Drop hammer device and method for simulating the lifting of ice loads by an underwater vehicle

Abstract

The application provides a drop hammer device and method for simulating the ice-breaking load of underwater submersible ascending, and belongs to the technical field of ship engineering test equipment. Through the design of the hammer head-elastic buffer- bearing table in the drop hammer mechanism, the instantaneous impact load is generated by the hammer head when falling and impacting, simulating the violent impact at the moment of ice breaking. Then the bearing table is pressed down by inertia, and the hammer head is applied with a continuous controllable thrust by compressing the elastic buffer, simulating the continuous extrusion of the ice layer. The load mode of impact + continuity truly reproduces the dynamic force process of the underwater submersible ascending and breaking ice. The application comprises a support frame, a drop hammer fixing frame, a drop hammer mechanism and an elevator. The drop hammer fixing frame is fixedly connected to the support frame, and the drop hammer mechanism is vertically and slidingly connected to the drop hammer fixing frame. The drop hammer mechanism comprises a bearing table, an elastic buffer and a hammer head. The hammer head is movably connected to the bearing table, and the elastic buffer is connected between the bearing table and the hammer head. The elevator is fixedly installed at the top of the drop hammer fixing frame.

Description

Technical Field

[0001] This invention relates to a drop hammer device and method for simulating ice-breaking loads during the surfacing of an underwater submersible, specifically belonging to the technical field of marine engineering testing equipment. Background Technology

[0002] With the increasing demand for polar scientific research and polar navigation, the icebreaking capability of underwater vehicles has become a key indicator for measuring their polar adaptability. During the process of underwater vehicles surfacing and breaking ice, the impact load between the hull and the ice layer directly determines the safety of the hull structure. Therefore, it is necessary to conduct experiments to accurately verify the structural response of underwater vehicles under this load.

[0003] In existing technologies, some studies use numerical simulation methods to predict the ice-breaking load of underwater vehicles. However, this method relies on simplified mechanical models and deviates from the actual physical process. Other experimental devices use cylinders to simulate the impact of the hull on the ice layer, but they have problems such as discontinuous load output and narrow parameter adjustment range, and cannot reproduce the dynamic characteristics of the instantaneous impact load and continuous compression load of the ice layer on the underwater vehicle when it surfaces and breaks through the ice. Summary of the Invention

[0004] The purpose of this invention is to provide a drop hammer device and method for simulating the ice-breaking load of an underwater submersible surfacing, so as to solve the problems of large deviations in the numerical simulation methods of the prior art and the inability of the cylinder loading device to reproduce the dynamic characteristics of the combined instantaneous impact and continuous compression load.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: The invention includes a support frame, a drop hammer fixing frame, a drop hammer mechanism, and a hoist. The drop hammer fixing frame is fixedly connected to the support frame, and the drop hammer mechanism is vertically slidably connected to the drop hammer fixing frame. The drop hammer mechanism includes a load-bearing platform, an elastic buffer, and a hammer head. The hammer head is movably connected to the load-bearing platform, and the elastic buffer is connected between the load-bearing platform and the hammer head. When the hammer head approaches the load-bearing platform, it compresses the elastic buffer. The hoist is fixedly installed on the top of the drop hammer fixing frame and is used to lift or release the drop hammer mechanism to realize the falling of the drop hammer mechanism.

[0006] Furthermore, by providing the initial impact through the falling of the drop hammer mechanism, and then providing the subsequent load through the continuous compression of the elastic buffer, the dynamic characteristics of the instantaneous impact load and continuous compression load experienced by the underwater submersible during ice breaking can be reproduced, solving the problem that existing devices cannot simulate this composite load. It also lays the foundation for simulating ice breaking loads under different working conditions by adjusting multiple parameters such as the weight of the drop hammer mechanism, the falling height, and the stiffness of the elastic buffer.

[0007] The support frame includes a horizontally arranged support beam and load-bearing legs fixedly connected to both ends of the support beam. The drop hammer fixing frame is slidably connected to the support beam, and a fixing bolt is threaded onto the drop hammer fixing frame. The drop hammer fixing frame is fixed to the support beam by the fixing bolt.

[0008] Furthermore, by setting up the supporting beam, load-bearing legs, and fixing bolts, the horizontal position of the drop hammer fixing frame is adjustable, which facilitates precise alignment with the test points of the scaled-down underwater submersible model, enhancing the flexibility of the device and the accuracy of the experiment.

[0009] Limiting frames are fixedly connected to both ends of the support beam. The limiting frames are used to prevent the drop hammer fixing frame from sliding off the end of the support beam.

[0010] Furthermore, by adding a limiting bracket to prevent the drop hammer fixing bracket from accidentally slipping off the support beam during adjustment, the safety and reliability of the device are improved.

[0011] The drop hammer fixing frame includes a frame and a vertical guide rail. The top of the frame is slidably connected to the support beam, and the bottom of the frame is provided with a drop hammer hole for the hammer head to pass through. The vertical guide rail is vertically fixed to the frame, and a guide sleeve is fixedly connected to the load-bearing platform. The guide sleeve is fitted onto the vertical guide rail.

[0012] Furthermore, the cooperation of the vertical guide rail and the guide sleeve provides precise guidance for the vertical movement of the drop hammer mechanism, ensuring the stability and verticality of the falling process, reducing swaying, and ensuring the accurate application of impact load.

[0013] It also includes a support rod, one end of which is fixedly connected to the support frame, and the other end of which is inclined upward and supported at the bottom of the drop hammer frame.

[0014] Furthermore, by adding inclined support rods, the support stiffness of the drop hammer fixing frame and the stability of the overall structure are significantly enhanced, enabling it to withstand the enormous reaction force brought about by the drop hammer impact.

[0015] The falling hammer mechanism also includes a connecting guide rod. One end of the connecting guide rod is fixedly connected to the hammer head, and the other end of the connecting guide rod is inserted into the support platform. One end of the connecting guide rod extending out of the support platform is fixedly connected to a limit plate. The limit plate contacts the top of the support platform, thereby restricting the connecting guide rod from sliding away from the support platform.

[0016] Furthermore, by setting up connecting guide rods and limiting plates, the movable connection and guidance between the hammer head and the load-bearing platform are realized, and the separation of the hammer head from the load-bearing platform when the elastic buffer rebounds is restricted, thus ensuring the integrity of the mechanism and the reliability of its operation.

[0017] The elastic buffer is set as a spring, and the connecting guide rod passes through the spring. The falling hammer mechanism also includes a first positioning seat and a second positioning seat. The first positioning seat is connected to the side of the support platform facing the hammer head, and the second positioning seat is connected to the side of the hammer head facing the support platform. A first positioning protrusion is fixedly connected to the first positioning seat, and a second positioning protrusion is fixedly connected to the second positioning seat. One end of the elastic buffer is sleeved on the first positioning protrusion, and the other end of the elastic buffer is sleeved on the second positioning protrusion.

[0018] Furthermore, the elastic buffer is specifically defined as a spring, and a positioning seat and a positioning protrusion are provided, which makes the spring installation and positioning more accurate and the operation more stable. It also makes it easier to replace springs with different stiffnesses according to experimental needs, further expanding the device's ability to simulate different load conditions.

[0019] It also includes an industrial control computer and a laser displacement sensor. The hoist and the laser displacement sensor are respectively connected to the industrial control computer for communication. The laser displacement sensor is connected to the top of the drop hammer fixing frame and faces the drop hammer mechanism. The laser displacement sensor is used to measure the distance between the drop hammer mechanism and the top of the drop hammer fixing frame.

[0020] Furthermore, by adding an industrial control computer and a laser displacement sensor, precise automatic control and real-time monitoring of the lifting height of the drop hammer mechanism were achieved, reducing human error and improving the repeatability of the experiment and the accuracy of the data.

[0021] An infrared sensor is fixedly connected to the bottom of the drop hammer mounting bracket. The infrared sensor is located at the lowest point of the drop hammer and is connected to the industrial control computer.

[0022] Furthermore, by adding an infrared sensor, the lowest point of the hammer's fall can be detected automatically and accurately, and the loading time can be controlled in conjunction with the industrial control computer, thus achieving precise control over the duration of continuous extrusion load and improving the automation and reliability of the experiment.

[0023] This invention also provides a method for simulating the ice-breaking load of an underwater submersible surfacing, applied to the aforementioned drop hammer device, comprising the following steps: installing an acceleration sensor at a test point on a scaled-down model of the underwater submersible; controlling a hoist to lift the drop hammer mechanism, raising the hammer head to a set height; controlling the hoist to release the drop hammer mechanism, causing the hammer head to fall and impact the top of the scaled-down model of the underwater submersible, simultaneously collecting acceleration data of the scaled-down model of the underwater submersible; when the hammer head falls to the set minimum position, starting the loading time timing; when the loading time reaches the set value, controlling the hoist to lock and stopping the hammer head from falling; generating an "acceleration-time" curve based on the data from the acceleration sensor.

[0024] Furthermore, by collecting acceleration data and generating "acceleration-time" curves, the dynamic changes of the load can be quantified and recorded, providing direct and reliable data support for analyzing the structural response of underwater vehicles. Combined with the automated control of the device, the entire testing process is more efficient and the risk of human intervention is reduced.

[0025] The beneficial effects of this invention are:

[0026] 1. The drop hammer device, through the collaborative design of mechanical structure and intelligent control system, achieves high-precision and repeatable simulation of the composite loads borne by the underwater submersible during the ice-breaking process. The core load generation unit consists of a support platform, a hammer head, and an elastic buffer (such as a spring) connecting the two. When the device falls, the hammer head first impacts the scaled-down model, generating an instantaneous impact load to simulate the violent impact at the moment of ice breaking. Subsequently, the support platform continues to press down under the action of inertia, compressing the elastic buffer and applying a continuous and controllable thrust to the hammer head, thereby accurately reproducing the continuous squeezing load of the ice layer on the hull. This "impact + continuous" load mode cannot be achieved by traditional cylinder or purely rigid drop hammer devices.

[0027] 2. By combining the support frame (including the support beam and load-bearing legs) with the sliding drop hammer fixing frame (positioned by fixing bolts), the entire impact system can be flexibly adjusted in the horizontal direction, facilitating precise centering of the model test point. The precise cooperation between the vertical guide rail and the guide sleeve ensures the verticality and stability of the drop hammer mechanism, avoiding experimental errors caused by lateral swaying. In addition, the inclined support fixing rod further enhances the rigidity of the drop hammer fixing frame, enabling it to withstand huge impact reaction forces. Inside the drop hammer mechanism, the connecting guide rod passes through the sliding bearing in the load-bearing platform, and its end is limited by the limiting plate. It works together with the first positioning seat, the second positioning seat, and the positioning protrusions on them to ensure smooth guidance of the relative movement between the hammer head and the load-bearing platform, as well as the precise positioning and easy replacement of the spring.

[0028] 3. Using an industrial control computer as the brain, the system receives real-time height feedback from the laser displacement sensor and precisely controls the hoist to lift the hammer to the set height. When the hammer falls to the lowest point, the infrared sensor is triggered, and the industrial control computer starts precisely timing the loading time. When the set value is reached, the hoist brakes, thus achieving fully automated control of the loading process. The acceleration data collected during this process is used to generate an "acceleration-time" curve, providing direct and reliable quantitative evidence for analyzing the structural response, greatly improving the efficiency and scientific rigor of the experiment. The automation of the device and the traceability of data can be achieved through the intelligent control system. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a schematic diagram showing the positional relationship between the support frame and the drop hammer fixing frame of the present invention; Figure 3 This is a schematic diagram showing the connection relationship between the drop hammer fixing frame and the drop hammer mechanism of the present invention; Figure 4 This is a schematic diagram of the falling hammer mechanism of the present invention; Figure 5 This is a schematic diagram of the internal structure of the load-bearing platform of the present invention; Figure 6 This is a schematic diagram of the limiting frame structure of the present invention; Figure 7 This is a schematic diagram showing the connection relationship between the frame and the supporting beam of the present invention.

[0030] 1. Support frame; 11. Support beam; 111. Limiting frame; 112. Buffer plate; 12. Load-bearing leg; 121. Base; 122. Pile leg; 2. Drop hammer fixing frame; 21. Frame; 211. Connecting slide; 212. Fixing bolt; 213. Drop hammer hole; 214. Guide rail fixing sleeve; 22. Vertical guide rail; 23. Laser displacement sensor; 3. Drop hammer mechanism; 31. Load-bearing platform; 311. Guide sleeve; 312. Connecting sleeve 313. First sleeve; 314. Second sleeve; 315. Sliding bearing; 32. Elastic buffer; 33. Hammer head; 34. Connecting guide rod; 35. First positioning seat; 351. First positioning protrusion; 36. Second positioning seat; 361. Second positioning protrusion; 4. Hoist; 5. Support fixing rod; 6. Limiting plate; 7. Industrial control computer; 8. Infrared sensing device; 9. Experimental water tank; 91. Scale model of underwater submersible; 92. Ballast iron. Detailed Implementation

[0031] Specific Implementation Method 1: The following is combined with... Figures 1 to 7 This paper provides a detailed description of a specific embodiment of the drop hammer device of the present invention for simulating the ice-breaking load of an underwater submersible during surfacing; such as... Figure 1 As shown, the drop hammer device in this embodiment mainly consists of a support frame 1, a drop hammer fixing frame 2, a drop hammer mechanism 3, and a hoist 4. The support frame 1 provides basic support for the entire device. The drop hammer fixing frame 2 is installed on the support frame 1 and can be adjusted in horizontal position. The drop hammer mechanism 3 is the core of this device. Through its unique "hammer head-elastic buffer-load-bearing platform" design, it is specifically designed to simulate the combined loads borne by underwater submersibles when breaking ice. The hoist 4 is installed on the top of the drop hammer fixing frame 2 and is used to control the lifting and releasing of the drop hammer mechanism 3. The drop hammer mechanism 3 includes a support platform 31, an elastic buffer 32, and a hammer head 33. The hammer head 33 is connected to the support platform 31 in a movable manner, and the elastic buffer 32 (such as a spring) is placed between the two. When the drop hammer mechanism 3 falls and impacts the scale model 91 of the underwater submersible, the hammer head 33 first generates an instantaneous impact force. Subsequently, the inertial downward pressure of the support platform 31 will cause the elastic buffer 32 to be continuously compressed, thereby applying a stable subsequent load to the hammer head 33. This "impact-continuous" load mode can realistically reproduce the mechanical effect of the ice layer on the underwater submersible when it rises.

[0032] Specifically, such as Figures 2-3 As shown, the support frame 1 is used to support the drop hammer fixing frame 2, the drop hammer mechanism 3 slides in the vertical direction, and the hammer head 33 is located at the bottom of the drop hammer mechanism 3; the drop hammer mechanism 3 is lifted or released by the hoist 4 to control the rise and fall of the hammer head 33; the elastic buffer 32 is installed between the hammer head 33 and the support platform 31. When the drop hammer mechanism 3 falls and impacts the scale model 91 of the underwater submersible, the elastic buffer 32 is compressed, and at the same time, the elastic buffer 32 continuously applies a continuous thrust to the hammer head 33. When using the drop hammer device, the drop hammer mechanism 3 is lifted to a designated height by the hoist 4, moving the scaled-down underwater vehicle model 91 below the hammer head 33, ensuring the impact point on the top of the model 91 is directly below the hammer head 33. An acceleration sensor is installed at the impact point on the top of the model 91. The hoist 4 is then released, causing the drop hammer mechanism 3 to fall, and the hammer head 33 impacts the impact point on the top of the model 91. When the hammer head 33 reaches the set minimum position, the loading timer begins. When the loading time reaches the set value, the hoist 4 is locked, preventing the drop hammer mechanism 3 from falling further. The load data received by the acceleration sensor is then collected. When the drop hammer reaches its lowest point, it first contacts the top of the scaled-down model 91 of the underwater vehicle, and the spring compression generates an instantaneous impact load, simulating the impact of the underwater vehicle hitting the ice. Subsequently, the spring continues to compress, providing a steady-state load and applying a continuous load to the scaled-down model 91 of the underwater vehicle, simulating the continuous compression of the hull by the ice layer. This reproduces the instantaneous impact load and continuous compression load of a real underwater vehicle breaking through ice.

[0033] In a preferred embodiment, the hoist 4 in this example is a free-fall winch. The end of its wire rope is connected to the support platform 31 of the drop hammer mechanism 3 via a hook. When lifting is required, the winch winds up the wire rope; when simulating a fall, its brake is released, allowing the drop hammer mechanism 3 to fall freely under gravity; when terminating the fall, the brake is engaged, preventing the drop hammer mechanism 3 from continuing to fall.

[0034] In some specific embodiments, the support frame 1 includes a horizontally arranged support beam 11 and load-bearing legs 12 respectively fixedly connected to both ends of the support beam 11. The drop hammer fixing frame 2 is slidably connected to the support beam 11. The drop hammer fixing frame 2 is threadedly connected with fixing bolts 212, and the drop hammer fixing frame 2 is fixed to the support beam 11 by fixing bolts 212.

[0035] Specifically, such as Figure 1 , Figure 7 As shown, the load-bearing legs 12 include a support base 121 and a pile leg 122. The support base 121 is fixed to the pile leg 122 by bolts, thus assembling the load-bearing legs 12 on both sides. Both ends of the support beam 11 are fixed to the load-bearing legs 12 by bolts. A connecting groove 211 is fixedly connected to the drop hammer fixing frame 2. The bottom of the support beam 11 slides into the connecting groove 211, achieving a sliding connection between the drop hammer fixing frame 2 and the support beam 11. The end of the fixing bolt 212 passes through the top of the drop hammer fixing frame 2 and presses against the bottom surface of the support beam 11, thereby achieving relative fixation between the drop hammer fixing frame 2 and the support beam 11. Alternatively, in another optional embodiment, the bottom of the support beam 11 has multiple threaded holes distributed along the sliding direction of the drop hammer fixing frame 2. The end of the fixing bolt 212 passes through the top of the drop hammer fixing frame 2 and is threadedly connected to the threaded holes at the bottom of the support beam 11, thereby achieving relative fixation between the drop hammer fixing frame 2 and the support beam 11.

[0036] In some specific embodiments, such as Figure 2 , Figure 6 As shown, limit frames 111 are fixedly connected to both ends of the support beam 11. The limit frames 111 are used to restrict the drop hammer fixing frame 2 from sliding off the end of the support beam 11.

[0037] Specifically, as shown in the figure, the limiting frame 111 is fixedly connected to the end of the supporting beam 11 by bolts. The limiting frame 111 is configured as a triangular frame structure, and a buffer plate 112 is welded to the bottom of the limiting frame 111 near the drop hammer fixing frame 2. The contact between the buffer plate 112 and the drop hammer fixing frame 2 restricts the drop hammer fixing frame 2 from sliding off the end of the supporting beam 11, thereby preventing it from falling due to excessive movement when adjusting the horizontal position of the drop hammer fixing frame 2, and improving safety performance.

[0038] In some specific embodiments, the drop hammer fixing frame 2 includes a frame 21 and a vertical guide rail 22. The top of the frame 21 is slidably connected to the supporting beam 11. The bottom of the frame 21 is provided with a drop hammer hole 213 for the hammer head 33 to pass through. The vertical guide rail 22 is vertically fixedly connected to the frame 21. A guide sleeve 311 is fixedly connected to the support platform 31, and the guide sleeve 311 is sleeved on the vertical guide rail 22.

[0039] Specifically, such as Figure 3 , Figure 4As shown, two vertical guide rails 22 are provided, respectively installed on both sides of the drop hammer mechanism 3. Guide rail fixing cylinders 214 are fixedly connected to the upper and lower ends of the frame 21, and the upper and lower guide rail fixing cylinders 214 are arranged facing each other. The vertical guide rails 22 are vertically arranged inside the frame 21. When installing the vertical guide rails 22, first, pass the two vertical guide rails 22 through the guide sleeves 311 respectively, extend the top end of the vertical guide rail 22 into the guide rail fixing cylinder 214 located above the frame 21, and extend the bottom end of the vertical guide rail 22 into the guide rail fixing cylinder 214 located below the frame 21. The two ends of the vertical guide rail 22 are then fixedly connected to the guide rail fixing cylinders 214 respectively by bolts. Two guide sleeves 311 are provided, one on each side of the support platform 31. The guide sleeves 311 are fitted onto the vertical guide rail 22, which guides the vertical movement of the drop hammer mechanism 3, improving the stability of the drop hammer mechanism 3 during lifting and falling. The hammer head 33 passes through the drop hammer hole 213 when it falls and impacts.

[0040] In some specific embodiments, a support fixing rod 5 is also included. One end of the support fixing rod 5 is fixedly connected to the support frame 1, and the other end of the support fixing rod 5 is inclined upward and supported at the bottom of the drop hammer fixing frame 2.

[0041] Specifically, such as Figure 2 , Figure 3 As shown, one end of the support rod 5 is fixed to the load-bearing leg 12 by bolts, and the other end of the support rod 5 is inclined upward and supported at the bottom of the frame 21, which improves the stability of the drop hammer fixing frame 2.

[0042] In some specific embodiments, the falling hammer mechanism 3 further includes a connecting guide rod 34, one end of which is fixedly connected to the hammer head 33, and the other end of which is inserted into the support platform 31. A limiting plate 6 is fixedly connected to one end of the connecting guide rod 34 extending out of the support platform 31. The limiting plate 6 contacts the top of the support platform 31 to restrict the connecting guide rod 34 from sliding away from the support platform 31.

[0043] Specifically, such as Figure 4 , Figure 5As shown, one end of the connecting guide rod 34 is bolted to the top of the hammer head 33, and the other end of the connecting guide rod 34 passes through the support platform 31 and is bolted to the limiting plate 6. The support platform 31 also includes a connecting sleeve 312, a first sleeve 313, a second sleeve 314, and a sliding bearing 315. The first sleeve 313 is bolted to the connecting sleeve 312, the second sleeve 314 is bolted to the first sleeve 313, and the sliding bearing 315 is bolted to the second sleeve 314. The connecting guide rod 34 passes through the sliding bearing 315. The longitudinal sliding of the connecting guide rod 34 within the sliding bearing 315 guides and limits the relative movement between the support platform 31 and the hammer head 33, and the three-layer nested structure ensures the stability of the vertical load applied by the falling hammer head 33.

[0044] In some specific embodiments, the elastic buffer 32 is configured as a spring. In other specific embodiments, the elastic buffer 32 may also be configured as multiple air spring bladders or multiple nitrogen springs, which are distributed in a circumferential array along the central axis of the connecting guide rod 34. When the elastic buffer 32 is configured as a spring, the connecting guide rod 34 passes through the spring. The drop hammer mechanism 3 also includes a first positioning seat 35 and a second positioning seat 36. The first positioning seat 35 is connected to the side of the support platform 31 facing the hammer head 33, and the second positioning seat 36 is connected to the side of the hammer head 33 facing the support platform 31. A first positioning protrusion 351 is fixedly connected to the first positioning seat 35, and a second positioning protrusion 361 is fixedly connected to the second positioning seat 36. One end of the spring is sleeved on the first positioning protrusion 351, and the other end of the spring is sleeved on the second positioning protrusion 361.

[0045] Specifically, such as Figure 4 As shown, the elastic buffer 32 is configured as a spring. One end of the spring is fitted onto the first positioning protrusion 351, and the first positioning seat 35 is fixed to the support platform 31 by bolts. The other end of the spring is fitted onto the second positioning protrusion 361, and the spring presses the second positioning seat 36 against the hammer head 33. The connecting guide rod 34 passes through the spring to position it and improve its stability during testing. Furthermore, springs with different stiffnesses can be replaced according to the compressive strength of the actual ice layer. When replacing the spring, it is only necessary to remove the bolts below the connecting guide rod 34 to disassemble the hammer head 33 and the second positioning seat 36, and then remove the spring from below the connecting guide rod 34 for replacement, achieving quick assembly and disassembly of the spring.

[0046] In some specific embodiments, an industrial control computer 7 and a laser displacement sensor 23 are also included. The hoist 4 and the laser displacement sensor 23 are respectively connected to the industrial control computer 7 for communication. The laser displacement sensor 23 is connected to the top of the drop hammer fixing frame 2 and faces the drop hammer mechanism 3. The laser displacement sensor 23 is used to measure the distance between the drop hammer mechanism 3 and the top of the drop hammer fixing frame 2.

[0047] Specifically, as shown in the figure, the laser displacement sensor 23 is fixedly connected to the bottom surface of the top of the frame 21, so that the laser displacement sensor 23 faces the upper surface of the support platform 31, thereby measuring the distance between the support platform 31 and the top surface of the frame 21 in real time when the drop hammer mechanism 3 is lifted. When lifting the drop hammer mechanism 3, the shortest distance between the support platform 31 and the top surface of the frame 21, i.e., the maximum height of the drop hammer mechanism 3, is set on the industrial control computer 7. The industrial control computer 7 lifts the drop hammer mechanism 3 through the hoist 4. When the laser displacement sensor 23 detects that the distance between the support platform 31 and the top surface of the frame 21 has reached the set shortest distance, it controls the hoist to stop, thereby achieving precise control of the lifting height of the drop hammer mechanism 3. At the same time, the laser displacement sensor 23 collects the displacement data of the drop hammer mechanism 3 in real time during the fall. By analyzing the relationship between the falling displacement data of the drop hammer mechanism 3 and time, the real-time falling speed and falling acceleration of the drop hammer mechanism 3 can be calculated.

[0048] Furthermore, an infrared sensor 8 is fixedly connected to the bottom of the drop hammer fixing frame 2. The infrared sensor 8 is located at the lowest point of the drop hammer head 33 and is communicatively connected to the industrial control computer 7.

[0049] The lifting, releasing, and stopping of the hoist 4 are controlled by the industrial control computer 7. An infrared sensor 8 is set at the lowest position of the hammer 33. When the hammer 33 falls to the set lowest position, the infrared sensor 8 is triggered by being blocked. Based on the trigger signal from the infrared sensor 8, the industrial control computer 7 starts timing the loading time. When the loading time reaches the set value, the hoist 4 is locked, thereby preventing the hammer dropping mechanism 3 from continuing to fall.

[0050] This application also provides a method for simulating the ice-breaking load of an underwater submersible surfacing, comprising the following steps: S0. Install a drop hammer device on the experimental water tank 9 and arrange the scaled-down model 91 of the underwater submersible. Install acceleration sensors at each test point of the scaled-down model 91 of the underwater submersible. Specifically, the supporting legs 12 are arranged on both sides of the experimental pool 9. A scaled-down model 91 of the underwater vehicle is selected as the test object. The scaled-down model 91 is 1:10 to 1:50 of the actual underwater vehicle, and the size of the model 91 is adjusted according to the experimental requirements. Accelerometers are installed at each test point of the scaled-down model 91. The scaled-down model 91 is moved so that the impact point at the top of the model 91 is directly below the hammer head 33. When moving the model 91, the position of the scaled-down model 91 can be calibrated with the assistance of a laser positioning device. The required weight of the hammer head 33 can be calculated based on the similarity ratio between the buoyancy energy of the actual underwater vehicle and the scaled-down model 91. Based on the calculation results, a hammer head 33 of corresponding mass is selected, or a ballast iron 92 of a certain weight is placed on the supporting platform 31 to adjust the weight of the falling hammer, ensuring that the weight of the falling hammer meets the working conditions and satisfies diverse experimental requirements.

[0051] S1. Control the hoist 4 to lift the drop hammer mechanism 3, so that the hammer head 33 is raised to the set height; Specifically, a winch is selected as the hoist 4, and the end of the winch's wire rope is fixed to the top of the support platform 31. The maximum height of the drop hammer mechanism 3 is set on the industrial control computer 7. The winch is started by the industrial control computer 7, thereby pulling the drop hammer mechanism 3 to lift. The laser displacement sensor 23 provides real-time measurement feedback on the drop hammer mechanism 3. When the drop hammer mechanism 3 is lifted to the set maximum height, the industrial control computer 7 controls the hoist to stop running.

[0052] S2. Control the hoist 4 to release the drop hammer mechanism 3, so that the hammer head 33 falls and hits the impact point on the top of the underwater submersible scale model 91, and simultaneously collects the acceleration data of each test point of the underwater submersible scale model 91.

[0053] Specifically, during the ice-breaking load simulation experiment, the operator uses the industrial control computer 7 to issue a release command through the PLC control system, thereby controlling the winch to release and causing the entire drop hammer mechanism 3 to fall. The hammer head 33 passes through the drop hammer hole 213 and impacts the top of the underwater submersible scale model 91. The industrial control computer 7 is communicatively connected to the acceleration sensor to collect acceleration data. The sampling frequency can be set through the industrial control computer 7, and the zero-point calibration of the acceleration sensor can be performed to ensure accurate acceleration data acquisition.

[0054] S3. When the hammer 33 falls to the set lowest position, the loading time is started. When the loading time reaches the set value, the hoist 4 is locked and the falling of the hammer 33 is stopped.

[0055] Specifically, the infrared sensor 8 is communicatively connected to the industrial control computer 7. When the hammer 33 falls to the set lowest position, it blocks the infrared sensor 8. The infrared sensor 8 sends a sensing signal to the industrial control computer 7. The industrial control computer 7 triggers a timer based on the received sensing signal to start the loading time. When the loading time meets the set time, the industrial control computer 7 controls the winch brake through the PLC control system to brake the winch's unwinding, preventing the hammer 33 from falling. Then, the industrial control computer 7 controls the winch to restart through the PLC control system, raising the hammer drop mechanism 3. When the hammer 33 falls to the lowest point, it first contacts the impact point on the top of the underwater submersible scale model 91. The spring compression generates an instantaneous impact load to simulate the impact of the underwater submersible hitting the ice. Subsequently, the spring continues to deform, applying a continuous load to the underwater submersible scale model 91 to simulate the continuous compression of the hull by the ice layer.

[0056] S4. Generate an "acceleration-time" curve based on the data from the accelerometer.

[0057] Specifically, the acceleration data of each detection point of the scaled-down model 91 of the underwater submersible is collected in real time by the acceleration sensor, and the acceleration data is transmitted to the industrial control computer 7. The industrial control computer generates an "acceleration-time" curve based on the relationship between the acceleration data and time through built-in software, which is used to record the key parameters of acceleration change.

[0058] After the test is completed, shut down the industrial control computer 7, remove the scaled-down model 91 of the underwater vehicle, and check the structural damage of the scaled-down model 91. Specifically, the scaled-down model 91 can be scanned with a 3D scanner to collect surface depression data. If the test needs to be repeated, this step can be skipped.

[0059] After each test, clean the dust from the surface of the vertical guide rail 22 and apply lubricant, such as lithium-based grease, to ensure smooth hammer descent. Regularly calibrate the accelerometer, for example, after every 30 tests, to ensure the accuracy of the acceleration data.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A drop hammer device for simulating the ice-breaking load of an underwater submersible during surfacing, characterized in that, It includes a support frame (1), a drop hammer fixing frame (2), a drop hammer mechanism (3) and a hoist (4). The drop hammer fixing frame (2) is fixedly connected to the support frame (1), and the drop hammer mechanism (3) is vertically slidably connected to the drop hammer fixing frame (2). The drop hammer mechanism (3) includes a support platform (31), an elastic buffer (32) and a hammer head (33). The hammer head (33) is movably connected to the support platform (31). The elastic buffer (32) is connected between the support platform (31) and the hammer head (33). When the hammer head (33) approaches the support platform (31), it compresses the elastic buffer (32). The hoist (4) is fixedly installed on the top of the drop hammer fixing frame (2) and is used to lift the drop hammer mechanism (3) or release the drop hammer mechanism (3) to realize the drop hammer mechanism (3) falling.

2. The drop hammer device for simulating the ice-breaking load of an underwater submersible upon surfacing, as described in claim 1, is characterized in that... The support frame (1) includes a horizontally arranged support beam (11) and load-bearing legs (12) fixedly connected to both ends of the support beam (11). The drop hammer fixing frame (2) is slidably connected to the support beam (11). The drop hammer fixing frame (2) is threaded with fixing bolts (212). The drop hammer fixing frame (2) is fixed to the support beam (11) by fixing bolts (212).

3. The drop hammer device for simulating the ice-breaking load of an underwater submersible upon surfacing, as described in claim 2, is characterized in that... Limiting frames (111) are fixedly connected to both ends of the supporting beam (11). The limiting frames (111) are used to restrict the falling hammer fixing frame (2) from sliding off the end of the supporting beam (11).

4. The drop hammer device for simulating the ice-breaking load of an underwater submersible upon surfacing, as described in claim 2, is characterized in that... The drop hammer fixing frame (2) includes a frame (21) and a vertical guide rail (22). The top of the frame (21) is slidably connected to the support beam (11). The bottom of the frame (21) is provided with a drop hammer hole (213) for the hammer head (33) to pass through. The vertical guide rail (22) is vertically fixedly connected to the frame (21). A guide sleeve (311) is fixedly connected to the load-bearing platform (31). The guide sleeve (311) is sleeved on the vertical guide rail (22).

5. The drop hammer device for simulating the ice-breaking load of an underwater submersible upon surfacing, as described in claim 1, is characterized in that... It also includes a support rod (5), one end of which is fixedly connected to the support frame (1), and the other end of which is inclined upward and supported at the bottom of the drop hammer fixing frame (2).

6. The drop hammer device for simulating the ice-breaking load of an underwater submersible upon surfacing, as described in claim 1, is characterized in that... The drop hammer mechanism (3) also includes a connecting guide rod (34), one end of which is fixedly connected to the hammer head (33), and the other end of which is inserted into the support platform (31). The end of the connecting guide rod (34) extending out of the support platform (31) is fixedly connected to a limiting plate (6). The limiting plate (6) contacts the top of the support platform (31) to restrict the connecting guide rod (34) from sliding away from the support platform (31).

7. The drop hammer device for simulating the ice-breaking load of an underwater submersible upon surfacing, as described in claim 6, is characterized in that... The elastic buffer (32) is set as a spring, and the connecting guide rod (34) passes through the spring. The drop hammer mechanism (3) also includes a first positioning seat (35) and a second positioning seat (36). The first positioning seat (35) is connected to the side of the support platform (31) facing the hammer head (33), and the second positioning seat (36) is connected to the side of the hammer head (33) facing the support platform (31). The first positioning protrusion (351) is fixedly connected to the first positioning seat (35), and the second positioning protrusion (361) is fixedly connected to the second positioning seat (36). One end of the elastic buffer (32) is sleeved on the first positioning protrusion (351), and the other end of the elastic buffer (32) is sleeved on the second positioning protrusion (361).

8. The drop hammer device for simulating the ice-breaking load of an underwater submersible upon surfacing, as described in claim 1, is characterized in that... It also includes an industrial control computer (7) and a laser displacement sensor (23). The hoist (4) and the laser displacement sensor (23) are respectively connected to the industrial control computer (7). The laser displacement sensor (23) is connected to the top of the drop hammer fixing frame (2) and faces the drop hammer mechanism (3). The laser displacement sensor (23) is used to measure the distance between the drop hammer mechanism (3) and the top of the drop hammer fixing frame (2).

9. A drop hammer device for simulating ice-breaking load during the surfacing of an underwater submersible, as described in claim 8, is characterized in that... The bottom of the drop hammer fixing frame (2) is fixedly connected to an infrared sensing device (8). The infrared sensing device (8) is located at the lowest position of the falling hammer head (33). The infrared sensing device (8) is connected to the industrial control computer (7) for communication.

10. A method for simulating the ice-breaking load of an underwater submersible surfacing, characterized in that, The falling hammer device according to any one of claims 1-9 comprises the following steps: Acceleration sensors were installed at test points on a scaled-down model (91) of the underwater submersible; The control hoist (4) lifts the drop hammer mechanism (3) so that the hammer head (33) is raised to the set height; Control the hoist (4) to release the drop hammer mechanism (3), so that the hammer head (33) falls and hits the top of the underwater submersible scale model (91), and simultaneously collects the acceleration data of the underwater submersible scale model (91); When the hammer (33) falls to the set lowest position, the loading time is started. When the loading time reaches the set value, the hoist (4) is locked and the hammer (33) stops falling. An "acceleration-time" curve is generated based on data from the accelerometer.

Images