Method and apparatus for testing internal and external friction of dynamic cables.

Abstract

To provide an inside and outside parts friction test method and apparatus executable for a dynamic cable.SOLUTION: According to an example, a dynamic cable inside and outside parts friction test method includes: a step S1 of attaching a dynamic cable; a step S2 of applying positive pressure; a step S3 of applying external friction test pulling force; a step S4 of preparing for an internal friction test; a step S5 of applying internal friction test pulling force; and a step S6 of calculating a coefficient of friction. An apparatus comprises: a traction rope for connecting to the dynamic cable; a telescopic rod connected with the traction rope; a hydraulic cylinder connected with the telescopic rod for supplying test pulling force; a support frame for supporting the dynamic cable; a plurality of pressing blocks for pressing down the dynamic cable; and a pressure device connected with the pressing blocks for supplying positive pressure. The above-described method is advantageous for laying cables without damage, and the above-described apparatus has high versatility and is easily arranged.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to the technical field of dynamic cable testing, and more particularly to a method for testing internal and external friction of dynamic cables and a dynamic cable testing apparatus. [Background technology]

[0002] Dynamic cables are essential equipment in offshore wind power plants and offshore oil and gas development. They are used to connect underwater production systems and between underwater production systems and floating bodies, serving as transmission lines for electrical energy and control signals. Dynamic cables include optical cables, electrical cables, and umbilical cables, which are laid in the ocean and constantly subjected to dynamic loads such as waves, ocean currents, wind, and floating body movement.

[0003] When laying dynamic cables, it is usually necessary to use equipment such as traction machines and tensioners to lay the cables. Furthermore, because dynamic cables generally contain multiple non-adhesive inner cores, armored steel wires, an outer sheath, and a filling layer, and their structure is unique, the amount of compressive force that the traction machine and tensioner use to ensure that the cables are laid with as little damage as possible during the laying process is extremely important, and this all depends on the performance parameter of the dynamic cable itself, namely the coefficient of friction between the inside and outside of the cable.

[0004] While many conventional methods and equipment already exist for testing the internal and external friction coefficients of materials, these methods and equipment are mostly designed for ordinary materials and cannot be applied to dynamic cables, which have unique structures and complex load-bearing requirements. There is currently no unified testing method or suitable testing equipment for testing the internal and external friction of dynamic cables. [Overview of the project] [Problems that the invention aims to solve]

[0005] Therefore, the technical problem that the present invention aims to solve is to address the problem of the prior art, in which internal and external friction testing methods and testing apparatus can only be applied to ordinary materials and are unsuitable for dynamic cable testing, and to provide a dynamic cable internal and external friction testing method and dynamic cable testing apparatus. [Means for solving the problem]

[0006] In the first aspect, in order to solve the above technical problems, the present invention provides Step S1 involves installing a dynamic cable, Step S1 involves fixing one end of the dynamic cable to be installed and leaving the other end of the dynamic cable as a free end, Step S2 involves applying positive pressure, Positive pressure P i Step S2 involves applying and holding the fluid to the outer sheath of the main body of the dynamic cable, Step S3 involves applying an external friction test tensile force. An external friction test tensile force is applied to the fixed end of the dynamic cable until the dynamic cable and the positive pressure application point slip and the test tensile force is unloaded. The test is repeated multiple times until the maximum external friction test tensile force T before the dynamic cable slips is reached. m1 Step S3 to record, Step S4 is to prepare for the internal friction test, Step S4 is a repeating operation of step S2, in which the outer sheath of the fixed end of the dynamic cable is stripped to expose the armored steel wire at the end, and positive pressure is applied. Step S5 involves applying tensile force for an internal friction test. An internal friction test tensile force is applied to the end of the dynamic cable where the armored wire is exposed until the armored wire and sheath of the dynamic cable slip and the test tensile force is unloaded, with the maximum internal friction test tensile force T before slippage. m2 Step S5 records the following: Step S6 for calculating the coefficient of friction, Maximum external friction test tensile force T m1 and positive pressure P iThe external friction coefficient of the dynamic cable is calculated, and the maximum internal friction test tensile force T is used. m2 and positive pressure P i The present invention provides a method for testing the internal and external friction of a dynamic cable, which includes step S6 for calculating the internal friction coefficient of the dynamic cable.

[0007] In one embodiment of the present invention, in step S2, the positive pressure application rate is less than 5 mm / min.

[0008] In one embodiment of the present invention, in step S2, the positive pressure is applied by pushing the dynamic cable up and down, or by pushing the dynamic cable up, down, left, and right.

[0009] In a second aspect, in order to solve the above technical problems, the present invention further provides: A dynamic cable testing apparatus for performing the above-described dynamic cable internal and external friction test method, A tow rope for connecting to the dynamic cable, A telescopic rod, one end of which is connected to the towing rope, A hydraulic cylinder connected to the other end of the aforementioned telescopic rod for supplying test tensile force, A support frame for supporting dynamic cables, Multiple retaining blocks for contacting and connecting to the outer sheath of a dynamic cable, The present invention provides a dynamic cable testing apparatus comprising a pressure device connected to multiple pressing blocks, which drives the multiple pressing blocks to move and press the dynamic cable, thereby supplying positive pressure.

[0010] In one embodiment of the present invention, the pressing block includes a body, a first pressing side, and a second pressing side, wherein the body is connected to a pressure device, the first pressing side and the second pressing side are connected to the same side of the body, and the first pressing side and the second pressing side are inclined relative to each other.

[0011] In one embodiment of the present invention, the inclination included angle between the first pressing side and the second pressing side is 150°.

[0012] In one embodiment of the present invention, the dynamic cable test device further includes a tensile bending test set, and the tensile bending test set a first rotating disk rotatably connected to the ground, a second rotating disk connected to the telescopic rod and around which the towing rope is wound, a rotation driving member connected to the second rotating disk for rotationally driving the second rotating disk, and includes When the tensile bending test set performs a tensile bending test on the dynamic cable, the dynamic cable is wound around the first rotating disk.

[0013] In one embodiment of the present invention, it further includes a first guide rail, and the pressure device is slidably connected to the first guide rail.

[0014] In one embodiment of the present invention, it further includes a second guide rail, and the second rotating disk is slidably connected to the second guide rail.

[0015] In one embodiment of the present invention, it further includes a hoist connected to the dynamic cable for supplying a test tensile force.

Advantages of the Invention

[0016] The above technical solution of the present invention has the following advantages compared with the prior art. The internal and external friction test method of the dynamic cable of the present invention can not only be applied to the performance test of general submarine cables, but also be an implementable internal and external friction test method for dynamic cables. By analyzing the test results, it accurately shows the internal and external friction coefficients of the dynamic cable, determines the optimal value of the pressing force used in the towing machine and tensioner during the laying process, and ensures the damage-free laying of the dynamic cable.

[0017] The dynamic cable test device of the present invention includes a towing rope for connecting to a dynamic cable, a telescopic rod connected to the towing rope, a hydraulic cylinder connected to the telescopic rod for supplying a test tensile force, a support frame for supporting the dynamic cable, a plurality of pressing blocks for pressing the dynamic cable, and a pressure device connected to the pressing blocks for supplying a positive pressure. When conducting a test, one end of the dynamic cable is pulled by the hydraulic cylinder, the plurality of pressing blocks abut against the dynamic cable, the pressure device supplies a positive pressure P i to obtain the maximum external friction test tensile force T m1 before the dynamic cable and the pressing blocks slide relative to each other, and the maximum external friction test tensile force T m2 before the outer sheath of the dynamic cable and the internal armored steel wires slide relative to each other. By applying the test tensile force and the positive pressure until these are obtained, an internal and external friction test of the dynamic cable is conducted. Moreover, the test device has a simple structure, is easy to arrange, and is easy to operate and implement.

[0018] In the dynamic cable test device of the present invention, a tensile bending test set is also arranged, so that the test device also has the ability to test the tensile bending performance of the dynamic cable. When conducting two different tests, there is no need to exchange places or the like, which facilitates the performance test of the dynamic cable and greatly improves the test efficiency.

Brief Description of the Drawings

[0019] To more clearly and easily understand the content of the present invention, the following will further describe the present invention in more detail in conjunction with specific embodiments of the present invention and the drawings. [Figure 1] It is an example of a schematic diagram of the force received when applying the external friction test tensile force of the dynamic cable in a preferred embodiment of the present invention. [Figure 2] It is an example of a schematic diagram of the force received when applying the internal friction test tensile force of the dynamic cable in a preferred embodiment of the present invention. [Figure 3]This is an example of a schematic diagram showing a preferred embodiment of the present invention where a positive pressure application method pushes the dynamic cable up and down. [Figure 4] This is an example of a schematic diagram showing a preferred embodiment of the present invention in which a positive pressure application method pushes the dynamic cable up, down, left, and right. [Figure 5] This is an example of a schematic diagram of the structure of a dynamic cable testing apparatus when performing an internal and external friction test of a dynamic cable in a preferred embodiment of the present invention. [Figure 6] Figure 5 shows an example of a schematic diagram of the retaining block of the dynamic cable testing apparatus. [Figure 7] This is an example of a schematic diagram of the structure of a dynamic cable testing apparatus when performing a dynamic cable tensile bending test in a preferred embodiment of the present invention. [Modes for carrying out the invention]

[0020] The present invention will be further described below with reference to the drawings and specific examples so that those skilled in the art can better understand and implement the present invention, but the examples given are not intended to limit the present invention.

[0021] Example 1 As shown in Figures 1 to 4, the present invention is The step of attaching the dynamic cable 11, Step S1 involves fixing one end of the dynamic cable 11 to be installed and leaving the other end of the dynamic cable 11 as a free end, A step of applying positive pressure, Positive pressure P i Step S2 involves applying the solution to the outer sheath 111 of the main body of the dynamic cable 11 and maintaining it at all times. The step of applying tensile force to an external friction test, An external friction test tensile force is applied to the fixed end of the dynamic cable 11 until the dynamic cable 11 and the positive pressure application point slip and the test tensile force is unloaded. The test is repeated multiple times until the maximum external friction test tensile force T before the dynamic cable 11 slips is reached. m1Step S3 to record, This is a step in preparing for an internal friction test. Step S4 involves repeating the operation of step S2, in which the outer sheath 111 of the dynamic cable fixed end 11 is stripped, exposing the armored steel wire 112 at the end, and positive pressure is applied. The internal friction test involves applying a tensile force, The armored steel wire 112 and the outer sheath 111 of the dynamic cable slipped and the test tensile force unraveled. Do Until slippage occurs, the internal friction test tensile force is applied to the exposed end of the dynamic cable 11 where the armored steel wire 112 is located, and the maximum internal friction test tensile force T is applied before slippage occurs. m2 Step S5 records the following: A step in which the coefficient of friction is calculated, Maximum external friction test tensile force T m1 and positive pressure P i The dynamic cable external friction coefficient is calculated from this, and the maximum internal friction test tensile force T is used. m2 and positive pressure P i A method for testing internal and external friction of a dynamic cable is disclosed, which includes step S6 of calculating the coefficient of friction inside the dynamic cable.

[0022] The aforementioned dynamic cable internal and external friction test method is not only applicable to performance testing of general submarine cables, but is also a feasible internal and external friction test method for dynamic cables. By analyzing the test results, the internal and external friction coefficient of the dynamic cable can be accurately determined, the optimal value of the pushing force used in traction machines and tensioners during the laying process can be determined, and the dynamic cable can be laid without damage.

[0023] Preferably, in step S2, the positive pressure application rate is less than 5 mm / min.

[0024] By setting the positive pressure application rate to less than 5 mm / min, each part inside the dynamic cable is fully subjected to the positive pressure, preventing damage to the dynamic cable from being directly subjected to maximum positive pressure, thereby improving the stability and reliability of the test.

[0025] Preferably, as shown in Figures 3 and 4, in step S2, the positive pressure application method is applied according to the usage conditions of the dynamic cable to be detected. If the submerged depth of the dynamic cable 11 to be detected is less than 1000m, the test may apply positive pressure by pushing the dynamic cable 11 up and down. If the submerged depth of the dynamic cable 11 to be detected exceeds 1000m, the test may apply positive pressure by pushing the dynamic cable 11 up, down, left, and right.

[0026] When the positive pressure is applied by pushing the dynamic cable 11 up and down, the formula for calculating the coefficient of friction μ1 on the outside of the dynamic cable is as follows. The formula for calculating the friction coefficient μ2 inside a dynamic cable is as follows: JPEG0007871223000001.jpg18170 JPEG0007871223000002.jpg19170 When the positive pressure application method applies pressure to the dynamic cable 11 in the up, down, left, and right directions, the formula for calculating the external friction coefficient μ1 of the dynamic cable is as follows. The formula for calculating the friction coefficient μ2 inside a dynamic cable is as follows: JPEG0007871223000003.jpg17170 JPEG0007871223000004.jpg19170

[0027] Example 2 As shown in Figures 5 to 7, the present invention further relates to a dynamic cable testing apparatus based on the dynamic cable internal and external friction testing method, A tow rope 1 for connecting to the dynamic cable 11, A telescopic rod 2, one end of which is connected to a towing rope 1, A hydraulic cylinder 3 is connected to the other end of the telescopic rod 2 to supply the test tensile force, A support frame 4 for supporting the dynamic cable 11, Multiple retaining blocks 5 for contacting and connecting to the outer sheath of the dynamic cable 11, A dynamic cable testing apparatus is disclosed, comprising a pressure device 6 connected to a plurality of presser blocks 5, which drives the plurality of presser blocks 5 to move and press the dynamic cable 11, thereby supplying positive pressure.

[0028] When the dynamic cable testing apparatus performs an internal and external friction test, the hydraulic cylinder 3 is fixed to the ground, one end of the dynamic cable 11 is pulled by the hydraulic cylinder 3, multiple retaining blocks 5 come into contact with the dynamic cable 11, and the pressure device 6 applies positive pressure P i The dynamic cable 11 and the retaining block 5 are supplied with the maximum external friction test tensile force T before they slide relative to each other. m1 And the maximum external friction test tensile force T before the outer sheath and inner armored steel wires of the dynamic cable 11 slide relative to each other. m2 Until the desired result is obtained, test tensile force and positive pressure are applied, thereby performing a dynamic internal and external friction test on the cable 11. Moreover, the test apparatus has a simple structure, is easy to set up, and is easy to operate and carry out.

[0029] In this embodiment, as shown in Figure 6, the pressing block 5 includes a main body 51, a first pressing side 52, and a second pressing side 53. The main body 51 is connected to the pressure device 6, and the first pressing side 52 and the second pressing side 53 are connected to the same side of the main body 51. The first pressing side 52 and the second pressing side 53 are inclined relative to each other. Specifically, the angle of inclination between the first pressing side 52 and the second pressing side 53 is 150°.

[0030] By positioning the first pressing side 52 and the second pressing side 53 at a relative inclination, the dynamic cable 11 is fitted into the joint between the first pressing side 52 and the second pressing side 53 during testing. This prevents the dynamic cable 11 from slipping against the retaining block 5 when positive pressure is applied, is advantageous for maintaining the shape of the dynamic cable 11, and prevents the dynamic cable 11 from being directly pressed by positive pressure and causing large-area deformation. The configuration, which sets the joint between the first pressing side 52 and the second pressing side 53 at a 150° inclination angle, simulates the pressing angle when the dynamic cable 11 is actually laid, adapts to actual working conditions, and improves the reliability and accuracy of the internal and external friction test of the dynamic cable 11.

[0031] In this embodiment, as shown in Figure 7, the dynamic cable testing apparatus further includes a tensile bending test set 7, and the tensile bending test set 7 is A first rotating disk 71 is rotatably connected to the ground, A second rotating disc 72 is connected to the telescopic rod 2 and around which the towing rope 1 is wound, It includes a rotational drive member 73 connected to the second rotating disk 72 for rotating the second rotating disk 72, When the tensile bending test set 7 performs a tensile bending test on the dynamic cable 11, the dynamic cable 11 is wound around the first rotating disk 71.

[0032] By providing the tensile bending test set 7, the dynamic cable testing apparatus also gains the capability to test the tensile bending performance of the dynamic cable 11. When performing a tensile bending test, the dynamic cable 11 is wrapped symmetrically around the first rotating disc 71, the traction rope 1 is wrapped around the second rotating disc 72, and both ends of the traction rope 1 are connected to both ends of the dynamic cable 11. The second rotating disc 72 is driven by the hydraulic cylinder 3 to move linearly, supplying tensile force to the dynamic cable 11 and pulling it. The rotational drive member 73 rotates the second rotating disc 72, causing the dynamic cable 11 to reciprocate and bend on the first rotating disc 71, thereby testing the tensile bending performance of the dynamic cable 11. There is no need to change locations or other equipment to perform two different tests, making performance testing of dynamic cables easier and significantly increasing testing efficiency.

[0033] In this embodiment, the dynamic cable testing apparatus further includes a first guide rail 8, and the pressure device 6 is slidably connected to the first guide rail 8.

[0034] The first guide rail 8 is fixed to the ground, and the pressure device 6 is slidably connected to the first guide rail 8. This allows the pressure device 6 to be easily moved when switching between two different performance tests of the dynamic cable, increasing the efficiency of the test preparation process.

[0035] In this embodiment, the dynamic cable testing apparatus includes a second guide rail 9, and the second rotating disk 72 is slidably connected to the second guide rail 9.

[0036] The second guide rail 9 is fixed to the ground, and the second rotating disc 72 is slidably connected to the second guide rail 9, which increases stability when the hydraulic cylinder 3 drives the second rotating disc 72, thereby improving the test reliability of the dynamic cable testing apparatus.

[0037] In this embodiment, the dynamic cable testing apparatus further includes a hoist 10, which is mounted on the ground. The hoist 10 functions as a backup power source and can provide tensile force in the event of a failure in the hydraulic cylinder 3, allowing the test to continue when connected to the dynamic cable 11. The provision of the hoist 10 improves the handling capabilities of the dynamic cable testing apparatus and ensures the reliability of performing the dynamic cable test.

[0038] The implementation principle of this embodiment is as follows: When the dynamic cable testing device performs an internal and external friction test, one end of the dynamic cable 11 is pulled by the hydraulic cylinder 3, multiple retaining blocks 5 come into contact with the dynamic cable 11, and the pressure device 6 applies positive pressure P i The dynamic cable 11 and the retaining block 5 are supplied with the maximum external friction test tensile force T before they slide relative to each other. m1 And the maximum external friction test tensile force T before the outer sheath and inner armored steel wires of the dynamic cable 11 slide relative to each other. m2 Until the desired result is obtained, test tensile force and positive pressure are applied, thereby performing an internal and external friction test on the dynamic cable 11.

[0039] The dynamic cable testing apparatus is equipped with a tensile bending test set 7, giving it the capability to test the tensile bending performance of dynamic cables. The dynamic cable testing apparatus according to the present invention can perform both internal and external friction performance tests and tensile bending performance tests of dynamic cables, thereby greatly expanding the range of applications of the dynamic cable testing apparatus and making performance testing of dynamic cables easier.

[0040] Of course, the above embodiments are merely illustrative examples and do not limit the embodiments. Those skilled in the art can make various other morphological changes and modifications based on the above description. It is not necessary, nor is it possible, to cover all embodiments here. Any obvious changes or variations derived therefrom are still within the scope of protection of the present invention. [Explanation of Symbols]

[0041] 1. Towing rope 2 Telescopic rods 3 Hydraulic Cylinder 4. Support frame 5. Pressing block 51 Main unit 52 First push side 53 Second push side 6. Pressure devices 7 Tensile bending test set 71 First Rotation Disc 72. Second rotation disc 73 Rotary drive member 8. First guide rail 9. Second guide rail 10 hoists 11 Dynamic Cable 111 Outer cover 112 Armored steel wire

Claims

1. A method for testing internal and external friction of dynamic cables, simulating the installation process of dynamic cables, Step S1 involves attaching a dynamic cable, Step S1 involves fixing one end of the dynamic cable to be installed and leaving the other end of the dynamic cable as a free end, Step S2 involves applying positive pressure, Positive pressure P ｉ Step S2 involves applying and holding the solution to the outer sheath of the main body of the dynamic cable, An external friction test tensile force is applied to the fixed end of the dynamic cable until the dynamic cable and the positive pressure application point slip and the test tensile force is unloaded, and positive pressure P ｉ The test involves repeatedly applying a certain force (T) to the outer sheath of the dynamic cable's main body, and then performing the maximum external friction test tensile force T before the dynamic cable begins to slip. ｍ１ Step S3 records, Step S4 is to prepare for an internal friction test, Strip the outer sheath from the fixed end of the dynamic cable to expose the armored steel wire at the end, and apply positive pressure P ｉ Step S4 involves repeating the operation of step S2, which involves applying the solution, An internal friction test tensile force is applied to the end of the dynamic cable where the armored wire is exposed until the armored wire and sheath of the dynamic cable slip and the test tensile force is unloaded, and positive pressure P ｉ The test involves repeatedly applying a certain force (T) to the outer sheath of the main body of the dynamic cable, and then performing a maximum internal friction test (tensile force T) before slippage occurs. ｍ２ Step S5 records the following: Step S6 for calculating the coefficient of friction, The maximum external friction test tensile force T ｍ１ and the normal pressure P applied in the external friction test ｉ to calculate the external friction coefficient of the dynamic cable, and the maximum internal friction test tensile force T ｍ２ and the normal pressure P applied in the internal friction test ｉ to calculate the internal friction coefficient of the dynamic cable, step S6 A method for testing internal and external friction of a dynamic cable, characterized by including the following:

2. The dynamic cable internal and external friction test method according to claim 1, characterized in that in step S2, the positive pressure application rate is less than 5 mm / min.

3. The method for testing internal and external friction of a dynamic cable according to claim 1, characterized in that in step S2, the positive pressure is applied by pushing the dynamic cable up and down, or by pushing the dynamic cable up, down, left, and right.

4. A dynamic cable testing apparatus for performing the dynamic cable internal and external friction testing method described in any one of claims 1 to 3, A tow rope for connecting to the dynamic cable, A telescopic rod, one end of which is connected to the towing rope, A hydraulic cylinder connected to the other end of the aforementioned telescopic rod for supplying test tensile force, A support frame for supporting dynamic cables, Multiple retaining blocks for contacting and connecting to the outer sheath of a dynamic cable, A pressure device connected to multiple retaining blocks, which moves and drives multiple retaining blocks to press a dynamic cable and supply positive pressure, A dynamic cable testing apparatus characterized by comprising the following features.

5. The dynamic cable testing apparatus according to claim 4, wherein the pressing block includes a main body, a first pressing side, and a second pressing side, the main body being connected to a pressure device, the first pressing side and the second pressing side being connected to the same side of the main body, and the first pressing side and the second pressing side being inclined relative to each other.

6. The dynamic cable testing apparatus according to claim 5, characterized in that the inclination angle between the first pressing side and the second pressing side is 150°.

7. The tensile bending test set further includes, A first rotating disc rotatably connected to the ground, A second rotating disc connected to the aforementioned telescopic rod and around which the towing rope is wound, Includes a rotational drive member connected to the second rotating disk for rotating the second rotating disk, The dynamic cable testing apparatus according to claim 4, characterized in that the dynamic cable is wound on the first rotating disk when the tensile bending test set performs a tensile bending test on the dynamic cable.

8. The dynamic cable testing apparatus according to claim 7, further comprising a first guide rail, wherein the pressure device is slidably connected to the first guide rail.

9. The dynamic cable testing apparatus according to claim 7, further comprising a second guide rail, wherein the second rotating disk is slidably connected to the second guide rail.

10. The dynamic cable testing apparatus according to claim 4, further comprising a hoist connected to the dynamic cable for supplying a test tensile force.

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