Device and method for testing anti-impact characteristic of protective material under dynamic load impact

Abstract

The invention relates to the technical field of rock-soil blasting engineering multi-parameter monitoring, in particular to a protective material anti-impact characteristic testing device under dynamic load impact, a load setting structure is arranged at the upper part of a frame body and comprises a magnetic lifting module and an impact module which are arranged up and down, and the magnetic lifting module comprises an electromagnet and a magnetic chuck with a hole in the middle; the electromagnet is arranged above the fixing plate; the impact module comprises an impact circular ring outer ring which is sleeved on a positioning sleeve; the anti-explosion plate is located under the impact ring, and the bottom face of the anti-explosion plate is connected with the lower bottom plate through a second elastic piece. A sample is connected between the bottom of the central column and the anti-explosion plate through a clamp. The invention also provides a method for testing the anti-impact characteristic of the protective material under the dynamic load impact, the quantitative test and evaluation of the anti-impact characteristic of the protective material can be realized, test equipment is provided for the research on the anti-impact characteristic of the protective material, the test method is enriched, and the application prospect is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-parameter monitoring of rock and soil blasting engineering, and in particular to a device and method for testing the impact resistance of protective materials under dynamic load impact. Background Art

[0002] Due to the different scales, methods and environments of blasting, blasting will cause different impact speeds, and different shock waves will have different degrees and ranges of impact on surrounding buildings, facilities and personnel. In engineering blasting construction, when flying rocks are ejected outward with huge impact force, the protective net can effectively intercept and buffer the energy of flying rocks with its tough material and tight grid structure. The flying rocks that could have caused serious damage are bound together within a certain range, greatly reducing the probability and degree of harm of accidents.

[0003] The traditional simulated impact device has a fixed fixture, which is not flexible enough. When testing the characteristics of the impact material, there is no comprehensive simulation of the simultaneous existence of tension and impact force. The simulated impact scene is not realistic and cannot reflect the actual impact situation of the sample. In addition, the stress points of the experimental object are concentrated, which will lead to the test results being unrepresentative and too one-sided. The structural adjustment of the impact is not flexible enough, and it is impossible to simulate multiple loads during the test. Therefore, it is urgent to develop a simulated impact damage test method and device to carry out experimental research on the dynamic response and damage mechanism of the impact of the test block after the protective material is pre-tightened. This is of great significance for exploring the relationship between the pre-tightening state, property parameters, speed and mass of the impact body and the interception performance and damage mechanism of the protective material, and further improving the impact tolerance and interception reliability of the protective material. Summary of the invention

[0004] In order to solve the technical problems existing in the simulated impact destruction test, the present invention provides a testing device and method for the impact resistance of protective materials under dynamic load impact, which can realize the impact conditions of the specimen under different impact forces, change the size and shape of the impact tool, and detect and analyze the dynamic response and damage mechanism of the wire rope such as tension vibration.

[0005] The technical solution of the present invention is as follows: A device for testing the impact resistance of protective materials under dynamic load impact, comprising a frame, wherein the frame comprises: The upper fixing plate and the lower base plate; A connecting structure, including a plurality of positioning sleeves, connected between the fixing plate and the lower base plate; A central column is located inside the connection structure, one end of which is connected to the bottom surface of the fixed plate and the other end of which extends downward; A load setting structure is arranged on the upper part of the frame, including a magnetic lifting module and an impact module arranged up and down, the magnetic lifting module includes an electromagnet and a magnetic suction cup with a hole in the middle, the electromagnet is arranged above the fixed plate, and the lower part of the fixed plate is elastically connected to the magnetic suction cup through a first elastic member, and the impact module includes an impact ring with a hole in the middle, and the outer ring of the impact ring is sleeved on the positioning sleeve; The lower end of the frame is provided with a bearing structure, including an explosion-proof plate, the bottom surface of which is connected to the lower bottom plate through a second elastic member; the explosion-proof plate is sleeved on the positioning sleeve and is located directly below the impact ring; The specimen is connected between the bottom of the central column and the explosion-proof plate through a clamp.

[0006] A hydraulic rod is arranged between the explosion-proof plate and the lower bottom plate.

[0007] The second elastic member is a plurality of spiral fixing springs.

[0008] The first elastic member is a plurality of detachable coil springs.

[0009] A plurality of hooks are arranged on the opposite sides of the fixing plate and the magnetic suction cup, and are used to realize the detachable connection of the detachable spiral spring.

[0010] A plurality of positioning sleeves are arranged in a ring shape in the middle of the frame body, a plurality of guide rods are located outside the positioning sleeves, high-speed cameras are installed on the guide rods, and speed sensors are arranged beside the explosion-proof plates.

[0011] The clamp is provided with one on the bottom surface of the central column and one on the upper surface of the explosion-proof plate, and the two are arranged opposite to each other. The clamp includes: A tightening sleeve having a clamping arm threadedly connected thereto; The clamping arm is divided into a first clamping part and a second clamping part with the same structure, which are arranged symmetrically on the left and right, with the outer arc being the inferior arc, and the opposite surfaces are arranged in parallel, and the opposite surfaces of the clamping arm are provided with grooves penetrating front and back; The clamping block is divided into two parts arranged symmetrically on the left and right, and can be detachably used to fix the specimen in the groove.

[0012] The device is also provided with a display output structure, including a first terminal and a second terminal, wherein the first terminal is electrically connected to a high-speed camera to generate a velocity strain curve; and the second terminal is electrically connected to a fixture to generate a resistivity change curve.

[0013] A method for testing the impact resistance of protective materials under dynamic load impact, using the above-mentioned device for testing the impact resistance of protective materials under dynamic load impact, comprises the following steps: S1: Installation device; Power on the electromagnet, suspend a detachable coil spring under the fixed plate, power on and debug the control of the electromagnet on the compression Δx of the coil spring; S2: Install the specimen on the fixture between the bottom of the central column and the explosion-proof plate and keep it in tension; S3: The number of detachable coil springs n, the compression amount Δx, and the mass m of the impact ring required for the specimen to reach the required speed are calculated; S3.1: Ignore friction, and the detachable coil spring is a light spring. The detachable coil spring is compressed by Δx. Calculate the total amount of elastic potential energy converted into the kinetic energy of the impact ring when the detachable coil spring returns to its original length; Get a removable coil spring to give the shock ring speed ; S3.2: Calculate the velocity of the free fall object that impacts the ring ; Then the speed when the impact ring separates from the magnetic chuck is: ; The detection speed is achieved by changing the required height Δx, the number of removable coil springs n, and the mass m of the impact ring; S4: Install n removable coil springs and impact rings of specified mass, and install the specimen; S5: Power on the high-speed camera and the speed sensor. If the sample is an insulating material, connect the first terminal; if the sample is a conductive material, connect the first terminal and the second terminal; S6: Cut off the power, demagnetize the electromagnet, release the impact ring, and complete one impact; S7: record and save data through monitoring equipment; A high-speed camera captures changes in the sample surface when the impact ring impacts the explosion-proof plate; a velocity sensor detects the speed at which the impact ring falls to the explosion-proof plate, as well as the difference between the speed and the detected speed, and inputs the speed-strain curve into the first terminal to generate a velocity-strain curve; if the sample is a conductive material, the second terminal generates a sample resistivity change curve.

[0014] S8: After disassembling the fixture, take out the sample; adjust the compression length Δx of the detachable coil spring, and replace the number n of detachable coil springs; Repeat S1 to S8 and proceed to the next test until all the predetermined impact velocities are tested, analyze all the data, and summarize the effect of the impact velocity on the resistivity of the conductive material.

[0015] A method for testing the impact resistance of protective materials under dynamic load impact, using the above-mentioned device for testing the impact resistance of protective materials under dynamic load impact, comprises the following steps: S1: Installation device; Power on the electromagnet, suspend a detachable coil spring under the fixed plate, power on and debug the control of the electromagnet on the compression Δx of the coil spring; S2: Install the specimen on the fixture between the bottom of the central column and the explosion-proof plate and keep it in tension; Set the tension of the hydraulic rod; S3: The number of detachable coil springs n, the compression amount Δx, and the mass m of the impact ring required for the specimen to reach the required speed are calculated; S3.1: Ignore friction, and the detachable coil spring is a light spring. The detachable coil spring is compressed by Δx. Calculate the total amount of elastic potential energy converted into the kinetic energy of the impact ring when the detachable coil spring returns to its original length; Get a removable coil spring to give the shock ring speed ; S3.2: Calculate the velocity of the free fall object that impacts the ring ; Then the speed when the impact ring separates from the magnetic chuck is: ; The detection speed is achieved by changing the required height Δx, the number of removable coil springs n, and the mass m of the impact ring; S4: Install n removable coil springs and impact rings of specified mass, and install the specimen; S5: Power on the high-speed camera and the speed sensor. If the sample is an insulating material, connect the first terminal; if the sample is a conductive material, connect the first terminal and the second terminal; S6: Cut off the power, demagnetize the electromagnet, release the impact ring, and complete one impact; S7: record and save data through monitoring equipment; A high-speed camera captures changes in the sample surface when the impact ring impacts the explosion-proof plate; a velocity sensor detects the speed at which the impact ring falls to the explosion-proof plate, as well as the difference between the speed and the detected speed, and inputs the speed-strain curve into the first terminal to generate a velocity-strain curve; if the sample is a conductive material, the second terminal generates a sample resistivity change curve.

[0016] S8: After disassembling the fixture, take out the sample; adjust the compression length Δx of the detachable coil spring, and replace the number n of detachable coil springs.

[0017] Compared with the existing device for simulating impact effect, the beneficial effects of the present invention are as follows: The unique detachable fixture design can easily clamp different types of specimens. It is designed with detachable and replaceable components to increase flexibility. The impact ring is indirectly controlled by an electromagnet, which has higher controllability. It can better simulate the impact effect by cooperating with the hydraulic rod. The impact speed can be flexibly adjusted by adjusting the impact height, number of springs and mass of the impact ring of the impact module, so as to examine the influence of the impact speed on the sample and guide the effective use of the blasting impact protection structure with the sample as the material. The design of the impact ring hitting the explosion-proof plate makes the explosion-proof plate bear force more evenly, preventing uneven force and inaccurate test results; and the impact path of the impact ring is fixed by the positioning sleeve to ensure the accurate position of the falling point; (4) The hydraulic rod fixed tension simulates the situation in which the material is stretched first and then impacted under real working conditions. It has a high degree of automation, is easy to operate, and has good test repeatability. (5) The development of the device is a useful supplement to the existing impact resistance test of protective materials, enriching the relevant test methods. It can realize quantitative and qualitative testing of the impact resistance of protective materials, and can carry out comprehensive evaluation of impact resistance of traditional stress, strain, resistivity and other multi-indicators, providing infrastructure support for the impact resistance test of new protective materials; (6) The overall test based on this device is easy to operate, easy to implement, simple and fast, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the attached picture: Figure 1 It is a schematic diagram of the overall effect of the present invention; Figure 2 It is a partial structural schematic diagram of the present invention; Figure 3 It is a partial structural schematic diagram of the present invention; Figure 4 It is a schematic diagram of the clamp structure of the present invention; Figure 5 It is a partial cross-sectional view of the clamp of the present invention; Figure 6 It is a partial structural schematic diagram of the present invention; Figure 7 It is a partial structural schematic diagram of the present invention; Figure 8 It is a schematic diagram to assist the calculation process; Fig. 9 This is a flow chart of the impact resistance testing method of the present invention; Fig.10 This is a flow chart of the impact test method under tension simulating real working conditions of the present invention; Fig.11 The figure is a flow chart of the tensile performance testing method of the present invention.

[0019] The components represented by the reference numerals in the figure are: 1. Load setting structure; 11. Electromagnet; 12. Magnetic chuck; 13. Impact ring; 14. Lower base plate; 2. Frame; 201. Fixed plate; 202. Hook; 203. Removable spiral spring; 204. Positioning sleeve; 205. Fixed stake; 206. Limit block; 207. Guide rod; 208. Clamp; 2081. Clamping arm; 2082. Fastening sleeve; 2083. Clamping block; 2084. Sample through hole; 209. Center column; 210. High-speed camera; 3. Bearing structure; 31. Cylinder; 32. Spiral fixing spring; 33. Speed ​​sensor; 34. Explosion-proof plate; 35. Hydraulic rod; 36. Hydraulic top plate; 4. Protection structure; 41. Load protection shell; 42. Base protection shell; 5. Display output structure; 51. First terminal; 52. Second terminal; 6. Sample. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is as follows: Reference Figure 1 and Figure 2 , a device for testing the impact resistance of protective materials under dynamic load impact, comprising a frame 2, the frame 2 comprising: The upper fixed plate 201 and the lower bottom plate 14; The connection structure includes a plurality of positioning sleeves 204 connected between the fixing plate 201 and the lower base plate 14; The central column 209 is located inside the connection structure, with one end connected to the bottom surface of the fixing plate 201 and the other end extending downward.

[0021] A fixed pile 205 is also provided between the fixed plate 201 and the lower bottom plate 14. The fixed pile 205 is divided into two left and right parts and is used to fix the entire device. The fixed plate 201 is supported by threaded connection to ensure that the pile does not deform or shake during the stress and contraction process of the sample 6.

[0022] A load setting structure 1 is arranged on the upper part of the frame 2, including a magnetic lifting module and an impact module arranged up and down. The magnetic lifting module includes an electromagnet 11 and a magnetic suction cup 12 with a hole in the middle. The electromagnet 11 is arranged above the fixed plate 201, and the magnetic suction cup 12 is elastically connected to the fixed plate 201 below through a first elastic member. The impact module includes an impact ring 13 with a hole in the middle, and the outer ring of the impact ring 13 is sleeved on the positioning sleeve 204.

[0023] The first elastic member is a plurality of detachable coil springs 203. Figure 3 A plurality of hooks 202 are provided on the opposite sides of the fixing plate 201 and the magnetic suction cup 12 for realizing the detachable connection of the detachable coil spring 203 .

[0024] A bearing structure 3 is provided at the lower end of the frame 2 , including an explosion-proof plate 34 , the bottom surface of which is connected to the lower bottom plate 14 via a second elastic member; the explosion-proof plate 34 is sleeved on the positioning sleeve 204 and is located directly below the impact ring 13 .

[0025] The second elastic member is a plurality of spiral fixing springs 32 movably connected to the lower bottom plate 14 . The spiral fixing springs 32 are used to buffer the speed after the impact of the ring 13 .

[0026] Furthermore, the helical fixing spring 32 may be connected to the lower base plate 14 by threads or by a connecting member.

[0027] The explosion-proof plate 34 is provided with a cylinder 31, and a hydraulic rod 35 is provided between the explosion-proof plate 34 and the lower bottom plate 14. The main body of the hydraulic rod 35 is composed of three sections of rod bodies that can be relatively slidably sleeved, and a sealing structure is provided between each rod body; the hydraulic rod 35 passes through the explosion-proof plate 34, and the hydraulic rod 35 is connected to the top of the explosion-proof plate 34 by a hydraulic top plate 36.

[0028] The hydraulic drive device includes a hydraulic pump, a hydraulic cylinder and a hydraulic pipeline connecting the two; the hydraulic cylinder is connected to the main body of the hydraulic rod 35 for transmission.

[0029] The hydraulic rod 35 is controlled by a microcomputer control system, including a microprocessor, a sensor and a control circuit. The sensor is used to monitor the position and load pressure information of the lifting rod body in real time, and transmit the monitoring data to the microprocessor. The microprocessor controls the start and stop of the hydraulic pump, the speed and the flow direction of the hydraulic oil through the control circuit according to the preset program and the received data, so as to achieve precise control of the lifting height and speed of the hydraulic rod 35 and give a certain pulling force to the specimen 6.

[0030] The sample 6 is connected between the bottom of the central column 209 and the explosion-proof plate 34 via a clamp 208 , and the clamp 208 is welded to the bottom of the central column 209 and the explosion-proof plate 34 .

[0031] The clamp 208 is provided on the bottom surface of the central column 209 and the upper surface of the explosion-proof plate 34, respectively, and the two are arranged oppositely. The clamp 208 includes: A fastening sleeve 2082, internally threaded with a clamping arm 2081; Combination Figure 4 For ease of understanding, the clamping arm 2081 is divided into a first clamping part and a second clamping part with the same structure, which are arranged symmetrically on both sides, and the outer arc is a minor arc. The opposite surfaces are arranged in parallel, and the opposite surfaces of the clamping arm 2081 are provided with grooves that penetrate the front and back. The outer surface of the clamping arm 2081 is threaded and is threadedly connected with the fastening sleeve 2082. A sample through hole 2084 is formed between the first clamping portion and the second clamping portion. Figure 5 , for sample 6 and resistivity detection wire to pass through.

[0032] The clamping block 2083 is divided into two parts which are arranged symmetrically on the left and right, and can detachably fix the sample 6 in the groove. The clamping block 2083 is made of conductive material, and the opposite surface is serrated. At the same time, the clamping block 2083 can be replaced when worn. The clamping block 2083 of appropriate size can be replaced according to the samples 6 of different specifications to keep the sample 6 firmly clamped.

[0033] A plurality of positioning sleeves 204 are arranged in an annular manner in the middle of the frame 2 to limit the vertical movement of the magnetic chuck 12; a plurality of guide rods 207 are located outside the positioning sleeves 204, and a high-speed camera 210 is installed on the guide rod 207. The high-speed camera 210 can change its position through the limit block 206 on the guide rod 207. The speed sensor 33 is placed beside the explosion-proof plate 34, and the position is as shown in FIG. Figure 6 and Figure 7 Schematic diagram; the high-speed camera 210 has a frame rate of more than 1000fps, which is used to shoot the deformation of the sample 6 during the impact process of the impact ring 13, and the vibration displacement waveform of the sample 6 is obtained through video analysis later.

[0034] The present invention is also provided with a display output structure 5, including a first terminal 51 and a second terminal 52, the first terminal 51 is electrically connected to the high-speed camera 210 to generate a velocity strain curve; the second terminal 52 is electrically connected to the fixture 208 to generate a resistivity change curve.

[0035] The device of the present invention further comprises a protection structure 4, which comprises a load protection shell 41 and a pedestal protection shell 42, which are respectively sleeved on the outside of the load setting structure 1 and the bearing structure 3 to protect the internal structure.

[0036] refer to Fig. 9 Flowchart, a method for testing the impact resistance of protective materials under dynamic load impact, using the above-mentioned device for testing the impact resistance of protective materials under dynamic load impact, comprising the following steps: S1: Installation device; The electromagnet 11 is energized, a detachable coil spring 203 is suspended under the fixed plate 201, and the control of the electromagnet 11 on the compression Δx of the coil spring is energized and debugged; S2: Mount the sample 6 on the fixture 208 between the bottom of the central column 209 and the explosion-proof plate 34, and keep it in a stretched state; S3: The number n of detachable coil springs 203, the compression amount Δx, and the mass m of the impact ring 13 required for the sample 6 to reach the required speed are calculated; S3.1: Ignore friction, and the detachable coil spring 203 is a light spring. The detachable coil spring 203 is compressed by Δx. Calculate the elastic potential energy converted into the kinetic energy of the impact ring 13 when the detachable coil spring 203 returns to its original length. The removable coil spring 203 provides the speed of the impact ring 13 ; S3.2: Calculate the velocity of the free fall of the impact ring 13 ; Then the speed at which the impact ring 13 separates from the magnetic chuck 12 is: ; The detection speed is achieved by changing the required height Δx, the number n of the detachable helical springs 203, and the mass m of the impact ring 13; S4: Install n detachable coil springs 203 and a designated mass impact ring 13, and install the specimen 6; S5: Power on the high-speed camera 210 and the speed sensor 33. If the sample 6 is an insulating material, the first terminal 51 is connected; if the sample 6 is a conductive material, the first terminal 51 and the second terminal 52 are connected; S6: Cut off the power, demagnetize the electromagnet 11, release the impact ring 13, and complete one impact; S7: record and save data through monitoring equipment; The high-speed camera 210 captures the surface changes of the sample 6 when the impact ring 13 impacts the explosion-proof plate 34; the speed sensor 33 detects the speed at which the impact ring 13 falls to the explosion-proof plate 34, as well as the difference with the detected speed, and inputs it into the first terminal 51 to generate a velocity strain curve; if the sample 6 is a conductive material, the second terminal 52 generates a resistivity change curve of the sample 6.

[0037] S8: After the fixture 208 is disassembled, the sample 6 is taken out; the compression length Δx of the detachable coil spring 203 is adjusted, and the number n of the detachable coil springs 203 is replaced; Repeat S1 to S8 and proceed to the next test until all the predetermined impact velocities are tested, analyze all the data, and summarize the effect of the impact velocity on the resistivity of the conductive material.

[0038] The removable coil spring 203 provides the speed of the impact ring 13 , the specific solution is as follows: , in, is the elastic potential energy, is the kinetic energy, and k is the elastic coefficient of the detachable coil spring 13.

[0039] The solution formula is: , in, The time required for the detachable coil spring 203 to return to its original length, The removable coil spring is retracted 203 to restore the amount, which is combined here Figure 8 It helps to understand; The velocity solution process of the impact ring 13 in the free fall process is: , , in, In order to restore the original length of the detachable coil spring 203 to the distance where it falls on the explosion-proof plate 34, the combination Figure 8 It is helpful to understand that t is the time from when the detachable coil spring 203 recovers its original length to when it falls on the explosion-proof plate 34. The final speed of impact ring 13.

[0040] refer to Fig.10 Flowchart, a method for testing the impact resistance of protective materials under dynamic load impact, using the above-mentioned device for testing the impact resistance of protective materials under dynamic load impact, comprising the following steps: S1: Installation device; The electromagnet 11 is energized, a detachable coil spring 203 is suspended under the fixed plate 201, and the control of the electromagnet 11 on the compression Δx of the coil spring is energized and debugged; S2: Mount the sample 6 on the fixture 208 between the bottom of the central column 209 and the explosion-proof plate 34, and keep it in a stretched state; Setting the pulling force of the hydraulic rod 35; S3: The number n of detachable coil springs 203, the compression amount Δx, and the mass m of the impact ring 13 required for the sample 6 to reach the required speed are calculated; S3.1: Ignore friction, and the detachable coil spring 203 is a light spring. The detachable coil spring 203 is compressed by Δx. Calculate the elastic potential energy converted into the kinetic energy of the impact ring 13 when the detachable coil spring 203 returns to its original length. The removable coil spring 203 provides the speed of the impact ring 13 ; S3.2: Calculate the velocity of the free fall of the impact ring 13 ; Then the speed at which the impact ring 13 separates from the magnetic chuck 12 is: ; The detection speed is achieved by changing the required height Δx, the number n of the detachable helical springs 203, and the mass m of the impact ring 13; S4: Install n detachable coil springs 203 and a designated mass impact ring 13, and install the specimen 6; S5: Power on the high-speed camera 210 and the speed sensor 33. If the sample 6 is an insulating material, the first terminal 51 is connected; if the sample 6 is a conductive material, the first terminal 51 and the second terminal 52 are connected; S6: Cut off the power, demagnetize the electromagnet 11, release the impact ring 13, and complete one impact; S7: record and save data through monitoring equipment; The high-speed camera 210 captures the surface changes of the sample 6 when the impact ring 13 impacts the explosion-proof plate 34; the speed sensor 33 detects the speed at which the impact ring 13 falls to the explosion-proof plate 34, as well as the difference with the detected speed, and inputs it into the first terminal 51 to generate a velocity strain curve; if the sample 6 is a conductive material, the second terminal 52 generates a resistivity change curve of the sample 6.

[0041] S8: After disassembling the fixture 208, take out the sample 6; adjust the compression length Δx of the detachable coil spring 203, and replace the number n of detachable coil springs 203.

[0042] refer to Fig.11 Flowchart, the present invention can also test the tensile strength of the sample, and the test method is as follows: S1: Installation device; S2: Mount the sample 6 on the fixture 208 between the bottom of the central column 209 and the explosion-proof plate 34, and keep it in a stretched state; S3: Power on the high-speed camera 210 and the speed sensor 33. If the sample 6 is an insulating material, the first terminal 51 is connected; if the sample 6 is a conductive material, the first terminal 51 and the second terminal 52 are connected; S4, setting the pulling force of the hydraulic rod 35; S5, start the hydraulic rod 35 and start applying tension; S6: Record and save data through monitoring equipment; The high-speed camera 210 captures the surface changes of the sample 6; the first terminal 51 is input to display the change process of the sample 6; if the sample 6 is a conductive material, the second terminal 52 generates a resistivity change curve of the sample 6; S7: Collect data and repeat the experiment to analyze the effect of tension on sample 6.

[0043] The principle adopted by the present invention to solve the technical problem is that the device for detecting blasting impact protective materials mainly consists of a frame 2, a load setting structure 1, a bearing structure 3, a protective structure 4 and a display output structure 5. The load setting structure 1 is located above the whole, and the impact size of the sample 6 is adjusted by the impact height, spring stiffness coefficient and mass of the load setting structure 1 to simulate the real blasting working condition.

Claims

1. A device for testing the impact resistance of protective materials under dynamic load impact, characterized in that: The invention comprises a frame (2), wherein the frame (2) comprises: An upper electromagnet (11) and a lower base plate (14); A connection structure, comprising a plurality of positioning sleeves (204), connected between the fixing plate (201) and the lower base plate (14); A central column (209) is located inside the connection structure, one end of which is connected to the bottom surface of the fixing plate (201) and the other end of which extends downward; A load setting structure (1) is arranged on the upper part of the frame (2), comprising a magnetic lifting module and an impact module arranged in an upper and lower part, the magnetic lifting module comprising an electromagnet (11) and a magnetic suction cup (12) with a hole in the middle, the electromagnet (11) being arranged above the fixing plate (201), and the magnetic suction cup (12) being elastically connected to the fixing plate (201) through a first elastic member below, and the impact module comprising an impact ring (13) with a hole in the middle, and the outer ring of the impact ring (13) is sleeved on the positioning sleeve (204); A bearing structure (3) is provided at the lower end of the frame (2), comprising an explosion-proof plate (34), the bottom surface of which is connected to the lower bottom plate (14) via a second elastic member; the explosion-proof plate (34) is sleeved on the positioning sleeve (204) and is located directly below the impact ring (13); The test specimen (6) is connected between the bottom of the central column (209) and the explosion-proof plate (34) via a clamp (208).

2. The device according to claim 1, characterized in that: A hydraulic rod (35) is provided between the explosion-proof plate (34) and the lower bottom plate (14).

3. The device according to claim 1, characterized in that: The second elastic member is a plurality of helical fixing springs (32).

4. The device according to claim 1, characterized in that: The first elastic member is a plurality of detachable coil springs (203).

5. The device according to claim 4, characterized in that: A plurality of hooks (202) are provided on the opposite surfaces of the fixing plate (201) and the magnetic suction cup (12) for realizing a detachable connection of the detachable coil spring (203).

6. The device according to claim 1, characterized in that: A plurality of positioning sleeves (204) are arranged in a ring shape in the middle of the frame (2), a plurality of guide rods (207) are located outside the positioning sleeves (204), a high-speed camera (210) is installed on the guide rods (207), and a speed sensor (33) is placed beside the explosion-proof plate (34).

7. The device according to claim 1, characterized in that: The clamp (208) is provided at a bottom surface of the central column (209) and at a top surface of the explosion-proof plate (34), respectively, and the two are arranged opposite to each other. The clamp (208) comprises: A tightening sleeve (2082) having a clamping arm (2081) internally threadedly connected thereto; The clamping arm (2081) is divided into a first clamping part and a second clamping part with the same structure, which are arranged symmetrically on the left and right, with the outer arc being a minor arc, and the opposite surfaces are arranged in parallel, and the opposite surfaces of the clamping arm (2081) are provided with grooves penetrating front and back; The clamping block (2083) is divided into two parts arranged symmetrically on the left and right, and the sample (6) is fixed in the groove in a detachable manner.

8. The device according to claim 6, characterized in that: The device is also provided with a display output structure (5), comprising a first terminal (51) and a second terminal (52), wherein the first terminal (51) is electrically connected to a high-speed camera (210) to generate a velocity-strain curve; and the second terminal (52) is electrically connected to a fixture (208) to generate a resistivity change curve.

9. A method for testing the impact resistance of protective materials under dynamic load impact, using a device for testing the impact resistance of protective materials under dynamic load impact as claimed in any one of claims 1 to 8, characterized in that: The steps include: S1: Installation device; The electromagnet (11) is energized, a detachable coil spring (203) is suspended under the fixed plate (201), and the control of the electromagnet (11) on the compression Δx of the coil spring is energized and debugged; S2: Mount the specimen (6) on the fixture (208) between the bottom of the central column (209) and the explosion-proof plate (34), and keep it in a tensile state; S3: The number n of detachable coil springs (203), the compression amount Δx, and the mass m of the impact ring (13) required for the specimen (6) to reach the required speed are calculated; S3.1: Ignore friction, and the detachable coil spring (203) is a light spring. The detachable coil spring (203) is compressed by Δx. Calculate the amount of elastic potential energy that is converted into kinetic energy of the impact ring (13) when the detachable coil spring (203) returns to its original length. The removable coil spring (203) imparts a velocity to the impact ring (13) ; S3.2: Calculate the velocity of the impact ring (13) in free fall ; Then the speed at which the impact ring (13) separates from the magnetic chuck (12) is: ; The detection speed is achieved by changing the required height Δx, the number n of the detachable coil springs (203), and the mass m of the impact ring (13); S4: Install n removable coil springs (203) and a designated mass impact ring (13), and install a test specimen (6); S5: Powering on the high-speed camera (210) and the speed sensor (33); if the sample (6) is an insulating material, connecting the first terminal (51); if the sample (6) is a conductive material, connecting the first terminal (51) and the second terminal (52); S6: power off, so that the electromagnet (11) is demagnetized and the impact ring (13) is released, completing one impact; S7: record and save data through monitoring equipment; A high-speed camera (210) captures changes in the surface of the sample (6) when the impact ring (13) impacts the explosion-proof plate (34); a velocity sensor (33) detects the speed at which the impact ring (13) falls onto the explosion-proof plate (34) and the difference between the speed and the detected speed, and inputs the speed-strain curve into a first terminal (51) to generate a velocity-strain curve; if the sample (6) is a conductive material, a second terminal (52) generates a resistivity change curve of the sample (6); S8: After disassembling the fixture (208), take out the sample (6); adjust the compression length Δx of the detachable coil spring (203), and replace the number n of detachable coil springs (203); Repeat S1 to S8 and proceed to the next test until all the predetermined impact velocities are tested, analyze all the data, and summarize the effect of the impact velocity on the resistivity of the conductive material.

10. A method for testing the impact resistance of protective materials under dynamic load impact, using a device for testing the impact resistance of protective materials under dynamic load impact as claimed in any one of claims 2 to 8, characterized in that: The steps include: S1: Installation device; The electromagnet (11) is energized, a detachable coil spring (203) is suspended under the fixed plate (201), and the control of the electromagnet (11) on the compression Δx of the coil spring is energized and debugged; S2: Mount the specimen (6) on the fixture (208) between the bottom of the central column (209) and the explosion-proof plate (34), and keep it in a tensile state; Setting the tension of the hydraulic rod (35); S3: The number n of detachable coil springs (203), the compression amount Δx, and the mass m of the impact ring (13) required for the specimen (6) to reach the required speed are calculated; S3.1: Ignore friction, and the detachable coil spring (203) is a light spring. The detachable coil spring (203) is compressed by Δx. Calculate the amount of elastic potential energy that is converted into kinetic energy of the impact ring (13) when the detachable coil spring (203) returns to its original length. The removable coil spring (203) imparts a velocity to the impact ring (13) ; S3.2: Calculate the velocity of the impact ring (13) in free fall ; Then the speed at which the impact ring (13) separates from the magnetic chuck (12) is: ; The detection speed is achieved by changing the required height Δx, the number n of the detachable coil springs (203), and the mass m of the impact ring (13); S4: Install n removable coil springs (203) and a designated mass impact ring (13), and install a test specimen (6); S5: Powering on the high-speed camera (210) and the speed sensor (33); if the sample (6) is an insulating material, connecting the first terminal (51); if the sample (6) is a conductive material, connecting the first terminal (51) and the second terminal (52); S6: power off, so that the electromagnet (11) is demagnetized and the impact ring (15) is released, completing one impact; S7: record and save data through monitoring equipment; A high-speed camera (210) captures changes in the surface of the sample (6) when the impact ring (13) impacts the explosion-proof plate (34); a velocity sensor (33) detects the speed at which the impact ring (13) falls onto the explosion-proof plate (34) and the difference between the speed and the detected speed, and inputs the speed-strain curve into a first terminal (51) to generate a velocity-strain curve; if the sample (6) is a conductive material, a second terminal (52) generates a resistivity change curve of the sample (6); S8: After disassembling the fixture (208), take out the sample (6); adjust the compression length Δx of the detachable coil spring (203), and replace the number n of detachable coil springs (203).

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