Device and method for measuring flat plate surface load under underwater explosion

Abstract

The invention relates to a device and method for measuring the surface load of a flat plate under underwater explosion, and the device comprises a steel frame which is used for fixing the flat plate and is formed by welding and combining high-strength channel steel; the testing flat plate is a high-strength steel plate, and channel steel stiffening ribs are welded on the back side of the testing flat plate to improve the anti-explosion strength; a plurality of bolt holes in a single row are reserved in supports on the four sides of the testing flat plate, and the testing flat plate and the steel frame can be firmly connected by high-strength bolts through the holes; a plurality of threaded holes are machined in the center area of the testing flat plate and used for installing wall surface reflection pressure sensors to measure reflection pressure at different testing point positions on the surface of the testing flat plate. The device can ensure that the sensitive surface of the wall reflection pressure sensor is flush with the surface of the test flat plate, so that irregular reflection at a test point is effectively avoided, and the surface reflection pressure change of the flat plate in an underwater explosion test can be effectively measured, including two stages of shock wave and bubble pulsation.

Description

Technical Field

[0001] The invention relates to a device and a method for measuring the surface load of a flat plate under underwater explosion, belonging to the technical field of underwater explosion test. Background Art

[0002] Underwater explosions are one of the most serious threats to underwater structures (such as ships, submarines, and offshore platforms). The study of the distribution law of surface loads on structures under underwater explosions has important theoretical and practical significance. At present, there are two main test methods for measuring surface loads on structures under underwater explosions: pasting pressure sensors on the wall and installing pressure sensors through holes in the wall. In the first method, since the pressure sensor is protruding on the surface of the structure, irregular reflections will be generated when the explosion shock wave propagates to the measuring point, resulting in inaccurate measurement results. In the second method, the hole in the wall destroys the integrity of the structure, which may lead to aggravation of local damage to the structure under the action of the explosion. In addition, it is usually difficult to obtain a complete structural surface load distribution when measuring the reflected pressure in the structural damage test, especially the load in the bubble pulsation stage. Therefore, a new test device and method are urgently needed to meet the effective measurement requirements of structural surface loads under underwater explosions. Summary of the invention

[0004] The present invention provides a device and method for measuring the surface load of a flat plate under underwater explosion, which can ensure that the sensitive surface of a wall reflection pressure sensor is flush with the surface of a test flat plate, thereby effectively avoiding irregular reflection at a measuring point, meeting the measurement requirements of an underwater explosion flat plate load test, and improving the accuracy of underwater explosion load measurement.

[0005] The technical solution adopted by the present invention to solve the technical problem is: A device for measuring the load on a flat plate surface under underwater explosion, comprising: The steel frame is a rectangular frame; The test plate is rectangular, and its four edges are fixed to the steel frame by a detachable fixing structure; The central area of ​​the test plate is processed with a plurality of threaded holes for installing a wall reflection pressure sensor to measure the underwater explosion load at different measuring points on the surface of the test plate. After installation, the sensitive surface of the wall reflection pressure sensor is flush with the surface of the test plate.

[0006] The four edges of the test plate are respectively provided with a plurality of bolt holes, and high-strength bolts can be passed through the bolt holes to fix the test plate to the steel frame.

[0007] A reaction force support is provided on the steel frame at the back side of the test plate.

[0008] The back side of the test plate is connected with a stiffening rib for improving explosion resistance.

[0009] The test plate is a steel plate with a strength grade not lower than Q355.

[0010] The present invention further discloses a testing method based on the device for measuring the load on a flat plate surface under underwater explosion, comprising the following steps: S1: hoist the steel frame into the explosion test pool and fix it to the test station of the explosion test pool; S2: hoist the test plate and flange to the front of the steel frame in sequence, and then firmly connect the test plate to the steel frame through a detachable fixing structure; S3: Install multiple wall reflection pressure sensors into the threaded holes on the test plate until the sensitive surface of the wall reflection pressure sensor is flush with the surface of the test plate, and perform multiple trigger tests on the wall reflection pressure sensor to ensure the normal operation of the data acquisition system; S4: Fill the explosion test pool with water to a preset water level, then hang the explosives into the preset position in the explosion test pool and detonate them to obtain the reflected pressure distribution on the surface of the test plate under the underwater explosion load.

[0011] Through the above technical solution, compared with the prior art, the present invention has the following beneficial effects: 1. The perforated test plate and the steel frame in the test device of the present invention are simple in structure and easy to process, have high rigidity and strength, and can be reused; 2. The present invention uses high-strength bolts and flanges to tightly connect the test plate and the steel frame, which is easy to assemble and disassemble; 3. The present invention adopts an installation method of screwing the wall reflection pressure sensor into the threaded hole of the test plate, which can ensure that the sensitive surface of the wall reflection pressure sensor is flush with the surface of the test plate, thereby effectively avoiding irregular reflection at the measuring point; 4. The test method of the present invention can obtain the pressure load distribution on the surface of a flat plate under underwater explosion of explosives of different equivalents, shapes and positions within a certain range. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is an overall installation diagram of a preferred embodiment provided by the present invention, In the figure: 1 is a target plate, 2 is a flange, 3 is a support, 4 is a reaction support, 5 is a bolt hole, 6 is a threaded hole, 7 is a stiffening rib, and 8 is a wall reflection pressure sensor.

[0013] Figure 2 is a schematic diagram of an underwater explosion test of a preferred embodiment provided by the present invention, In the figure: 9 is explosives.

[0014] Figure 3 It is a reflection pressure measurement curve of three measuring points on the surface of a flat plate under underwater explosion in a preferred embodiment provided by the present invention. DETAILED DESCRIPTION

[0016] The present invention will now be described in further detail with reference to the accompanying drawings.

[0017] The invention provides a device for measuring the surface load of a plate under underwater explosion, comprising a steel frame for fixing the plate, which is formed by welding and assembling channel steels; the test plate is a high-strength test plate, and a channel steel stiffening rib is welded on the back side of the test plate to improve the explosion resistance; a single row of multiple bolt holes are reserved on the four side supports of the test plate, and high-strength bolts can firmly connect the test plate and the steel frame through the bolt holes; a plurality of threaded holes are processed in the central area of ​​the test plate, which are used to install a wall reflection pressure sensor to measure the underwater explosion load at different measuring points on the surface of the test plate.

[0018] The device and method for underwater explosion test of plate specimens specifically include the following steps: Step S1: hoisting the processed steel frame into the explosion test water pool, and fixing it to the explosion test water pool by welding or other methods; Step S2: hoisting the test plate and the flange to the front of the steel frame in sequence, and then firmly connecting the test plate and the steel frame with bolts; Step S3: Screw the wall reflection pressure sensor into the threaded hole of the test plate, and perform multiple trigger tests on the wall reflection pressure sensor to ensure that the data acquisition system operates normally; Step S4: Fill the explosion test pool with water to a preset water level, then hang the explosives into a preset position in the explosion test pool and detonate them to obtain the reflected pressure distribution on the flat plate surface under the underwater explosion load.

[0019] Using the provided method, an underwater explosion test of 400g TNT charge was carried out. The distance from the explosive to the center of the flat surface and to the water surface was 1 meter. The reflected pressure curves at the three measuring points were obtained, such as Figure 2 It can be seen that the collected reflected pressure curves have good consistency, and the load characteristics of the shock wave and bubble pulsation generated by the underwater explosion are obvious, which proves the effectiveness of the adopted test method.

[0020] In summary, the test device and method provided in the present application can effectively realize the collection of flat plate surface reflection pressure data in underwater explosion tests.

Claims

1. A device for measuring the load on a flat plate surface under underwater explosion, characterized in that: include: The steel frame is a rectangular frame; The test plate is rectangular, and its four edges are fixed to the steel frame by a detachable fixing structure; The central area of ​​the test plate is processed with a plurality of threaded holes for installing a wall reflection pressure sensor to measure the underwater explosion load at different measuring points on the surface of the test plate. After installation, the sensitive surface of the wall reflection pressure sensor is flush with the surface of the test plate.

2. The device for measuring the load on a flat plate surface under underwater explosion according to claim 1, characterized in that: The four edges of the test plate are respectively provided with a plurality of bolt holes, and high-strength bolts can be passed through the bolt holes to fix the test plate to the steel frame.

3. The device for measuring the load on a flat plate surface under underwater explosion according to claim 1, characterized in that: A reaction force support is provided on the steel frame at the back side of the test plate.

4. The device for measuring the load on a flat plate surface under underwater explosion according to claim 1, characterized in that: The back side of the test plate is connected with a stiffening rib for improving explosion resistance.

5. The device for measuring the load on a flat plate surface under underwater explosion according to claim 1, characterized in that: The test plate is a steel plate with a strength grade not lower than Q355.

6. A testing method for a device for measuring the load on a flat plate surface under underwater explosion according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: hoist the steel frame into the explosion test pool and fix it to the test station of the explosion test pool; S2: hoist the test plate and flange to the front of the steel frame in sequence, and then firmly connect the test plate to the steel frame through a detachable fixing structure; S3: Install multiple wall reflection pressure sensors into the threaded holes on the test plate until the sensitive surface of the wall reflection pressure sensor is flush with the surface of the test plate, and perform multiple trigger tests on the wall reflection pressure sensor to ensure the normal operation of the data acquisition system; S4: Fill the explosion test pool with water to a preset water level, then hang the explosives into the preset position in the explosion test pool and detonate them to obtain the reflected pressure distribution on the surface of the test plate under the underwater explosion load.

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