Experimental device and method for drop hammer spring system for simulating gas explosion load

Abstract

The present application relates to a kind of experimental device and method for simulating the drop hammer spring system of gas explosion load, the device of the present application includes rack, electromagnet release mechanism, drop hammer mechanism and test piece fixing mechanism, the electromagnet release mechanism is respectively located above and below inside the rack, the electromagnet release mechanism is used to adsorb drop hammer mechanism and release drop hammer mechanism at preset time, drop hammer mechanism is adsorbed on electromagnet release mechanism when it is located just above test piece fixing mechanism, drop hammer mechanism includes drop hammer, spring, damper and contact sheet, the spring and damper are all vertically fixed between the lower surface of drop hammer and the upper surface of contact sheet, the test piece fixing mechanism is used to fix and place installation test piece.The present application is convenient for experimental personnel to accurately test the various physical and mechanical parameters and dynamic response process of concrete and other materials and structures under the action of gas explosion load, and the entire loading experimental device has high strength and good safety performance.

Description

TECHNICAL FIELD

[0001] The present application relates to gas explosion safety protection technology, in particular to an experimental device and method of a drop hammer spring system for simulating gas explosion load. BACKGROUND

[0002] With the continuous development of urban construction and infrastructure, as one of the main energy sources for the normal operation of the city, the safety research of gas explosion has been paid more and more attention by researchers. Gas leakage and explosion accidents occur from time to time, which seriously threatens the safety of the city and the safety of the life and property of residents. Due to the influence of factors such as concentration, ignition energy, ignition position and structure type on the destructive effect of gas explosion, there is obvious difference between the form of gas explosion load and condensed explosive explosion, and the pressure-time curve of gas explosion load is more gentle and the action time is longer. For experimental research, due to the characteristics of colorless and easy leakage of general gas, gas explosion experiment is easy to cause safety accidents, so small model is generally used for gas explosion experiment, but small model has significant size effect, so some scholars consider using equivalent alternative experimental method, but due to the characteristics of long action time of gas explosion load, general explosive, drop hammer, Hopkinson bar and light gas gun experimental system cannot produce similar loading curve of gas explosion load, therefore, it has important practical significance and broad application value to research an experimental device and method of a drop hammer spring system for simulating gas explosion load. SUMMARY

[0003] The technical problem to be solved by the present application is to provide an experimental device and method of a drop hammer spring system for simulating gas explosion load, which can effectively simulate the loading rate, peak value and loading duration of gas explosion load, further simulate the dynamic process of concrete and other materials and structures under the action of gas explosion load, and finally obtain the dynamic response and damage distribution of concrete and other materials and structures under the action of gas explosion load through experiments.

[0004] To solve the above technical problems, the present application adopts the following technical scheme:

[0005] The experimental device of the drop hammer spring system for simulating gas explosion load comprises a rack, an electromagnet release mechanism, a drop hammer mechanism and a test piece fixing mechanism, the electromagnet release mechanism and the test piece fixing mechanism are arranged above and below the inside of the rack respectively, the electromagnet release mechanism is used for adsorbing the drop hammer mechanism and releasing the drop hammer mechanism at a preset time, the drop hammer mechanism is located directly above the test piece fixing mechanism when the drop hammer mechanism is adsorbed on the electromagnet release mechanism, the drop hammer mechanism comprises a drop hammer, a spring, a damper and a contact sheet, the spring and the damper are both vertically fixed between the lower surface of the drop hammer and the upper surface of the contact sheet, and the test piece fixing mechanism is used for fixing and placing the installed test piece.

[0006] Compared with the prior art, the application has the following advantages:

[0007] The application is convenient to install and use, avoids the experimental safety risk caused by direct use of gas, facilitates the accurate testing of various physical and mechanical parameters and dynamic response processes of materials and structures such as concrete under the action of gas explosion load by experimenters, and has high strength and good safety performance.

[0008] The application further uses the electromagnet to adsorb the drop hammer, realizes the convenient operation of semi-automatically lifting the drop hammer, ensures the safety of experimenters, has beneficial effects on experimental scenes such as a heavy drop hammer and fewer experimenters, and can improve experimental efficiency.

[0009] The application welds a spring, a damper and a contact sheet at the bottom of the drop hammer, the stiffness coefficient of the spring can be adjusted by different spring specifications, the drop hammer is hindered by the spring force and the damper during falling, changes from uniform acceleration motion to variable deceleration motion, that is, the action time of the drop hammer falling and colliding with the concrete test piece is prolonged, thereby simulating the characteristic of long action time of the gas explosion load time curve, and the instantaneous release of the drop hammer spring combination is realized by the de-energization of the electromagnet, avoiding the problem that the traditional drop hammer experiment has a pull rope attached to the top, which affects the posture of the drop hammer during free fall and falling.

[0010] Further, the electromagnet release mechanism includes an electric hoist, a pull rope and an electromagnet, the electric hoist is installed on the rack through a hook welded at the top and is used to drive the electromagnet up and down through the pull rope, and the bottom of the electromagnet contains a circular magnetic sheet, which can be adsorbed or released by controlling the on-off power of the electromagnet.

[0011] The beneficial effect of the above further scheme is that the drop hammer can be in a free falling state instantaneously by the on-off operation of the electromagnet, and the drop hammer spring combination can be automatically lifted to a predetermined height by the pull rope through the electric hoist, thereby saving labor and ensuring the safety of personnel.

[0012] Further, in the drop hammer mechanism, the upper ends of the damper and the spring are welded at the center of the bottom of the drop hammer, the lower ends of the damper and the spring are welded at the center position of the surface of the contact sheet, and the contact sheet is parallel to the bottom surface of the drop hammer.

[0013] The beneficial effects of adopting the above-mentioned further solution are: ensuring that the drop hammer spring assembly does not tip over during the falling collision process, that the spring is always in the elastic deformation stage, and that the drop hammer spring assembly can have a positive collision with the concrete specimen.

[0014] Furthermore, the specimen fixing mechanism includes two C-shaped clamping steel plates and a screw. The two C-shaped clamping steel plates are located on both sides of the specimen, and the screw is used to fix the specimen to the C-shaped clamping steel plates.

[0015] The beneficial effects of adopting the above-mentioned further scheme are: ensuring that the concrete specimen will not be displaced during the impact test, thus affecting the experimental results; creating boundary conditions that meet the experimental requirements; and fixing the specimen with a clamping steel plate to offset the boundary effect caused by the specimen size, thereby improving the accuracy of the experiment.

[0016] Furthermore, the frame consists of a square steel material frame and positioning steel bars. The positioning steel bars are used to install the electromagnet release mechanism and are welded to the top of the steel frame. The position of the positioning steel bars can be adjusted according to the experiment.

[0017] The beneficial effect of adopting the above-mentioned further solution is that by selecting a steel frame with appropriate thickness and strength, it is possible to ensure that no large deformation occurs after the drop hammer spring assembly and electromagnet device are suspended, thus ensuring that the drop hammer's falling position can be adjusted.

[0018] The experimental method for simulating the load of a gas explosion using a drop hammer spring system includes the following steps:

[0019] Step 1: Fix the specimen on the specimen fixing mechanism, with the middle of the specimen suspended in the air to simulate the condition of a concrete specimen that is fixed and constrained on all four sides. Use the electromagnet release mechanism to attract the drop hammer mechanism and lift the drop hammer mechanism to the preset height.

[0020] Step 2: De-energize the electromagnet of the electromagnet release mechanism to release the falling hammer mechanism at a specified time.

[0021] Step 3: The drop hammer mechanism falls downwards. The drop hammer in the drop hammer mechanism collides with the specimen multiple times in a positive direction through the spring force and damper below, to conduct a simulation experiment.

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a general structural diagram of the present invention;

[0024] Figure 2 This is a schematic diagram of the electromagnet release mechanism.

[0025] Figure 3 This is a schematic diagram of the drop hammer mechanism.

[0026] Figure 4 This is a schematic diagram of the specimen fixing mechanism.

[0027] In the attached diagram, the meanings of each number are as follows:

[0028] 1. Frame; 2. Electromagnet release mechanism; 3. Drop hammer mechanism; 4. Specimen fixing mechanism; 21. Electric lift; 22. Pull rope; 23. Electromagnet; 31. Drop hammer; 32. Spring; 33. Damper; 34. Contact plate; 41. C-shaped clamping steel plate; 42. Screw Detailed Implementation

[0029] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0030] like Figure 1 As shown, the experimental apparatus for simulating the load of a gas explosion using a drop hammer spring system includes a frame 1, an electromagnet release mechanism 2, a drop hammer mechanism 3, and a specimen fixing mechanism 4. The electromagnet release mechanism 2 is located above and below the frame 1. The electromagnet release mechanism 2 is used to attract the drop hammer mechanism 3 and release it after a preset time. When the drop hammer mechanism 3 is attracted to the electromagnet release mechanism 2, it is located directly above the specimen fixing mechanism 4. The drop hammer mechanism 3 includes a drop hammer 31, a spring 32, a damper 33, and a contact plate 34. The spring 32 and the damper 33 are both vertically fixed between the lower surface of the drop hammer 31 and the upper surface of the contact plate 34. The specimen fixing mechanism 4 is used to fix and place the specimen.

[0031] As one implementation method, such as Figure 2 As shown, the electromagnet release mechanism 2 includes an electric lift 21, a pull rope 22, and an electromagnet 23. The electric lift 21 is installed on the frame 1 via a hook welded to the top. The electric lift is connected to the electromagnet via a steel pull rope. The electric lift can control the lifting height of the electromagnet. The drop hammer is an iron drop hammer. After the electromagnet is energized, it attracts the drop hammer through magnetic force and lifts it to a specified height under the control of the electric lift. The drop hammer spring assembly is released instantaneously when the electromagnet is de-energized. This avoids the problems of the traditional drop hammer experiment where the pull rope attached to the top affects the free fall of the drop hammer and makes it difficult to maintain its posture during the fall.

[0032] As one implementation method, such as Figure 3As shown, the drop hammer mechanism includes a circular drop hammer 31, a steel spring 32, a steel contact plate 34, and a damper 33. The circular drop hammer is designed to only translate without rotating during the falling process. The size and strength of the steel spring are designed to ensure that the drop hammer will not exceed the effective elastic deformation limit of the spring during the falling process. The size and strength of the steel contact plate are designed to ensure that the contact plate will not deform significantly during the collision with the concrete specimen. The upper end of the damper and the spring is welded to the center of the bottom of the drop hammer, and the lower end of the damper and the spring is welded to the center of the surface of the contact plate. The contact plate is parallel to the bottom surface of the drop hammer. The spring, the damper, and the contact plate are welded to the bottom of the drop hammer. The stiffness coefficient of the spring can be adjusted by using different spring specifications. The drop hammer is subjected to the spring force and the resistance of the damper during the falling process, and changes from uniform acceleration to variable deceleration. That is, the action time of the drop hammer falling and colliding with the concrete specimen is extended, thereby simulating the long action time of the gas explosion load time history curve.

[0033] As an embodiment, as shown in Figure 4 As shown, the specimen fixing mechanism 4 includes two C-shaped clamping steel plates 41 and a screw rod 42. The two C-shaped clamping steel plates 41 are respectively located on both sides of the specimen, and the screw rod 42 is used to fix the specimen and the C-shaped clamping steel plates 41. The clamping steel plates, the specimen, and the fixer are pressed together by the screw rod. The boundary effect of the experiment is eliminated under the clamping action. The fixer lifts the two ends of the specimen, and the central part of the specimen is suspended, thereby ensuring the similarity between the experimental model and the actual application scenario.

[0034] As an embodiment, the rack 1 is a square steel material frame, and a positioning steel bar is used to mount the electromagnet release mechanism 2 and is welded to the top of the steel rack. The position of the positioning steel bar can be adjusted according to the experiment.

[0035] The experimental method of the drop hammer spring system for simulating the gas explosion load includes the following steps:

[0036] Step 1: Fix the specimen on the specimen fixing mechanism 4, and suspend the specimen in the middle to simulate the condition of the four-side fixed concrete specimen. Use the electromagnet release mechanism 2 to adsorb the drop hammer mechanism 3, and lift the drop hammer mechanism 3 to a predetermined height.

[0037] Step 2: Turn off the electromagnet 23 of the electromagnet release mechanism 2 to release the drop hammer mechanism 3 at a specified time.

[0038] Step 3: The drop hammer mechanism 3 falls downward. The drop hammer in the drop hammer mechanism collides with the specimen multiple times through the spring force and the damper below, and the simulation experiment is performed.

[0039] Compared with the single drop hammer impact experiment method in the prior art, the application achieves the impact effect of simulating the gas explosion load by the elastic deformation of the spring to reduce the loading rate of the impact force, prolong the drop hammer impact time and avoid the high strain rate dynamic load generated by the direct drop hammer impact, thereby achieving the impact effect of simulating the gas explosion load. On the other hand, compared with the gas explosion experiment, the application can avoid the harm of gas leakage to the experiment personnel, and the application is more suitable for the rapid adjustment of various experimental conditions, such as different impact force loading rates and peak values, and the damper can be adjusted in cooperation with the action time, so that the application can simulate various experimental conditions, and effectively save the experimental cost.

[0040] The above is an example of the best embodiment of the application, wherein the parts not described in detail are the common knowledge of ordinary skilled in the art. The protection scope of the application is subject to the content of the claims, and any equivalent transformation based on the technical inspiration of the application is also within the protection scope of the application.

Claims

1. An experimental set-up for simulating a drop hammer spring system for gas explosion load, characterized in that, The utility model relates to a kind of experimental device for simulating the impact of concrete, including rack (1), electromagnetic iron release mechanism (2), drop hammer mechanism (3) and test piece fixing mechanism (4), the electromagnetic iron release mechanism (2) and test piece fixing mechanism (4) are respectively arranged in the upper and lower inside rack (1), the electromagnetic iron release mechanism (2) is used to adsorb drop hammer mechanism (3) and release drop hammer mechanism (3) at preset time, drop hammer mechanism (3) is located just above test piece fixing mechanism (4) when being adsorbed on electromagnetic iron release mechanism (2), drop hammer mechanism (3) includes drop hammer (31), spring (32), damper (33) and contact sheet (34), the spring (32) and damper (33) are both vertically fixed between drop hammer (31) lower surface and contact sheet (34) upper surface, and the test piece fixing mechanism (4) is used to fix and place installation test piece.

2. The experimental setup of drop hammer spring system for simulating gas explosion load according to claim 1, characterized in that, The electromagnetic iron release mechanism (2) includes electric lift (21), pull rope (22) and electromagnetic iron (23), the electric lift (21) is installed on the rack (1) by the hook welded on the top, and is used to drive electromagnetic iron (23) up and down movement by pull rope (22), the bottom of electromagnetic iron (23) contains circular magnetic attraction sheet, and drop hammer (31) can be adsorbed or released by controlling the on-off electricity of electromagnetic iron (23).

3. The experimental setup for drop hammer spring system simulating gas explosion load as claimed in claim 1 wherein, In the drop hammer mechanism (3), the upper end of damper (33) and spring (32) is welded in the center of the bottom of drop hammer (31), the lower end of damper (33) and spring (32) is welded in the center position of the surface of contact sheet, and the contact sheet is parallel to the bottom surface of drop hammer (31).

4. The experimental setup for drop hammer spring system simulating gas explosion load as claimed in claim 1 wherein, The test piece fixing mechanism (4) includes two C-shaped clamping steel plates (41) and screw rod (42), the two C-shaped clamping steel plates (41) are located on both sides of test piece respectively, and screw rod (42) is used to fix test piece with C-shaped clamping steel plate (41).

5. The experimental setup for drop hammer spring system simulating gas explosion load as claimed in claim 1 wherein, The rack (1) is square steel material frame and positioning steel bar, the positioning steel bar is used to install electromagnetic iron release mechanism (2) and is welded on the top of steel frame, and the position of the positioning steel bar can be adjusted according to experiment.

6. Experimental method for simulating the drop hammer spring system of a gas explosion load, characterized in that, The experiment is carried out by using the experimental device of any one of claims 1-5, and includes the following steps: Step 1, fix the test piece on the test piece fixing mechanism (4), the test piece is suspended in the middle, simulate the condition of the concrete test piece with four sides fixed constraint, adsorb drop hammer mechanism (3) by using electromagnetic iron release mechanism (2), and lift drop hammer mechanism (3) to preset height; Step 2, release drop hammer mechanism (3) at specified time by deenergizing electromagnetic iron (23) of electromagnetic iron release mechanism (2); Step 3, drop hammer mechanism (3) falls down, the drop hammer in drop hammer mechanism collides with test piece multiple times by spring elastic force and damper below, and simulation experiment is carried out.

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