A high-temperature SHPB dynamic compression test device

Abstract

The application discloses a high-temperature SHPB dynamic compression test device, wherein a gas gun and a heating furnace are fixed on a rack, an incident rod and a transmission rod are arranged on the two sides of the heating furnace, strain gauges are attached to the incident rod and the transmission rod, a sample is arranged in the heating furnace, a plurality of fasteners are fixed on the rack and arranged on the two sides of the heating furnace, the incident rod and the transmission rod are fixed on each group of fasteners, two locking blocks are fixed on the incident rod and the transmission rod, two driving members are slidingly connected to the rack and can be horizontally rotated, driving blocks are arranged on the driving members, the two driving members are driven to linearly displace by an electric driving mechanism arranged on the rack, the driving blocks abut against the corresponding locking blocks to drive the incident rod and the transmission rod to linearly displace towards the heating furnace during the linear displacement of the driving members, and the driving members are horizontally rotated by 180 DEG, so that the incident rod and the transmission rod linearly displace away from the heating furnace. The application solves the problem of long test time and influence on test results caused by manual push rods in the traditional device.

Description

TECHNICAL FIELD

[0001] The present application relates to a high-temperature SHPB dynamic compression test device, belonging to the field of material sample testing. BACKGROUND

[0002] The high-temperature Hopkinson pressure bar (SHPB) test is designed to study the dynamic mechanical properties of materials at high temperature and high strain rate. By measuring the propagation of stress waves in the bar, the stress-strain relationship, dynamic strength and failure mode of materials under high-temperature impact coupling are analyzed. The basic principle is to measure the dynamic response of materials by using the propagation of stress waves in an elastic bar. The experimental device mainly includes a gas gun, a heating furnace, an incident bar (close to the gas gun) and a transmission bar. When the bullet (i.e. the launch bar) fired by the gas gun hits the incident bar, a stress wave is generated in the incident bar. According to the propagation theory of stress waves at the interface between different media, part of the wave will pass through the sample into the transmission bar, and part of the wave will be reflected back to the incident bar. The strain signals of the incident wave, the reflected wave and the transmitted wave are measured by the strain gauges attached to the bar. Combined with the one-dimensional stress wave theory, the stress, strain and strain rate of the sample are calculated. The defects of the existing structure are as follows:

[0003] Because high temperature will affect the propagation of stress waves in the bar (i.e. the incident bar and the transmission bar), thus affecting the experimental data and experimental results, the longest time of the bar in the high-temperature furnace cannot exceed ten seconds. The traditional high-temperature SHPB device can only be pushed manually, and the pre-preparation work such as pushing the bar and inflating the gas gun far exceeds ten seconds, which not only affects the test results, but also causes the bullet to be triggered or the data acquisition system to be started in time due to the tension of human operation.

[0004] Some equipment adopts the scheme of integrated electric actuator to realize the automatic advancement of the incident bar and the transmission bar. Most of them directly fix the linear free end of the electric actuator with the incident bar and the transmission bar (such as directly fixing the slider of the electric slider unit with the incident bar and the transmission bar, and directly fixing the chain of the cooperation and chain wheel chain unit with the incident bar and the transmission bar). The defect of this structure is that the incident bar and the transmission bar will rebound after being impacted by the high-speed launch bar during the test. The rebound force will directly act on the motor of the electric actuator, which will damage the motor over time. SUMMARY

[0005] The present application is to solve the problems existing in the prior art and provides a high-temperature SHPB dynamic compression test device.

[0006] The technical scheme adopted by the present application is:

[0007] The utility model provides a kind of high-temperature SHPB dynamic compression test device, including rack, incident rod, transmission rod, gas gun and heating furnace, the gas gun is fixed on rack with heating furnace, incident rod and transmission rod are located in heating furnace both sides, and incident rod is close to the side of gas gun, strain gauge is pasted on incident rod and transmission rod, further including fastener, locking block, driving part and sample, the sample is placed in heating furnace, several fasteners are fixed on rack and are placed in heating furnace both sides, incident rod and transmission rod are fixed on each group of fastener respectively, and can be axially moved relative to fastener, two locking blocks are fixed on incident rod and transmission rod respectively, two driving parts are slidably connected on rack, and driving part can be horizontally rotated, driving block is provided on driving part, two driving parts are driven linear displacement by electric drive mechanism arranged on rack, and incident rod and transmission rod are driven linear displacement towards heating furnace by driving block abutting corresponding locking block in the process of linear displacement of driving part, and driving part is horizontally rotated 180 °, so that incident rod and transmission rod linearly displace away from the heating furnace.

[0008] Further, two electric linear guides are fixed on the rack, and the linear free ends of the electric linear guides are fixedly connected with the driving parts and drive the driving parts to linearly displace on the rack.

[0009] Further, a horizontal rotation structure for driving the driving parts to horizontally rotate 180 ° is fixed on the electric linear guides, and the horizontal rotation structure includes a servo motor and a rotating disc, the motor shaft of the servo motor is fixed with the rotating disc, and the driving parts are fixed on the rotating disc.

[0010] Further, the horizontal rotation structure further includes a limiting seat and a limiting pin, the limiting seat is fixed on the electric linear guide, the limiting pin is fixed on the rotating disc and rotates with the rotating disc, and two limiting grooves are provided on the limiting seat and located on the rotating path of the limiting pin.

[0011] Further, a spring buffer is provided on the rack, and the spring buffer is located on one side of the transmission rod.

[0012] Further, the driving block on the driving part can be one-way vertically flipped.

[0013] Further, the driving block is a right-angle block, which is rotatably connected to the driving part through a rotating shaft, a torsional spring is provided on the rotating shaft, and the horizontal edge of the driving block abuts on the driving part under the torsional force of the torsional spring.

[0014] Further, the outer edge of the vertical edge of the driving block is an arc surface structure.

[0015] Further, the fastener comprises an upper seat, a lower seat, three adjusting rods and three rollers, the upper seat and the lower seat are fixedly connected by a quick release structure, the three adjusting rods are arranged at equal angles and connected to the upper seat and the lower seat, and the rollers are rotatably connected to the ends of the adjusting rods, the positions of the adjusting rods on the corresponding upper seat and lower seat are adjustable, so as to adjust the relative distance between the three rollers.

[0016] Further, the quick release structure comprises two symmetrically arranged inserts provided on the upper seat, a clamping groove provided on each of the inserts, an insert slot, a lock and a spring provided on the lower seat, the lock is rotatably connected to the lower seat and has one end extending into the insert slot, the spring is arranged in the insert slot and has one end abutting against the lock and the other end abutting against the inner wall of the insert slot, the inserts are inserted into the insert slots, and the corresponding end of the lock abuts against the clamping groove under the elastic force of the spring.

[0017] Further, the heating furnace comprises an outer thermal insulation cover, an electric heating pipe and an inner thermal insulation pipe, the electric heating pipe and the inner thermal insulation pipe are coaxially arranged, the inner thermal insulation pipe is arranged in the electric heating pipe, the electric heating pipe is arranged in the outer thermal insulation cover, and the sample is arranged in the inner thermal insulation pipe.

[0018] Further, the inner wall of the inner thermal insulation pipe is provided with a limiting groove in the axial direction, and a limiting rib is arranged on the outer wall of the sample, and the limiting rib is slidably arranged in the limiting groove.

[0019] The present application has the following beneficial effects:

[0020] (1) The present application solves the problem of long test time caused by manual push rod in the traditional device, which affects the test results.

[0021] (2) In view of the problem that the motor of the electric drive mechanism is damaged by the rebound force of the incident rod and the transmission rod after being impacted by the high-speed impact of the emission rod in the traditional device, the driving part of the present application can rotate horizontally, the incident rod and the transmission rod are separated and away from the electric drive mechanism after being impacted, which effectively avoids the damage of the electric drive mechanism and prolongs the service life of the equipment.

[0022] (3) In the test process, the incident rod and the transmission rod will produce a rebound force after being impacted by the high-speed impact of the emission rod. In the traditional device, this rebound force will directly act on the driving mechanism, which may cause damage to the driving mechanism. The driving block of the present application can be vertically flipped in one direction, and when the locking block hits the driving block, the driving block can be flipped, thereby effectively removing the force of the locking block hitting the driving block, reducing the impact on the electric linear guide rail and other driving mechanisms, and protecting the driving mechanism from damage. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The structure diagram of the present application.

[0024] Figure 2 The assembly diagram of the transmission rod and the heating furnace on the rack.

[0025] Figure 3 Assemble view of locking block on transmission rod and driving member below it.

[0026] Figure 4 Assemble view of locking block on transmission rod and driving member below it. Figure 3 View of driving member after horizontal 180° rotation.

[0027] Figure 5 View of driving member after horizontal 180° rotation.

[0028] Figure 6 View of fastener.

[0029] Figure 7 Assemble view of fastener.

[0030] Figure 8 Exploded view of heating furnace.

[0031] Figure 9 View of sample.

[0032] The following are the components mentioned in the text and their numbers:

[0033] 1, frame; 10, spring buffer; 11, electric linear guide; 12, servo motor; 13, rotary disc; 14, limit seat; 15, limit pin; 16, mounting seat;

[0034] 2, incident rod; 3, transmission rod; 4, gas gun; 5, heating furnace; 51, outer insulation cover; 52, electric heating tube; 53, inner insulation tube;

[0035] 6, fastener; 61, upper seat; 611, inserted rib; 62, lower seat; 621, lock catch; 622, spring; 63, adjusting rod; 64, roller;

[0036] 7, locking block; 8, driving member; 81, driving block; 82, torsional spring; 9, sample; 91, limit rib;

[0037] Figure 2 、 Figure 3 、 Figure 6 and Figure 7 Corresponding letters A, B in the text are the guide numbers of the enlarged view. DETAILED DESCRIPTION

[0038] The application will be further described below in conjunction with the drawings.

[0039] As Figure 1 and Figure 2 , the application is a high-temperature SHPB dynamic compression test device, which comprises a frame 1, an incident rod 2, a transmission rod 3, a gas gun 4, a heating furnace 5, a fastener 6, a locking block 7, a driving member 8, and a sample 9.

[0040] The rack 1 comprises a base and a crossbeam fixed on the base, the air gun 4 and the heating furnace 5 are fixed on the crossbeam of the rack 1, the incident rod 2 and the transmission rod 3 are arranged on the two sides of the heating furnace 5, and the incident rod 2 is close to the side of the air gun 4, and the strain gauges are attached on the incident rod and the transmission rod for measuring the strain signals of the incident rod and the transmission rod.

[0041] The sample 9 is arranged in the heating furnace 5, the plurality of fasteners 6 are fixed on the crossbeam of the rack 1 and arranged on the two sides of the heating furnace 5, the incident rod 2 and the transmission rod 3 are respectively fixed on each group of fasteners 6 and can move axially relative to the fasteners, the two locking blocks 7 are respectively fixed on the incident rod 2 and the transmission rod 3, the two driving members 8 are slidingly connected to the crossbeam and can rotate horizontally by 180°, the driving blocks 81 protruding from the driving members 8, the two driving members 8 are driven to move linearly by the electric driving mechanism arranged on the crossbeam, the driving blocks 81 of the driving members 8 abut against the corresponding locking blocks 7 to drive the incident rod 2 and the transmission rod 3 to move linearly towards the heating furnace 5 during the linear movement of the driving members 8, and the driving members 8 rotate horizontally by 180° to drive the incident rod 2 and the transmission rod 3 to move linearly away from the heating furnace 5.

[0042] The experimental process of the device is described below.

[0043] Before the formal experiment, the sample 9 is arranged in the heating furnace 5, the incident rod 2 and the transmission rod 3 are fixed, and the sample 9 is heated in the heating furnace 5, since the incident rod 2 and the transmission rod 3 are made of spring steel, the incident rod 2 and the transmission rod 3 need to be withdrawn from the furnace during the heating process. After the sample 9 is heated to the required temperature, the heating furnace 5 is turned off, the air gun 4 starts to inflate, and the two driving members 8 are started, the two driving members 8 move linearly and drive the incident rod 2 and the transmission rod 3 to move linearly towards the heating furnace 5 by abutting against the corresponding locking blocks 7 through the corresponding driving blocks 81, and finally push the incident rod and the transmission rod into the furnace.

[0044] When the incident rod and the transmission rod are pushed into the furnace and contact the sample, the two driving members 8 are quickly rotated horizontally by 180°, so that the driving blocks 81 are horizontally adjusted by one position relative to the locking blocks 7 on the side. Figure 1 Taking the left transmission rod 3 as an example, when the transmission rod 3 is pushed towards the heating furnace 5, the driving block 81 is located on the left side of the locking block 7 on the transmission rod 3 (as shown in Figure 3 ). Before the air gun 4 fires the bullet, the driving block 81 is rotated horizontally by 180° to the right side of the locking block 7 (as shown in Figure 4 ). The bullet (i.e. the firing rod) fired by the air gun 4 hits the incident rod 2, and the sample 9 is pushed out of the furnace by the incident rod 2. The incident rod 2 and the transmission rod 3 are separated and move away from the electric driving mechanism after being impacted, effectively avoiding damage to the electric driving mechanism.

[0045] In combination with the above experimental process, the specific structure of the present application is further described as follows.

[0046] The electric driving mechanism in the present application is an electric linear guide rail 11 (the structure is a mature component, so the principle and structure of the present application are not described in detail), the linear free end of the electric linear guide rail 11 is fixedly connected with the driving piece 8, and drives the driving piece 8 to linearly displace on the rack 1.

[0047] As Figure 5 , the structure for realizing the horizontal 180° rotation of the driving block 81 is:

[0048] A horizontal rotation structure for driving the driving piece 8 to horizontally rotate 180° is fixed on the electric linear guide rail 11, the horizontal rotation structure comprises a servo motor 12 and a rotating disc 13, the motor shaft of the servo motor 12 is fixed with the rotating disc 13, and the driving piece 8 is fixed on the rotating disc 13.

[0049] In order to further limit the rotation angle of the driving block 81, the horizontal rotation structure further comprises a limiting seat 14 and a limiting pin 15, the limiting seat 14 is fixed on the electric linear guide rail 11, the limiting pin 15 is fixed on the rotating disc 13 and rotates with the rotating disc 13, two circular arc open limiting grooves are symmetrically arranged on the limiting seat 14, and the two limiting grooves are located on the rotation path of the limiting pin 15, through the cooperation (corresponding proximity switch is arranged) of the limiting pin 15 and the limiting groove, the accurate switching of the driving block 81 between 0°-180° can be further ensured.

[0050] When the bullet fired by the air gun 4 hits the incident rod 2, in order to avoid directly separating from the transmission rod 3 rack, a spring buffer 10 is arranged on the rack 1, and the spring buffer 10 is located on one side of the transmission rod 3. The spring buffer 10 comprises a guide rod and a spring, the guide rod is a T-shaped rod, a position-adjustable mounting seat 16 is arranged on the cross beam of the rack 1, the guide rod is inserted into the mounting seat 16, a nut is axially limited by screwing on the guide rod, the spring is sleeved on the guide rod, and one end of the spring abuts against the mounting seat 16 and the other end abuts against the T head of the guide rod.

[0051] After the incident rod 2 hits the transmission rod 3 and the transmission rod 3 hits the spring buffer 10, the incident rod 2 and the transmission rod 3 will be bounced back, the locking block 7 will hit the driving block 81 in the rebound process, and the electric linear guide rail 11 may also be impacted to a certain extent. In order to reduce the impact damage caused by the rebound, the driving block 81 of the present application can be one-way vertically flipped on the driving piece 8. The specific structure is:

[0052] The driving block 81 selects a right-angle block, the horizontal edge of the right-angle block is rotationally connected to the driving piece 8 through a rotating shaft, a torsional spring 82 is arranged on the rotating shaft, and under the action of the torsional spring force of the torsional spring 82, the horizontal edge of the driving block 81 abuts against the driving piece 8.

[0053] The one-way vertical flip has the advantage that when the incident rod 2 and the transmission rod 3 rebound, the driving part 8 rotates horizontally by 180°, and the driving block 81 rotates to the initial state position for abutting against the locking block 7. When the locking block 7 abuts against the driving block 81 during rebounding, the driving block 81 is flipped, and at this time, the force of the locking block 7 hitting the driving block 81 can be effectively removed, and the impact on the electric linear guide rail 11 is reduced.

[0054] The outer edge of the vertical edge of the driving block 81 is an arc surface structure, which reduces damage to the locking block 7. After the arc surface of the driving block 81 contacts the locking block 7 after being flipped, it also has a certain "brake effect", which is used to stop the incident rod 2 and the transmission rod 3.

[0055] Since the SHPB test is based on one-dimensional stress wave theory and stress uniformity assumption, after the incident rod 2 and the transmission rod 3 are installed, the centering adjustment is performed, that is, it is necessary to ensure that the air gun 4, the incident rod 2, the transmission rod 3 and the sample 9 are on the same axis. The fastener 6 of the present application can adjust the height of the incident rod 2 and the transmission rod 3 in the vertical direction. The structure of the air gun 4 and the vertical adjustment structure are conventional structures, and the present application does not describe the structure of the air gun 4 itself and the vertical direction lifting.

[0056] The vertical height of the spring buffer 10 can be unchanged, and only the T-head area of the guide rod needs to be enlarged. The structure of the fastener 6 is described in detail below.

[0057] As Figure 6 , the fastener 6 includes an upper seat 61, a lower seat 62, an adjusting rod 63 and a roller 64. The upper seat 61 and the lower seat 62 are fixed and integrated in a quick release structure, three adjusting rods 63 are arranged at equal angles and connected to the upper seat 61 and the lower seat 62. In this embodiment, two adjusting rods 63 are arranged on the lower seat 62, and one adjusting rod 63 is arranged on the upper seat 61. The roller 64 is rotatably connected to the end of the adjusting rod 63. The adjusting rod 63 is a hand screw structure, and the corresponding positions of the upper seat 61 and the lower seat 62 are adjustable, which is used to adjust the relative distance between the three rollers 64.

[0058] The three rollers 64 abut and clamp the corresponding incident rod 2 and transmission rod 3, and the roller 64 can ensure the axial movement of the incident rod 2 and the transmission rod 3 relative to the fastener 6.

[0059] As Figure 7The quick release structure between the upper seat 61 and the lower seat 62 is that two inserting ribs 611 are symmetrically arranged on the upper seat 61, the inserting rib 611 is provided with a buckling groove, the lower seat 62 is provided with an inserting groove, a lock buckle 621 and a spring 622, the lock buckle 621 is rotationally connected to the lower seat 62 and extends into the inserting groove at one end, the spring 622 is arranged in the inserting groove and abuts against the lock buckle 621 at one end and the inner wall of the inserting groove at the other end, the inserting rib 611 is inserted into the inserting groove, and the corresponding end of the lock buckle 621 abuts against the buckling groove under the spring force. When the upper seat 61 and the lower seat 62 need to be removed, the lock buckle 621 is pulled (at this time, the spring 622 is compressed), the lock buckle 621 is separated from the buckling groove on the inserting rib 611, and then the upper seat 61 can be pulled out.

[0060] As Figure 8 The heating furnace 5 in the application comprises an outer insulation cover 51, an electric heating pipe 52 and an inner insulation pipe 53, the electric heating pipe 52 and the inner insulation pipe 53 are coaxially arranged, the inner insulation pipe 53 is arranged in the electric heating pipe 52, the electric heating pipe 52 is arranged in the outer insulation cover 51, and the sample 9 is arranged in the inner insulation pipe 53.

[0061] As Figure 9 After the sample 9 is arranged in the inner insulation pipe 53, the limit groove is arranged on the inner wall of the inner insulation pipe 53 in the axial direction to avoid the sample 9 from falling, and the limit rib 91 is arranged on the outer wall of the sample 9 and is slidingly arranged in the limit groove.

[0062] The above is only the preferred embodiment of the application, and it should be noted that the ordinary skilled in the art can make several improvements without departing from the principles of the application, and these improvements should be considered as the protection scope of the application.

Claims

1. A high-temperature SHPB dynamic compression testing device, comprising a frame (1), an incident rod (2), a transmission rod (3), an air cannon (4), and a heating furnace (5), wherein the air cannon (4) and the heating furnace (5) are fixed on the frame (1), the incident rod (2) and the transmission rod (3) are disposed on both sides of the heating furnace (5), and strain gauges are attached to the incident rod and the transmission rod, characterized in that: It also includes fasteners (6), locking blocks (7), driving components (8), and a sample (9). The sample (9) is placed inside the heating furnace (5). Several fasteners (6) are fixed in two groups on the frame (1) and placed on both sides of the heating furnace (5). The incident rod (2) and the transmission rod (3) are fixed on each group of fasteners (6) and can move axially relative to the fasteners. Two locking blocks (7) are fixed on the incident rod (2) and the transmission rod (3) respectively. Two driving components (8) are slidably connected to the frame (1) and drive... The moving part (8) can rotate horizontally. A protruding driving block (81) is provided on the driving part (8). The two driving parts (8) are driven to linear displacement by an electric driving mechanism set on the frame (1). During the linear displacement, the driving part (8) abuts against the corresponding locking block (7) through the driving block (81), which drives the incident rod (2) and the transmission rod (3) to move linearly towards the heating furnace (5). The driving part (8) rotates horizontally by 180° so that the incident rod (2) and the transmission rod (3) can move linearly away from the heating furnace (5). The electric drive mechanism is an electric linear guide (11), which drives the drive component (8) to move linearly on the frame (1). A horizontal rotating structure for driving the drive component (8) to rotate horizontally by 180° is fixed on the electric linear guide (11). The horizontal rotating structure includes a servo motor (12) and a turntable (13). The motor shaft of the servo motor (12) is fixed to the turntable (13), and the drive component (8) is fixed on the turntable (13). The drive block (81) can be vertically flipped in one direction on the drive member (8); The fastener (6) includes an upper seat (61), a lower seat (62), an adjusting rod (63), and a roller (64). The upper seat (61) and the lower seat (62) are fixed together by a quick-release structure. The three adjusting rods (63) are arranged at equal angles and connected to the upper seat (61) and the lower seat (62). The roller (64) is rotatably connected to the end of the adjusting rod (63). The position of the adjusting rod (63) on the corresponding upper seat (61) and lower seat (62) is adjustable to adjust the relative distance between the three rollers (64).

2. The high-temperature SHPB dynamic compression testing apparatus as described in claim 1, characterized in that: The horizontal rotation structure also includes a limiting seat (14) and a limiting pin (15). The limiting seat (14) is fixed on the electric linear guide rail (11), and the limiting pin (15) is fixed on the turntable (13) and rotates with the turntable (13). Two limiting grooves are provided on the limiting seat (14) and on the rotation path of the limiting pin (15).

3. The high-temperature SHPB dynamic compression testing apparatus as described in claim 1, characterized in that: The frame (1) is provided with a spring buffer (10), which is located on one side of the transmission rod (3).

4. The high-temperature SHPB dynamic compression testing apparatus as described in claim 1, characterized in that: The drive block (81) is a right-angle block, which is rotatably connected to the drive member (8) through a rotating shaft. A torsion spring (82) is provided on the rotating shaft. Under the action of the torsion spring force of the torsion spring (82), the horizontal edge of the drive block (81) abuts against the drive member (8).

5. The high-temperature SHPB dynamic compression testing apparatus as described in claim 1, characterized in that: The quick-release structure is as follows: two inserts (611) are symmetrically arranged on the upper seat (61), and the inserts (611) are provided with a buckle groove. The lower seat (62) is provided with a slot, a buckle (621) and a spring (622). The buckle (621) is rotatably connected to the lower seat (62) and one end extends into the slot. The spring (622) is located in the slot, and one end abuts against the buckle (621) and the other end abuts against the inner wall of the slot. The inserts (611) are inserted into the slot, and the corresponding end of the buckle (621) abuts against the buckle groove under the action of the spring force.

6. The high-temperature SHPB dynamic compression testing apparatus as described in claim 1, characterized in that: The heating furnace (5) includes an outer heat insulation cover (51), an electric heating tube (52) and an inner heat insulation tube (53). The electric heating tube (52) and the inner heat insulation tube (53) are arranged coaxially, and the inner heat insulation tube (53) is placed inside the electric heating tube (52). The electric heating tube (52) is placed inside the outer heat insulation cover (51), and the sample (9) is placed inside the inner heat insulation tube (53).

7. The high-temperature SHPB dynamic compression testing apparatus as described in claim 6, characterized in that: The inner wall of the inner insulation pipe (53) is provided with a limiting groove in the axial direction, and a limiting rib (91) is provided on the outer wall of the sample (9). The limiting rib is slidably placed in the limiting groove.

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