Experimental method for studying transient failure of buoy mooring system based on truncation design

Abstract

The present invention discloses an experimental method for studying the instantaneous failure of a buoy mooring system based on a truncation design. The method first performs a truncation design of the mooring system, and then combines similarity theory to obtain basic parameters of the mooring system under test conditions. The truncation design of the mooring system needs to ensure that the static recovery characteristics of the mooring system under the full water depth and the truncation water depth are consistent. The truncation design method can obtain the length of the mooring line, the diameter of the anchor ring, the position of the anchor point, the stiffness of the anchor chain and the weight of the anchor chain under the truncation water depth. The experimental method quantitatively calculates the stiffness and length of the spring in series with the anchor chain through the proposed formula, thereby building the required test device. The method of the present invention can solve the problem that the existing method cannot perform full-water-depth scale simulation of large offshore buoy moorings or submarine cables, and the anchor point can be freely adjusted, and the layout angle of the mooring line and the length of the bottom-lying section can be quantitatively adjusted without moving the base, so that the experimental study of the instantaneous breakage of the buoy mooring system can be carried out.

Description

Technical Field

[0001] The invention relates to a method for testing the hydrodynamics of an ocean buoy. The method can utilize an ocean engineering water pool of limited size to complete the test simulation of the dynamic effect of the buoy and the instantaneous failure of the mooring system. Background Art

[0002] Model test is one of the important means to study actual marine engineering. The real marine environment is complex, and field tests are difficult and costly. The advantages of tank tests are lower cost and better simulation accuracy. When conducting model tests, it is usually necessary to scale down according to Froude similarity theory. For large offshore buoys, there are usually contradictory choices in the scale selection. If the scale is smaller, the experimental size of the buoys around the buoy is too small and the waterline ratio needs to be consistent. There is a significant size effect in the model experiment, and the small variables in the experiment will cause a large error in the result. If a larger scale is selected, the large harbor in the laboratory often does not meet the requirements in the depth direction. This is the main problem faced in the buoy model test. At present, the experimental research on deep-sea platforms mainly uses extremely small-scale models and conducts experiments in natural waters. When designing the truncation of the mooring system, it is mainly aimed at deep-sea floating structures. For large offshore buoys with buoys, there is a lack of truncation design experience. In order to obtain the parameters of the mooring system after truncation, it is necessary to consider factors such as mooring radius, anchor ring diameter, anchor chain stiffness, anchor chain weight and anchor point position at the same time, and the trial calculation work is cumbersome. At the same time, due to global warming and the increasing frequency of extreme climates in recent years, the problem of instantaneous breakage of mooring systems in extreme marine environments has become increasingly prominent. A test device and method for studying the instantaneous effect of mooring system breakage in the laboratory is needed, especially after considering the truncation design of the mooring system. Based on the above considerations, the present invention proposes a test method and device for studying the failure of buoy mooring systems under truncation design. Summary of the invention

[0003] In view of the problems existing in traditional deep-sea test research methods, such as inaccurate test results at extremely small scales, difficulty in simulating working conditions in natural waters, and cumbersome truncation design work, the present invention relates to a test method for studying the transient failure of a buoy mooring system under truncation design. In the truncation design, numerical simulation technology is used as a means, and the calculation of the stiffness curve and the initial iteration value are considered to ensure that the horizontal recovery stiffness of the mooring system and the tension of the main mooring line before and after the truncation have good consistency, which is not only conducive to ensuring the preset working conditions in a port with limited water depth, but also can ensure that the test results have high accuracy, and the transient failure analysis of the mooring system can be carried out during the hydrodynamic test process.

[0004] In order to achieve all the above purposes, the technical solution adopted by the present invention is:

[0005] A test method for studying instantaneous failure of a buoy mooring system based on a truncation design, wherein the buoy mooring system is a catenary mooring system. The method comprises the following steps: firstly, a truncation design of the buoy mooring system is performed to obtain basic parameters of the mooring system under the truncation water depth; then, the truncation is performed using similarity theory to obtain basic parameters of the mooring system under test conditions (including mooring line length, mooring radius, anchor ring diameter, anchor point position, anchor chain stiffness and anchor chain weight); the truncation design of the mooring system obtains initial values ​​of basic parameters of the mooring system through the empirical formula provided by the present invention, and then the parameters are adjusted through iterative calculation. Ultimately, it is ensured that the recovery characteristics of the mooring system at full water depth and cut-off water depth are consistent, that is, the horizontal restoring force of the mooring system and the tension of the main mooring line are consistent within the required movement range before and after cut-off; a test device is built based on the basic parameters of the mooring system under test conditions; the buoy mooring system in the test device is caused to break instantaneously, and the dynamic response results considering the instantaneous breaking effect of the mooring system are measured; since the cut-off design ensures the consistency of the recovery characteristics of the buoy mooring system, the dynamic response of the actual buoy mooring system is obtained after amplification by the similarity ratio, thereby realizing the instantaneous failure study of the actual buoy mooring system.

[0006] The test method can solve the problem that deep-sea mooring and submarine cables cannot be directly simulated on a reduced scale due to the limited size of the marine engineering water tank; the test device can conduct experimental research on the instantaneous failure of the buoy mooring system.

[0007] In the above technical solution, in the truncation design method, the truncation factor is calculated according to the water depth after truncation and the water depth before truncation, and the truncation factor is substituted into the following formula to calculate the initial values ​​of the mooring radius, anchor chain stiffness, anchor chain weight and anchor ring diameter:

[0008]

[0009] L 1 =(L 0 -L laid )·C'+L laid

[0010] EA 1 =EA 0 ·C'

[0011]

[0012]

[0013] Where C' is the cutoff factor, H 1 is the water depth after cutoff, H 0 Indicates the water depth before cutoff, L 1 is the mooring radius after truncation, L 0 is the anchor radius before truncation, L laidis the anchor chain lying length, EA 1 is the anchor chain stiffness after the stage, EA 0 is the anchor chain stiffness before truncation, M 1 is the weight of the anchor chain after truncation, M 0 is the weight of the anchor chain before cutting, d 1 is the diameter of the anchor ring after truncation, d 0 The diameter of the anchor ring before truncation;

[0014] By iterating the above initial values, the parameter values ​​of the basic parameters of the mooring system after truncation can be obtained, which can greatly reduce the trial calculation time.

[0015] Furthermore, through the Froude number similarity criterion, a scaled design is carried out on the basis of the truncated model to obtain the basic parameters of the mooring system under test conditions. Based on this, a test device is built, and the stiffness recovery characteristics of the mooring system and the platform motion response can be obtained in the test device.

[0016] Furthermore, the buoy mooring system adopts electromagnetic breaking, and the specific method is: the electromagnetic core and coil after power is supplied are used to connect the anchor chains at both ends, and when the mooring tension reaches a predetermined value, the mooring line is instantly broken by powering off.

[0017] Furthermore, the test device includes: an ocean wave and current environment simulation device, a buoy system, an anchor system and a measuring device; the ocean wave and current environment simulation device includes a harbor, a fan arranged at the edge of the harbor, a wave-making array arranged along the short side and the long side of one side of the harbor, and a wave-breaking plate arranged corresponding to the wave-making array; the buoy system includes a scaled buoy body and a plurality of buoys evenly arranged around the buoy body; the anchor system is composed of a plurality of anchor plates and anchor lines, each of which includes an anchor chain, a spring for adjusting the stiffness of the anchor chain, an instantaneous anchor chain breaking device and a variable anchor point structure; the measuring device includes a wave height meter, a current meter, a six-degree-of-freedom motion monitor and an anchor system tension sampling device. The instantaneous breaking device of the anchor chain is arranged in the anchor chain around the buoy and the buoy body; the fan is used to assist in wind generation; the wave-making array includes a wave-making plate and a stepping system for wave generation; the wave-breaking plate is arranged relative to the wave-making array to eliminate reflected waves; the current meter is provided at the wave-making plate on the short side of the harbor to measure the flow velocity; the wave height meter is arranged near the short side wave-making plate and around the buoy system to monitor the time-course wave changes; the tension acquisition and converter of the mooring system is used to collect the real-time tension of the anchor chain and perform data conversion; the six-degree-of-freedom motion monitor is used to collect the position of the buoy system in real time to obtain the six-degree-of-freedom motion response of the buoy body and its attached buoy;

[0018] The instantaneous anchor chain breaking device comprises an insulating shell, an insulating base and a power switch, wherein a stainless steel cylindrical shell is arranged inside the insulating shell, an electromagnet core and a coil are arranged on the insulating base, and the electromagnet core and the coil of the insulating base are inserted into the stainless steel cylindrical shell; the instantaneous anchor chain breaking device divides an anchor chain into two sections, the insulating base is connected to one end of the anchor chain through a tension sensor, and the other end is connected to the other end of the anchor chain through the insulating shell; the power switch is immediately turned off when the tension of the anchor chain reaches a predetermined value, and the tension sensor measures a dynamic response result considering the instantaneous breaking effect of the mooring system;

[0019] The variable anchor point structure is as follows: a circular groove is provided on the anchor plate, and a rotating disk is provided in the circular groove, and the rotating disk can rotate freely around the rotating bearing in the circular groove; the rotating disk is connected to the anchor plate through a rotating bearing; a sliding guide rail is provided on the rotating disk, and a bolt hole array is provided on the sliding guide rail, and a slider is provided in the sliding guide rail, and the slider is connected with a spring, and the spring is connected in series with the bottom of the anchor chain; the position of the slider is the anchor point position, and the anchor point position can be changed by adjusting the position of the slider. When the anchor point position is determined, the slider can be fixed to the sliding guide rail by bolts, and the rotating disk is pressed and fixed by bolts and base bolt holes provided on the anchor plate.

[0020] Furthermore, at the anchor point, the anchor chain and the spring are connected in series and the spring end is connected to the anchor point. The stiffness and length of the spring are determined by the proposed calculation formula:

[0021]

[0022]

[0023]

[0024] k p / k m =λ 2

[0025] Among them, the subscript p represents the prototype mooring system, the subscript m represents the mooring system in the test device after being scaled down according to the similarity theory, the subscript s represents the spring, F is the force of the mooring system, λ is the model scale, E is the elastic modulus, A is the equivalent cross-sectional area of ​​the anchor chain, l is the component length, Δl is the deformation length, and k=EA / l is the component stiffness.

[0026] Furthermore, the coil has a waterproof coating on the outside, the inner diameter of the stainless steel cylindrical shell is tangent to the outside of the coil, and the inner diameter of the insulating shell is tangent to the outside of the insulating base. The method of use is to turn on the power supply, close the insulating shell and the insulating base and put them into water; when the tension reaches a predetermined value, suddenly turn off the power switch of the main mooring line electromagnet, and at this time, the dynamic response result considering the instantaneous breaking effect of the mooring system is measured by the measuring device.

[0027] In the present invention, when it is necessary to change the parameters of the mooring system in the test device, the displacement and angle of the change are quantitatively obtained by adjusting the variable anchor point structure, and after redetermining the parameters, all the anchor point structures are tightened and fixed with bolts, and the test is repeated. The present invention provides a variable anchor point structure that can flexibly change the anchor point position. When it is necessary to change the parameters of the test mooring system, the displacement and angle of the change of the anchor point are quantitatively obtained by adjusting the variable anchor point structure. With the variable anchor point structure of the present invention, the anchor radius is adjusted by moving the slider, and the angles of all the mooring systems are adjusted by rotating the rotating disk. After all the parameters are determined, the variable anchor point structures are all fixed with bolts.

[0028] The present invention is beneficial in that:

[0029] The present invention provides a test method for studying the instantaneous failure of a buoy mooring system based on a truncation design. The method first determines the full water depth and the water depth after truncation to calculate the truncation factor, and on this basis obtains the initial iteration values ​​of the anchor chain radius, anchor chain stiffness, anchor chain weight and anchor ring diameter, thereby improving the efficiency of the truncation trial calculation. The stiffness and length of the spring to be connected are given by the formula provided by the present invention. The present invention tests the test device after the truncation design through the Froude number similarity criterion, which meets the water depth requirement, can also improve the accuracy of the test, and reduce the trial calculation time of engineers when conducting buoy tests. The test method and device provided by the present invention can study the response problem of the instantaneous failure of the mooring system, and obtain the six-degree-of-freedom motion response and drift trajectory of the buoy structure in the test. The mooring system parameters can be more conveniently adjusted in both rotation and translation directions through the variable anchor point structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of the test method for studying instantaneous failure of a buoy mooring system based on a truncation design of the present invention;

[0031] Figure 2 is a truncated schematic diagram of the mooring system of the present invention;

[0032] Figure 3 It is a schematic diagram of the longitudinal and transverse recovery stiffness results of the mooring system of the present invention before and after truncation;

[0033] Figure 4It is a schematic diagram of the main mooring line tension results before and after the mooring system of the present invention is cut off;

[0034] Figure 5 It is a schematic diagram of the underwater breaking design of the buoy of the present invention;

[0035] Figure 6 It is a schematic diagram of the arrangement of the buoy hydrodynamic test device of the present invention;

[0036] Figure 7 It is a schematic diagram of the spring and variable anchor point structure of the present invention;

[0037] Among them, 1. power switch, 2. electromagnet core and coil, 3. insulating base, 4. tension sensor, 5. insulating shell, 6 waterproof coating, 7. stainless steel cylindrical shell, 8. buoy system, 9. six-degree-of-freedom motion monitor, 10. wave-making array, 11. wave-breaking plate, 12. spring, 13. wave height meter, 14. current meter, 15. large fan, 16. anchor system tension acquisition and converter, 17. control terminal, 18. slider, 19. bolt hole array, 20. sliding guide rail, 21. rotating disk, 22. base bolt hole, 23. rotating bearing, 24. anchor plate. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific implementation examples, but the protection scope of the present invention is not limited to the implementation examples.

[0039] Figure 1 The present invention is a flow chart of the test method for studying the instantaneous failure of a buoy mooring system based on a truncation design. The buoy mooring system is a catenary mooring system.

[0040] Figure 2 The figure is a schematic diagram of the truncated design of the mooring system of the present invention. The initial values ​​of the mooring radius, anchor chain stiffness, anchor chain weight and anchor ring diameter are obtained by the following formula:

[0041]

[0042] L 1 =(L 0 -L laid )·C'+L laid

[0043] EA 1 =EA 0 ·C'

[0044]

[0045]

[0046] Where C' is the cutoff factor, H 1 is the water depth after cutoff, H 0 Indicates the water depth before cutoff, L 1 is the mooring radius after truncation, L 0 is the anchor radius before truncation, L laid is the anchor chain lying length, EA 1 is the anchor chain stiffness after the stage, EA 0 is the anchor chain stiffness before truncation, M 1 is the weight of the anchor chain after truncation, M 0 is the weight of the anchor chain before cutting, d 1 is the diameter of the anchor ring after truncation, d 0 is the diameter of the anchor ring before truncation. The initial values ​​of the above mooring system are iterated to obtain the parameter values ​​of the basic parameters of the mooring system after truncation.

[0047] Firstly, the basic parameters of the mooring system at full water depth are obtained, and the truncation factor of the mooring system is determined according to the existing test environment. Taking the truncation factor as the basic means, the iterative initial values ​​of the mooring radius, anchor chain stiffness, anchor chain weight and anchor ring diameter are determined, and the stiffness-displacement characteristic curve of the mooring system before and after truncation is iteratively calculated to ensure that the overall static horizontal recovery stiffness after truncation is consistent with the tension of the main mooring line.

[0048] Figure 3 It is a schematic diagram of the horizontal recovery stiffness result of the mooring system of the present invention. It can be seen from the figure that within the given platform motion range, the horizontal recovery stiffness of the mooring system before and after truncation is basically the same near the equilibrium position.

[0049] Figure 4 The schematic diagram of the main mooring line tension results before and after truncation of the present invention is shown in FIG. 1 . The parameters of the spring 12 connected in series with the anchor chain in the test device can be determined by the following formula:

[0050]

[0051]

[0052]

[0053] k p / k m =λ 2

[0054] Among them, the subscript p represents the prototype mooring system, the subscript m represents the mooring system in the test device after being scaled down according to the similarity theory, the subscript s represents the spring, F is the force of the mooring system, λ is the model scale, E is the elastic modulus, A is the equivalent cross-sectional area of ​​the anchor chain, l is the component length, Δl is the deformation length, and k=EA / l is the component stiffness.

[0055] The test device used in the present invention includes: an ocean wave and current environment simulation device, a buoy system 8, an anchor system and a measuring device. The buoy system 8 includes a scaled buoy body and three buoys evenly arranged around the buoy body. The anchor system is composed of a plurality of anchor plates 24 and anchor lines, each of which includes an anchor chain, a spring 12 for adjusting the stiffness of the anchor chain, an anchor chain instantaneous breaking device and a variable anchor point structure.

[0056] Figure 5 The diagram is a schematic diagram of the instantaneous breaking device of the anchor chain used in the present invention. The instantaneous breaking device of the anchor chain includes an insulating shell 5, an insulating base 3 and a power switch. A stainless steel cylindrical shell 7 is provided inside the insulating shell 5. An electromagnet core and a coil are provided on the insulating base. The electromagnet core and the coil of the insulating base are inserted into the stainless steel cylindrical shell 7. The instantaneous breaking device of the anchor chain divides an anchor chain into two sections. The insulating base is connected to one end of the anchor chain through a tension sensor, and the other end is connected to the other end of the anchor chain through the insulating shell. The coil is provided with a waterproof coating 6 on the outside. The inner diameter of the stainless steel cylindrical shell 7 is tangent to the outside of the coil, and the inner diameter of the insulating shell is tangent to the outside of the insulating base. Turn on the power supply 1, close the insulating shell 5 and the base 7 and put them into the water. At the same time, turn on the large fan 15 placed on the edge of the harbor, and create target waves through the push plate array 10. When the tension reaches a predetermined value, the power switch 1 of the main mooring line electromagnet is suddenly turned off, and the tension sensor 4 measures the dynamic response of the mooring system. At this time, the dynamic response result considering the instantaneous breaking effect of the mooring system can be obtained through the control terminal 17.

[0057] Figure 6 The schematic diagram of the arrangement of the buoy hydrodynamic test measuring device of the present invention includes a wave height meter 13, a current meter 14, a mooring system tension acquisition and converter 16 and a six-degree-of-freedom motion monitor 9. The ocean wave and current environment simulation device includes: a large fan 15, fixed to the edge of the harbor; a wave-making array 10 including a wave-making plate and a stepping system, which is spread over a short side and a long side of the harbor for wave-making; a wave-breaking plate 11 is arranged opposite to the wave-making array 10 to achieve the purpose of eliminating reflected waves.

[0058] The velocity meter 14 is placed at the upstream position of the harbor (i.e., at the wave-making plate on the short side of the harbor) to measure the velocity; the two wave height meters 13 are used to measure the wave parameters near the wave-making array 10 and the wave breaking near the buoy system 8; the mooring system tension acquisition and converter 16 can collect the real-time tension of the anchor chain and perform data conversion through the control terminal 17; the six-degree-of-freedom motion monitor 9 can collect the position of the buoy system 8 in real time to obtain the six-degree-of-freedom motion response of the buoy system 8 in the time domain. When the mooring line of the mooring system passes through Figure 5 When the instantaneous breaking device of the anchor chain shown produces instantaneous breaking, the above-mentioned implementation process can be repeated.

[0059] Figure 7The variable anchor point structure adopted by the present invention, the spring 12 is connected to the slider 18, the slider 18 is placed inside the sliding rail 20, the side of the sliding rail 20 has a bolt hole array 19, after the anchor point position is determined, it is pressed with the slider 18 by two bolts. The sliding rail 20 and the lower rotating disc 21 are completely fixed by welding, the rotating disc 21 and the anchor plate 24 are connected by a rotating bearing 23, so that the rotating disc 21 can rotate freely in the groove of the anchor plate 24, and the side of the anchor plate 24 is provided with two base bolt holes 22. After the position of the anchor point (i.e. the slider 18) is determined, the rotating disc 21 is pressed and fixed by bolts.

[0060] Of course, the above are only specific application examples of the present invention. The present invention has other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A test method for studying instantaneous failure of a buoy mooring system based on a truncation design, wherein the buoy mooring system is a catenary mooring system, characterized in that: The method is as follows: firstly, a prototype mooring system is designed for truncation to obtain basic parameters of the mooring system under the truncation water depth; then, the basic parameters of the mooring system under test conditions are obtained by scaling down using similarity theory; the basic parameters of the mooring system are mooring line length, mooring radius, anchor ring diameter, anchor point position, anchor chain stiffness and anchor chain weight; a test device is built based on the basic parameters of the mooring system under test conditions; the buoy mooring system in the test device is caused to break instantaneously, and the dynamic response result considering the instantaneous breaking effect of the mooring system is measured, and the dynamic response of the actual mooring system is obtained after amplification by similarity ratio, so that the instantaneous failure study of the actual buoy mooring system can be realized; The catenary characteristics of the mooring line must be kept unchanged before and after the truncation design, that is, the horizontal restoring force of the mooring system and the tension of the main mooring line must be kept consistent within the required range of motion before and after the truncation. The truncation factor is calculated based on the water depth after and before the truncation, and the initial values ​​of the mooring radius, anchor chain stiffness, anchor chain weight and anchor ring diameter of the mooring system under the truncation water depth are calculated using the truncation factor: L1=(L0-L laid )·C'+L laid EA1=EA0·C' Among them, C' is the cutoff factor, H1 is the water depth after cutoff, H0 is the water depth before cutoff, L1 is the mooring radius after cutoff, L0 is the mooring radius before cutoff, L laid is the anchor chain lying length, EA1 is the anchor chain stiffness after the stage, EA0 is the anchor chain stiffness before truncation, M1 is the anchor chain weight after truncation, M0 is the anchor chain weight before truncation, d1 is the anchor ring diameter after truncation, d0 is the anchor ring diameter before truncation; By iterating the above initial values, the parameter values ​​of the basic parameters of the mooring system after truncation can be obtained.

2. The test method for studying instantaneous failure of a buoy mooring system based on a truncated design according to claim 1 is characterized in that: The buoy mooring system adopts electromagnetic breaking, and the specific method is: the electromagnetic core and coil after power-on are used to connect the anchor chains at both ends, and when the anchoring tension reaches a predetermined value, the mooring line is instantly broken by powering off.

3. The test method for studying instantaneous failure of a buoy mooring system based on a truncated design according to claim 1 is characterized in that: The test device includes: an ocean wave and current environment simulation device, a buoy system, an anchor system and a measuring device; the ocean wave and current environment simulation device includes a harbor, a fan arranged at the edge of the harbor, a wave-making array arranged along the short side and the long side of one side of the harbor, and a wave-breaking plate arranged corresponding to the wave-making array; the buoy system includes a scaled buoy body and a plurality of buoys evenly arranged around the buoy body; the anchor system consists of a plurality of anchor plates and anchor lines, each of which includes an anchor chain, a spring for adjusting the stiffness of the anchor chain, an anchor chain instantaneous breaking device and a variable anchor point structure; the measuring device includes a wave height meter, a current meter, a six-degree-of-freedom motion monitor and an anchor system tension acquisition and converter; the instantaneous breaking device of the anchor chain is arranged in the anchor chain around the buoy and the buoy body; the fan is used to assist in wind generation; the wave-making array includes a wave-making plate and a stepping system for wave generation; the wave-breaking plate is arranged relative to the wave-making array to eliminate reflected waves; the current meter is provided at the wave-making plate on the short side of the harbor to measure the flow velocity; the wave height meter is arranged near the short-side wave-making plate and around the buoy system to monitor the time-course wave changes; the tension acquisition and converter of the mooring system is used to collect the real-time tension of the anchor chain and perform data conversion; the six-degree-of-freedom motion monitor is used to collect the position of the buoy system in real time to obtain the six-degree-of-freedom motion response of the buoy body and its attached buoy; The instantaneous anchor chain breaking device comprises an insulating shell, an insulating base and a power switch, wherein a stainless steel cylindrical shell is arranged inside the insulating shell, an electromagnet core and a coil are arranged on the insulating base, and the electromagnet core and the coil of the insulating base are inserted into the stainless steel cylindrical shell; the instantaneous anchor chain breaking device divides an anchor chain into two sections, the insulating base is connected to one end of the anchor chain through a tension sensor, and the other end is connected to the other end of the anchor chain through the insulating shell; the power switch is immediately turned off when the tension of the anchor chain reaches a predetermined value, and the tension sensor measures a dynamic response result considering the instantaneous breaking effect of the mooring system; The variable anchor point structure is as follows: a circular groove is provided on the anchor plate, and a rotating disk is provided in the circular groove, and the rotating disk can rotate freely around the rotating bearing in the circular groove; the rotating disk is connected to the anchor plate through a rotating bearing; a sliding guide rail is provided on the rotating disk, and a bolt hole array is provided on the sliding guide rail, and a slider is provided in the sliding guide rail, and the slider is connected with a spring, and the spring is connected in series with the bottom of the anchor chain; the position of the slider is the anchor point position, and the anchor point position can be changed by adjusting the position of the slider. When the anchor point position is determined, the slider can be fixed to the sliding guide rail by bolts, and the rotating disk is pressed and fixed by bolts and base bolt holes provided on the anchor plate.

4. The test method for studying instantaneous failure of a buoy mooring system based on a truncated design according to claim 3 is characterized in that: The coil is provided with a waterproof coating on its exterior, the inner diameter of the stainless steel cylindrical shell is tangent to the exterior of the coil, and the inner diameter of the insulating shell is tangent to the exterior of the insulating base.

5. The test method for studying instantaneous failure of a buoy mooring system based on a truncated design according to claim 3 is characterized in that: In the test device, the anchor chain and the spring are connected in series and the spring end is connected to the anchor point. The length and stiffness of the spring are calculated according to the following formula: k p / k m =λ 2 Among them, the subscript p represents the prototype mooring system, the subscript m represents the mooring system in the test device after being scaled down according to the similarity theory, the subscript s represents the spring, F is the force of the mooring system, λ is the model scale, E is the elastic modulus, A is the equivalent cross-sectional area of ​​the anchor chain, l is the component length, Δl is the deformation length, and k=EA / l is the component stiffness.

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