A ship collision model test method and device in a water tank

Abstract

The present invention discloses a method and apparatus for testing a ship collision model in a water tank. The bow of the striking ship model is connected to a traction device. The struck ship model is fixed in front of the striking ship model at a set angle by using an electromagnet and a laser photoelectric switch. A force sensor is installed at the bow of the striking ship model, wave height meters are installed on both sides of the struck ship model, and an optical three-dimensional motion capture system is installed on both sides of the water tank. The striking ship model is towed by the traction device to sail. Before the collision, the traction device releases the striking ship model, and the electromagnet releases the struck ship model, causing a free collision between the two. The collected collision force, wave heights on the port and starboard sides of the struck ship model, and six-degree-of-freedom motion parameter data of the two models are processed to analyze and obtain a collision depth time history curve, the relative wave heights on the port and starboard sides of the struck ship model, and the energy dissipation value during the collision. The deformation profile and deformation size of the side structure are measured. The present invention does not require human intervention during the experimental process and can accurately simulate collision conditions at preset locations and angles.

Description

Technical Field

[0001] The present invention relates to the technical field of ship model collision experiments, and in particular to a ship collision model experiment method and device in a water tank. Background Art

[0002] Ship collisions are a significant factor in damaging ship structures, often resulting in significant economic losses and casualties. However, ship collisions are complex phenomena, with many details difficult to capture using theoretical models. Therefore, experimental research is essential to obtain reliable data and explore collision damage mechanisms, which are of immeasurable significance and value in preventing accidents and protecting life and property.

[0003] Since the phenomenon of ship collision is extremely complex, many details such as hull motion, structural damage, marine environment, etc. are difficult to express realistically and comprehensively using theoretical methods or finite element numerical analysis methods. Moreover, ships are large-scale structures, and real ship collision experiments require a lot of financial, manpower and time support. Therefore, it is necessary to use ship models instead of real ships to conduct small-scale model experiments in order to explore the damage mechanism of real ship collisions, obtain intuitive motion laws and experimental data results during ship collisions, and provide reliable data support for theoretical models, numerical simulations and other related technical research methods. Therefore, designing an objective ship model collision test system and realizing ship collision model experimental research has become an urgent problem to be solved.

[0004] Chinese patent CN108613788A discloses a ship-to-ship model collision test system and method. This system uses a propulsion device and navigation channel limits to ensure the motion of the impacting ship model is close to the real world. Through proper adjustments, the motion of the impacting ship model is not affected by the ship model acceleration device. A three-dimensional motion capture system can also be used to measure the motion of the two ships during the entire collision process. However, in practice, this patent still has the following shortcomings:

[0005] 1. Manually cutting the string before the two ship models collided makes it impossible to precisely control the position of the colliding ship models. Waves and other factors as the colliding ship models moved forward could easily cause the colliding ship to deviate from the predetermined position and angle.

[0006] 2. The propulsion device of the ship model acceleration device is an electric propeller, and it is controlled by a remote control. The first disadvantage is that the method of using an electric propeller to propel the ship model at the tail cannot meet the control requirements of the impact position, because the impact ship model has a long distance to travel before the collision occurs, and the method of propelling from the tail will continuously amplify the degree of deviation of the ship model from the predetermined trajectory, resulting in a larger lateral offset of the impact point compared to the target impact position; and propelling from the tail will cause the impact ship model to form a more obvious head-raising phenomenon during the forward movement, resulting in a larger vertical offset of the impact point compared to the target impact position. The second disadvantage is that the speed adjustment range of the electric propeller is small, the repeatability is poor, and the control accuracy is poor. The third disadvantage is that the remote control is used to manually control the start and stop of the electric propeller, which is difficult to control, especially when the experimenter on the shore cannot observe the collision scene well. It is easy to stop early, resulting in the impact speed not meeting the requirements, or to stop late, resulting in the impact ship model still being subjected to the thrust of the propeller when the collision occurs.

[0007] 3. The width of the navigation channel used in this invention is greater than the width of the ship that impacts the ship model, which will cause the ship model to be unable to maintain a stable forward movement. Repeated lateral collisions with the channel will increase the horizontal deviation of the ship model.

[0008] 4. This method cannot separate the influence of fluid on energy consumption during the collision process, nor does it explore the energy absorption of the structure and the energy dissipation of the system. Summary of the Invention

[0009] The main purpose of the present invention is to provide a method and device for testing ship collision models in a water tank. Before the experiment begins, the striking ship model is constrained to make it move in the required single direction, and the struck ship model is moored at arbitrary angles at both ends of the bow and stern. At the beginning of the experiment, the striking ship model is pulled to move by a traction device connected to the striking ship model, and the constraints of the two ship models are cancelled when the collision is about to occur (the traction force also disappears at this time). In the real environment of a laboratory water tank, considering the interaction between the hull and the surrounding waters, the ship collision characteristics under fully coupled conditions can be studied, and the collision energy dissipation law of the hull movement and structural damage and deformation can be explored.

[0010] The technical solution adopted in the present invention is:

[0011] A ship collision model test method in a water tank comprises the following steps:

[0012] S1. Arrange the experimental apparatus: Install two transverse restraining baffles in the pool, place the impacting ship model between the channels formed by the two transverse restraining baffles, install a traction device on the pool, and connect the bow of the impacting ship model to the traction device via a traction rope; use an electromagnet and a laser photoelectric switch to fix the impacted ship model in front of the impacting ship model at a set angle; install a force sensor on the bow of the impacting ship model, install wave height meters on both sides of the impacted ship model, and install several optical 3D motion capture systems on both sides of the pool. Connect the force sensor, wave height meter, and optical 3D motion capture system to the data acquisition instrument.

[0013] S2. Start the experiment: Use a traction device to tow the striking ship model at a predetermined speed. Just before the collision occurs, the traction device automatically releases the striking ship model, and the electromagnet automatically releases the struck ship model, allowing the striking ship model and the struck ship model to freely collide. During the collision, the collision force is measured using a pressure sensor and an acceleration sensor, the wave height on both sides of the struck ship model is measured using a wave height meter, and the six-degree-of-freedom motion parameters of the two models are collected using an optical three-dimensional motion capture system.

[0014] S3. Data processing: Process the collected collision force, wave heights on the starboard and starboard sides of the struck ship model, and six-degree-of-freedom motion parameter data of the two models, and analyze the collision depth history curve, the relative wave heights on the starboard and starboard sides of the struck ship model, and the energy dissipation value during the collision process;

[0015] S4. Damage measurement: Measure the deformation profile and final deformation size of the side structure after the collision.

[0016] In the above solution, in step S3, the analysis method of the collision depth history curve is as follows: assuming that the collision point P is relatively fixed to the respective hulls and does not change with the deformation of the side structure, the following can be obtained at each moment based on the coordinates of the center of gravity of the two ships and the relative position vector of constant magnitude in the coordinate system of the optical three-dimensional motion capture system:

[0017]

[0018] Where, vector δ represents the impact depth; Represents the vector from the origin in the global coordinate system to the center of gravity of the impactor; represents the vector from the origin to the center of gravity of the struck ship in the global coordinate system; The vector from the center of gravity of the impact ship to the front vertex of the bulbous bow; The vector representing the distance from the center of gravity of the struck ship to the point of initial impact on the side.

[0019] In the above scheme, in step S3, the analysis method of the relative wave heights on the port and starboard sides of the struck ship model is as follows: Since the struck ship model undergoes significant rolling motion after being subjected to the collision load during the experiment, which introduces measurement errors of the relative wave heights, it is necessary to use the rolling motion of the struck ship model to correct the measurement of the relative wave heights, and use the following formula to obtain the relative water level changes on the port and starboard sides of the struck ship model:

[0020] H p1 =L 左 -ΔL

[0021] H p2 =L 右 +ΔL

[0022] Where H p1 and H p2 are the changes in water levels on the port and starboard sides respectively; L 左 and L 右 are the wave height meter measurements on the left and right sides of the struck ship model, respectively; ΔL is the distance the wave height meter is immersed in or lifted out of the water due to the rolling during the collision;

[0023] Then the relative wave height ΔH on the starboard and starboard sides of the struck ship model is: ΔH=H p2 -H p1 =L 左 -L 右 -2ΔL.

[0024] In the above solution, in step S3, the energy dissipation value is analyzed by:

[0025] (1) According to the energy conservation principle, and replacing the influence of the fluid around the two ship models with the additional mass coefficient, the energy of the system before collision is first solved as:

[0026]

[0027] Where, E K0 is the kinetic energy of the system before collision, M a and M b are the masses of the striking ship model and the struck ship model, m a and m b are the additional mass of the longitudinal motion of the striking ship model and the additional mass of the transverse motion of the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; V a0 and V b0 are the longitudinal motion velocity of the striking ship model and the transverse motion velocity of the struck ship model before the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system;

[0028] (2) Solve the residual energy of the system after the collision:

[0029]

[0030] Where, E Kt is the kinetic energy of the system after the collision, I a and I b are the moments of inertia of the striking ship model and the struck ship model, m a,t and m b,t are the translational additional masses of the striking ship model and the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; J a and J b are the rotational added mass of the striking ship model and the rotational added mass of the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; V a,t and V b,t are the linear velocity of the impacting ship model and the linear velocity of the struck ship model after the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system; ω a and ω b are the rotational angular velocities of the striking ship model and the struck ship model after the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system;

[0031] (3) Finally, the energy dissipation value during the collision is:

[0032] ΔE=E K0 -E Kt .

[0033] In the above scheme, a height-adjustable horizontal fixed pulley is installed on the inner side of the pool wall on the long side of the water pool, and the horizontal fixed pulley is located between the struck ship model and the striking ship model and close to the struck ship model; the traction device is installed on the pool wall on the short side of the water pool; an adjustable height limit pile is installed inside the pool between the struck ship model and the traction device, and the adjustable height limit pile is arranged close to the traction and impact, and a limit pile fixed pulley is provided on the top; height-adjustable pull rods are respectively installed on both sides of the bow of the striking ship model; one end of the two traction ropes is connected to the pull rod on the port / starboard side of the striking ship model, and the other end passes through the horizontal fixed pulley, the limit pile fixed pulley in turn and is connected to the traction device; by coordinating the height adjustment of the pull rod, the horizontal fixed pulley and the adjustable height limit pile, the traction rope is coordinated to pull it to both sides along the horizontal direction at the same height as the center of gravity of the striking ship model.

[0034] In the above scheme, the traction rope is equipped with a motion termination block, which is located between the fixed pulley of the limit pile and the horizontal fixed pulley. When the striking ship model moves close to the struck ship model, the motion termination block reaches the fixed pulley of the limit pile. As the traction device continues to run, the traction rope between the traction device and the fixed pulley of the limit pile is broken, thereby releasing the striking ship model.

[0035] In the above scheme, a number of collision angle control fixed pulleys are also installed on the inner side of the pool wall on the long side of the water pool; two laser photoelectric switches are installed inside the water pool, and the two laser photoelectric switches are arranged opposite each other and close to the model of the ship being hit; an electromagnet device is installed at the bow and stern ends of the ship being hit, respectively, comprising an electromagnet base and an electromagnet with a wire, the wire passing through the collision angle control fixed pulley on the pool wall and connected to the laser photoelectric switch, and the two laser photoelectric switches are connected by a wire to form a loop; at the beginning of the experiment, the two electromagnets at the bow and stern of the ship being hit are in a working adsorption state, and the wire is in a taut state, thereby fixing the position of the ship being hit, and at this time the laser photoelectric switches are unobstructed; then the hitting ship model accelerates, and when it moves between the two laser photoelectric switches, the electromagnet is immediately disconnected, the constraint of the ship being hit is released, and the two models collide freely.

[0036] In the above solution, a roller clamping device is installed on the side of the impact ship model, and the end rollers of the roller clamping device are rollingly connected to the lateral restraining baffle to achieve rolling friction between the impact ship model and the lateral restraining baffle.

[0037] The present invention also proposes an experimental device for ship collision model in a water pool, comprising a water pool system, an experimental data acquisition system, and a ship model control system. The water pool system is provided with a striking ship model and a struck ship model. The two ship models finally collide freely under the traction and constraint of the ship model control system, and the experimental data during the collision is captured by the experimental data acquisition system. A traction device is installed on the water pool, and an adjustable height limit pile is installed inside the water pool between the struck ship model and the traction device. The adjustable height limit pile is arranged close to the traction device, and a limit pile fixed pulley is provided on the top. The experimental data acquisition system includes a pressure sensor, a wave height ... Instrument, optical three-dimensional motion capture system; the pressure sensor is installed between the front end of the striking ship model and the impact head, and is used to obtain the impact force time history curve during the collision process; the wave height meter is installed around the impact area of ​​the parallel mid-body section of the struck ship model, and its sensing wire is kept outward, and is used to obtain the changes in the relative water levels on the left and right sides of the struck ship model during the collision; the optical three-dimensional motion capture system is installed on the outer shore of the pool, and is used to obtain the six-degree-of-freedom motion state of the two ships during the collision; the ship model control system includes a lateral restraining baffle, a roller clamping device, a pull rod, a traction rope, a horizontal fixed pulley, a laser photoelectric switch, and an electromagnet; The two transverse constraint baffles are installed in the pool, and an acceleration channel for the impact ship model is formed in the middle; the roller clamping device is installed on the side of the impact ship model, and the end rollers of the roller clamping device are rollingly connected with the transverse constraint baffles to realize rolling friction between the impact ship model and the transverse constraint baffles; the pull rod is installed on the two sides of the bow of the impact ship model, and the height can be adjusted according to the change of the center of gravity height of the impact ship model, and through two traction ropes, it first passes through the horizontal fixed pulley installed on the pool wall, and then converges to pass through the limit pile fixed pulley of the adjustable height limit pile, and finally connected to the traction device on the shore; the two laser photoelectric switches are installed The laser photoelectric switches are installed inside the pool, arranged on both sides opposite to each other and close to the model of the struck ship. An electromagnet device is installed at both ends of the struck ship model, including an electromagnet base and an electromagnet with a wire. The wire passes through the collision angle control fixed pulley and is connected to the laser photoelectric switch. The two laser photoelectric switches are connected by a wire to form a loop. When the laser photoelectric switch is not blocked by the striking ship model, the electromagnet is controlled to be in an adsorption state. Combined with the taut electromagnet wire, the movement of the struck ship model is constrained. When the striking ship model moves to the position between the two laser photoelectric switches and blocks them, the electromagnet is immediately disconnected and the struck ship model is automatically released.

[0038] In the above scheme, the ship model control system also includes two motion termination blocks, which are respectively tied to two traction ropes and located between the fixed pulley of the limit pile and the horizontal fixed pulley. When the striking ship model moves close to the struck ship model, the motion termination block arrives at the fixed pulley of the limit pile. As the traction device continues to run, the traction rope between the traction device and the fixed pulley of the limit pile is broken, thereby releasing the striking ship model.

[0039] The beneficial effects produced by the present invention are:

[0040] 1. By attaching a motion-terminating block to the towing rope behind an adjustable-height limit post, the present invention can control the movement distance of the striking ship model according to experimental speed and other requirements. This ensures that when the striking ship model is about to approach the struck ship model, the motion-terminating block reaches the fixed pulley of the limit post. As the towing device continues to operate, the towing rope between the towing device and the fixed pulley of the limit post is broken, thereby releasing the striking ship model. Simultaneously, the combination of a laser photoelectric switch and an electromagnet can achieve mooring constraints at both ends of the struck ship just before impact. When impact is imminent, the electromagnet is de-energized, freeing the struck ship and allowing the two ship models to collide freely. No human intervention is required during the experiment, and collision conditions at preset locations and angles can be accurately simulated.

[0041] 2. The ship model acceleration device adopts traction on both sides. The pull rod, horizontal fixed pulley and adjustable height limit pile can all be adjusted in height according to actual needs. Their respective positions can be adjusted accordingly according to the change of the center of gravity of the impact ship model, so that the traction rope can coordinately pull it to both sides in the horizontal direction at the same height as the center of gravity of the impact ship model, and always keep the point of action of the traction force of the impact ship model at the height of the center of gravity, and no additional torque will be generated to affect the movement state of the impact ship model, avoiding the vertical offset of the impact position; at the same time, the direction of the traction force of the impact ship model can be kept along the longitudinal direction of the water pool. Compared with other propulsion methods, the synchronous traction on both sides can realize real-time adjustment of the heading, ensure the heading of the impact ship model, and achieve high-precision control of the lateral offset of the impact position; the acceleration device can also adapt to high-speed collision conditions.

[0042] 3. Roller clamping devices are installed on both sides of the impact ship model to constrain the movement direction of the impact ship between the lateral constraint baffles. The roller clamping devices are tightly connected to the baffles, so that the heading of the impact ship model is always fixed during its movement between the baffles. At the same time, rolling friction is used, so the friction force generated on the baffles during the impact ship's forward movement is almost zero.

[0043] 4. The present invention obtains the impact force time history curve during the collision process through a pressure sensor, and obtains the six-degree-of-freedom motion state of the two ship models during the collision process through an optical three-dimensional motion capture system. The collision depth time history curve can be analyzed and obtained. According to the collision depth time history curve, combined with the impact force time history curve collected by the pressure sensor, the force-displacement curve is obtained, and then the energy absorption characteristics of the side impacted structure can be obtained by integrating it. By using the changes in the immersion depth during the collision process recorded by the wave height meter and reducing the roll effect of the impacted ship model collected by the optical three-dimensional motion capture system, the change law of the relative water level on the left and right sides of the impacted ship model during the collision process can be measured. The fluid resistance caused by the movement of the ship model is further calculated in combination with the wave height change formula, and the influence law of the fluid around the ship model during the collision process is explored. The present invention can also perform system energy dissipation analysis and deformation damage mode analysis. By obtaining these corresponding experimental results, reliable data support is provided for theoretical, numerical simulation and other related technical research methods.

[0044] 5. The present invention can carry out free collision conditions at any angle, any impact position (location), any impact speed and impact mass, further improving the test capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 This is an overall structural diagram of the ship collision model experimental device in a water tank of the present invention;

[0047] Figure 2 yes Figure 1 Cross-section along the inside of the pool wall;

[0048] Figure 3 It is a schematic diagram of the critical collision state when the collision angle is 90°;

[0049] Figure 4 It is a schematic diagram of the collision state when the collision angle is 60°;

[0050] Figure 5 This is the structural diagram of the bow of the ramming ship model;

[0051] Figure 6 This is a structural diagram of an adjustable height limit pile;

[0052] Figure 7 This is a structural diagram of an optical 3D motion capture system;

[0053] Figure 8 It is the structural diagram of the lateral restraint baffle;

[0054] Figure 9 It is the structural diagram of the roller clamping device;

[0055] Figure 10 This is the structural diagram of the horizontal fixed pulley on the pool wall;

[0056] Figure 11 This is the structure diagram of the laser photoelectric switch;

[0057] Figure 12 This is a schematic diagram of the post-processing of the experimental impact depth history;

[0058] Figure 13 This is a schematic diagram of the post-processing of the relative water level changes on the left and right sides of the experimental ship model that was hit.

[0059] Figure 11: Water tank; 12: Model of the striking ship; 121: Hull of the striking ship; 122: Force sensor base; 123: Impacting head; 13: Model of the struck ship; 14: Adjustable height limit pile; 141: Retractable support for the limit pile; 142: Fixed pulley for the limit pile; 15: Fixed pulley for collision angle control; 16: Traction device;

[0060] 21. Pressure sensor; 22. Wave height meter; 23. Optical 3D motion capture system; 231. Tripod; 232. 3D motion capture camera;

[0061] 31. Horizontal restraining baffle; 311. Baffle; 312. Support rod; 32. Roller clamping device; 321. Fastening bolt; 322. Arc clamp; 323. Triangular clamp; 324. Roller; 33. Pull rod; 331. Vertical guide rail; 332. Sliding pull block; 333. Pull block bolt; 334. Pull block gasket; 335. Pull block nut; 34. Traction rope; 35. Horizontal fixed pulley; 351. Guide rail; 352. Grooved fixed pulley; 36. Laser photoelectric switch; 361. Laser emitting end; 362. Photoelectric switch retractable support; 363. Photoelectric switch bracket; 37. Electromagnet; 38. Motion termination block. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0063] It should be noted that the illustrations provided in the embodiments of the present invention are only schematic illustrations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0064] In the present invention, it should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like are used to indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present application and to simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present application. Furthermore, the terms "first" and "second" are used solely for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0065] like Figure 1-11 As shown, the present invention provides a ship collision model experimental device in a water tank, including a water tank system, an experimental data acquisition system, and a ship model control system; the water tank system is provided with a striking ship model 12 and a struck ship model 13, and the two ship models eventually collide freely under the traction and constraint of the ship model control system, and the experimental data during the collision process is captured by the experimental data acquisition system.

[0066] The water tank system includes a water tank 11, a striking ship model 12, a struck ship model 13, an adjustable height limit pile 14, a collision angle control fixed pulley 15, and a traction device 16. The striking ship model 12 and the struck ship model 13 float in the water tank 11 according to the experimental draft; the adjustable height limit pile 14 is fixed at the rear of the water tank; a plurality of collision angle control fixed pulleys 15 are arranged along the length of the water tank wall to adjust the initial angle of the struck ship model 13 (see Figure 3 The 90° collision angle and Figure 4 At the same time, the connecting line is fixed so that the struck ship will not shake before the collision occurs.

[0067] The experimental data acquisition system includes a pressure sensor 21, a wave height meter 22, and an optical 3D motion capture system 23. The pressure sensor 21 is bolted to the force sensor base 122 and the impact head 123 at the front end of the impact ship hull 121, see Figure 5The pressure sensor 21 is connected to the data acquisition instrument and the data processing terminal through a wire for use, and the impact force time history curve during the collision process is obtained. The optical three-dimensional motion capture system 23 is located on the outer shore of the pool 11, and is connected to the data acquisition instrument and the data processing terminal through a wire for use, and the six-degree-of-freedom motion state of the two ship models during the collision process is obtained. The wave height meter 22 is installed around the impact area of ​​the parallel mid-body section of the impacted ship model 13, and its sensing wire is kept outward. The wave height meter 22 is connected to the data acquisition instrument and the data processing terminal through a wire for use, and the immersion depth change during the collision process recorded by the wave height meter is used to reduce the roll effect of the impacted ship model collected by the optical three-dimensional motion capture system. The change law of the relative water level on the left and right sides of the impacted ship model during the collision process can be measured, and the fluid resistance caused by the ship model movement can be further calculated in combination with the wave height change formula to explore the influence law of the fluid around the ship model during the collision process.

[0068] The ship model control system includes a transverse restraining baffle 31, a roller clamping device 32, a pull rod 33, a traction rope 34, a horizontal fixed pulley 35, a laser photoelectric switch 36, an electromagnet 37, and a motion termination block 38. Two transverse restraining baffles 31 are installed in the pool, forming an acceleration channel for the impact ship model 12 in the middle, restraining the lateral movement of the impact ship model 12 before the collision occurs, ensuring the accuracy of the impact position required for the experiment. The roller clamping device 32 is installed on the side of the impact ship model 12 to achieve rolling friction between the impact ship model 12 and the transverse restraining baffle 31, and the friction resistance can be ignored. The pull rod 33 is installed on both sides of the bow of the impact ship model 12. The height can be adjusted according to the change in the center of gravity height of the impact ship model 12. It is connected to the traction device 16 on the shore through two traction ropes 34, first passing through the horizontal fixed pulley 35, then converging and passing through the lower edge of the adjustable height limit pile 14 at the end of the pool. Two laser photoelectric switches 36 are installed inside the pool. The two laser photoelectric switches 36 are arranged opposite each other and close to the struck ship model 13. An electromagnet device is installed at the bow and stern ends of the struck ship model 13, respectively, comprising an electromagnet base and an electromagnet 37 with a wire. The wire passes through the collision angle control fixed pulley 15 on the pool wall and is connected to the laser photoelectric switch 36. The two laser photoelectric switches 36 are connected by a wire to form a loop. During operation, the two electromagnets 37 at the bow and stern of the struck ship model 13 are in a working adsorption state, and the wire is in a taut state, thereby fixing the position of the struck ship model 13. At this time, the laser photoelectric switches 36 are unobstructed. Then the striking ship model 12 accelerates, and when it moves between the two laser photoelectric switches 36, the electromagnet 37 is immediately disconnected, thereby releasing the constraint of the struck ship model 13 and allowing the two models to collide freely. The two motion termination blocks 38 are respectively tied to the two traction ropes 34 and are located between the fixed pulley 142 of the limit pile and the horizontal fixed pulley 35. The motion termination blocks 38 can control the movement distance of the impact ship model according to the requirements of the experimental speed, etc., to ensure that when the impact ship model 12 is about to approach the impacted ship model 13, the motion termination blocks 38 arrive at the fixed pulley of the limit pile. As the traction device 16 continues to run, the traction rope between the traction device 16 and the fixed pulley of the limit pile is broken, thereby releasing the impact ship model 12 and causing the two ship models to collide freely.

[0069] Further optimization is that the size of the pool 11 is large enough not to affect the rotation of the ship model, and the pool wall and pool bottom can be used to fix the test device.

[0070] Further optimization is carried out, the impact ship model 12 is limited between the lateral restraining baffles 31 in the pool 11 by the roller clamping device 32 for linear motion, and is connected together by the traction rope 34, which is connected to the height-adjustable pull rod 33 and the traction device 16 fixed on the bow side of the impact ship model 12 at both ends.

[0071] For further optimization, a hole is opened at the port side parallel to the midbody of the struck ship model 13, and the experimental replaceable structure is connected by bolts around it. The electromagnet 37 controlled by the laser photoelectric switch 36 can be connected to the collision angle control fixed pulley 15 fixed on the pool wall.

[0072] Further optimization, such as Figure 6 As shown, the adjustable height limit pile 14 includes a limit pile telescopic support 141 and a limit pile fixed pulley 142. The limit pile fixed pulley 142 is fixed to the top of the limit pile telescopic support 141, and the limit pile telescopic support 141 is fixed to the bottom of the pool 11 by a pressure iron. The height of the adjustable height limit pile 14 can be adjusted according to actual needs. The position of the adjustable height limit pile can be arbitrarily changed so that the center point of the lower edge of the adjustable height limit pile is on the same horizontal plane as the center of gravity of the impact ship model and is located in the forward direction of the impact ship model, so that the impact ship is subjected to a completely horizontal tension.

[0073] Further optimization, such as Figure 7 As shown, the optical 3D motion capture system 23 includes a tripod 231 and a 3D motion capture camera 232. The 3D motion capture camera 232 is fixed to the top of the tripod 231. Four optical 3D motion capture systems 23 and a 3D motion data processing terminal are used in series to capture the motion of marker balls placed on the striking ship model 12 and the struck ship model 13, reflecting the motion states of both models. Based on the relative motion of the two ships, a time-dependent impact depth curve is generated during the collision. Combined with the time-dependent impact force curve collected by the pressure sensor 21, a force-displacement curve is generated. This curve is then integrated to determine the energy absorption characteristics of the struck side structure.

[0074] Further optimization, such as Figure 8 As shown, the transverse restraining baffle 31 comprises a baffle 311 and a strut 312. Baffle 311 has four screws at one end and two screws at the other end. The short end of the strut 312 is bolted to the baffle 311, and the long end is secured to the bottom of the pool 11 via a weight. The height of the strut 312 is adjustable. Transverse restraining baffle 311 can be placed anywhere in the pool and oriented in any direction according to experimental conditions. Its height can be adjusted based on changes in the pool water level, making it flexible and convenient to use, taking up minimal space, and removable after use.

[0075] Further optimization, such as Figure 9As shown, the roller clamping device 32 includes a fastening bolt 321, an arc-shaped clamp 322, a triangular clamp 323, and a roller 324. The arc-shaped clamp 322 clamps the upper end of the side and is fixed by the fastening bolt 321. The triangular clamp 323 is welded above the arc-shaped clamp 322 and bolted to the roller 324. The roller 324 is in rolling contact with the baffle 311. The roller clamping device 32 is primarily used to constrain the movement direction of the striker between the transverse restraining baffles. It is closely connected to the baffles and uses rolling friction to reduce the friction force generated by the baffles during the striker's forward movement to almost zero. The roller is also reinforced in the main direction of force applied to the roller, making the structure more stable and reliable.

[0076] Further optimization, such as Figure 5 As shown, the pull rod 33 includes a vertical guide rail 331, a sliding pull block 332, a pull block bolt 333, a pull block washer 334, and a pull block nut 335. The vertical guide rail 331 is fixed to the left and right side surfaces of the bow of the impact ship model 12 by screws. The sliding pull block 332 can move along the vertical guide rail 331 and is fixed by the pull block bolt 333, the pull block washer 334, and the pull block nut 335. The sliding pull block 332 is provided with a pull ring connected to the towing rope 34. The position of the sliding pull block 332 can be changed according to the change of the center of gravity of the impact ship model, so that the towing rope 34 can coordinately pull the impact ship model 12 in a horizontal direction at the same height as the center of gravity. This always keeps the traction force of the impact ship model 12 at the center of gravity height, ensures the heading of the impact ship model 12, and can also adapt to high-speed collision conditions. Compared with other propulsion methods, it can make real-time adjustments to the heading without generating additional torque that affects the motion state of the impact ship model 12.

[0077] Further optimization, such as Figure 10 As shown, the horizontal fixed pulley 35 includes a guide rail 351 and a grooved fixed pulley 352. The guide rail 351 is fixed on the two pool walls 10 to 20 cm in front of the impact area on the side of the struck ship model 13, keeping the same distance from the impact point; the grooved fixed pulley 352 is installed on the guide rail 351 with the groove horizontal, and can move up and down along the guide rail 351 to adapt to the height of the sliding pull block 332, so that the traction force always acts on the horizontal plane at the height of the center of gravity of the striking ship model 12.

[0078] Further optimization, such as Figure 11As shown, the laser photoelectric switch 36 comprises a laser emitting end 361, a retractable photoelectric switch support 362, and a photoelectric switch bracket 363. The laser emitting end 361 is secured to the photoelectric switch bracket 363 via a nut. Wires attached to the laser emitting end 361 connect the power source and the electromagnet 37. The photoelectric switch bracket 363 is placed on the platform atop the retractable photoelectric switch support 362, which is secured to the bottom of the pool 11. The position of the laser emitting end 361 can be adjusted arbitrarily based on the draft and motion of the striking vessel model 12. The combination of the laser photoelectric switch 36 and the electromagnet allows the struck vessel to be moored immediately before impact. When impact is imminent, the electromagnet is de-energized, freeing the struck vessel completely, accurately simulating a collision at a predetermined angle. Furthermore, the photoelectric switch bracket can adjust the switch height based on the draft of the striking vessel.

[0079] The present invention also provides a ship collision model test method in a water tank, comprising the following steps:

[0080] S1. Arrange the experimental apparatus: Set up two transverse restraining baffles in the pool, place the striking ship model between the channels formed by the two transverse restraining baffles, install a traction device on the pool, and connect the bow of the striking ship model to the traction device via a traction rope; install the side structure of the struck ship model 13, and fix the struck ship model at a set angle and a certain distance in front of the striking ship model in the pool through the cooperation of an electromagnet and a laser photoelectric switch; install a force sensor at the bow of the striking ship model, install wave height meters on both sides of the struck ship model, and install several optical 3D motion capture systems on both sides of the pool, and connect the force sensor, wave height meter, and optical 3D motion capture system to the data acquisition instrument respectively.

[0081] Then debugging is carried out, including: debugging the data acquisition instrument to ensure that the signal is normal; adjusting the floating state of the impact ship model 12 and the impacted ship model 13; connecting the traction device to make the impact ship model 12 move forward at a certain speed and debugging the speed.

[0082] S2. Start the experiment: Use a traction device to tow the impacting ship model at a predetermined speed. When the collision is about to occur, the towing rope is broken to release the impacting ship model. At the same time, the impacting ship model controls the electromagnet to release the struck ship model through the laser photoelectric switch, so that the impacting ship model and the struck ship model collide freely. During the collision, the collision force is collected by the force sensor, the wave height on the port and starboard sides of the struck ship model is collected by the wave height meter, and the six-degree-of-freedom motion parameters of the two models are collected by the optical three-dimensional motion capture system.

[0083] S3. Data processing: Process the collected collision force, wave heights on the starboard and starboard sides of the struck ship model, and the six-degree-of-freedom motion parameter data of the two models, and analyze the collision depth history curve, the relative wave heights on the starboard and starboard sides of the struck ship model, and the energy dissipation value during the collision.

[0084] The analysis method of the impact depth history curve is as follows: Figure 12 As shown in Figure 1, the collision depth history curve is obtained based on the relative displacement of the collision point P during the contact period between the two ships. Point P represents the point of first contact between the two ships, that is, the front vertex of the striking ship's bulbous bow model and the initial impact point on the side of the struck ship in this experiment. Assuming that the collision point P is relatively fixed relative to the respective hulls and does not change with the deformation of the side structure, the relative position vector of the center of gravity of the two ships and a constant magnitude can be obtained in the coordinate system of the optical 3D motion capture system at each moment:

[0085]

[0086] Where, vector δ represents the impact depth; Represents the vector from the origin in the global coordinate system to the center of gravity of the impactor; represents the vector from the origin to the center of gravity of the struck ship in the global coordinate system; The vector from the center of gravity of the impact ship to the front vertex of the bulbous bow; The vector from the center of gravity of the struck ship to the initial impact point on the side of the ship. The force-displacement curve is derived from the impact depth-time history curve and combined with the impact force-time history curve collected by the pressure sensor. The integration of this curve yields the energy absorption characteristics of the struck side structure.

[0087] The analysis method of the relative wave height on the starboard and starboard sides of the struck ship model is as follows: Figure 13 As shown in the figure, during the experiment, the model of the struck ship experienced significant rolling motion after being subjected to the collision load, which introduced measurement errors of the relative wave height. Therefore, it was necessary to use the rolling motion of the model of the struck ship to correct the measurement of the relative wave height, and the following formula was used to obtain the relative water level changes on the left and right sides of the model of the struck ship:

[0088] H p1 =L 左 -ΔL

[0089] H p2 =L 右 +ΔL

[0090] Where H p1 and H p2 are the changes in water levels on the port and starboard sides respectively; L 左 and L 右 are the measurement values ​​of the wave height meters on the left and right sides of the struck ship model, and ΔL is the distance that the wave height meter is immersed in or lifted out of the water due to the rolling during the collision.

[0091] Then the relative wave height ΔH on the starboard and starboard sides of the struck ship model is: ΔH=H p2 -H p1 =L 左 -L 右 -2ΔL. The relative wave height combined with the wave height change formula can be used to further calculate the fluid resistance caused by the ship model movement and explore the influence of the fluid around the ship model during the collision process.

[0092] The analysis method of collision energy dissipation value is:

[0093] (1) According to the energy conservation principle, and replacing the influence of the fluid around the two ship models with the additional mass coefficient, the energy of the system before the collision (at time t0, that is, the initial moment when the two ship models come into contact, which corresponds to the moment when the collision force-time curve rapidly increases from zero) is solved as follows:

[0094]

[0095] Where, E K0 is the kinetic energy of the system before collision, M a and M b are the masses of the striking ship model and the struck ship model, m a and m b are the additional mass of the longitudinal motion of the striking ship model and the additional mass of the transverse motion of the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; V a0 and V b0 are the longitudinal motion velocity of the striking ship model and the transverse motion velocity of the struck ship model before the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system;

[0096] (2) Solve the residual energy of the system after the collision (t s The moment (i.e., the moment when the two ship models first break away from contact, which corresponds to the moment when the collision force-time curve falls back to zero) is:

[0097]

[0098] Where, E Kt is the kinetic energy of the system after the collision, I a and I b are the moments of inertia of the striking ship model and the struck ship model, m a,t and m b,t are the translational additional masses of the striking ship model and the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; J a and J b are the rotational added mass of the striking ship model and the rotational added mass of the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; Va,t and V b,t are the linear velocity of the impacting ship model and the linear velocity of the struck ship model after the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system; ω a and ω b are the rotational angular velocities of the striking ship model and the struck ship model after the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system;

[0099] (3) Finally, the energy dissipation value during the collision is:

[0100] ΔE=E K0 -E Kt .

[0101] S4. Damage measurement: Measure the deformation profile and final deformation size of the side structure after the collision.

[0102] Further optimization, step S1 also includes: installing a horizontal fixed pulley on the inner side of the pool wall on the long side of the pool, the horizontal fixed pulley is located between the struck ship model and the striking ship model and close to the struck ship model; installing a traction device on the pool wall on the short side of the pool; installing an adjustable height limit pile inside the pool between the struck ship model and the traction device, close to the traction and impact arrangement, with a limit pile fixed pulley on the top; installing height-adjustable pull rods on both sides of the bow of the striking ship model; one end of the two traction ropes is connected to the pull rods on the port / starboard side of the striking ship model, and the other end passes through the horizontal fixed pulley and the limit pile fixed pulley in sequence and is connected to the traction device.

[0103] Further optimization, step S1 also includes: a motion termination block is tied to the traction rope, and the motion termination block is located between the fixed pulley of the limit pile and the horizontal fixed pulley. When the striking ship model moves close to the struck ship model, the motion termination block reaches the fixed pulley of the limit pile. As the traction device continues to run, the traction rope between the traction device and the fixed pulley of the limit pile is broken, thereby releasing the striking ship model.

[0104] Further optimization, step S1 also includes: a number of collision angle control fixed pulleys are installed on the inner side of the pool wall on the long side of the pool; two laser photoelectric switches are installed inside the pool, the two laser photoelectric switches are arranged opposite each other and close to the model of the ship being struck; an electromagnet device is installed at the head and tail ends of the ship being struck, respectively, including an electromagnet base and an electromagnet with a wire, the wire passes through the collision angle control fixed pulley on the pool wall and is connected to the laser photoelectric switch, and the two laser photoelectric switches are connected by a wire to form a loop; during the working process, the two electromagnets at the head and tail of the ship being struck are in a working adsorption state, and the wire is in a taut state, thereby fixing the position of the ship being struck, and the laser photoelectric switch is not blocked at this time; then the striking ship model accelerates, and when it moves between the two laser photoelectric switches, the electromagnet is immediately disconnected, the constraint of the ship being struck is released, and the two models collide freely.

[0105] Further optimization, step S1 also includes: installing a roller clamping device on the side of the impact ship model, and the end rollers of the roller clamping device are rollingly connected with the lateral constraint baffle to achieve rolling friction between the impact ship model and the lateral constraint baffle.

[0106] Further optimization is carried out, and the deck height of the impact ship model is kept lower than the lower edge of the lateral restraint baffle, and the movement trajectory of the roller is guaranteed to be always on the baffle. At the same time, it is ensured that the laser photoelectric switch detects the passing of an object only when the roller clamping device at the rear leaves the baffle, and disconnects the electromagnet, which can prevent the movement of the impact ship from being interfered with by other devices. At the same time, it is ensured that the impacted ship is fully restrained before the collision and completely free when the collision occurs, adapting to collision conditions under different collision parameters.

[0107] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0108] The size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0109] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A ship collision model test method in a water tank, characterized in that: The following steps are involved: S1. Arrange the experimental apparatus: Set up two transverse restraining baffles in the pool, place the impacting ship model between the channels formed by the two transverse restraining baffles, install a traction device on the pool, and connect the bow of the impacting ship model to the traction device via a traction rope; use electromagnets and laser photoelectric switches to fix the impacted ship model in front of the impacting ship model at a set angle. The specific method is as follows: install several fixed pulleys for controlling the collision angle on the inner side of the pool wall on the long side of the pool, install two laser photoelectric switches inside the pool, and arrange the two laser photoelectric switches opposite each other and close to the impacted ship model. Install an electromagnet device at both the bow and stern of the impacted ship model. The system comprises an electromagnet base and an electromagnet with a wire. The wire passes through a fixed pulley for controlling the collision angle on the pool wall and is connected to the laser photoelectric switch. The two laser photoelectric switches are connected by a wire to form a loop. At the beginning of the experiment, the two electromagnets at the bow and stern of the struck ship model are in a working adsorption state, and the wire is in a taut state, thereby fixing the position of the struck ship. At this time, the laser photoelectric switch is unobstructed. A force sensor is installed at the bow of the striking ship model, and wave height meters are installed on both sides of the struck ship model. Several optical three-dimensional motion capture systems are installed on both sides of the pool, and the force sensor, wave height meter, and optical three-dimensional motion capture system are respectively connected to the data acquisition instrument for signal connection. S2. Start the experiment: Use a traction device to tow the striking ship model at a predetermined speed. Before the collision is about to occur, the traction device automatically releases the striking ship model. When the striking ship model moves between the two laser photoelectric switches, the electromagnet is immediately disconnected, releasing the constraints of the struck ship model, allowing the striking ship model and the struck ship model to freely collide. During the collision, the impact force is measured using a pressure sensor and an acceleration sensor, the wave height on the port and starboard sides of the struck ship model is measured using a wave height meter, and the six-degree-of-freedom motion parameters of the two models are collected using an optical three-dimensional motion capture system. S3. Data processing: Process the collected collision force, wave heights on the starboard and starboard sides of the struck ship model, and six-degree-of-freedom motion parameter data of the two models, and analyze the collision depth history curve, the relative wave heights on the starboard and starboard sides of the struck ship model, and the energy dissipation value during the collision process; S4. Damage measurement: Measure the deformation profile and final deformation size of the side structure after the collision.

2. The ship collision model test method in a water tank according to claim 1, characterized in that: In step S3, the analysis method of the collision depth history curve is as follows: assuming that the collision point P is relatively fixed to the respective hulls and does not change with the deformation of the side structure, the following can be obtained at each moment based on the coordinates of the center of gravity of the two ships and the constant relative position vector in the coordinate system of the optical 3D motion capture system: In the formula, the vector δ It represents deep impact; Represents the vector from the origin in the global coordinate system to the center of gravity of the impactor; represents the vector from the origin to the center of gravity of the struck ship in the global coordinate system; The vector from the center of gravity of the impact ship to the front vertex of the bulbous bow; The vector representing the distance from the center of gravity of the struck ship to the point of initial impact on the side.

3. The ship collision model test method in a water tank according to claim 1, characterized in that: In step S3, the analysis method of the relative wave heights on the port and starboard sides of the struck ship model is as follows: Since the struck ship model undergoes significant rolling motion after being subjected to the collision load during the experiment, which introduces measurement errors of the relative wave heights, it is necessary to use the rolling motion of the struck ship model to correct the measurement of the relative wave heights, and use the following formula to obtain the relative water level changes on the port and starboard sides of the struck ship model: H p1 =L 左 -ΔL H p2 =L 右 +ΔL Where H p1 and H p2 are the changes in water levels on the port and starboard sides respectively; L 左 and L 右 are the wave height meter measurements on the left and right sides of the struck ship model, respectively; ΔL is the distance the wave height meter is immersed in or lifted out of the water due to the rolling during the collision; Then the relative wave height ΔH on the starboard and starboard sides of the struck ship model is: ΔH = H p2 -H p1 =L 左 -L 右 -2ΔL.

4. The ship collision model test method in a water tank according to claim 1, characterized in that: In step S3, the energy dissipation value is analyzed by: (1) According to the energy conservation principle, and replacing the influence of the fluid around the two ship models with the additional mass coefficient, the energy of the system before collision is first solved as: Where, E K0 is the kinetic energy of the system before collision, M a and M b are the masses of the striking ship model and the struck ship model, m a and m b are the additional mass of the longitudinal motion of the striking ship model and the additional mass of the transverse motion of the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; V a0 and V b0 are the longitudinal motion velocity of the striking ship model and the transverse motion velocity of the struck ship model before the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system; (2) Solve the residual energy of the system after the collision: Where, E Kt is the kinetic energy of the system after the collision, I a and I b are the moments of inertia of the striking ship model and the struck ship model, m a,t and m b,t are the translational additional mass of the striking ship model and the translational additional mass of the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; J a and J b are the rotational added mass of the striking ship model and the rotational added mass of the struck ship model, respectively, and their values ​​are obtained according to empirical formulas or numerical software; V a,t and V b,t are the translational linear velocities of the impacting ship model and the struck ship model after the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system; ω a and ω b are the rotational angular velocities of the striking ship model and the struck ship model after the collision, respectively, obtained by processing the experimental data recorded by the optical 3D motion capture system; (3) Ultimately, the energy dissipation during the collision is: 。 5. The ship collision model test method in a water tank according to claim 1, characterized in that: A height-adjustable horizontal fixed pulley is installed on the inner side of the pool wall on the long side of the pool, and the horizontal fixed pulley is located between the struck ship model and the striking ship model and close to the struck ship model; the traction device is installed on the pool wall on the short side of the pool; an adjustable height limit pile is installed inside the pool between the struck ship model and the traction device, and the adjustable height limit pile is arranged close to the traction device, and a limit pile fixed pulley is provided on the top; height-adjustable pull rods are respectively installed on both sides of the bow of the striking ship model; one end of the two traction ropes is connected to the pull rod on the port / starboard side of the striking ship model, and the other end passes through the horizontal fixed pulley, the limit pile fixed pulley in turn and is connected to the traction device; by coordinating the height adjustment of the pull rod, the horizontal fixed pulley and the adjustable height limit pile, the traction rope can be coordinated to pull it to both sides along the horizontal direction at the same height as the center of gravity of the striking ship model.

6. The ship collision model test method in a water tank according to claim 5, characterized in that: The traction rope is provided with a motion termination block, which is located between the fixed pulley of the limit pile and the horizontal fixed pulley. When the striking ship model moves close to the struck ship model, the motion termination block reaches the fixed pulley of the limit pile. As the traction device continues to run, the traction rope between the traction device and the fixed pulley of the limit pile is broken, thereby releasing the striking ship model.

7. The ship collision model test method in a water tank according to claim 1, characterized in that: A roller clamping device is installed on the side of the impact ship model, and the end rollers of the roller clamping device are rollingly connected with the transverse constraint baffle to achieve rolling friction between the impact ship model and the transverse constraint baffle.

8. A ship collision model test device in a water tank, characterized in that: The system comprises a water tank system, an experimental data acquisition system, and a ship model control system; the water tank system comprises a water tank in which a striking ship model and a struck ship model are placed. The two ship models eventually collide freely under the traction and constraint of the ship model control system, and the experimental data during the collision is captured by the experimental data acquisition system; A traction device is installed on the water pool, and an adjustable height limit pile is installed inside the water pool between the model of the struck ship and the traction device; The experimental data acquisition system includes a pressure sensor, a wave height meter, and an optical three-dimensional motion capture system. The pressure sensor is installed between the front end of the striking ship model and the impact head to obtain the impact force time history curve during the collision process. The wave height meter is installed around the impact area of ​​the parallel mid-body section of the struck ship model, with its sensing wire facing outward, to obtain the changes in the relative water levels on the left and right sides of the struck ship model during the collision. The optical three-dimensional motion capture system is installed on the outer shore of the pool to obtain the six-degree-of-freedom motion state of the two ships during the collision. The ship model control system includes a transverse restraint baffle, a pull rod, a traction rope, a horizontal fixed pulley, a laser photoelectric switch, and an electromagnet; two transverse restraint baffles are installed in the pool, forming an acceleration channel for the impact ship model in the middle; the pull rod is installed on both sides of the bow of the impact ship model, and the height can be adjusted according to the change of the center of gravity height of the impact ship model, and through two traction ropes, it first passes through the horizontal fixed pulley installed on the pool wall, and then converges and passes through the limit pile fixed pulley on the adjustable height limit pile, and finally connects to the traction device on the shore; two laser photoelectric switches are installed inside the pool, on both sides The two laser photoelectric switches are arranged opposite to each other and close to the model of the struck ship. An electromagnet device is installed at both ends of the struck ship model, including an electromagnet base and an electromagnet with a wire. The wire passes through the fixed pulley for controlling the collision angle and is connected to the laser photoelectric switch. The two laser photoelectric switches are connected by a wire to form a loop. When the laser photoelectric switch is not blocked by the striking ship model, the electromagnet is controlled to be in an adsorption state. Combined with the taut electromagnet wire, the movement of the struck ship model is constrained. When the striking ship model moves to the position between the two laser photoelectric switches and blocks them, the electromagnet is immediately disconnected and the struck ship model is automatically released.

9. The ship collision model test device in a water tank according to claim 8, characterized in that: The ship model control system also includes two motion termination blocks, which are respectively tied to two traction ropes and located between the fixed pulley of the limit pile and the horizontal fixed pulley. When the striking ship model moves close to the struck ship model, the motion termination blocks arrive at the fixed pulley of the limit pile. As the traction device continues to run, the traction rope between the traction device and the fixed pulley of the limit pile is broken, thereby releasing the striking ship model.

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