Ship bottom plate grounding simulation test device and method using relative motion

Abstract

The present invention relates to a grounding simulation test device for a ship bottom plate using relative motion, which includes a test plate, a reef model, a triaxial force sensor, an adjustable fixing fixture, a movable reef base and a guide rail frame; the adjustable fixing fixture includes a lifting column, a hydraulic tilting device and a fixture plate connected in sequence, and the fixture plate is used for fixedly installing the test plate, and the height and tilting angle of the test plate are adjusted through the lifting column and the hydraulic tilting device respectively; the movable reef base is installed on the guide rail frame through a sliding device, the lower end of the triaxial force sensor is connected to the movable reef base, and the upper end is connected to the reef model; the movable reef base is moved to the acceleration section of the guide rail frame and then released, so that the reef model acts on the test plate with a certain initial kinetic energy to simulate the ship grounding process. The present invention utilizes relative motion, which not only considers the dynamic effect of the ship grounding process, but also ensures the simplicity of installation and replacement, the operability of adjusting relevant parameters, and the feasibility of monitoring relevant data.

Description

Technical Field

[0001] The present invention relates to the technical field of ship grounding tests, and particularly relates to a ship bottom plate grounding simulation test device and method using relative motion. Background Art

[0002] With the rapid development of economy and science and technology, ships are developing towards large tonnage and high speed, and ship shipping is becoming increasingly busy. This has also led to the fact that ship grounding accidents have always been one of the most frequent and serious maritime accidents, which may bring serious consequences such as hull damage, casualties, property losses, and environmental pollution caused by oil spills. Therefore, studying the ship grounding damage mechanism has important guiding significance for ship design and construction, the establishment of navigation regulations, and rescue work after a grounding accident occurs.

[0003] However, due to the huge volume of ships and the relatively complex process of ship grounding, which belongs to a destructive test, full-scale ship grounding tests are often costly and difficult to control; for full-scale ship scaled-down model grounding tests, due to difficulties such as scale effects and boundary control, their accuracy and controllability still need to be improved; although static cutting tests are relatively easy to control, they ignore the dynamic effects in ship grounding. Therefore, there is still a great lack of a large amount of reliable dynamic grounding test data.

[0004] Moreover, with the demand for shipping and the development of shipbuilding and materials science, the ship type, plate structure, and hull materials are constantly updated and optimized. Considering the serious consequences of ship grounding accidents, in order to study the grounding damage mechanism of the bottom plates of existing and continuously updated and advanced new ships and meet the safety requirements of the existing hull structures, a ship bottom plate grounding test simulation device that is easy to operate and control, has high accuracy, and low cost is needed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a ship bottom plate grounding simulation test device and method using relative motion in view of the deficiencies of the above-mentioned existing technologies. By using relative motion and combining corresponding fixing devices, both the dynamic effects in the ship grounding process are considered, and the simplicity of installation and replacement, the operability of adjusting relevant parameters, and the feasibility of monitoring relevant data are ensured.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] A ship bottom plate grounding simulation test device using relative motion, including a test plate, a reef model, and a triaxial force sensor, further including an adjustable fixing fixture, a movable reef base, and a guide rail frame; the adjustable fixing fixture includes a lifting column, a hydraulic tilting device, and a fixture plate. The height of the lifting column can be adjusted. The lower end of the lifting column is fixed to the ground, and the upper end is installed with the hydraulic tilting device. The fixture plate is installed on the top of the hydraulic tilting device for fixedly installing the test plate. The height of the test plate is adjusted by the lifting column to simulate different grounding heights, and the tilting angle of the test plate is adjusted by the hydraulic tilting device to simulate different grounding angles;

[0008] The movable reef base includes a base body and a sliding device installed on the base body; the guide rail frame includes an acceleration section and a horizontal section; the movable reef base is installed on the guide rail frame through the sliding device. The lower end of the triaxial force sensor is connected to the movable reef base, and the upper end is connected to the reef model; by moving the movable reef base to the acceleration section of the guide rail frame and then releasing it, the reef model acts on the test plate with a certain initial kinetic energy to simulate the process of ship grounding.

[0009] In the above solution, the test device further includes a high-speed camera system and a three-dimensional digital speckle strain measurement system. The high-speed camera system is installed on one side of the horizontal section of the guide rail frame for monitoring the movement of the reef model, and the three-dimensional digital speckle strain measurement system is used to capture the full-field strain of the test plate.

[0010] In the above solution, marker points are pasted on the base body of the movable reef base, and the high-speed camera system records the velocity change when the reef model interacts with the test plate by tracking the marker points.

[0011] In the above solution, the adjustable fixing fixture further includes a base plate, which includes an upper base plate and a lower base plate. The lower base plate is horizontally fixed to the top of the lifting column. The upper base plate is hinged to one side of the lower base plate. The hydraulic tilting device is arranged between the upper base plate and the lower base plate for adjusting the tilting angle of the upper base plate; the fixture plate is installed on the upper base plate.

[0012] In the above solution, the fixture plate includes an upper fixture plate and a lower fixture plate. The lower fixture plate is fixedly installed on the surface of the upper base plate. The test plate is installed between the lower fixture plate and the upper fixture plate. The lower fixture plate, the test plate, and the upper fixture plate are fixedly connected in a detachable manner.

[0013] In the above solution, the movable reef base further includes a counterweight screw installed below the base body and a number of counterweight weights installed on the counterweight screw, which are used to change the total mass of the movable reef base, thereby changing the magnitude of the initial kinetic energy in the grounding test.

[0014] In the above solution, the movable reef base further includes a lifting connecting platform, which is used to connect the triaxial force sensor. The lifting connecting platform can change its own height, so as to accurately set the initial relative height between the reef model and the test plate.

[0015] In the above solution, the guide rail frame further includes anti-rollover plates arranged on both sides of the horizontal section and a protective tail post arranged at the end of the horizontal section.

[0016] In the above solution, the triaxial force sensor includes a sensor main shaft, a sensor upper connecting plate and a sensor lower connecting plate respectively arranged at both ends of the sensor main shaft. The sensor lower connecting plate is connected to the movable reef base, and the sensor upper connecting plate is connected to the reef model.

[0017] Correspondingly, the present invention also proposes a method for simulating the grounding of a ship bottom plate using relative motion. Using the above device, it includes the following steps:

[0018] S1. Fix the test plate on the adjustable fixture according to the test plate structure form, test plate size, relative grounding height H, and grounding angle α, and adjust the lifting column and hydraulic tilting device in the adjustable fixture to make the center of gravity of the test plate reach a certain height H 1 , and the test plate forms a certain angle α with the vertical direction;

[0019] S2. Select the reef model to be used according to the relative grounding height H, and adjust the lifting connecting platform in the movable reef base to make the tip of the reef model reach a certain height H when the movable reef base is on the horizontal section of the guide rail frame 2 , and the relative grounding height H in the test condition is H 2 -H 1 ;

[0020] S3. Add counterweight weights on the movable reef base and fix them according to the initial grounding kinetic energy E k , initial grounding velocity V 0 to make the total mass of the whole movable reef base reach M. The total mass M is obtained based on the kinetic energy calculation formula M = 2E k / (V 0 ·V 0 );

[0021] S4. According to the initial grounding velocity V 0 , fix the movable reef base at a certain initial height Hv on the guide rail frame with a rope. Hv is calculated based on the law of conservation of energy to obtain H v = V 0 2 2g;

[0022] S5. Stick fiducial points on the substrate in the movable reef base, and arrange and adjust the high-speed photography system to the optimal angle; spray speckles on the upper surface of the test plate, and arrange and adjust the three-dimensional digital speckle strain measurement system to the optimal angle.

[0023] S6. Cut off the rope, and the movable reef base will slide down along the track frame to the horizontal section. The reef model will interact with the test plate at the set initial stranding velocity V 0 and the test plate will show varying degrees of deformation and damage based on the test conditions; the high-speed photography system

[0024] S7. Change the structural form of the test plate, replace the reef model, replace the counterweight, and set different relative stranding heights H, stranding angles α, initial stranding kinetic energies E k , initial stranding velocities V 0 , and repeat steps S1 to S6 to conduct ship bottom plate stranding simulation test studies under different conditions.

[0025] The beneficial effects of the present invention are as follows:

[0026] 1. The device of the present invention utilizes the relative motion principle. The reef model is installed on the movable reef base to endow it with initial kinetic energy, and the test plate is fixed by an adjustable fixture to simulate the stranding process of the ship bottom plate - reef model. On the basis of considering the dynamic effects during the stranding process, the experimental device is simplified, and at the same time, the operability (measurability of test results) and controllability (precise control of test initial conditions) of the test are enhanced.

[0027] 2. The device of the present invention utilizes the relative motion principle and adopts the method of a reef impacting and fixing the ship bottom plate to simulate the ship bottom plate - reef stranding process. Its advantages are: it can fix and narrow the test monitoring range to obtain more effective data (such as the full-field strain of the test plate, etc.); it can be applied to ship bottom plates with more structures and sizes (if the structure of the ship bottom plate needs to be accelerated, its size will be greatly restricted by the size of the guide rail frame, etc.); it can simulate more test conditions, such as not being limited to the self-weight of the test plate, and the initial stranding kinetic energy can be changed by changing the counterweight of the movable reef base, while avoiding the interference of the counterweight on the test plate structure, ensuring the accuracy of the research.

[0028] 3. The design of the combined fixture of the present invention is not only convenient for installation and disassembly, but also can adapt to the installation of test plates with multiple sizes and different structural test plates (single plate, longitudinally stiffened plate, transversely stiffened plate, longitudinally and transversely stiffened plate, sandwich plate, double bottom). By fixing the measurement range, it is convenient for the three-dimensional digital speckle strain measurement system (DIC) to obtain the full-field strain of the test plate; by pasting a fiducial point on the left side of the square substrate during the test, the high-speed camera system can record the velocity change when the reef model interacts with the test plate by tracking this fiducial point; thus ensuring the measurability of the test results.

[0029] 4. In the present invention, the application of the liftable column and the liftable connecting platform enables the change of the initial grounding height of the test, and the combination of the tiltable hydraulic device and the fixed base plate enables the change of the relative angle between the bottom plate of the ship and the reef during the test, fully simulating the relative movement in the horizontal and vertical directions during the ship grounding process. At the same time, combined with the adjustable design of the initial kinetic energy and height of the reef model, this device realizes a ship model grounding test with adjustable multi-parameters (initial grounding speed, initial kinetic energy of grounding, grounding height, grounding angle, bottom plate form).

[0030] 5. The device of the present invention has a simple structure, convenient operation, reliable operation, strong repeatability, and reduces the cost of such destructive tests. Description of the Drawings

[0031] The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0032] Figure 1 is the overall structural schematic diagram of a ship bottom plate grounding simulation test device using relative movement according to the present invention;

[0033] Figure 2 is Figure 1 the three-dimensional view of the guide rail frame of the test device shown;

[0034] Figure 3 is Figure 1 the schematic diagram of the movable reef base of the test device shown;

[0035] Figure 4 is Figure 1 the schematic diagram of the three-axis force sensor shown;

[0036] Figure 5 is Figure 1 the schematic diagram of the reef model shown;

[0037] Figure 6 is Figure 1 the schematic diagram of the adjustable fixed fixture of the test device shown;

[0038] Figure 7 is Figure 6 the schematic diagram of the liftable column and the tiltable base plate in the adjustable fixed fixture of the test device shown;

[0039] Figure 8 is Figure 7 the schematic diagram of the hydraulic tilt device shown;

[0040] Figure 9 is Figure 6 the schematic diagram of the lower fixture plate and the upper fixture plate shown.

[0041] In the figure: 10, test plate;

[0042] 20. Reef model; 21. Reef body; 22. Reef connecting screw;

[0043] 30. Adjustable fixing fixture; 31. Lifting column; 311. Fixed column foot; 312. Column body; 313. Lifting knob; 32. Hydraulic tilting device; 321. Hydraulic shaft; 322. Hinge rotating shaft; 323. Shaft end fixing; 324. End shaft sleeve; 325. Cylindrical support; 33. Substrate; 331. Upper substrate; 332. Lower substrate; 34. Upper fixture plate; 341. First upper fixture plate block; 342. Second upper fixture plate block; 35. Lower fixture plate;

[0044] 40. Movable reef base; 41. Matrix; 42. Sliding device; 43. Counterweight screw; 44. Fixed bolt; 45. Lifting connecting platform; 46. Counterweight; 47. Pull ring;

[0045] 50. Guide rail frame; 51. Acceleration section; 52. Horizontal section; 53. Anti-rollover plate; 54. Protective tail post;

[0046] 60. Triaxial force sensor; 61. Sensor main shaft; 62. Sensor upper connecting plate; 63. Sensor lower connecting plate;

[0047] 70. High-speed camera system;

[0048] 80. 3D digital speckle strain measurement system. Detailed implementation manners

[0049] For a clearer understanding of the technical features, objectives, and effects of the present invention, the detailed implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

[0050] As Figure 1 shown, a ship bottom plate stranding simulation test device using relative motion provided by an embodiment of the present invention includes a test plate 10, a reef model 20, a combined adjustable fixing fixture 30 for fixing the test plate 10, a movable reef base 40 for installing the reef model 20 and capable of driving the reef model 20 to move, a guide rail frame 50 for restricting the movable reef base 40, a triaxial force sensor 60 for measuring the stranding force, a high-speed camera system 70 for monitoring the movement of the reef model 20, and a 3D digital speckle strain measurement system (DIC) 80 for capturing the full-field strain of the test plate 10.

[0051] As Figure 2As shown in the figure, the guide rail frame 50 for restricting the movement track of the movable reef base 40 and providing initial kinetic energy by converting gravitational potential energy includes an acceleration section 51, a horizontal section 52, an anti-rollover plate 53, and a protective tail post 54. In the test, the movable reef base 40 is first placed at a certain height H position in the acceleration section and released. The movable reef base 40 drives the reef model 20 to accelerate through the sliding device 42 in the acceleration section 51 of the guide rail frame 50, so that the movable reef base 40, the triaxial force sensor 60, and the reef model 20 as a whole obtain an initial kinetic energy, and then act on the test plate 10 in the horizontal section 52 to simulate the grounding of the ship bottom plate. The anti-rollover plates 53 are arranged on both sides of the horizontal section 52, and the distance from the horizontal section 52 is slightly larger than the diameter of the pulley shaft of the pulley group of the sliding device 42. The anti-rollover plates 53 do not increase friction as much as possible and prevent the reef base 40 from tipping over during the grounding process. The protective tail post 54 can prevent the movable reef base 40 from detaching from the guide rail frame 50.

[0052] As Figure 3 As shown in the figure, the movable reef base 40 includes a square base 41, a sliding device 42, a counterweight screw 43, a fixing bolt 44, a lifting connection platform 45, a counterweight weight 46, and a pull ring 47. The movable reef base 40 is a left-right symmetric device. Among them, the sliding device 42 is composed of several pulley groups, arranged on both sides of the base 41, and matches the guide rail frame 50. The lifting connection platform 45 is arranged on the top of the base 41. There are several internal threaded holes on the lifting connection platform 45, which can be connected to the triaxial force sensor 60 through bolts. The lifting connection platform 45 can accurately set the initial relative height between the reef model 20 and the test plate 10 by changing its own height, thereby indirectly adjusting the grounding depth of the reef model 20. There are 4 pull rings 47 of the same size on the back and both sides of the square base 41, which can be used for the traction of the rope at the beginning of the test (after being pulled to a certain set height H of the guide rail frame 50, the rope is cut and it moves downward along the guide rail frame 50). A counterweight screw 43 is arranged at the bottom of the square base 41, and a counterweight weight 46 can be added on it and fixed through the fixing bolt 44, which is used to change the total mass of the movable reef base 40, thereby changing the initial kinetic energy size in the test. A marking point is pasted on the left side of the square base 41 during the test. The high-speed imaging system 70 can record the speed change when the reef model 20 interacts with the test plate 10 by tracking this marking point.

[0053] As Figure 4 As shown in the figure, the triaxial force sensor 60 includes a sensor main shaft 61 and a sensor upper connecting plate 62 and a sensor lower connecting plate 63 respectively arranged at both ends of the sensor main shaft 61. There are several through holes on both the sensor upper connecting plate 62 and the sensor lower connecting plate 63. The sensor upper connecting plate 62 is connected to the reef model, and the sensor lower connecting plate 63 is connected to the lifting connection platform 45 in the movable reef base 40 through bolts.

[0054] AsFigure 5 As shown in the figure, the reef model 20 includes a reef body 21 and reef connection screws 22. The reef connection screws 22 are used to connect with the sensor upper connecting plate 62 of the triaxial force sensor 60. The reef body 21 is the part that mainly acts on the test plate 10.

[0055] As Figure 6 shown in the figure, the adjustable fixing fixture 30 includes: lifting columns 31, a hydraulic tilting device 32, a base plate 33, an upper fixture plate 34, and a lower fixture plate 35. There are a total of four lifting columns 31, and their installation positions can be changed according to the size of the test plate 10. They are fixed to the ground through the fixed column feet 311 at their lower ends, which is convenient for adjustment and disassembly, and ensures that the movable reef base 40 is not blocked during the stranding process, guaranteeing the acquisition of the stranding speed by the high-speed imaging system 70 during the stranding process. Each lifting column includes: a fixed column foot 311, a column body 312, and a lifting knob 313. A simple hydraulic lifting device is provided inside the column body 312, and the height of the column body 312 can be adjusted through the lifting knob 313, thereby changing the relative height between the test plate 10 and the reef model 20, as Figure 7 shown in the figure.

[0056] The base plate 33 includes an upper base plate 331 and a lower base plate 332. A number of internal threaded holes are provided on the upper base plate 331 for connecting with the lower fixture plate 35, and the lower base plate 332 is horizontally welded to the top of the lifting column 31. A hydraulic tilting device 32 is provided between the upper base plate 331 and the lower base plate 332 for adjusting the tilting angle of the upper base plate 331, thereby adjusting the stranding angle between the test plate 10 and the reef model 20.

[0057] As Figure 8 shown in the figure, the hydraulic tilting device 32 includes: a hydraulic shaft 321, a hinge rotating shaft 322, shaft end fixation 323, an end shaft sleeve 324, and a cylindrical support 325. The upper base plate 331 and the lower base plate 332 are hinged through the hinge rotating shaft 322. The hydraulic shaft 321 is arranged between the upper base plate 331 and the lower base plate 332, and the upper base plate 331 can be driven to rotate around the hinge rotating shaft 322 to a set angle through the hydraulic shaft 321. The shaft end fixation 323 and the end shaft sleeve 324 are used for the installation, fixation, and use in cooperation with the hinge rotating shaft 322. The cylindrical support 325 is the fulcrum when the upper base plate is parallel to the lower base plate.

[0058] The thicknesses of both the upper fixture plate 34 and the lower fixture plate 35 are more than 10 times the thickness of the test plate 10, which is used to ensure the fixed support boundary conditions. The upper fixture plate 34 is of a split type and can be replaced arbitrarily according to the structure of the test plate 10. As Figure 9 shown in the figure, it includes two pieces, namely a first upper fixture plate block 341 and a second upper fixture plate block 342; the lower fixture plate 35 is of a frame type, and a number of threaded holes are provided on both the upper fixture plate 34 and the lower fixture plate 35, which can be used to fix the test plate 10 and connect with the base plate 33.

[0059] The device of the present invention utilizes the principle of relative motion. The reef model 20 is installed on the movable reef base 40 to endow it with initial kinetic energy. The test plate 10 is fixed by the adjustable fixture 30 to simulate the grounding process of the ship bottom plate - reef model, which simplifies the experimental device, fixes the measurement range, and facilitates the acquisition of the full-field strain of the test plate 10 by the three-dimensional digital speckle strain measurement system (DIC) 80. On the basis of considering the dynamic effects during the grounding process, this device simplifies the test device, making it convenient to operate, reliable in operation, highly repeatable, and reducing the cost of such destructive tests. At the same time, this device realizes the ship model grounding test with adjustable multi-parameters (initial grounding speed, initial grounding kinetic energy, grounding height, grounding angle, ship bottom plate form).

[0060] Correspondingly, the present invention also proposes a ship bottom plate grounding simulation test method using relative motion. This method is carried out by using the above device and includes the following steps:

[0061] S1. According to the test conditions (including the structure form of the test plate, the size of the test plate, the relative grounding height H, the grounding angle α), fixedly install the test plate 10 on the adjustable fixture 30, and adjust the lifting knob 313 of the lifting column 31 and the hydraulic tilting device 32 in the adjustable fixture 30 to make the center of gravity of the test plate 10 reach a certain height H 1 , and the test plate forms a certain angle α with the vertical direction;

[0062] S2. According to the test conditions (including the relative grounding height H), select the used reef model 20, and adjust the lifting connecting platform 45 in the movable reef base 40 to make the tip of the reef model 20 reach a certain height H when the movable reef base 40 is on the horizontal section 52 of the guide rail frame 50 2 , and the relative grounding height H in the test conditions = H 2 - H 1 ;

[0063] S3. According to the test conditions (initial grounding kinetic energy E k , initial grounding speed V 0 ), add counterweight weights 46 on the movable reef base 40 and fix them to make the total mass of the whole movable reef base 40 reach M. The total mass M can be obtained based on the kinetic energy calculation formula as M = 2E k / (V 0 · V 0 );

[0064] S4. According to the test conditions (initial grounding speed V 0 ), fix the movable reef base 40 at a certain initial height Hv on the guide rail frame with a rope. Hv can be calculated based on the law of conservation of energy as H v = V 0 2 2g;

[0065] S5. Stick fiducial points on the square base body 41 in the movable reef base 40, and arrange and adjust the high-speed photography system 70 to the optimal angle; spray speckles on the upper surface of the test plate 10, and arrange and adjust the three-dimensional digital speckle strain measurement system (DIC) 80 to the optimal angle.

[0066] S6. Cut off the rope, and the movable reef base 40 will slide down along the track frame 50 to the horizontal section 52, and the reef model 20 will interact with the test plate 10 at the set initial grounding velocity V 0 The test plate 10 will exhibit varying degrees of deformation damage (dents, tears, etc.) based on the test conditions; the main meaningful results that can be obtained from this test are as follows:

[0067] (1) The damage length and width values of the test plate 10 can be obtained using common measuring tools such as vernier calipers.

[0068] (2) The horizontal grounding force-time history curve and the vertical grounding force-time history curve can be obtained using the triaxial force sensor 60 under the reef.

[0069] (3) The displacement-time history curve, velocity-time curve, etc. of the reef during the test can be obtained by shooting and processing using the high-speed photography system 70.

[0070] (4) The full-field strain of the test plate during grounding can be obtained using the three-dimensional digital speckle strain measurement system (DIC) 80 (which helps analyze the failure process of the ship bottom plate structure), as well as the final damage deformation mode (which can be mutually verified with the results obtained in (1)).

[0071] S7. Change the structural form of the test plate 10, replace the reef model 20, replace the counterweight, and set different relative grounding heights H, grounding angles α, initial grounding kinetic energies E k and initial grounding velocities V 0 etc., and repeat steps S1 to S6 to conduct ship bottom plate grounding simulation test studies under different conditions.

[0072] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts between the various embodiments, reference can be made to each other.

[0073] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Those of ordinary skill in the art, under the inspiration of the present invention and without departing from the spirit and scope protected by the present invention's claims, can also make many forms, and all of these fall within the protection scope of the present invention.

Claims

1. A ship bottom plate grounding simulation test device using relative motion, comprising a test plate, a reef model, and a triaxial force sensor. Characterized in that, It further includes an adjustable fixing fixture, a movable reef base, and a guide rail frame; the adjustable fixing fixture includes a lifting column, a hydraulic tilting device, and a fixture plate. The height of the lifting column can be adjusted. The lower end of the lifting column is fixed to the ground, and the upper end is installed with the hydraulic tilting device. The fixture plate is installed on the top of the hydraulic tilting device and is used to fixedly install the test plate. The height of the test plate is adjusted by the lifting column to simulate different grounding heights, and the tilting angle of the test plate is adjusted by the hydraulic tilting device to simulate different grounding angles. The movable reef base includes a base body and a sliding device installed on the base body; the guide rail frame includes an acceleration section and a horizontal section; the movable reef base is installed on the guide rail frame through the sliding device. The lower end of the triaxial force sensor is connected to the movable reef base, and the upper end is connected to the reef model; by moving the movable reef base to the acceleration section of the guide rail frame and then releasing it, the reef model acts on the test plate with a certain initial kinetic energy to simulate the process of ship grounding.

2. The ship bottom plate grounding simulation test device using relative motion according to claim 1, Characterized in that, The test device further includes a high-speed camera system and a three-dimensional digital speckle strain measurement system. The high-speed camera system is installed on one side of the horizontal section of the guide rail frame and is used to monitor the movement of the reef model. The three-dimensional digital speckle strain measurement system is used to capture the full-field strain of the test plate.

3. The ship bottom plate grounding simulation test device using relative motion according to claim 2, Characterized in that, Marker points are pasted on the base body of the movable reef base, and the high-speed camera system records the speed change when the reef model interacts with the test plate by tracking the marker points.

4. The ship bottom plate grounding simulation test device using relative motion according to claim 1, Characterized in that, The adjustable fixing fixture further includes a base plate, which includes an upper base plate and a lower base plate. The lower base plate is horizontally fixed to the top of the lifting column. The upper base plate is hinged to one side of the lower base plate. The hydraulic tilting device is arranged between the upper base plate and the lower base plate and is used to adjust the tilting angle of the upper base plate; the fixture plate is installed on the upper base plate.

5. The ship bottom plate grounding simulation test device using relative motion according to claim 4, Characterized in that, The fixture plate includes an upper fixture plate and a lower fixture plate. The lower fixture plate is fixedly installed on the surface of the upper base plate. The test plate is installed between the lower fixture plate and the upper fixture plate. The lower fixture plate, the test plate, and the upper fixture plate are fixedly connected in a detachable manner.

6. The ship bottom plate grounding simulation test device using relative motion according to claim 1, Characterized in that, The movable reef base further includes a counterweight screw installed under the base body and a number of counterweight weights installed on the counterweight screw, which are used to change the total mass of the movable reef base, thereby changing the size of the initial kinetic energy in the grounding test.

7. The ship bottom plate grounding simulation test device using relative motion according to claim 1, characterized in that, the movable reef base further includes a lifting connection platform for connecting the triaxial force sensor. The lifting connection platform can change its own height to accurately set the initial relative height between the reef model and the test plate.

8. The ship bottom plate grounding simulation test device using relative motion according to claim 1, characterized in that, the guide rail frame further includes anti-rollover plates arranged on both sides of the horizontal section and a protective tail post arranged at the end of the horizontal section.

9. The ship bottom plate grounding simulation test device using relative motion according to claim 1, characterized in that, the triaxial force sensor includes a sensor main shaft, a sensor upper connecting plate and a sensor lower connecting plate respectively arranged at both ends of the sensor main shaft. The sensor lower connecting plate is connected to the movable reef base, and the sensor upper connecting plate is connected to the reef model.

10. A ship bottom plate grounding simulation test method using relative motion, characterized in that, using the device according to any one of claims 1-9, comprising the following steps: S1. Fix the test plate on the adjustable fixture according to the structural form of the test plate, the size of the test plate, the relative grounding height H, and the grounding angle α, and adjust the lifting column and the hydraulic tilting device in the adjustable fixture to make the center of gravity of the test plate reach a certain height H 1 , and the test plate forms a certain angle α with the vertical direction; S2. Select the reef model to be used according to the relative grounding height H, and adjust the lifting connecting platform in the movable reef base so that the tip of the reef model reaches a certain height H when the movable reef base is on the horizontal section of the guide rail frame 2 , where the relative grounding height H in the test condition is H 2 -H 1 ; S3. According to the initial grounding kinetic energy E k and the initial grounding velocity V 0 Add counterweight weights to the movable reef base and fix them so that the total mass of the entire movable reef base reaches M. The total mass M is obtained based on the kinetic energy calculation formula as M = 2E k / (V 0 ·V 0 ); S4. According to the initial stranding velocity V 0 , fix the movable reef base at a certain initial height Hv of the guide rail frame with a rope, and Hv is calculated based on the law of conservation of energy S5. Stick marker points on the matrix in the movable reef base, and arrange and adjust the high-speed photography system to the optimal angle; spray speckles on the upper surface of the test plate, and arrange and adjust the three-dimensional digital speckle strain measurement system to the optimal angle; S6. Cut off the rope, and the movable reef base will slide down along the track frame to the horizontal section. The reef model will have an initial stranding velocity V 0 and interact with the test plate, and the test plate will show varying degrees of deformation and damage based on the test conditions; the high-speed photography system S7. Change the structural form of the test plate, replace the reef model, replace the counterweight, and set different relative grounding heights H, grounding angles α, and initial grounding kinetic energies E k , initial grounding velocities V 0 . Repeat steps S1 to S6 to conduct ship bottom plate grounding simulation test studies under different working conditions.

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