An underwater explosion loading and structural response visualization test device and method

Abstract

The present invention discloses an underwater explosion loading and structural response visualization test device and method, specifically relating to the field of underwater explosion test technology. The device comprises a transparent water tank, a structural model, an underwater explosion detonation module, multiple underwater pressure sensors, a small camera, and a steel bracket. The transparent water tank is arranged inside the steel bracket, and multiple underwater pressure sensors are equidistantly installed on the side walls and bottom of the transparent water tank. The small camera is installed on the bottom of the steel bracket. The test device also includes: an attitude adjustment module and a shock wave visualization module. The present invention utilizes a transparent water tank and visualization test, combined with shock wave power signal acquisition, to realize the visualization process of gas-liquid-solid interaction formed by impact rupture, bubble pulsation, and structural response, as well as the corresponding underwater shock wave power field; and utilizes the attitude adjustment module to realize underwater explosion test testing of structural models with different attitude angles in two typical states: surface and underwater.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater explosion testing, and in particular to an underwater explosion loading and structural response visualization testing device and method. Background Art

[0002] Currently, underwater explosion tests are mainly divided into real ship underwater explosion tests, structural model underwater explosion tests, and laboratory underwater explosion tests. The damage to the hull caused by underwater explosions is mainly caused by shock wave loads and bubble loads. The complex loads formed by shock waves and bubble pulses act on the surface of the structure in a very short time. However, current real and model tests have problems such as high testing costs and difficulty in obtaining test information. It is generally difficult to visualize the gas-liquid-solid interaction process formed by shock waves, bubble pulsations, and structural responses, and it is impossible to accurately reconstruct the structural underwater explosion force field. This makes the protection and failure mechanism analysis of ship protective structures difficult and costly. Summary of the Invention

[0003] In view of the relevant technical problems of existing underwater explosion test equipment, the present invention provides an underwater explosion loading and structural response visualization test device and method. By constructing an in-situ visualization test device for underwater explosion shock waves, bubble pulses and structural responses, combined with underwater explosion shock wave pressure field testing, a method for visualizing the shock wave power field of surface / underwater structure models with different postures under underwater explosion loads is studied. Not only can the in-situ visualization of the entire process be achieved, but also the reconstruction of the underwater explosion loading power field can be completed in combination with the measured pressure field. While improving the controllability and safety of underwater explosion testing, the test cost is reduced, providing an efficient and reliable technical support for the protection and failure mechanism of ship protective structures, so as to solve the problems raised in the background technology.

[0004] The specific technical solutions are as follows:

[0005] An underwater explosion loading and structural response visualization test device includes a transparent water tank, a structural model, an underwater explosion detonation module, a shock wave visualization module, multiple underwater pressure sensors, a small camera, and a steel bracket. The transparent water tank is arranged inside the steel bracket, and multiple underwater pressure sensors are equidistantly installed on the side wall and bottom of the transparent water tank. The small camera is installed on the bottom of the steel bracket. The test device also includes:

[0006] The attitude adjustment module is arranged on the side wall of the transparent water tank. The attitude adjustment module includes a slide, a slider, a traction line and a wire bundler. The wire bundler is fixed to the slider, and the traction line is coiled in the wire bundler and can be freely extended or contracted. The slider slides freely on the slide, and one end of the slider is connected to the structural model through the traction line. By adjusting the position of the slider, the structural model can be placed on the water surface or underwater at different attitude angles, realizing the requirements of underwater explosive loading test of surface or underwater structures.

[0007] The underwater explosion module includes a charge, a detonating cord, an initiation controller, and a remote detonation switch; one end of the detonating cord is connected to the charge, and the other end of the detonating cord is connected to the initiation controller; the charge is fixed at the center of the side of the structural model, and the initiation controller is placed outside the transparent water tank. One end of the detonating cord is connected to the initiation controller, and the other end of the detonating cord is connected to the charge. The remote detonation switch is used to control the initiation controller to ignite the detonating cord, causing the charge to explode; and

[0008] A shock wave visualization module, which faces the structural model and the charge and is located on one side of the transparent water tank. The module includes a high-speed camera, a prism, a point light source, and a diffuse reflection light curtain. The prism is attached to the lens of a small camera. The point light source and the high-speed camera are placed at the same height to produce uniform light intensity, which converges at a focal point through a convex lens and is reflected by the prism to a point light source sufficient to observe the loading surface position of the structural model inside the transparent water tank. The shock wave generated by the explosion of the charge propagates to the loading end surface of the structural model and is reflected and converged underwater. During this process, the shock wave is projected onto the diffuse reflection light curtain in the form of a shadow and captured by the small camera.

[0009] A small camera captures the real-time evolution of explosion shock waves and bubbles, as well as their interaction with the structural model. An underwater pressure sensor is used to test the underwater pressure field, thereby achieving the goals of safe, controllable and highly repeatable underwater explosion tests. The high-speed camera captures the process of shock waves loading onto the end face of the structural model while obtaining the deformation response of the structural model during the loading process.

[0010] Preferably, the structural model includes any one of the structural forms of a surface hull and an underwater hull.

[0011] Preferably, the small camera is installed at the bottom of the steel bracket, and the small camera is located directly below the charge and the structural model. The focus is adjusted so that it can shoot the position between the charge and the structural model to assist the high-speed camera in capturing the process of bubble generation, propagation and loading onto the end face of the structural model caused by the underwater explosion.

[0012] Preferably, three underwater pressure sensors are arranged at the bottom of the transparent water tank at equal distances from the medicine column, and one is arranged at equal distances at the same height as the medicine column; the data transmission line of the underwater pressure sensor is fixed by a positioning mechanism.

[0013] Preferably, the traction line is made of ultra-high molecular weight polyethylene synthetic fiber material.

[0014] Preferably, the transparent water tank is made of acrylic material and has a removed top.

[0015] The present invention also discloses a method for visualizing underwater explosion loading and structural response testing. The method is based on the above-mentioned test device and includes the following steps:

[0016] Step 1: Install the steel bracket 8, fix the transparent water tank 1 on the steel bracket 8, and add water to the transparent water tank 1 to a predetermined water level;

[0017] Step 2: Install the posture adjustment modules 2 symmetrically on both sides of the transparent water tank 1, and fix the slides 21 to the side walls of the transparent water tank 1 with a high-strength adhesive; connect the sliders 22 to the structural model 3 with the traction lines 23, move the sliders 22 and adjust the length of the traction lines 23 to make the structural model 3 reach the posture and position required by the test;

[0018] Step 3: Install the underwater explosion initiation module 5 and fix the explosive column 51 through the positioning mechanism so that the explosive column 51 is suspended at the center of the side wall of the structural model 3;

[0019] Step 4: Arrange multiple underwater pressure sensors 6 at the bottom of the transparent water tank 1 and at the height of the medicine column 51 to collect pressure signals;

[0020] Step 5: Fix the small camera 7 on the ground and adjust its position and focal length so that it can shoot the position between the charge 51 and the structural model 3 from the bottom.

[0021] Step 6: Adjust the height of the high-speed camera 41 so that it is equal to the center of the drug column 51, adhere the prism 42 to the lens of the high-speed camera 41, adjust the position of the point light source 43 so that the prism 42 is located at the position where the light emitted by the point light source 43 is focused, and adjust the focal length of the high-speed camera 41 so that it can fully capture the water area between the structural model 3 and the drug column 51;

[0022] Step 7: Arrange a diffuse reflection light curtain 44 on the other side wall of the transparent water tank 1 facing the high-speed camera 41 so that the shadows produced by the structural model 3 and the charge 51 and the shadow formed by the total reflection of the shock wave appear on the diffuse reflection light curtain 44;

[0023] Step 8: Start the test by activating the remote detonation switch 54 and simultaneously turning on the high-speed camera 41 and the small high-speed camera 7 to collect the shock wave propagation process, bubble evolution, and the deformation response process of the interaction between the two and the end face of the structural model 3, and obtain the explosion loading power field through the pressure sensor.

[0024] The present invention has the following advantages:

[0025] The present invention utilizes a transparent water tank and visualization test, combined with shock wave power signal collection, to realize the visualization process of gas-liquid-solid interaction formed by impact burst, bubble pulsation and structural response, as well as the corresponding underwater shock wave power field; and utilizes an attitude adjustment module to realize underwater explosion test of structural models with different attitude angles under two typical states: surface and underwater.

[0026] The present invention utilizes a simple, low-cost test device to complete underwater explosion loading and structural response visualization tests in a controllable, safe, and efficient manner, providing an efficient and reliable technical support for the protection and failure mechanism of ship protective structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the overall structure of the underwater explosion loading and structural response visualization test device provided by the present invention;

[0028] Figure 2 A schematic structural diagram of the posture adjustment module provided by the present invention;

[0029] Figure 3 A schematic structural diagram of the underwater explosion module provided by the present invention;

[0030] Figure 4 A schematic diagram of the structure of the shock wave visualization module provided by the present invention;

[0031] Figure 5 This is a diagram of the underwater shock wave visualization test results provided by the present invention;

[0032] Figure 6 A schematic diagram of the cavitation propagation process under the action of underwater explosion shock waves provided by the present invention;

[0033] Figure 7 Schematic diagram of gas-liquid-solid interaction of impact burst, bubble pulsation and structural response provided by the present invention;

[0034] In the figure: 1. Transparent water tank; 2. Attitude adjustment module; 21. Slide; 22. Slider; 23. Towing line; 24. Wire bundler; 3. Structural model; 4. Shock wave visualization module; 41. High-speed camera; 42. Prism; 43. Point light source; 44. Diffuse reflection light curtain; 5. Underwater explosion detonation module; 51. Explosive column; 52. Detonating cord; 53. Detonation controller; 54. Remote control detonation switch; 6. Underwater pressure sensor; 7. Small camera; 8. Steel bracket. DETAILED DESCRIPTION

[0035] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0036] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] Reference Figure 1 、 Figure 2 、 Figure 3 and Figure 4 This embodiment provides an underwater explosion loading and structural response visualization test device. This embodiment uses a sliding module device to realize the posture control of the structural model, and meets the needs of underwater explosion loading testing of surface or underwater structures. The shock wave visualization module 4 and the small camera 7 are used to obtain the real-time evolution of the explosion shock wave and bubbles and their interaction process with the structural model 3. The underwater pressure sensor is used to test the underwater pressure field, thereby realizing the functions of safe, controllable and highly repeatable underwater explosion testing.

[0039] The transparent water tank 1 is a roofless acrylic tank with good light transmittance and stability, which facilitates the capture of experimental phenomena using a high-speed camera 41 and a small high-speed video camera 7. The sidewalls of the transparent water tank 1 have threaded holes above the predetermined water level and at the bottom of the sidewalls for securing the slide 21.

[0040] like Figure 2 As shown, the sliding modules are symmetrically mounted on the sidewalls of the transparent water tank 1, with slideways 21 fixed to the sidewalls by adhesive. Based on the test requirements of the structural model 3, the lengths of the traction lines 23 at multiple locations on both sides are adjusted to achieve the desired conditions for the structural model 3 to withstand underwater explosive loading at different angles, either on the surface or underwater.

[0041] like Figure 3 As shown, the wireless detonator consists of a charge 51, a detonating cord 52, a detonation controller 53, and a remote detonation switch 54. The charge 51 is the explosive source, and its detonating cord, after waterproofing, is connected to the detonation controller 53. When the detonation controller 53 receives a signal from the remote detonation switch 54, it detonates the charge 51. The length of the detonating cord 52 is adjusted so that the charge 51 is suspended at any desired location on the side of the structural model 3.

[0042] The traction line 23 can be made of ultra-high molecular weight polyethylene synthetic fiber material, which has the characteristics of high strength and high toughness. During the explosion process, it will not be broken by the effects of high-speed fragments and shock waves.

[0043] Underwater pressure sensors 6 are placed at the bottom of the transparent water tank 1 and at the same height as the charge 51. Three sensors are evenly spaced on the bottom of the transparent water tank 1, directly below the charge. One identical pressure sensor is installed on the side wall of the charge 51 at the same height. Each pressure sensor 6 is secured to its mounting position with adhesive. The data cable of the underwater pressure sensor is pulled through the adhesive along the transparent tank wall to the outside, where it is connected to a charge amplifier and an oscilloscope.

[0044] The small camera 7 is arranged directly below the transparent water tank 1, and the lens of the small camera 7 is focused on the position between the structural model 3 and the medicine column 51. The small camera 7 enables it to accurately capture the real-time evolution of the bubbles and their interaction with the structural model 3. Figure 6 As shown in Figure 2, the underwater explosion shock wave acts on the end face of the structural model, causing structural deformation, and then forming liquid cavitation caused by the interaction between the shock wave and structural deformation on the fluid-solid interaction surface, namely, Figure 6 The cavitation evolution phenomenon in the fluid-solid interface. The cavitation region is formed near the fluid-solid interface, with the cavitation front moving in two directions. The cavitation front near the fluid-solid interface transforms at the interface to form a closed front, which then moves in the opposite direction, chasing the closed front on the other side until the cavitation completely collapses.

[0045] High-speed camera 41 Figure 4 As shown, a reflective prism 42 with an inclination angle of 45° is tightly adhered in front of the high-speed camera 41. The position of the point light source 43 is adjusted so that the light emitted by the point light source 43 is focused on the prism 42, and the light is reflected and emitted into the transparent water tank 1. The high-speed camera 41 is adjusted to focus on the loading surface side of the structural model 3. When the shock wave generated by the explosion fully reflects the light, the shock wave will form a shadow on the diffuse reflection light curtain 44, and this shadow will be captured by the high-speed camera 41. The dynamic deformation process of the structural model 3 can be captured by the high-speed camera 41. Figure 5 The figure shows the process of shock wave propagation, reflection and convergence underwater recorded by high-speed camera. Figure 7 As shown in the figure, after the shock wave completes its interaction with the structure, the pulsating pressure of the bubbles continues to act on the structural model. A small camera 7 is used to further capture the process of bubble generation, evolution, collapse, and interaction with the structural surface. This achieves the goal of visualizing the propagation of shock waves and bubbles, as well as their interaction with the deformation of the structural model 3.

[0046] Based on the explosive underwater explosion bubble pulsation test device provided by the present invention, the present invention provides a simple small-scale underwater explosion bubble simulation test method, which specifically includes the following steps:

[0047] Step 1: Install the steel bracket 8, fix the transparent water tank 1 on the steel bracket 8, and add water to the transparent water tank 1 to a predetermined water level.

[0048] Step 2: Install the posture adjustment modules 2 symmetrically on both sides of the transparent water tank 1. Determine the underwater explosion loading conditions for the structural model 3, adjust the positions of the two sliders 22 and the length of the traction line 23, and after determining the correct position and tightening the traction line 23, secure the wire retractor 24 so that the structural model 3 achieves the desired posture angle, either floating on the water surface or suspended underwater.

[0049] Step 3: Place four underwater pressure sensors 6 on the sidewall of the transparent water tank 1. One is placed at the same height as the charge 51. The other three are placed on the bulkhead directly below the charge 51, spaced evenly apart. The bottom middle underwater pressure sensor 6 is located directly below the charge 51. The data transmission cable of the sensor is pulled along the bulkhead to the outside of the transparent water tank 1 and connected to a charge amplifier. The pressure signal is collected using an oscilloscope.

[0050] Step 4: Connect one end of the detonation controller 53 to the explosive charge 51. Secure the explosive charge 51 in the water at a predetermined position using the transparent water tank 1. Secure the detonating cord 52 using the positioning mechanism to prevent significant changes in the position of the explosive charge 51. Place the detonation controller 53 outside the transparent water tank 1 and secure it in a position that accurately receives and responds to the signal from the remote detonation switch 54.

[0051] Step 5: Place the small camera 7 on the bracket below the transparent water tank 1 and adjust the focal length so that it focuses on the position between the small medicine column and the structural model in the transparent water tank 1, so that it can accurately capture the real-time evolution of the bubble and its interaction process with the end face of the structural model.

[0052] Step 6. Install and adjust the shock wave visualization module 4. Install the high-speed camera 41 to one side of the transparent water tank 1, focusing its lens on the loading end face of the structural model 3, and fix the diffuse reflection light curtain 44 on the opposite side. Install the prism 42, and stick the reflective prism 42 with a 45° inclination angle tightly to the lens of the high-speed camera 41. Adjust the position of the point light source 43 so that its light is focused exactly on the end face of the prism 42. After reflection, the light irradiation range includes the end face of the structural model 3 and the nearby water area. Adjust the parameters of the high-speed camera 41 and ensure that the sampling frame rate is not less than 50,000 frames / second.

[0053] Step 7: Complete test preparations. Turn on point light source 43, set the oscilloscope trigger parameters, and turn on remote detonator 54 to detonate explosive charge 51. After the explosion is heard, start recording with miniature camera 7 and high-speed camera 41. This captures the real-time fluid-structure interaction process of the water surface or underwater structure model under the influence of shock waves and bubbles during underwater explosion loading at different postures, and also captures the underwater pressure field.

[0054] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. An underwater explosion loading and structural response visualization test device, comprising a transparent water tank, a structural model, an underwater explosion detonation module, multiple underwater pressure sensors, a small camera, and a steel bracket. The transparent water tank is disposed inside the steel bracket, multiple underwater pressure sensors are equidistantly installed on the sidewalls and bottom of the transparent water tank, and the small camera is mounted on the bottom of the steel bracket. The device is characterized by: The test apparatus also includes: The attitude adjustment module is arranged on the side wall of the transparent water tank. The attitude adjustment module includes a slide, a slider, a traction line and a wire bundler. The wire bundler is fixed to the slider, and the traction line is coiled in the wire bundler and can be freely extended or contracted. The slider slides freely on the slide, and one end of the slider is connected to the structural model through the traction line. By adjusting the position of the slider, the structural model can be placed on the water surface or underwater at different attitude angles, realizing the requirements of underwater explosive loading test of surface or underwater structures. The underwater explosion module includes a charge, a detonating cord, an initiation controller, and a remote detonation switch; one end of the detonating cord is connected to the charge, and the other end of the detonating cord is connected to the initiation controller. The charge is fixed at the center of the side of the structural model, and the initiation controller is placed outside the transparent water tank. One end of the detonating cord is connected to the initiation controller, and the other end of the detonating cord is connected to the charge. The remote detonation switch is used to control the initiation controller to ignite the detonating cord, causing the charge to explode; and A shock wave visualization module, which faces the structural model and the explosive column and is located on one side of the transparent water tank. The shock wave visualization module includes a high-speed camera, a prism, a point light source, and a diffuse reflection light curtain. The prism is attached to the lens of a small camera. The point light source and the high-speed camera are placed at the same height to generate a uniform parallel light source that converges at the focus of the prism through a convex lens. The light source is reflected by the prism to generate a point light source sufficient to observe the loading side of the internal structural model of the transparent water tank. The shock wave generated by the explosion of the explosive column propagates to the loading end face of the structural model and is reflected and converged underwater. During this process, the shock wave is projected onto the diffuse reflection light curtain in the form of a shadow and is captured by the small camera. The diffuse reflection light curtain corresponds to the high-speed camera and is placed on the other side of the transparent water tank. A small camera captures the real-time evolution of explosion shock waves and bubbles, as well as their interaction with the structural model. An underwater pressure sensor is used to test the underwater pressure field, thereby achieving the goals of safe, controllable and highly repeatable underwater explosion tests. The high-speed camera captures the process of shock waves loading onto the end face of the structural model while obtaining the deformation response of the structural model during the loading process.

2. The underwater explosion loading and structural response visualization test device according to claim 1, characterized in that: The structural model includes any one of the structural forms of a surface hull and an underwater hull.

3. The underwater explosion loading and structural response visualization test device according to claim 1, characterized in that: The small camera is installed at the bottom of the steel bracket. The small camera is located directly below the charge and the structural model. The focus is adjusted to shoot the position between the charge and the structural model to assist the high-speed camera in capturing the process of bubble generation, propagation and loading onto the end face of the structural model caused by the underwater explosion.

4. The underwater explosion loading and structural response visualization test device according to claim 1, characterized in that: Three underwater pressure sensors are arranged at the bottom of the transparent water tank at equal distances from the medicine column, and one is arranged at equal distances at the same height as the medicine column; the data transmission line of the underwater pressure sensor is fixed by a positioning mechanism.

5. The underwater explosion loading and structural response visualization test device according to claim 1, characterized in that: The traction line is made of ultra-high molecular weight polyethylene synthetic fiber.

6. The underwater explosion loading and structural response visualization test device according to claim 1, characterized in that: The transparent water tank is made of acrylic material and has a removed top.

7. A method for visualizing underwater explosion loading and structural response testing, characterized by: The method is based on the test device according to any one of claims 1 to 6, and the method comprises the following steps: Step 1: Install the steel bracket, fix the transparent water tank on the steel bracket, and add water to the transparent water tank to a predetermined water level; Step 2: Install posture adjustment modules symmetrically on both sides of the transparent water tank, and fix the slides to the side walls of the transparent water tank with a high-strength adhesive; connect the sliders to the structural model with a traction line, move the sliders and adjust the length of the traction line to make the structural model reach the posture and position required by the test; Step 3: Install the underwater explosion initiation module and fix the explosive column by a positioning mechanism so that the explosive column is suspended at the center of the side wall of the structural model; Step 4: Arrange multiple underwater pressure sensors at the bottom of the transparent water tank and at the height of the medicine column to collect pressure signals; Step 5: Fix the small camera on the ground and adjust its position and focal length so that it can shoot the position between the grain and the structural model from the bottom; Step 6: Adjust the height of the high-speed camera so that it is equal to the center of the medicine column, adhere the prism to the lens of the high-speed camera, adjust the position of the point light source so that the prism is located at the position where the light emitted by the point light source is focused, and adjust the focal length of the high-speed camera so that it can fully capture the water area between the structural model and the medicine column; Step 7: Arrange a diffuse reflection light curtain on the other side wall of the transparent water tank facing the high-speed camera, so that the shadows produced by the structural model and the charge and the shadows formed by the total reflection of the shock wave appear on the diffuse reflection light curtain; Step 8. Start the test by activating the remote detonation switch and simultaneously turning on the high-speed camera and the small high-speed video camera to collect the shock wave propagation process, bubble evolution, and the deformation response process of the interaction between the two and the end face of the structural model, and obtain the explosion loading power field through the pressure sensor.

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