Axial compression testing device and axial compression testing method for ocean cable

Abstract

The embodiment of the invention provides an axial compression testing device and testing method for an ocean cable, and relates to the field of ocean cables. The axial compression testing device of the ocean cable comprises a first end limiting clamp, a second end limiting clamp, a middle limiting clamp, a force value brake and a rotary brake, the first end limiting clamp is clamped at the first end of the ocean cable, the second end limiting clamp is clamped at the second end of the ocean cable, and the middle limiting clamp is clamped in the middle of the ocean cable. According to the testing device, the first end limiting clamp and the second end limiting clamp are used for clamping the two ends of the marine cable respectively, then the rotary brake is used for enabling the marine cable to be in different bending conditions, meanwhile, axial pressure is applied to the marine cable through the force value brake, and therefore stress of the marine cable under the actual condition is simulated more truly, and the testing accuracy is improved. Therefore, the axial compression value of the marine cable can be measured more accurately. The embodiment of the invention further provides a testing method which is realized based on the axial compression testing device.

Description

Technical Field

[0001] The present invention relates to the field of marine cables, and in particular to an axial compression test device and a test method for marine cables. Background Art

[0002] The submarine cable may be subjected to axial compressive loads during installation or operation. Large axial compressive loads may cause local buckling of the submarine cable, affecting the integrity and use of the submarine cable structure.

[0003] At present, axial compression tests are often conducted on short samples, and axial loads are directly applied to both ends of the sample marine cable. Existing studies have shown that local buckling of marine cables is often related to compression loads and cyclic bending. However, the above test method ignores the fact that marine cables are also affected by bending while being subjected to axial compression, and the test results deviate greatly from the actual allowable capacity value of the marine cable. Summary of the invention

[0004] The present invention provides an axial compression test device and a test method for a marine cable, which can perform an axial compression test in a cable bending state, thereby improving the accuracy of testing the actual axial compression value of the marine cable.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] An embodiment of the present invention provides an axial compression test device for a marine cable, comprising:

[0007] A first end limit clamp, the first end limit clamp is used to be arranged at the first end of the marine cable;

[0008] A second end limit clamp, the second end limit clamp is used to be arranged at the second end of the marine cable;

[0009] An intermediate limiting clamp is arranged between the first end limiting clamp and the second end limiting clamp, and is used to clamp the middle part of the marine cable and can slide freely as the marine cable bends;

[0010] A force brake, which is arranged at the end of the marine cable and is used to apply an axial compressive load to the marine cable;

[0011] Rotation brakes, Rotation brakes are used to apply cyclic bending loads to marine cables.

[0012] Optionally, there are multiple intermediate limiting clamps, and the multiple intermediate limiting clamps are arranged at intervals from each other.

[0013] Optionally, the axial compression test device further comprises a test frame, the first end limit clamp and the second end limit clamp are fixedly arranged on the test frame, and the middle limit clamp is movably arranged on the test frame.

[0014] Optionally, a slide plate is provided on the test stand, a slide plate is provided with a slide groove, the middle limit clamp is connected to the slide plate, and the middle limit clamp can slide and move along the slide groove.

[0015] Optionally, the test frame includes multiple vertical support beams, multiple transverse support beams and multiple connecting beams, the two ends of each transverse support beam are respectively connected to two adjacent vertical support beams, and the two ends of each connecting beam are respectively connected to two adjacent transverse support beams.

[0016] Optionally, there are two rotating brakes, which are respectively located at two ends of the marine cable, wherein one rotating brake is connected to the first end limit clamp, and the other rotating brake is connected to the second end limit clamp.

[0017] Optionally, the axial compression test device further comprises a plurality of inclination sensors, and the plurality of inclination sensors are respectively arranged at different positions of the outer side wall of the marine cable.

[0018] Optionally, the middle limiting clamp includes at least one pair of horizontal rollers and at least one pair of vertical rollers, wherein the pair of horizontal rollers are spaced apart and arranged in parallel, and the pair of vertical rollers are spaced apart and arranged in parallel.

[0019] An embodiment of the present invention further provides a testing method, using the above-mentioned axial compression testing device, comprising:

[0020] preparing a sample marine cable for testing, and installing the sample marine cable into an axial compression test device;

[0021] Apply an axial compressive load F1 to the sample marine cable through a force brake;

[0022] Apply a cyclic bending load to the sample ocean cable by rotating the brake, so that the sample ocean cable is bent with a bending radius of R;

[0023] The test results of the sample ocean cable are obtained, and the test results are evaluated including whether the sample ocean cable is damaged.

[0024] Optionally, the step of evaluating the test results including whether the sample marine cable is damaged comprises:

[0025] Visually inspect the appearance of the sample ocean cable to see if it is damaged, dissect the sample ocean cable and check if local buckling occurs inside the ocean cable.

[0026] Beneficial effects of the embodiments of the present invention:

[0027] The axial compression test device of the marine cable comprises a first end limit clamp, a second end limit clamp, an intermediate limit clamp, a force brake and a rotation brake, wherein the first end limit clamp is clamped at the first end of the marine cable, the second end limit clamp is clamped at the second end of the marine cable, the intermediate limit clamp is arranged between the first end limit clamp and the second end limit clamp, the intermediate limit clamp is clamped at the middle of the marine cable, and the force brake applies an axial compression load to the marine cable. The test device of the embodiment of the present invention uses the first end limit clamp and the second end limit clamp to clamp at both ends of the marine cable respectively, and then uses the rotation brake to put the marine cable in different bending conditions, and at the same time applies axial pressure to the marine cable through the force brake, thereby more realistically simulating the force of the marine cable in actual conditions, so as to more accurately measure the axial compression value of the marine cable.

[0028] The test method includes: preparing a sample marine cable for testing, and installing the sample marine cable to an axial compression test device; applying an axial compression load F1 to the sample marine cable through a force brake; applying a cyclic bending load to the sample marine cable through a rotating brake to bend the sample marine cable with a bending radius of R; obtaining the test result of the sample marine cable, and evaluating the test result including whether the sample marine cable is damaged. The test method is based on the above-mentioned axial compression test device, and can accurately measure the axial compression value of the marine cable in actual conditions, so as to understand the ultimate compression value and degree of damage of the marine cable; the test method is simple to operate, and can be repeatedly tested in different bending states or under different axial compression loads, and has good functionality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a schematic structural diagram of an axial compression test device for a marine cable provided in an embodiment of the present invention;

[0031] Figure 2 A partial enlarged view of the middle limit clamp provided in an embodiment of the present invention;

[0032] Figure 3 A partial enlarged view of a first end limit clamp provided in an embodiment of the present invention;

[0033] Figure 4 A partial enlarged view of the second end limiting clip provided in an embodiment of the present invention;

[0034] Figure 5 It is a schematic diagram of the appearance of an umbilical cable provided in an embodiment of the present invention;

[0035] Figure 6 It is a schematic diagram of the cross-sectional structure of the umbilical cable provided in an embodiment of the present invention.

[0036] Icons: 1- first end limit clamp; 2- second end limit clamp; 3- middle limit clamp; 30- horizontal roller; 31- vertical roller; 4- test frame; 40- vertical support beam; 41- horizontal support beam; 42- connecting beam; 5- slide plate; 50- slide trough; 6- umbilical cable; 60- end plate; 61- steel wire rope; 62- steel pipe; 63- hole; 7- force brake; 8- rotation brake. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0042] The terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0043] Unless otherwise clearly specified and limited, the terms "disposed", "connected" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] It should be noted that, for the aforementioned various method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, some steps can be performed in other orders or simultaneously. The steps in the method of the embodiment of the present application can be adjusted in order, combined, and deleted according to actual needs.

[0045] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0046] At present, axial compression tests on marine cables are mostly conducted using shorter sample marine cables, for example, the length of the sample marine cables is 0.5-1m. During the test, axial loads are directly applied to both ends of the sample marine cables. This test method does not take into account that the marine cable is not only subjected to a single axial compression load. The actual marine cable is in a bent state while being subjected to the axial compression load. Therefore, the existing test method cannot accurately restore the load conditions borne by the marine cable during installation or operation. The test results deviate greatly from the actual allowable axial compression value of the marine cable, and it is also impossible to accurately predict the failure or damage that may be caused by the axial compression load on the marine cable.

[0047] Based on this, an embodiment of the present invention provides an axial compression test device and a test method for a marine cable. The test device and the test method can solve the above problems, which will be described in detail below.

[0048] Please refer to Figure 1The axial compression test device of the marine cable comprises a first end limit clamp 1, a second end limit clamp 2, an intermediate limit clamp 3, a force brake 7 and a rotation brake 8. The first end limit clamp 1 is clamped at the first end of the marine cable, the second end limit clamp 2 is clamped at the second end of the marine cable, the intermediate limit clamp 3 is arranged between the first end limit clamp 1 and the second end limit clamp 2, the intermediate limit clamp 3 is clamped at the middle of the marine cable and can slide freely as the marine cable bends, the force brake 7 is arranged at one end of the second end limit clamp 2, the force brake 7 applies an axial compression load to the marine cable, and the rotation brake 8 is used to apply a cyclic bending load to the marine cable.

[0049] The test device of the embodiment of the present invention uses the first end limit clamp 1 and the second end limit clamp 2 to clamp the two ends of the marine cable respectively, and then uses the rotating brake 8 to put the marine cable in different bending conditions, and at the same time applies axial pressure to the marine cable through the force value brake 7, so as to more realistically simulate the force of the marine cable in actual conditions, so as to more accurately measure the axial compression value of the marine cable. It should be noted that the embodiment of the present invention is based on the existing test method for the marine cable and does not take into account that the marine cable is in a bending state under actual conditions. Therefore, the embodiment of the present invention uses a marine cable with a length reaching a predetermined value for testing, which is used to simulate the axial compression changes of the marine cable under different bending conditions.

[0050] In this embodiment, the middle limit clamp 3 includes a pair of horizontal rollers 30 and two pairs of vertical rollers 31. The pair of horizontal rollers 30 are spaced apart and arranged in parallel with each other, and the two pairs of vertical rollers 31 are also spaced apart and arranged in parallel with each other. The plane where the pair of horizontal rollers 30 are located is perpendicular to the plane where the two pairs of vertical rollers 31 are located, that is, the planes where the two pairs of vertical rollers 31 are located are parallel to each other; a pair of vertical rollers 31 is located at one end of the pair of horizontal rollers 30, and the other pair of vertical rollers 31 is located at the other end of the pair of horizontal rollers 30.

[0051] refer to Figure 2 The middle limit clamp 3 also includes a horizontal mounting seat and two vertical mounting seats. The horizontal mounting seat is provided with four horizontal support ears, each of which is provided with a slot hole. Bearings are sleeved at both ends of the horizontal roller 30 and then installed in the slot holes of the horizontal support ears, so that the horizontal roller 30 can rotate; the two vertical mounting seats are perpendicular to the plane of the horizontal mounting seat, and the two vertical mounting seats are respectively located at both ends of the horizontal roller 30. Each vertical mounting seat includes a top plate, a bottom plate and two side plates, and the two ends of the top plate are connected to one end of the two side plates, and the two ends of the bottom plate are connected to the other ends of the two side plates. A pair of vertical rollers 31 is arranged between the two side plates, and two top connecting holes are provided on the top plate, and two bottom connecting holes are provided on the bottom plate. The two top connecting holes correspond to the two bottom connecting holes, and bearings are installed in the top connecting hole and the bottom connecting hole. The two ends of the vertical roller 31 are plugged into the bearings, so that the vertical roller 31 can rotate.

[0052] When the test device is used to test the sample ocean cable, the sample ocean cable is placed through the gap between the two pairs of vertical rollers 31 and the surface of the sample ocean cable is connected to a pair of horizontal rollers 30. The horizontal rollers 30 and the vertical rollers 31 provided in the intermediate limit clamp 3 play the role of bearing the sample ocean cable and reducing the friction between the sample ocean cable and the outside world. This is because when the sample ocean cable is bent and axially pressed, other external forces need to be eliminated to avoid external friction from adversely affecting the accuracy of the test results of the sample ocean cable.

[0053] In this embodiment, a rotary brake 8 is provided at each end of the sample ocean cable. By driving the rotary brake 8 to bend the sample ocean cable, the middle limit clamp 3 can move freely according to the bending state change of the sample ocean cable. Of course, the number of rotary brakes 8 can be more than two, but at least one is provided at each end of the sample ocean cable. The maximum axial compression force that the sample ocean cable can withstand under a certain bending radius is tested by applying a cyclic bending load to the sample ocean cable. The maximum axial compression force that causes the sample ocean cable to fail under the cyclic bending load is the limit axial compression value allowed by the sample ocean cable under the bending radius.

[0054] In other embodiments, the sample ocean cable can be bent by pulling the intermediate limit clamp 3, for example, the intermediate limit clamp 3 can also be connected to a mobile driving member, and the sample ocean cable can be bent by pulling and moving the mobile driving member. It is worth mentioning that the movable direction of the intermediate limit clamp 3 is along the radial direction of the sample ocean cable and is a unidirectional reciprocating movement. The mobile driving member can be pneumatically, hydraulically or electrically driven, such as using a cylinder or a push rod motor to drive the intermediate limit clamp 3.

[0055] It should be known that the number of intermediate limit clamps 3 can be one or more, and the specific number of intermediate limit clamps 3 depends on the situation of the sample ocean cable. If the sample ocean cable is longer, more intermediate limit clamps 3 are required. When multiple intermediate limit clamps 3 are set, the multiple intermediate limit clamps 3 are arranged at intervals from each other.

[0056] In order to accurately grasp the bending degree of each position of the sample marine cable during the test, multiple inclination sensors are set at different positions of the outer wall of the sample marine cable, and the multiple inclination sensors are used to detect the bending deformation degree of each part of the sample marine cable.

[0057] refer to Figure 3 and Figure 4 The structures of the first end limit clamp 1 and the second end limit clamp 2 are similar to those of the middle limit clamp 3. The first end limit clamp 1 and the second end limit clamp 2 are also provided with horizontal rollers 30 and vertical rollers 31. The functions of the horizontal rollers 30 and the vertical rollers 31 are also the same as those in the middle limit clamp 3.

[0058] In other embodiments, the first end limit clamp 1 and the second end limit clamp 2 may also be other forms of clamping structures. The structures of the first end limit clamp 1 and the second end limit clamp 2 shown in the embodiments of the present invention are only used as examples and are not used to limit the structures of the first end limit clamp 1 and the second end limit clamp 2.

[0059] Continue to refer Figure 1 The axial compression test device also includes a test frame 4, a first end limit clamp 1 and a second end limit clamp 2 are fixedly arranged on the test frame 4, and an intermediate limit clamp 3 is movably arranged on the test frame 4, so that the sample ocean cable can be operated conveniently during the test through the test frame 4. When preparing for the test of the sample ocean cable, one end of the sample ocean cable can be fixed on the second end limit clamp 2, and then an axial compression load is applied through the force brake 7. The positions of the first end limit clamp 1 and the second end limit clamp 2 are relatively fixed and will not move.

[0060] In this embodiment, the test frame 4 includes four vertical support beams 40, two transverse support beams 41 and multiple connecting beams 42; the four vertical support beams 40 are of equal length, the two transverse support beams 41 are of equal length, the two ends of one transverse support beam 41 are respectively connected to the two vertical support beams 40, the two ends of another transverse support beam 41 are respectively connected to the other two vertical support beams 40, and the two ends of multiple connecting beams 42 are respectively connected to the two transverse support beams 41, so that the four vertical support beams 40, the two transverse support beams 41 and the multiple connecting beams 42 are connected to form a frame structure. Of course, the multiple connecting beams 42 are spaced apart and arranged in parallel.

[0061] Optionally, in order to reinforce the entire test frame 4 , a reinforcement rod may be provided between the four vertical support beams 40 , with both ends of the reinforcement rod being connected to two adjacent vertical support beams 40 .

[0062] In this embodiment, the first end limit clamp 1 and the second end limit clamp 2 are respectively located at the leftmost end and the rightmost end of the test frame 4, that is, at both ends of the transverse support beam 41. Two end ends of the two transverse support beams 41 are respectively connected to two fixing plates, the first end limit clamp 1 is fixed to one of the fixing plates, and the second end limit clamp 2 is fixed to the other fixing plate.

[0063] The intermediate limit clamp 3 is arranged on the connecting beam 42 , and the intermediate limit clamp 3 can be moved on the connecting beam 42 to facilitate carrying the sample marine cable, and the number of the intermediate limit clamps 3 matches the number of the connecting beams 42 .

[0064] Optionally, the upper part of each connecting beam 42 is covered with a slide plate 5, the long side direction of the slide plate 5 is consistent with the long side direction of the connecting beam 42, the slide plate 5 is provided with a slide groove 50 along its own long side direction, and the lower part of the horizontal mounting seat of the middle limit clamp 3 is provided with a protruding slider, the slider is stuck in the slide groove 50 and can slide along the slide groove 50, thereby driving the entire middle limit clamp 3 to move.

[0065] After the test frame 4 of this embodiment is manufactured, its overall size and shape cannot be changed. Therefore, when designing the test frame 4, it is necessary to consider the types of sample marine cables that may be tested and the length range of the sample marine cables, so as to ensure that more types and more length ranges of sample marine cables can be tested as much as possible.

[0066] In other embodiments, the test stand 4 may also be a structure of other forms. This embodiment is merely described in an exemplary manner and is not intended to limit the structure and form of the test stand 4 .

[0067] The testing device of the embodiment of the present invention can be used to test a relatively long sample ocean cable, by placing the sample ocean cable in different bending conditions and applying an axial compression load, to test the limit axial compression load allowed by the sample ocean cable.

[0068] An embodiment of the present invention further provides a testing method, which is implemented by using the above-mentioned axial compression testing device, and the testing method comprises the following steps:

[0069] S1: Prepare a sample marine cable for testing and install the sample marine cable into an axial compression test device;

[0070] S2: applying an axial compressive load F1 to the sample marine cable through the force brake 7;

[0071] S3: applying a cyclic bending load to the sample ocean cable by rotating the brake 8, so that the sample ocean cable is bent with a bending radius of R;

[0072] S4: Obtain test results of the sample ocean cable, and evaluate the test results including whether the sample ocean cable is damaged.

[0073] Among them, in step S4, the test results of the sample marine cable are evaluated, and the evaluation content includes but is not limited to visually inspecting whether the appearance of the sample marine cable has overall twisting or wear, dissecting the sample marine cable to observe whether the armored steel wire has local buckling or "birdcage" and other phenomena, and detecting whether the sample marine cable has electrical failure by measuring the conductor resistance and insulation resistance.

[0074] As an example, the umbilical cable 6 is taken as an example for further description.

[0075] The umbilical cable 6 is a combination of electrical cables, optical cables, hydraulic or chemical pipes. The umbilical cable 6 is a key equipment in the fields of submarine oil and gas exploration and production, marine engineering, etc. It mainly provides electricity, gas hydraulic power, chemical injection and data transmission for deep-sea production systems. During the installation process of the umbilical cable 6, due to the movement of the installation ship and the influence of waves and currents, the umbilical cable 6 is easily affected by the compression load at the mud contact point. Relevant research shows that this is also closely related to the cyclic bending load on the umbilical cable 6. Excessive compression load can easily cause local buckling of the umbilical cable 6, and even cause overall over-torsion failure.

[0076] The length of existing sample marine cables is mostly 0.5 to 1 meter, while the length of the umbilical cable 6 selected in this embodiment is 4 meters or more. The longer length can make the umbilical cable 6 easier to bend for testing, and the test results obtained are more realistic.

[0077] refer to Figure 5 and Figure 6 , the umbilical cable 6 includes two steel tubes 62, and the steel tubes 62 are arranged along the axial direction of the umbilical cable 6. One end of the umbilical cable 6 used in the test is covered by an end plate 60, and two holes are provided on the end plate 60. A steel wire rope 61 is inserted from the other end of the umbilical cable 6 along one of the steel tubes 62, and the steel wire rope 61 extends out of the end plate 60 and passes through the other steel tube 62. The steel wire rope 61 finally extends from the end of the umbilical cable 6 away from the end plate 60. When the steel wire rope 61 is pulled, an axial compression load F1 is applied to the umbilical cable 6. Of course, if there is no steel tube 62 in the sample marine cable used in other tests, a hole 63 can be set in the filling body of the sample marine cable, and the steel wire rope 61 is connected to the force value brake 7 by using the preset hole 63 to achieve the effect of applying an axial compression load.

[0078] After the umbilical cable 6 is prepared, it is installed on the test device, and the side of the umbilical cable 6 away from the end plate 60 is fixedly clamped on the second end limit clamp 2 and clamped, and then the wire rope 61 is pulled by the force brake 7 to apply an axial compression load F1 to the umbilical cable 6.

[0079] Optionally, the maximum axial compression load of the umbilical cable 6 is estimated using previous test experience, and then the minimum bending radius of the umbilical cable 6 during installation or operation is simulated using simulation software to provide a certain basis for actual testing. A certain safety margin is considered in the actual test, so the test axial compression load is the estimated value multiplied by a certain safety factor, for example, the safety factor is 2.5.

[0080] For example, during actual testing, 2.5 times the estimated axial compression load is applied to the steel wire rope 61 to drive the rotary brakes 8 at both ends of the umbilical cable 6, so that the curvature of the umbilical cable 6 along the cable length is close to 1 / R, and the maximum curvature of the umbilical cable 6 along the cable length is measured using multiple inclination sensors arranged on the outside of the umbilical cable 6.

[0081] Evaluate the test results of the umbilical cable 6 and observe whether the appearance of the umbilical cable 6 is damaged; dissect the umbilical cable 6 to check whether local buckling occurs inside; measure the conductor resistance and insulation resistance inside the umbilical cable 6 and compare them with the resistance value before the test.

[0082] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An axial compression test device for a marine cable, characterized in that: include: A first end limiting clamp (1), the first end limiting clamp (1) being used for being arranged at a first end of a marine cable; A second end limiting clamp (2), the second end limiting clamp (2) being used for being arranged at the second end of the marine cable; An intermediate limiting clamp (3), the intermediate limiting clamp (3) being arranged between the first end limiting clamp (1) and the second end limiting clamp (2), the intermediate limiting clamp (3) being used to clamp the middle part of the marine cable and being able to slide freely as the marine cable bends; A force brake (7), the force brake (7) being arranged at the end of the marine cable, the force brake (7) being used to apply an axial compressive load to the marine cable; A rotation brake (8) is used to apply cyclic bending loads to a marine cable.

2. The axial compression test device for marine cables according to claim 1, characterized in that: The number of the intermediate limiting clamps (3) is multiple, and the multiple intermediate limiting clamps (3) are arranged at intervals from each other.

3. The axial compression test device for marine cables according to claim 1, characterized in that: The axial compression test device further comprises a test frame (4), the first end limit clamp (1) and the second end limit clamp (2) are fixedly arranged on the test frame (4), and the middle limit clamp (3) is movably arranged on the test frame (4).

4. The axial compression test device for marine cables according to claim 3, characterized in that: The test frame (4) is provided with a slide plate (5), the slide plate (5) is provided with a slide groove (50), the intermediate limiting clamp (3) is connected to the slide plate (5), and the intermediate limiting clamp (3) can slide and move along the slide groove (50).

5. The axial compression test device for marine cables according to claim 3, characterized in that: The test frame (4) comprises a plurality of vertical support beams (40), a plurality of transverse support beams (41) and a plurality of connecting beams (42), wherein two ends of each transverse support beam (41) are respectively connected to two adjacent vertical support beams (40), and two ends of each connecting beam (42) are respectively connected to two adjacent transverse support beams (41).

6. The axial compression test device for marine cables according to claim 1, characterized in that: The number of the rotating brakes (8) is two, and the two rotating brakes (8) are respectively located at the two ends of the marine cable, one of the rotating brakes (8) is connected to the first end limit clamp (1), and the other rotating brake (8) is connected to the second end limit clamp (2).

7. The axial compression test device for marine cables according to claim 1, characterized in that: The axial compression test device further comprises a plurality of inclination sensors, which are respectively arranged at different positions of the outer side wall of the marine cable.

8. The axial compression test device for marine cables according to any one of claims 1 to 7, characterized in that: The intermediate limiting clamp (3) comprises at least one pair of horizontal rollers (30) and at least one pair of vertical rollers (31); the pair of horizontal rollers (30) are arranged at intervals and in parallel, and the pair of vertical rollers (31) are arranged at intervals and in parallel.

9. A testing method, characterized in that: The axial compression test device according to any one of claims 1 to 8 is used, comprising: Preparing a sample marine cable for testing, and installing the sample marine cable into the axial compression testing device; Applying an axial compressive load F1 to the sample marine cable through the force brake (7); Applying a cyclic bending load to the sample ocean cable through the rotating brake (8) to make the sample ocean cable bend with a bending radius of R; The test result of the sample ocean cable is obtained, and the test result is evaluated to determine whether the sample ocean cable is damaged.

10. The testing method according to claim 9, characterized in that: The steps of evaluating the test results including whether the sample marine cable is damaged include: Visually inspect the appearance of the sample ocean cable to see if it is damaged, dissect the sample ocean cable and check if local buckling occurs inside the ocean cable.

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