Experimental method for simulating impact load loading in high hydrostatic pressure environment

Abstract

The invention provides an experimental method for simulating impact load loading in a high hydrostatic pressure environment, which comprises the following steps of: assembling a pressure-resistant shock tube, putting an experimental test piece into the pressure-resistant shock tube, then filling the pressure-resistant shock tube with water for sealing, and synchronously erecting a high-speed photography system and connecting a pressure sensor; putting a flyer into the gas gun accelerating tube and inflating; a hydraulic oil cylinder is used for pressurizing water in a pressure-resistant shock tube to the specified pressure, a gas gun valve is released, a flyer in a gas gun accelerating tube flies out to impact the pressure-resistant shock tube, and data are collected through a high-speed photographing system and a pressure sensor; the hydraulic oil cylinder is adjusted to a middle gear for pressure relief, subsequent experiment operation is facilitated, the experiment method can be used for simulating the action process of the impact load on the underwater structure under the pressure environment of the water depth within 500m, the preparation time of the impact response experiment of the deepwater structure is shortened, the experiment cost is saved, and the experiment efficiency is improved. And obtaining an overpressure curve of the shock wave under the conditions of deep water and high hydrostatic pressure and a dynamic response process of the structure.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater impact experiments, and in particular relates to an experimental method for simulating impact load loading in a high hydrostatic pressure environment. Background Art

[0002] In deep water, strong and short-lived pressure waves or impact forces are generated for some reason (such as explosions, high-speed collisions of underwater objects, etc.). Such loads are usually extremely energetic and destructive. When impact loads act on structures in water (such as submarines, underwater facilities, etc.), they will cause deformation, rupture, or even complete destruction of the structures. At the same time, under the action of deep-water impact loads, complex and strong interactions will occur between the structures in the water (solids), the surrounding water (liquids), and possible gases (such as bubbles, cavities, etc.). These interactions include the transmission of pressure waves, the dynamic response of fluids, the deformation and fracture of solids, etc. They are intertwined and affect each other, making the entire process very complicated and bringing considerable difficulties to experimental research.

[0003] Deepwater explosion experiments have brought great difficulties to the development of related experiments due to factors such as long preparation period, high cost, many restrictions and limited testing methods. The difficulty in studying the impact load and structural response in deepwater environment has led to limited research and insufficient understanding of the mechanism of interaction between impact load and structure.

[0004] In recent years, in order to study the mechanism of interaction between shock waves and underwater structures, an experimental method using a transparent shock tube to observe this process has emerged. This type of device has the advantages of simple experimental preparation, rapid implementation, low cost, precise loading, and easy capture of the dynamic response of the medium and structure. However, the current use of this type of device to study the structural response behavior under the action of underwater pressure waves is limited to a relatively small pressure environment, and its potential for application in deepwater fields has not been fully explored, and it cannot meet the requirements of experimental research on structural shock response in deepwater environments. Summary of the invention

[0005] In order to solve the above problems of the prior art, an embodiment of the present invention provides an experimental method for simulating impact load loading in a high hydrostatic pressure environment.

[0006] According to one aspect of the present invention, there is provided an experimental method for simulating impact load loading in a high hydrostatic pressure environment, 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 to seal it, and simultaneously set up a high-speed photography system and connect a pressure sensor;

[0008] S2. Put flying pieces into the accelerating tube of the air gun and pump air into it;

[0009] S3, using a hydraulic cylinder to pressurize the water in the pressure-resistant shock tube to a specified pressure, releasing the gas gun valve, so that the flying pieces in the gas gun acceleration tube are ejected to impact the pressure-resistant shock tube, and collecting data through the high-speed photography system and the pressure sensor;

[0010] S4. Adjust the hydraulic cylinder to the middle gear to release pressure, so as to facilitate subsequent experimental operations.

[0011] Preferably, the pressure-resistant shock tube includes an organic glass inner tube, a piston, an outer tube, a water pressure gauge and a baffle. The organic glass inner tube is composed of a plurality of organic glass branch tubes. The pistons are installed at both ends of the organic glass inner tube. The plurality of organic glass branch tubes and the piston and the organic glass inner tube are sealed by star rings. The organic glass inner tube is provided with a plurality of threaded holes. The water pressure gauge and the pressure sensor are installed on the organic glass inner tube through the corresponding threaded holes. The outer side of the organic glass inner tube is sleeved with the outer 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, an observation window and a sensor mounting hole are provided on the tube wall of the outer tube, the observation window facilitates the high-speed photography system to capture the dynamic response process of the experimental specimen, and the sensor mounting hole is arranged correspondingly to the threaded hole for mounting the pressure sensor.

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

[0014] Preferably, the baffle is fixedly mounted on the outer side of one of the flanges, and a through hole is opened at the center of the baffle.

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

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

[0017] Preferably, it also includes S5, when repeating the test after the completion of this experiment, judging whether the piston and the experimental specimen need to be replaced, if replacement is required, disassembling the baffle and the hydraulic cylinder, and repeating S1-S4; if replacement is not required, repeating S2-S4.

[0018] The beneficial effects brought by the present invention are as follows:

[0019] It can be seen from the above scheme that the embodiment of the present invention provides an experimental method for simulating impact load loading in a high hydrostatic pressure environment, which can be used to simulate the effect of impact load on underwater structures in a pressure environment within 500m. In this experimental method, an impact load is generated by a high-speed flying piece impacting a piston, and the impact load is transmitted into the water of a pressure-resistant shock tube to form a shock wave. The water in the organic glass inner tube is compressed by a hydraulic cylinder to generate high hydrostatic pressure, and the overpressure curve of the shock wave in the water is measured by an IEPE pressure sensor installed on the organic glass inner tube. The dynamic response process of the experimental specimen structure is obtained through the observation window opened on the aluminum alloy outer tube by a high-speed photography system. At the same time, using this experimental method, the preparation time for the deep-water structure impact response experiment 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flowchart showing the steps of an experimental method for simulating impact load loading in a high hydrostatic pressure environment 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 showing the sealing structure of a star ring according to an embodiment of the present invention;

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

[0024] Figure 5 Three views showing a piston according to an embodiment of the present invention;

[0025] Figure 6 Three views showing a baffle according to an embodiment of the present invention;

[0026] Figure 7 Three views showing the first organic glass branch pipe of an embodiment of the present invention;

[0027] Figure 8 Three views showing the second organic glass branch pipe of the embodiment of the present invention;

[0028] Fig. 9 Three views of the third organic glass branch tube according to the embodiment of the present invention are shown.

[0029] In the figure, 1 is an inner tube of organic glass; 2 is a piston; 3 is an outer tube; 4 is a mounting hole for a pressure sensor; 5 is a water pressure gauge; 6 is a baffle; 7 is a mounting plate for a hydraulic cylinder; 8 is a star ring; 9 is a flange; 10 is an observation window; 11 is a wide groove; 12 is a through hole; 13 is a first organic glass branch tube; 14 is a second organic glass branch tube; and 15 is a third organic glass branch tube. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example

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

[0033] S1. Before the experiment begins, the pressure-resistant shock tube is preliminarily assembled. After the experimental specimen and the piston 2 are placed in the pressure-resistant shock tube, the pressure-resistant shock tube is filled with water and the air is exhausted, and then sealed. A high-speed photography system is set up simultaneously and a pressure sensor is connected. The pressure sensor is an IEPE type pressure sensor.

[0034] S2. Place the flying pieces in the accelerating tube of the gas gun and pump air into it. This completes the preparation work before the experiment.

[0035] S3, using a hydraulic cylinder to pressurize the water in the pressure-resistant shock tube to a specified pressure, releasing the gas gun valve, so that the flying pieces in the gas gun acceleration tube are ejected to impact the pressure-resistant shock tube, and at the same time triggering the high-speed photography system and the pressure sensor to collect data and record experimental data;

[0036] S4, after loading is completed, the hydraulic cylinder is adjusted to the middle gear to release pressure, so as to facilitate subsequent experimental operations, and an experiment is completed;

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

[0038] Further, such as Figure 2As shown, the pressure-resistant shock tube includes an organic glass inner tube 1, a piston 2, an outer tube 3, a water pressure gauge 5 and a baffle 6. The organic glass inner tube 1 is composed of a plurality of organic glass branch tubes. Figures 7 to 9 As shown, there are three organic glass branch tubes in this embodiment, namely, a first organic glass branch tube 13, a second organic glass branch tube 14 and a third organic glass branch tube 15. The first organic glass branch tube 13, the second organic glass branch tube 14 and the third organic glass branch tube 15 are sequentially assembled from left to right to form a complete organic glass inner tube 1. The organic glass inner tube 1 has a total length of 1m, an inner diameter of 35mm and an outer diameter of 70mm. The pistons 2 are installed at both ends of the organic glass inner tube 1. The plurality of organic glass branch tubes and the pistons 2 and the organic glass inner tube 1 are sealed by star rings 8. Figure 3 As shown, the seal between the piston 2 and the organic glass inner tube 1 adopts a 35mm reference hole seal, and the seal between the organic glass branch tubes selects a 55mm reference hole seal, and no retaining ring is added. A plurality of threaded holes are opened on the organic glass inner tube 1, and the water pressure gauge 5 and the pressure sensor are installed on the organic glass inner tube 1 through the corresponding threaded holes. The outer side of the organic glass inner tube 1 is sleeved with the outer tube 3, and the outer tube 3 is made of aluminum alloy. Flanges 9 are installed at both ends of the outer tube 3, and the flanges 9 are used to fix the baffle 6 and the hydraulic cylinder.

[0039] Further, such as Figure 4 As shown, an observation window 10 and a pressure sensor mounting hole 4 are provided on the wall of the outer tube 3. 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 correspondingly to the threaded hole for mounting the pressure sensor.

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

[0041] Further, such as Figure 6 As shown, the baffle 6 is made of aluminum alloy, and is fixedly mounted on the outside of one of the flanges 9 . A through hole 12 with a diameter of 25 mm is opened at the center of the baffle 6 .

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

[0043] Furthermore, the measuring range of the water pressure gauge 5 is 0-5MPa, and the interface type is consistent with the opening of the organic glass inner tube 1.

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

[0045] Furthermore, the gas gun acceleration tube accelerates the flying pieces to a given speed by means of compressed gas, gunpowder gas, etc., and then impacts the piston 2 in the pressure-resistant shock tube; the pressure sensor belongs to the digital sampling system, and the digital sampling system also includes a digital sampler, and the digital sampling system is mainly used to obtain the shock wave overpressure curve in water; the hydraulic cylinder is part of the pressurization system, and the pressurization system also includes a hydraulic oil pump and pipelines, etc., which are mainly used to provide the pressure required for pressurization. The above systems can select appropriate performance and parameters according to experimental needs.

[0046] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An experimental method for simulating impact load loading in a high hydrostatic pressure environment, characterized in that: The steps include: 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 to seal it, and simultaneously set up a high-speed photography system and connect a pressure sensor; S2. Put flying pieces into the accelerating tube of the air gun and pump air into it; S3, using a hydraulic cylinder to pressurize the water in the pressure-resistant shock tube to a specified pressure, releasing the gas gun valve, so that the flying pieces in the gas gun acceleration tube are ejected to impact the pressure-resistant shock tube, and collecting data through the high-speed photography system and the pressure sensor; S4. Adjust the hydraulic cylinder to the middle gear to release pressure, so as to facilitate subsequent experimental operations.

2. The experimental method for simulating impact load loading in a high hydrostatic pressure environment according to claim 1, characterized in that: The pressure-resistant shock tube comprises an organic glass inner tube (1), a piston (2), an outer tube (3), a water pressure gauge (5) and a baffle (6). The organic glass inner tube (1) is composed of a plurality of organic glass branch tubes. The piston (2) is installed at both ends of the organic glass inner tube (1). The plurality of organic glass branch tubes and the piston (2) and the organic glass inner tube (1) are sealed by star rings (8). The organic glass inner tube (1) is provided with a plurality of threaded holes. The water pressure gauge (5) and the pressure sensor are installed on the organic glass inner tube (1) through the corresponding threaded holes. The outer side of the organic glass inner tube (1) is sleeved with the outer tube (3). 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.

3. The experimental method for simulating impact load loading in a high hydrostatic pressure environment according to claim 2, characterized in that: An observation window (10) and a sensor mounting hole are provided on the wall of the outer tube (3); the observation window (10) facilitates the high-speed photography system to capture the dynamic response process of the experimental specimen; and the sensor mounting hole is arranged in correspondence with the threaded hole for mounting the pressure sensor.

4. The experimental method for simulating impact load loading in a high hydrostatic pressure environment according to claim 2, characterized in that: The piston (2) is made of aluminum alloy, and a wide annular groove (11) is provided at the center of the height direction of the piston (2). After the flying piece enters the pressure-resistant shock tube, it impacts one of the pistons (2).

5. The experimental method for simulating impact load loading in a high hydrostatic pressure environment according to claim 2, characterized in that: The baffle plate (6) is fixedly mounted on the outside of one of the flanges (9), and a through hole (12) is provided at the center of the baffle plate (6).

6. The experimental method for simulating impact load loading in a high hydrostatic pressure environment according to claim 1, characterized in that: The high-speed photography system comprises a high-speed camera and a synchronous trigger, wherein the high-speed camera is connected to the synchronous trigger signal.

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

8. The experimental method for simulating impact load loading in a high hydrostatic pressure environment according to claim 2, characterized in that: The method further includes S5, when repeating the experiment after the completion of the current experiment, determining 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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