 2, such as the pitch, helix angle, and wire arrangement density, change continuously along the cable axis, avoiding sudden changes in local stiffness between adjacent stress zones due to abrupt changes in structural parameters. This reduces the contact pressure and relative slippage between the steel wires, thereby reducing fatigue damage and wear.

[0059] In this embodiment of the invention, each stress zone is determined based on the hydrodynamic analysis results of the dynamic submarine cable. First, a hydrodynamic analysis model of the dynamic submarine cable is established based on the structural parameters, installation method, buoyancy module arrangement, water depth, platform motion, waves, ocean currents, and wind loads of the dynamic submarine cable. The axial stress distribution of the dynamic submarine cable under the design conditions or the most unfavorable conditions is calculated using hydrodynamic analysis software.

[0060] The hydrodynamic analysis results include parameters such as axial tension, bending curvature, and bending moment of the dynamic submarine cable. Based on the distribution characteristics and variation patterns of these parameters, and through fatigue life verification and cable interference verification, the areas for setting counterweights and buoyancy blocks, i.e., the second and third stress zones, are determined. Then, the first and fourth stress zones are divided according to the remaining cable area.

[0061] Preferably, the hydrodynamic analysis software is OrcaFlex, but other hydrodynamic analysis software capable of obtaining the dynamic force distribution along the axial direction of the submarine cable can also be used.

[0062] The first stress zone corresponds to the area of ​​the dynamic submarine cable near the suspension end. The axial tension in this area is at a relatively high level for the entire dynamic submarine cable, and it also experiences some cyclic bending due to platform movement. However, the primary controlling load is axial tension. Therefore, the main design objectives for this area are to improve axial load-bearing capacity, reduce stress concentration on the steel wires, and increase fatigue life. A smaller armor pitch and a larger steel wire arrangement density are used to improve the overall load-bearing capacity of the armor layer.

[0063] The second stress zone corresponds to the transition area between the suspension end and the buoyancy module. In this zone, the axial tension gradually decreases, while the bending curvature and rate of change of curvature increase significantly, making it a region where dynamic bending of the submarine cable is most concentrated. The main control load in this zone is the cyclic bending load. The primary design objectives are to reduce local bending stiffness, minimize relative slippage of the steel wires, and avoid abrupt changes in stiffness. A gradual design with armored pitch and helix angle is adopted, and a gradual transition zone is included.

[0064] The third stress zone corresponds to the area where the buoyancy module operates. Due to the change in buoyancy at the end of the buoyancy module, there will be abrupt changes in bending moment and curvature. Therefore, the main control load in this area is the local bending load caused by the change in buoyancy. The main design goals are to improve the flexibility of the submarine cable, reduce stress concentration at the end of the buoyancy module, and reduce cyclic fatigue. A larger armor pitch and a suitable helix angle can be used.

[0065] The fourth stress zone corresponds to the free suspension section and the seabed contact area. The free suspension section mainly bears the cable's own weight and residual axial tension. In addition to the aforementioned loads, the seabed contact area also bears seabed support reaction force, contact pressure, and friction loads; the stress characteristics of the two differ. Therefore, in one embodiment, the free suspension section and the seabed contact area can be designed as a unified fourth stress zone. In another embodiment, based on hydrodynamic analysis results, it can be further subdivided into a free suspension sub-region and a seabed contact sub-region, with different armor parameters set for each to meet fatigue and wear resistance requirements under different stress environments.

[0066] The starting and ending points of each stress zone are determined based on the hydrodynamic analysis results.

[0067] The working principle of this invention is as follows: During operation, the suspension end, buoyancy module area, and seabed contact area of ​​the dynamic submarine cable bear different mechanical loads. Each stress-bearing area employs different armor structure parameters according to its stress characteristics, ensuring that the local stiffness of the armor layer matches the stress state of the corresponding area. Simultaneously, a gradual transition zone 25 enables continuous variation of structural parameters between stress-bearing areas, reducing contact pressure and relative slippage between steel wires, minimizing localized wear and stress concentration, and improving the overall stress uniformity of the dynamic submarine cable, thereby enhancing its fatigue resistance and service life.

[0068] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: In this embodiment of the invention, the armor layer is designed with stress zoning based on the load distribution characteristics of different regions along the axial direction of the dynamic submarine cable. Different structural parameters such as armor wire pitch, helix angle, and arrangement density are set for each stress region. At the same time, a gradual transition zone is set between adjacent stress regions, so that the armor structural parameters change continuously along the axial direction. This makes the local stiffness and load-bearing capacity of the armor layer match the stress state of different positions of the dynamic submarine cable, avoiding stress concentration and excessive contact pressure between steel wires caused by abrupt changes in stiffness in traditional uniform armor structures. This reduces relative slippage and wear of armor steel wires, improves the fatigue resistance and long-term service reliability of the dynamic submarine cable, and reduces structural redundancy in low-stress areas, thereby improving the overall flexibility of the submarine cable.

[0069] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the preferred embodiments, while those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0070] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dynamic submarine cable with a gradually changing armor layer based on axial stress zoning, characterized in that, include: The submarine cable body (1), the armor layer (2) disposed on the outside of the submarine cable body (1), and the outer sheath (3) covering the outside of the armor layer (2); The armor layer (2) is divided into multiple stress-bearing areas along the axial direction of the dynamic submarine cable. Each stress-bearing area is configured with corresponding armor structure parameters according to the load distribution characteristics of the dynamic submarine cable along the axial direction. A gradual transition zone (25) is provided between two adjacent stress-bearing areas. The gradual transition zone (25) is used to make the armor structure parameters between adjacent stress-bearing areas change continuously along the axial direction. The stress-bearing areas specifically include a first stress-bearing area (21), a second stress-bearing area (22), a third stress-bearing area (23), and a fourth stress-bearing area (24) arranged sequentially along the axis of the dynamic submarine cable. The armor structure parameters include the armor wire pitch, armor wire helix angle, and armor wire arrangement density, so that the structural parameters of the armor layer (2) match the stress state of different axial regions of the dynamic submarine cable.

2. The dynamic submarine cable with a gradually changing armor layer based on axial stress zoning as described in claim 1, characterized in that, The armor layer (2) includes a plurality of armor steel wires spirally wound around the outer periphery of the submarine cable body (1), and each of the armor steel wires is arranged at intervals along the circumference of the submarine cable body (1) to form an armor structure.

3. The dynamic submarine cable with a gradually changing armor layer based on axial stress zoning as described in claim 1, characterized in that, The armored steel wire is provided with a wear-resistant layer, an anti-corrosion layer, or a surface structure that reduces the coefficient of friction.

4. The dynamic submarine cable with a gradually changing armor layer based on axial stress zoning according to claim 1, characterized in that, The armor layer (2) is specifically a single-layer armor structure, a double-layer armor structure, or a multi-layer armor structure; Each layer of armor structure has gradually varying structural parameters based on the axial stress distribution of the dynamic submarine cable.

5. The dynamic submarine cable with a gradually changing armor layer based on axial stress zoning according to claim 1, characterized in that, The first stress zone (21) is located in the area of ​​the suspension end of the dynamic submarine cable; The second stress zone (22) is located in the bending transition area between the suspension end and the buoyancy module; The third force-bearing zone (23) is located in the buoyancy module's working area; The fourth stress zone (24) is located in the free suspension area or the seabed contact area.

6. The dynamic submarine cable with a gradually changing armor layer based on axial stress zoning according to claim 1, characterized in that, The structural parameters of the armor layer in the first stress-bearing zone (21) are set as follows: The pitch of the armored steel wire is smaller than the pitch of the adjacent stress area, and the steel wire arrangement density is greater than the arrangement density of the adjacent stress area; The armor structure parameters of the second stress zone (22) are set according to the characteristics of cyclic bending load, and the armor wire pitch or helix angle of the second stress zone (22) gradually changes along the axis of the dynamic submarine cable. The armor structure parameters of the third stress zone (23) are set according to the bending moment change and dynamic swing load of the buoyancy module area. The third stress zone (23) adopts a medium armor steel wire pitch and a helix angle that is adapted to the stress state of the area. The fourth stress zone (24) sets the armor structure parameters according to the load characteristics of the free suspension area and the seabed contact area.

7. The dynamic submarine cable with a gradually changing armor layer based on axial stress partitioning according to claim 1, characterized in that, The starting end of the gradual transition zone (25) adopts the armor structure parameters corresponding to the previous stress area, and the ending end adopts the armor structure parameters corresponding to the next stress area.

8. The dynamic submarine cable with a gradually changing armor layer based on axial stress partitioning according to claim 1, characterized in that, The armored wire pitch in the first stress zone (21) is smaller than that in the second stress zone (22), the third stress zone (23) and the fourth stress zone (24), and the armored wire arrangement density in the first stress zone (21) is greater than that in other stress zones.

9. The dynamic submarine cable with a gradually changing armor layer based on axial stress zoning according to claim 1, characterized in that, The pitch of the armored steel wire in the gradual transition zone (25) is adjusted by linear gradual change, curved gradual change or segmented continuous gradual change. The armor wire pitch is achieved by changing the number of wire turns per unit axial length.

10. The dynamic submarine cable with a gradually changing armor layer based on axial stress zoning according to claim 1, characterized in that, The helix angle of the armored steel wire in the gradual transition zone (25) is achieved by adjusting the winding angle of the armored steel wire relative to the axis of the submarine cable; In areas with large bending loads, compliance can be improved by reducing local bending stiffness; In areas with high axial load requirements, the axial load capacity can be improved by adjusting the helix angle.

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