An experimental method for simulating impact load loading under high hydrostatic pressure environment

Abstract

This invention provides an experimental method for simulating impact load loading under high hydrostatic pressure conditions, comprising the following steps: assembling a pressure-resistant shock tube; placing the experimental specimen into the pressure-resistant shock tube and then filling it with water and sealing it; simultaneously setting up a high-speed photography system and connecting a pressure sensor; placing a flyer in the air gun acceleration tube and inflating it; using a hydraulic cylinder to pressurize the water in the pressure-resistant shock tube to a specified pressure, releasing the air gun valve to allow the flyer in the air gun acceleration tube to be ejected and impact the pressure-resistant shock tube; collecting data through the high-speed photography system and pressure sensor; adjusting the hydraulic cylinder to the middle position to release pressure for easier subsequent experimental operations. This experimental method can be used to simulate the impact load effect on underwater structures under pressure conditions within 500m of water depth, shortening the preparation time for deep-water structure impact response experiments, saving experimental costs, and obtaining the overpressure curve of the shock wave under deep-water high hydrostatic pressure conditions and the dynamic response process of the structure.

Description

Technical Field

[0001] This invention belongs to the field of underwater impact testing technology, and specifically relates to an experimental method for simulating impact load loading under high hydrostatic pressure environment. Background Technology

[0002] In deep water, intense, short-lived pressure waves or impacts generated by various causes (such as explosions or high-speed impacts from underwater objects) typically possess extremely high energy and destructive power. When impact loads act on underwater structures (such as submarines and underwater facilities), they can cause deformation, rupture, or even complete destruction. Furthermore, under deep-water impact loads, complex and intense interactions occur between the underwater structure (solid), the surrounding water (liquid), and any present gases (such as bubbles or cavities). These interactions include the transmission of pressure waves, the dynamic response of the fluid, and the deformation and fracture of the solid. These interactions are intertwined and mutually influential, making the entire process highly complex and posing significant challenges to experimental research.

[0003] Deep-water explosion experiments face significant challenges due to their long preparation time, high cost, numerous limitations, and limited testing methods. The difficulty in studying the interaction between impact loads and structural response in deep-water environments has resulted in limited understanding and knowledge of the mechanisms underlying this interaction.

[0004] In recent years, to study the interaction mechanism between shock waves and underwater structures, an experimental method using transparent shock tubes to observe this process has emerged. This type of device offers advantages such as simple experimental preparation, rapid deployment, low cost, precise loading, and ease of capturing the dynamic response of the medium and structure. However, current research on the structural response behavior under underwater pressure waves using this device is limited to relatively low-pressure environments. Its potential for application in deep water has not been fully explored, failing to meet the requirements of experimental research on structural shock response in deep-water environments. Summary of the Invention

[0005] To address the problems of the prior art, embodiments of the present invention provide an experimental method for simulating impact load loading under high hydrostatic pressure.

[0006] According to one aspect of the present invention, an experimental method for simulating impact load loading under high hydrostatic pressure is provided, comprising the following steps:

[0007] S1. Assemble the pressure-resistant shock tube, place the experimental specimen into the pressure-resistant shock tube, fill the pressure-resistant shock tube with water and seal it, and simultaneously set up the high-speed photography system and connect the pressure sensor.

[0008] S2. Place the flying piece inside the air cannon's acceleration tube and inflate it with air;

[0009] S3. Use a hydraulic cylinder to pressurize the water in the pressure-resistant shock tube to a specified pressure, release the air cannon valve, and cause the flying piece in the air cannon acceleration tube to fly out and impact the pressure-resistant shock tube. Data is collected by the high-speed photography system and the pressure sensor.

[0010] S4. Adjust the hydraulic cylinder to the middle position to release pressure, which will facilitate subsequent experimental operations.

[0011] Preferably, the pressure-resistant shock tube includes an inner acrylic tube, a piston, an outer tube, a water pressure gauge, and a baffle. The inner acrylic tube is composed of multiple acrylic sub-tubes assembled together. The piston is installed at both ends of the inner acrylic tube. The multiple acrylic sub-tubes and the piston and the inner acrylic tube are sealed with star-shaped rings. The inner acrylic tube has multiple threaded holes. The water pressure gauge and the pressure sensor are installed on the inner acrylic tube through the corresponding threaded holes. The outer tube is sleeved on the outside of the inner acrylic tube. Flanges are installed at both ends of the outer tube. The flanges are used to fix the baffle and the hydraulic cylinder.

[0012] Preferably, the outer tube has an observation window and a sensor mounting hole on its wall. The observation window facilitates the high-speed photography system in capturing the dynamic response process of the experimental specimen. The sensor mounting hole is arranged vertically in correspondence with the threaded hole for mounting the pressure sensor.

[0013] Preferably, the piston is made of aluminum alloy, and a wide annular groove is formed at the center along the height direction of the piston. The flyer enters the pressure-resistant shock tube and impacts one of the pistons.

[0014] Preferably, the baffle is fixedly installed on the outside of one of the flanges, and the baffle has a through hole in its center.

[0015] Preferably, the high-speed photography system includes a high-speed camera and a synchronization trigger, wherein the high-speed camera is signal-connected to the synchronization trigger.

[0016] Preferably, the range of the water pressure gauge is 0-5 MPa.

[0017] Preferably, the experiment also includes step S5: when repeating the experiment after the current experiment is completed, determine whether the piston and the experimental specimen need to be replaced. If replacement is required, disassemble the baffle and the hydraulic cylinder and repeat steps S1-S4; if replacement is not required, repeat steps S2-S4.

[0018] The beneficial effects of this invention are as follows:

[0019] As can be seen from the above scheme, the embodiments of the present invention provide an experimental method for simulating impact load loading under high hydrostatic pressure conditions, which can be used to simulate the effect of impact load on underwater structures under pressure conditions in water depths of up to 500m. In this experimental method, an impact load is generated by a high-speed flying plate impacting a piston, and the impact load is transmitted into the water in a pressure-resistant shock tube to form a shock wave. High hydrostatic pressure is generated by compressing the water in the inner plexiglass tube by a hydraulic cylinder. The overpressure curve of the shock wave in the water is measured by an IEPE-type pressure sensor installed on the inner plexiglass tube. The dynamic response process of the experimental specimen structure is obtained through an observation window opened on the outer aluminum alloy tube by a high-speed photography system. At the same time, using this experimental method, the preparation time for the impact response experiment of deep-water structures can be greatly shortened, the experimental cost can be saved, and the overpressure curve of the shock wave under deep-water high hydrostatic pressure conditions and the dynamic response process of the structure can be obtained. Attached Figure Description

[0020] Figure 1 A flowchart illustrating the steps of an experimental method for simulating impact load loading under high hydrostatic pressure, according to an embodiment of the present invention;

[0021] Figure 2 A schematic diagram showing the structure of a pressure-resistant shock tube according to an embodiment of the present invention;

[0022] Figure 3 A schematic diagram illustrating the sealing structure of the star-shaped ring according to an embodiment of the present invention;

[0023] Figure 4 Three views showing the aluminum alloy outer tube according to an embodiment of the present invention;

[0024] Figure 5 The three views of the piston in an embodiment of the present invention are shown.

[0025] Figure 6 The three views of the baffle in an embodiment of the present invention are shown.

[0026] Figure 7 This shows the three views of the first acrylic tube according to an embodiment of the present invention;

[0027] Figure 8 This shows a three-view diagram of the second acrylic tube according to an embodiment of the present invention;

[0028] Figure 9 The three views represent the third acrylic tube according to an embodiment of the present invention.

[0029] In the diagram, 1 is the inner plexiglass tube; 2 is the piston; 3 is the outer tube; 4 is the pressure sensor mounting hole; 5 is the water pressure gauge; 6 is the baffle; 7 is the hydraulic cylinder mounting plate; 8 is the star-shaped ring; 9 is the flange; 10 is the observation window; 11 is the wide groove; 12 is the through hole; 13 is the first plexiglass branch pipe; 14 is the second plexiglass branch pipe; and 15 is the third plexiglass branch pipe. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0031] Example

[0032] like Figures 1 to 9 As shown, this embodiment of the invention provides an experimental method for simulating impact load loading under high hydrostatic pressure, comprising the following steps:

[0033] S1. Before the experiment begins, the pressure-resistant shock tube is initially assembled. After the experimental specimen and piston 2 are placed into the pressure-resistant shock tube, the pressure-resistant shock tube is filled with water and the air is removed. Then it is sealed. At the same time, the high-speed photography system is set up and the pressure sensor is connected. The pressure sensor is an IEPE type pressure sensor.

[0034] S2. Place the flying piece into the air cannon acceleration tube and pump air to complete the preparation work before the experiment.

[0035] S3. Use a hydraulic cylinder to pressurize the water in the pressure-resistant shock tube to a specified pressure, release the air cannon valve, and cause the flying piece in the air cannon acceleration tube to fly out and impact the pressure-resistant shock tube. At the same time, trigger the high-speed photography system and the pressure sensor to collect data and record experimental data.

[0036] S4. After loading is completed, adjust the hydraulic cylinder to the middle position to release pressure, which will facilitate subsequent experimental operations. Thus, one experiment is completed.

[0037] S5. When repeating the experiment after this experiment is completed, determine whether the piston 2 and the experimental specimen need to be replaced. If replacement is required, disassemble the baffle 6 and the hydraulic cylinder, and repeat steps S1-S4; if replacement is not required, repeat steps S2-S4.

[0038] Furthermore, such as Figure 2As shown, the pressure-resistant shock tube includes an inner acrylic tube 1, a piston 2, an outer tube 3, a pressure gauge 5, and a baffle 6. The inner acrylic tube 1 is composed of multiple acrylic sub-tubes assembled together, such as... Figures 7 to 9 As shown, this embodiment has three acrylic tubes: a first acrylic tube 13, a second acrylic tube 14, and a third acrylic tube 15. These three tubes are assembled from left to right to form a complete acrylic inner tube 1. The total length of the acrylic inner tube 1 is 1m, with an inner diameter of 35mm and an outer diameter of 70mm. Pistons 2 are installed at both ends of the acrylic inner tube 1. The multiple acrylic tubes and the pistons 2 are sealed to each other and to the acrylic inner tube 1 using star-shaped rings 8. Figure 3 As shown, the seal between piston 2 and inner plexiglass tube 1 is achieved using a 35mm reference hole seal, and the seal between plexiglass branch tubes is achieved using a 55mm reference hole seal without adding a retaining ring. The inner plexiglass tube 1 has multiple threaded holes, and the water pressure gauge 5 and the pressure sensor are installed on the inner plexiglass tube 1 through the corresponding threaded holes. The outer tube 3 is sleeved on the outside of the inner plexiglass tube 1. The outer tube 3 is made of aluminum alloy, and flanges 9 are installed at both ends of the outer tube 3. The flanges 9 are used to fix the baffle 6 and the hydraulic cylinder.

[0039] Furthermore, such as Figure 4 As shown, the outer tube 3 has an observation window 10 and a pressure sensor mounting hole 4 on its tube wall. The observation window 10 facilitates the high-speed photography system to capture the dynamic response process of the experimental specimen. The pressure sensor mounting hole 4 is arranged vertically to the threaded hole for mounting the pressure sensor.

[0040] Furthermore, such as Figure 5 As shown, the piston 2 is made of aluminum alloy, with an outer diameter of 35mm and a thickness of 12mm. A 4mm wide annular groove 11 with a groove diameter of 28.6mm is opened at the center along the height direction of the piston 2. After the flying plate enters the pressure-resistant shock tube, it impacts one of the pistons 2.

[0041] Furthermore, such as Figure 6 As shown, the baffle 6 is made of aluminum alloy and is fixedly installed on the outside of one of the flanges 9. The baffle 6 has a through hole 12 with a diameter of 25mm in the center.

[0042] Furthermore, the high-speed photography system includes a high-speed camera, a light source, and a synchronization trigger. The high-speed camera is signal-connected to the synchronization trigger. The high-speed photography system is mainly used to acquire the process of structural response under impact load.

[0043] Furthermore, the pressure gauge 5 has a range of 0-5 MPa and its interface type is consistent with the opening of the plexiglass inner tube 1.

[0044] Furthermore, a hydraulic cylinder mounting plate 7 is fixedly installed on the outer side of another flange 9 away from the baffle 6, and the hydraulic cylinder is fixedly installed on the hydraulic cylinder mounting plate 7.

[0045] Furthermore, the gas cannon acceleration tube accelerates the flying blade to a given speed through compressed gas, propellant gases, etc., thereby impacting the piston 2 in the pressure-resistant shock tube; the pressure sensor is part of the digital sampling system, which also includes a digital sampler, and is mainly used to acquire the overpressure curve of the shock wave in water; the hydraulic cylinder is part of the pressurization system, which also includes a hydraulic pump and pipelines, and is mainly used to provide the pressure required for pressurization. All of the above systems can be configured with appropriate performance and parameters according to experimental needs.

[0046] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An experimental method for simulating impact load loading under high hydrostatic pressure environment, characterized in that, Includes the following steps: S1. Assemble the pressure-resistant shock tube, place the experimental specimen into the pressure-resistant shock tube, fill the pressure-resistant shock tube with water and seal it, and simultaneously set up the high-speed photography system and connect the pressure sensor. S2. Place the flying piece inside the air cannon's acceleration tube and inflate it with air; S3. Use a hydraulic cylinder to pressurize the water in the pressure-resistant shock tube to a specified pressure, release the air cannon valve, and cause the flying piece in the air cannon acceleration tube to fly out and impact the pressure-resistant shock tube. Data is collected by the high-speed photography system and the pressure sensor. S4. Adjust the hydraulic cylinder to the middle position to release pressure, which will facilitate subsequent experimental operations; The pressure-resistant shock tube includes an inner plexiglass tube (1), a piston (2), an outer tube (3), a water pressure gauge (5), and a baffle (6). The inner plexiglass tube (1) is composed of multiple plexiglass sub-tubes. The piston (2) is installed at both ends of the inner plexiglass tube (1). The multiple plexiglass sub-tubes and the piston (2) and the inner plexiglass tube (1) are sealed by star rings (8). The inner plexiglass tube (1) has multiple threaded holes. The water pressure gauge (5) and the pressure sensor are installed on the inner plexiglass tube (1) through the corresponding threaded holes. The outer tube (3) is sleeved on the outside of the inner plexiglass tube (1). Flanges (9) are installed at both ends of the outer tube (3). The flanges (9) are used to fix the baffle (6) and the hydraulic cylinder. The outer tube (3) has an observation window (10) and a sensor mounting hole on its wall. The observation window (10) facilitates the high-speed photography system to capture the dynamic response process of the experimental specimen. The sensor mounting hole is arranged vertically and vertically with the threaded hole for mounting the pressure sensor. The piston (2) is made of aluminum alloy and has an annular wide groove (11) at the center along the height direction of the piston (2). After the flying plate enters the pressure shock tube, it impacts one of the pistons (2). The baffle (6) is fixedly installed on the outside of one of the flanges (9), and a through hole (12) is provided in the center of the baffle (6). The high-speed photography system includes a high-speed camera and a synchronization trigger, wherein the high-speed camera is signal-connected to the synchronization trigger.

2. The experimental method for simulating impact load loading under high hydrostatic pressure environment according to claim 1, characterized in that, The range of the pressure gauge (5) is 0-5 MPa.

3. The experimental method for simulating impact load loading under high hydrostatic pressure environment according to claim 1, characterized in that, It also includes S5. When repeating the experiment after the current experiment is completed, it is determined whether the piston (2) and the experimental specimen need to be replaced. If replacement is required, the baffle (6) and the hydraulic cylinder are disassembled and steps S1-S4 are repeated. If replacement is not required, steps S2-S4 are repeated.

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