Real-time visual mooring test device based on platform-mooring-anchoring foundation coupling

Abstract

The invention discloses a real-time visual mooring test device based on platform-mooring-anchoring foundation coupling. The real-time visual mooring test device comprises a pool, a mooring rope, an anchoring device and a test beam. An inclinometer, an inductance magnetic ring and a tension sensor are arranged on the mooring rope; a measuring platform and a full-degree-of-freedom oscillation device are arranged on the test beam; an inductance type distance measuring sensor is arranged on the measuring platform; a first motor for driving the lower arm to rotate is arranged on a base of the full-degree-of-freedom oscillation device, and a second motor for driving the middle arm to rotate is arranged between the middle arm and the lower arm; a third motor for driving the upper arm to rotate is arranged between the middle arm and the upper arm; a motor assembly for driving the rear plate to rotate is arranged on the upper arm; a first hydraulic column and a middle plate are arranged on the rear plate; a first front plate with a transverse groove is arranged on the middle plate, and second front plates with longitudinal grooves are arranged on two sides of the middle plate; second hydraulic columns are arranged in the transverse grooves and the longitudinal grooves; one end of the mooring rope is connected with the second hydraulic column; complex movement of the platform under a real sea condition is simulated, and movement of a mooring cable in a soil body and the shape of an anchor chain in the soil are observed in real time.

Description

Technical Field

[0001] The present invention relates to the field of marine engineering technology, and in particular to a real-time visual mooring test device based on platform-mooring-anchor foundation coupling. Background Art

[0002] In recent years, the depth of ocean exploration has gradually entered the deepwater and ultra-deepwater realms, placing higher demands on marine mooring systems. Mooring systems are used for the long-term or temporary anchoring and positioning of floating structures. They ensure the positioning of marine floating structures at sea and withstand harsh load conditions, allowing offshore platforms to operate normally within a relatively fixed water area. The mooring system consists of a mooring cable and an anchor foundation, one end of which is connected to the floating structure and the other end is connected to the underwater anchor foundation. The tension of the mooring cable limits the movement of the floating structure, keeping it within the allowable range and maintaining overall smooth operation. Its bearing capacity is mainly provided by the gravity of the floating and bottom-lying sections of the mooring cable, as well as the soil resistance of the embedded section. Under extreme working conditions, the bottom-lying section is guaranteed to have a certain length to prevent the anchor foundation from being subjected to uplift forces.

[0003] When an offshore floating wind turbine system is operating, it will be subject to the coupling effects of aerodynamic loads, hydrodynamic loads, seabed soil loads, and other loads. Among the existing model tests to explore the motion response of floating wind turbine structures, some only conduct hydrodynamic research on mooring cables in seawater, some only consider the impact of floating wind turbine platforms on mooring cables, and some only consider the impact of mooring cables and anchor foundations in the soil. Existing test devices do not comprehensively consider the coupling effects of anchor-soil interaction, chain-soil interaction, underwater force characteristics of mooring cables, and floating platforms. Therefore, establishing a fully coupled test model of wind turbine-platform-mooring system-anchor foundation, considering the complex interactions of platform-mooring-anchor foundation, and exploring the motion response of the mooring system under different environmental conditions is the basis for ensuring the development of offshore floating structures.

[0004] How to simulate the soil part, soil surface and water part of the mooring system based on the model test in the existing technology to achieve the purpose of real-time observation of the movement of the mooring cable in the soil, realize special working conditions such as platform offset and the application of cyclic loads, and simulate the complex movement of the platform under real sea conditions is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] Purpose of the invention: In order to ensure the authenticity and reliability of model tests and to remedy the defects in the prior art, the present invention proposes a real-time visual mooring test device based on platform-mooring-anchor foundation coupling. The full-degree-of-freedom oscillation device realistically simulates the response characteristics and synergistic effects of the various parts of the platform-mooring-anchor foundation, and then simulates the soil part, soil surface and water part of the mooring system. Different test types are adapted according to test needs, and the movement of the mooring cable in the soil and the shape of the anchor chain in the soil are observed in real time. The special working conditions of the platform offset and the application of cyclic loads are realized, and the complex movement of the platform under real sea conditions is simulated.

[0006] Technical solution: The present invention is a real-time visual mooring test device based on platform-mooring-anchor foundation coupling, which includes a water pool, mooring cables, anchoring devices, and a test beam with guide rails located above the water pool;

[0007] There are multiple equidistant measuring points on the mooring rope, each of which is equipped with an inclinometer, an inductive magnetic ring and a tension sensor;

[0008] There are a measuring platform and a full-freedom oscillation device on the test beam; the measuring platform is equidistantly provided with inductive distance measuring sensors that sense the position of the inductive magnetic rings;

[0009] The full-freedom oscillation device includes a base, a lower arm, a middle arm, an upper arm, a rear plate, a middle plate and a front plate; the bottom of the measuring platform and the base is provided with a directional pulley moving along the guide rail;

[0010] A first motor is provided on the base to drive the lower arm to rotate in the XY plane, a second motor is provided between the middle arm and the lower arm to drive the middle arm to rotate in the XZ plane; a third motor is provided between the middle arm and the upper arm to drive the upper arm to rotate in the YZ plane; the upper arm is also provided with a motor assembly to drive the rear plate to rotate in the XZ plane;

[0011] The first hydraulic columns are distributed at the four corners above the rear plate, and the middle plate is located above the first hydraulic columns; the first hydraulic columns drive the middle plate to deflect through combined telescoping;

[0012] A first front plate with a transverse groove is provided above the center of the middle plate, and second front plates with longitudinal grooves are provided on both sides of the center of the middle plate; second hydraulic columns are installed in the transverse groove of the first front plate and the longitudinal groove of the second front plate; one end of a mooring cable is connected to the second hydraulic columns in the transverse and longitudinal grooves, and the other end of the mooring cable is connected to the anchor foundation;

[0013] A rod and a guide groove with a guide hole are provided on the measuring platform. One end of the rod passes through the guide hole of the guide groove and is connected with the base.

[0014] The upper arm comprises a cylindrical rod, and a concave shell is connected to the cylindrical rod.

[0015] The motor assembly is a fourth motor located on both sides of the concave shell and drives the rear plate to rotate in the XZ plane.

[0016] The mooring cable includes an embedded anchor chain section, a bottom-lying anchor chain section and a water-suspended cable section. There are multiple equidistant measuring points on the embedded anchor chain section, and inclinometers and inductive magnetic rings are provided on the equidistant measuring points.

[0017] The embedded section of the mooring cable forms an anti-catenary linear geometric section in the soil.

[0018] The first hydraulic column drives the middle plate to deflect in the XZ plane or the XY plane by telescoping.

[0019] The inductive distance measuring sensor includes a coil, an electrical signal processing device and an output device. The coil senses the position of the inductive magnetic ring, the electrical signal processing device calculates the distance to the inductive magnetic ring, and the output device outputs the buried depth of the inductive magnetic ring.

[0020] A fixing point for connecting a mooring rope is provided at the bottom of the second hydraulic column. The mooring rope is fixed and connected by tying, buckling or gluing according to the test requirements.

[0021] Guide grooves with guide holes are provided on both sides of the measuring platform, and one end of the rod passes through the guide hole of the guide groove and is connected to the base.

[0022] The second hydraulic column on the first front plate extends to drive the second hydraulic column on the second front plate to move the mooring rope along the longitudinal groove.

[0023] Working Principle: The present invention's real-time visualization of the platform-mooring-anchor foundation coupling mooring test device uses a water tank to simulate the subsoil, soil surface, and water components of the mooring system. Furthermore, a full-degree-of-freedom oscillation device is used to simulate a floating platform under complex sea conditions. The base of the full-degree-of-freedom oscillation device moves horizontally on a test beam, and the top of the base is connected to the lower arm via a motor. The lower arm is driven by a motor to move the device in the XY plane, while the middle and upper arms are driven by motors to move in the YZ plane. The front plate is driven in the XZ plane by the combined action of the hydraulic column, lower arm, middle arm, and upper arm, ultimately achieving full spatial freedom of movement of the rear plate, thereby simulating special operating conditions such as platform excursion. The front plate is fixedly connected to the mooring cable via a hydraulic column. The hydraulic column on the front plate is controlled to apply unidirectional or cyclic loads, simulating the complex operating conditions of the mooring platform, thereby comprehensively simulating the mooring system under the platform-mooring-anchor foundation coupling.

[0024] Compared to existing model tests, the present test device integrates the experimental content of previous model tests and takes into account the impact of the platform-mooring-anchor foundation coupling on the mooring system. Based on this, an inclinometer and an inductive distance sensor are used to monitor the inclination angle and burial depth of the mooring cable in the soil, and a tension sensor is used to collect the tension in the mooring cable. The inclinometer and an inductive magnetic ring are placed within the anchor chain at a certain distance. The inclinometer measures the inclination angle of the current anchor chain segment, while the inductive magnetic ring is sensed by the inductive distance sensor above, which in turn measures the burial depth of the current anchor chain segment. By measuring the inclination angle and burial depth of each anchor chain segment in real time, the shape of the embedded anchor chain segment in the soil is determined, and the cross-sectional motion trajectory of the anchor chain in the soil is observed in real time, achieving the purpose of real-time observation of the mooring cable movement in the soil. A full-degree-of-freedom oscillation device is used to simulate the platform's complex motion under real-world sea conditions, which is of great research significance for the dynamic response analysis of the mooring system.

[0025] Beneficial effects: Compared with the existing technology, the real-time visual mooring test device based on platform-mooring-anchor foundation coupling of the present invention has the following advantages:

[0026] (1) The experimental device of the present invention is a water tank test device for coupling the interaction between the platform and the mooring, the hydrodynamic response of the mooring, and the interaction between the mooring and the soil. It truly simulates the motion response of the soil part, the soil surface part and the water part of the mooring system under the combined action of environmental loads and complex working conditions, as well as the synergistic effect results. It makes up for the existing experimental devices that only explore local response characteristics, and comprehensively studies the mooring system under the coupling action of the platform-mooring-anchor foundation, thereby reducing the redundancy of the mooring system design and improving the economy of the mooring system.

[0027] (2) The experimental device of the present invention uses an inductive distance sensor, an inductive magnetic ring and an inclinometer to measure the position changes of the mooring cable in the soil in real time, which is conducive to exploring the motion response characteristics of mooring in the soil under environmental loads and complex working conditions.

[0028] (3) The experimental device of the present invention realizes special working conditions such as platform offset and the application of cyclic loads through a full-degree-of-freedom oscillation device, simulating the complex movement of the platform under real sea conditions, and providing real and diverse working conditions for studying the mooring system under the coupling of platform-mooring-anchor foundation.

[0029] (4) The experimental device of the present invention can meet different types of tests by changing some devices. It can adapt to pool tests with different mooring connection methods, different mooring numbers, different load application methods, different platform positions and different anchoring devices, and can be fully applied to the testing and research of various mooring systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the real-time visual mooring test device based on platform-mooring-anchor foundation coupling of the present invention;

[0031] Figure 2 This is a front view of the test device structure of the present invention;

[0032] Figure 3 This is a front view of the structure of the full-degree-of-freedom oscillation device of the present invention;

[0033] Figure 4 This is a rear view of the full-degree-of-freedom oscillation device structure of the present invention;

[0034] Figure 5 This is a left view of the full-degree-of-freedom oscillation device structure of the present invention;

[0035] Figure 6 Detailed schematic diagram of the anchor chain in the measuring section of the present invention;

[0036] Figure 7 Detailed schematic diagram of the inductive distance measuring sensor in the present invention;

[0037] Figure 8 This is a schematic diagram of the test device test work in the present invention;

[0038] Figure 9 Schematic diagram of the anchor chain for measuring the embedded soil section in the present invention;

[0039] Figure 10 A schematic diagram of adapting the test device of the present invention to various tests;

[0040] Figure (10-1) is a schematic diagram of the chain-soil double mooring test device;

[0041] Figure (10-2) is a schematic diagram of the double-mooring test device considering the influence of platform offset;

[0042] Figure (10-3) is a schematic diagram of the single mooring test device for exploring the chain-soil relationship;

[0043] Figure (10-4) is a schematic diagram of the experimental device for exploring the flat plate anchor penetration process. DETAILED DESCRIPTION

[0044] Reference numerals in the figure: 1. full-degree-of-freedom oscillation device; 2. water tank; 3. mooring rope; 4. inclinometer; 5. inductive distance sensor; 6. inductive magnetic ring; 7. tension sensor; 8. measuring platform; 9. rod; 10. test beam; 11. anchoring device; 12. coil; 13. electrical signal processing device; 14. output device; 15. motor; 16. hydraulic column; 17. base; 18. lower arm; 19. middle arm; 20. upper arm; 21. rear plate; 22. middle plate; 23. front plate; 24. directional pulley; 25. guide groove.

[0045] like Figure 1 and Figure 2 As shown, the real-time visualization mooring test device based on platform-mooring-anchor foundation coupling of the present invention includes a full-degree-of-freedom oscillation device 1, a water pool 2, a mooring cable 3, an inclinometer 4, an inductive distance sensor 5, an inductive magnetic ring 6, a tension sensor 7, a measuring platform 8, a rod 9, a test beam 10, an anchoring device 11 and a directional pulley 24.

[0046] There are multiple equidistant measuring points on the mooring rope 3, and the equidistant measuring points are provided with an inclinometer 4, an inductive magnetic ring 6 and a tension sensor 7.

[0047] The pool 2 provides the water and soil environment required for the test. A mooring cable 3 is installed in the pool 2, a test beam 10 is installed above the pool 2, and an anchoring device 11 is installed at the bottom. The mooring cable 3 includes an embedded anchor chain section, a bottom anchor chain section, and a submerged suspended cable section. One end of the mooring cable 3 is fixedly connected to the full-degree-of-freedom oscillation device 1, and the other end is connected in sequence to the tension sensor 7, the inductive magnetic ring 6, the inclinometer 4, and the anchoring device 11. Both the measuring platform 8 and the bottom of the full-degree-of-freedom oscillation device 1 have directional pulleys 24, which are mounted on the test beam 10 above the pool.

[0048] The measuring platform 8 is equipped with an inductive distance sensor 5 and has a directional pulley 24 at its bottom. The measuring platform 8 moves on the guide rail of the test beam 10 via the directional pulley 24 at its bottom. Two guide slots 25 are arranged on both sides of the upper surface of the measuring platform 8. The rod 9 is fixed through the holes in the guide slots 25 and is fixedly connected to the base 17 of the full-degree-of-freedom oscillation device 1 at its other end, allowing the measuring platform 8 and the full-degree-of-freedom oscillation device 1 to move simultaneously.

[0049] In this embodiment, according to different test types and requirements, rods 9 of different lengths are replaced to change the distance between the measuring platform 8 and the full-freedom oscillation device 1 .

[0050] like Figures 3 to 5As shown, the full-degree-of-freedom oscillation device 1 includes a motor 15, a hydraulic column 16, a base 17, a lower arm 18, a middle arm 19, an upper arm 20, a rear plate 21, a middle plate 22, a front plate 23, and a directional pulley 24, used to simulate a moored platform in water. The bottom of the base 17 is mounted on the test beam 10 via a directional pulley and moves horizontally on the test beam 10. The upper surface of the base 17 is connected to the lower arm 18 via a first motor; the lower arm 18 is sequentially connected to the middle arm 19, the upper arm 20, and the rear plate 21 via a second motor. The motors cause the upper arm 20, the middle arm 19, and the lower arm 18 to move in corresponding planes. The bottom surface of the lower arm 18, i.e., the XY plane, serves as the output side, and is driven by the first motor on the base 17 to rotate, thereby achieving rotational motion of the lower arm 18 in the XY plane.

[0051] The side surface of the lower arm 18 away from the base end, i.e., the XZ surface, is rigidly connected to the driving side of the second motor, and the XZ surface of the middle arm 19 is directly connected to the output end of the second motor. The second motor drives the middle arm 19 to rotate on the XZ surface through rotational motion, thereby enabling the middle arm 19 to realize rotational motion on the XZ plane through the second motor.

[0052] The middle arm 19 is rigidly connected to the driving side of the third motor at one end of the XZ surface away from the lower arm 18, and the output side of the third motor is axially connected to the ZY surface of the upper arm 20. The third motor drives the upper arm 20 to perform axial rotational motion on the XZ surface of the middle arm 19, thereby realizing rotational motion of the middle arm 19 and the upper arm 20 in the YZ plane through the third motor.

[0053] The upper arm 20 is formed by a cylindrical rod and a concave shell rigidly connected, forming an overall T-shape. The cylindrical rod is axially connected to the middle arm 19 via a third motor 15. A fourth motor is installed on both sides of the concave shell at the other end. The inner surface of the concave shell, i.e., the XZ surface, is rigidly connected to the drive side of the fourth motor. The output side of the fourth motor is connected to the side surface, i.e., the XZ surface, of the rear plate 21. The fourth motor drives the rear plate 21 to axially rotate on the XZ surface of the concave shell on both sides of the upper arm 20, thereby achieving rotational motion of the rear plate 21 in the XZ plane via the upper arm 20 and the fourth motor. In this embodiment, the concave shell is a concave rectangular shell.

[0054] In summary, through the rotational movement of the three motors on different planes, the lower arm 18, the middle arm 19 and the upper arm 20 are driven to move in the XY plane, the YZ plane and the XZ plane respectively; and the two fourth motors in the concave shell of the upper arm 20 make the rear plate 21 further rotate in the XZ plane. These multi-directional movements are finally transmitted to the rear plate 21 through the lower arm 18, the middle arm 19, the upper arm 20 and the fourth motor, so that the rear plate 21 moves and rotates in six degrees of freedom in space.

[0055] Four hydraulic columns 16 are arranged on the upper surface of the rear plate 21. By controlling the extension and contraction of each hydraulic column 16, the movement of the middle plate 22 in the XY plane and the XZ plane is controlled. In this embodiment, the hydraulic column on the rear plate 21 is the first hydraulic column. Figure 5 For example, if the two hydraulic columns 16 on the left are lifted and the two hydraulic columns on the right are lowered, the middle plate 22 is controlled to deflect to the right on the XY surface; if the two hydraulic columns on the upper side are lifted and the two hydraulic columns on the lower side are lowered, the middle plate is controlled to deflect downward on the XZ surface.

[0056] Three front panels 23 are arranged in the central area of ​​the center plate 22, located in three directions: above, to the left of, and to the right of the center. The first front panel, located above the center, has a transverse groove, while the second front panels, located on either side of the center, have vertical grooves. A hydraulic column 16 is positioned within each groove in the front panel, and the columns 16 move along the groove under the action of an external force. The ends of the hydraulic columns 16 are designed with rectangular lashing points for securing the mooring lines 3. Before testing, the mooring lines 3 are fixed to the rectangular lashing points at the bottoms of the three hydraulic columns 16 using ropes, loops, or adhesive, depending on the test requirements. This allows the movement of the mooring lines 3 to be controlled by adjusting the displacement of each hydraulic column 16. To better control the hydraulic columns 16 and adjust the movement of the mooring lines 3 during the test, all three hydraulic columns 16 are placed in the same telescopic displacement state before the test, with the initial displacement being in the middle position. In this embodiment, the hydraulic columns 16 installed on the first and second front panels are the second hydraulic columns.

[0057] The three hydraulic columns 16 on the front plate 23 control their own length and length, jointly moving in four directions: up, down, left, and right—i.e., motion in the YZ plane. Because the mooring lines 3 are fixedly connected to the rectangular lashing points at the bottoms of the three hydraulic columns, the motion of the three second hydraulic columns in the YZ plane is transmitted to the mooring lines 3. For example, if the top second hydraulic column extends, the vertical grooves on the bottoms of the left and right second hydraulic columns, along with the mooring lines 3, are fixedly connected. This pushes the left and right second hydraulic columns and the mooring lines 3 downward, i.e., motion in the negative Z-axis direction. If the left second hydraulic column extends while the right second hydraulic column shortens, the horizontal grooves on the bottoms of the top second hydraulic column, along with the mooring lines 3, are fixedly connected. This causes the top second hydraulic column and the mooring lines 3 to move rightward, i.e., motion in the positive Y-axis direction. Thus, the three hydraulic columns on the front plate 23, through their combined extension and retraction motion, impart motion in the YZ plane to the fixedly connected mooring lines 3.

[0058] To sum up, through the joint telescopic movement of multiple hydraulic columns 16, the rear plate 21, the middle plate 22, and the front plate 23 are driven to move in the XY plane, XZ plane, and YZ plane respectively. These multi-directional movements are ultimately transmitted to the connection end point of the mooring cable 3 through the rear plate 21, the middle plate 22, the front plate 23, and the hydraulic columns 16, so that the connection end point of the mooring cable 3 moves in six degrees of freedom in space.

[0059] The rear plate 21 is moved by the upper arm 20, the middle arm 19 and the lower arm 18, and the rear plate 21 is connected to the front plate 23 through the first hydraulic column, thereby driving the front plate 23 to move, thereby simulating the platform movement in a real ocean environment, and at the same time, one end of the mooring cable 3 connected to the front plate 23 moves, thereby simulating the interaction of the structural platform with the mooring system in a real ocean environment.

[0060] The present invention realizes the position and angle control of the rear plate 21 in six degrees of freedom in space through the combined movement of the motor 15, the lower arm 18, the middle arm 19 and the upper arm 20, and then the rear plate 21 transmits the movement to the middle plate 22, the front plate 23 and the connection end point of the mooring cable 3 through the connected first hydraulic column, finally realizing the position and angle control of the full-freedom oscillation device 1 in six degrees of freedom in space.

[0061] Combine Figures 3 to 5 , adjust the test device of the present invention to Figure 10-2 The specific operation is as follows: the lower arm 18 rotates counterclockwise to the Y axis on the XY plane through the first motor, so that Figure 10-2 The full-degree-of-freedom oscillator 1 in the figure moves counterclockwise on the XY plane to the position shown in the figure; the middle arm 19 drives one side of the output end to rotate in the XZ plane close to the X-axis through the second motor, driving the full-degree-of-freedom oscillator 1 in Figure 10-2 to move counterclockwise downward on the XZ plane until it reaches the predetermined target position of the test; the upper arm 20 drives the rear plate 21 to perform axial rotational movement in the YZ plane through the third motor, causing the rear plate 21 to rotate in the YZ plane, thereby achieving the predetermined angle required for the test in the YZ plane. In summary, controlling the motors between the lower arm 18, the middle arm 19, and the upper arm 20 enables the full-degree-of-freedom oscillator to move in six degrees of freedom in space to meet the test requirements for different points on the mooring cable 3.

[0062] like Figure 3 and Figure 5As shown, by adjusting the length of the first hydraulic ram between the rear plate 21 and the middle plate 22, the front plate 23 is moved forward and backward, thereby applying multi-directional motion to the mooring line 3 connected to it. By repeatedly controlling the length of the second hydraulic ram, a reciprocating motion is imparted to the mooring line 3, simulating the cyclic loading applied to the mooring system by the platform under wind and wave conditions. Thus, the multi-directional motion control of the end connected to the mooring line 3 is achieved through the first hydraulic ram between the middle plate 22 and the rear plate 21 and the second hydraulic ram on the front plate, thereby simulating the multi-directional motion of the platform under complex operating conditions and the cyclic loading applied to the mooring system.

[0063] like Figure 6 As shown, inclinometers 4 are evenly spaced along mooring line 3 and connected to mooring line 3 and inductive magnetic ring 6. They measure the instrument's horizontal angle in real time and infer the inclination angle of a small section of mooring line 3 at each end of inclinometer 4. Tension sensors 7 are installed on mooring line 3 to measure the tension acting on it.

[0064] The present invention provides a real-time visual mooring test method based on platform-mooring-anchor foundation coupling, comprising the following steps:

[0065] (1) Connect one end of the mooring cable 3 to the fixed anchoring device 11, and the other end to the full-freedom oscillation device 1 through the soil and water. Figure 8 As shown, the entire mooring cable 3 is divided into an embedded section in the soil, a bottom section lying on the soil, and an underwater section in the water. The intersection of the embedded section and the bottom section (the intersection of the soil and the water in the mooring cable 3) is called the embedded point. The embedded point is located above the soil and can be observed with the naked eye. The position is directly recorded using a relevant tool ruler.

[0066] like Figure 9 As shown, N equally spaced measurement points (five for example) are distributed along the mooring cable 3. At each measurement point, an inclinometer 4 and an inductive magnetic ring 6 are installed on the mooring cable 3. The inclinometer 4 measures the horizontal angle of the instrument itself and determines the inclination angle of the mooring cable 3 at both ends of the inclinometer 4, which is recorded as θ. The inductive magnetic ring 6 is sensed by the inductive distance sensor 5 above it, which then measures the buried depth of the mooring cable 3 at both ends of the inductive magnetic ring 6, which is recorded as Y.

[0067] The calculation method of burial depth is as follows: Figure 7As shown, the inductive distance measuring sensor 5 includes a coil 12, an electrical signal processing device 13, and an output device 14. The inductive distance measuring sensor 5 is equidistantly arranged on the measuring platform. The coil 12 generates an alternating magnetic field, which senses the position of the underlying inductive ring 6. The electrical signal processing device 13 calculates the distance between the coil 12 and the inductive ring 6, and the output device 14 outputs the distance D between the coil 12 and the underlying inductive ring 6. The distance U between the measuring platform and the soil surface is then subtracted from this distance D to determine the burial depth Y of the mooring cable 3 on either side of the inductive ring 6, i.e., Y = DU.

[0068] (2) The inclination angle and burial depth measured at each different measuring point are recorded as θ1 and Y1, θ2 and Y2, θ3 and Y3, θ4 and Y4, and θ5 and Y5. At the same time, the connection point of the mooring cable 3 on the anchoring device 11 is used as the coordinate origin, and a coordinate system is established with the X axis as the horizontal direction and the Y axis as the vertical direction. During the experiment, the position of the embedded point of the mooring cable 3 at the junction of the soil and the water body is recorded in real time. Given the origin position, the embedded point position, and the inclination angle and burial depth of the measuring point, a broken line graph is obtained by connecting the origin, the measuring point, and the embedded point in sequence. The broken line graph is then fitted into a curve graph through the inclination angle of each measuring point. The curve graph is the cross-sectional geometry of the embedded section of the mooring cable 3 in the soil.

[0069] (3) In addition, the accuracy of measuring the embedded section's profile geometry can be improved by increasing the number of measurement points. Since the inclinometer 4 and the inductive distance sensor 5 record the inclination angle and burial depth of the measurement points in real time, and the origin position is fixed and the embedding point position is directly measured, the embedded section's profile geometry of the mooring cable 3 can be calculated in real time, thereby deriving the profile motion characteristics of the embedded section of the anchor chain during the experiment.

[0070] like Figure 10-3 As shown, a single mooring experiment is used as an example. A single mooring line 3 is divided into three sections: a soil-embedded section, a subsurface section, and a submerged section. Inclinometers 4 and inductive magnetic rings 6 are evenly spaced within the soil-embedded section to measure the inclination angle and burial depth of the embedded section. One end of the mooring line 3, the soil-embedded section, is directly connected to the anchor foundation 11, while the other end, the submerged section, is connected to a full-degree-of-freedom oscillation device.

[0071] Before the test begins, one end of the mooring cable 3 is connected to the anchoring device 11, and the other end is connected to the full-freedom oscillation device 1; soil and water are then added to the pool 2 in sequence; a measuring platform 8 is installed on the test beam 10, and the rod 9 is connected to the base of the full-freedom oscillation device 1 through the guide groove 25 on the measuring platform 8. The length of the rod 9 is determined by the length of the mooring cable 3. After completing the test preparations, the full-freedom oscillation device 1 is controlled to move and tow the mooring cable 3. In addition, if Figure 10-2 As shown, the position and angle of the rear plate 21 in the full-degree-of-freedom oscillation device 1 are controlled to change the position of the connected front plate 23, thereby changing the connection position of the mooring cable 3 and the front plate 23, thereby simulating the impact of the platform position change on the mooring system to represent the special working condition of the platform offset.

[0072] At the same time, if Figure 3 and Figure 5 As shown, the first hydraulic column between the middle plate 22 and the rear plate 21 and the second hydraulic column on the front plate cause the cable to reciprocate up and down, achieving multi-directional motion control of the end connected to the mooring cable 3. This simulates the multi-directional displacement of the platform under complex working conditions and the cyclic loading of the mooring system. During the towing process, the embedded section of the mooring cable 3 interacts with the soil, forming an anti-catenary linear geometric cross-sectional characteristic in the soil. The bottom section of the mooring cable 3 interacts with the soil surface due to the towing motion and its own gravity, leaving a groove. The submerged section of the mooring cable 3 interacts with the water. The movement of the front plate on the full-degree-of-freedom oscillation device 1 simulates the platform's motion, forming a real-time visualization single mooring test device based on the platform-mooring-anchor foundation coupling. Therefore, measurement data from the inclinometer 4, the inductive distance sensor 5, and the tension sensor 7 are collected. Based on this data, the cross-sectional motion and tension characteristics of the single mooring cable 3 based on the platform-mooring-anchor foundation coupling can be explored.

[0073] like Figure 10 As shown, from top to bottom, there are a chain-soil double-mooring test rig, a double-mooring test rig considering the influence of platform offset, a chain-soil single-mooring test rig, and a test rig for exploring the penetration process of a flat plate anchor. The chain-soil double-mooring test rig uses two mooring cables 3, one end of which is fixed to the anchor devices 11 on both sides and the other end is connected to the full-degree-of-freedom oscillation device 1. By controlling the position and angle of the full-degree-of-freedom oscillation device 1, displacement and load can be applied to the mooring cables 3, or complex working conditions such as platform offset can be simulated. The chain-soil single-mooring test rig is similar to the double-mooring test rig, but only requires a single mooring cable 3, one end of which is fixed to the central anchor device 11. The test rig for exploring the penetration process of a flat plate anchor requires a flat plate anchor model, connected to one end of the mooring cable 2 and the other end to the full-degree-of-freedom oscillation device 1. As the test progressed, the full-degree-of-freedom oscillation device 1 moved rightward, driving the flat anchor at one end of the mooring cable 3 into the soil, simulating the installation process of the flat anchor during towing. The mooring cable, inductive magnetic ring, inclinometer, tension sensor, and anchoring device used in these tests were adapted to varying degrees based on test requirements, allowing for diverse testing using the same setup.

Claims

1. A real-time visual mooring test device based on platform-mooring-anchor foundation coupling, characterized by: It comprises a water pool (2), a mooring rope (3), an anchoring device (11), and a test beam (10) with a guide rail located above the water pool (2); There are a plurality of equidistant measuring points on the mooring rope (3), and the equidistant measuring points are provided with an inclinometer (4), an inductive magnetic ring (6) and a tension sensor (7); The test beam (10) is provided with a measuring platform (8) and a full-freedom oscillation device (1); the measuring platform (8) is provided with an inductive distance measuring sensor (5) for sensing the position of the inductive magnetic ring (6); The full-freedom oscillation device (1) comprises a base (17), a lower arm (18), a middle arm (19), an upper arm (20), a rear plate (21), a middle plate (22) and a front plate (23); the bottom of the measuring platform (8) and the base (17) is provided with a directional pulley that moves along the guide rail; The base (17) is provided with a first motor for driving the lower arm (18) to rotate in the XY plane; a second motor for driving the middle arm (19) to rotate in the XZ plane is provided between the middle arm (19) and the lower arm (18); a third motor for driving the upper arm (20) to rotate in the YZ plane is provided between the middle arm (19) and the upper arm (20); and a motor assembly for driving the rear plate (21) to rotate in the XZ plane is also provided on the upper arm (20); First hydraulic columns are distributed at the four corners above the rear plate (21), and the middle plate (22) is located above the first hydraulic columns; the first hydraulic columns are extended and retracted by combination to drive the middle plate (22) to deflect; A first front plate with a transverse groove is provided above the center of the middle plate (22), and second front plates with longitudinal grooves are provided on both sides of the center of the middle plate (22); second hydraulic columns are installed in the transverse groove of the first front plate and the longitudinal groove of the second front plate; one end of the mooring cable (3) is connected to the second hydraulic column in the transverse groove and the longitudinal groove, and the other end of the mooring cable (3) is connected to the anchor foundation (11); The measuring platform (8) is provided with a rod (9) and a guide groove (25) with a guide hole, and one end of the rod (9) passes through the guide hole of the guide groove (25) and is connected to the base (17).

2. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 1 is characterized by: The upper arm (20) comprises a cylindrical rod, to which a concave housing is connected.

3. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 2 is characterized by: The motor assembly is a fourth motor located on both sides of the concave housing and driving the rear plate (21) to rotate in the XZ plane.

4. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 1 is characterized in that: The mooring cable (3) comprises an embedded anchor chain section, a bottom-lying anchor chain section and a submerged suspended cable section. The embedded anchor chain section is provided with a plurality of equidistant measuring points, and the equidistant measuring points are provided with inclinometers (4) and inductive magnetic rings (6).

5. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 1 is characterized in that: The embedded segment anchor chain of the mooring cable (3) forms an anti-catenary linear geometric section in the soil.

6. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 1 is characterized by: The first hydraulic column drives the middle plate (22) to deflect in the XZ plane or the XY plane through combined telescoping.

7. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 1 is characterized by: The inductive distance measuring sensor (5) comprises a coil (12), an electrical signal processing device (13) and an output device (14); the coil (12) senses the position of an inductive magnetic ring (6); the electrical signal processing device (13) calculates the distance to the inductive magnetic ring (6); and the output device outputs the buried depth of the inductive magnetic ring (6).

8. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 1 is characterized by: A fixing point for connecting a mooring rope (3) is provided at the bottom of the second hydraulic column.

9. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 1 is characterized by: Guide grooves (25) with guide holes are provided on both sides of the measuring platform (8), and one end of the rod (9) passes through the guide holes of the guide grooves (25) and is connected to the base (17).

10. The real-time visual mooring test device based on platform-mooring-anchor foundation coupling according to claim 1, characterized in that: The second hydraulic column on the first front plate extends to drive the second hydraulic column on the second front plate to drive the mooring rope (3) to move along the longitudinal groove.

Images