Hopkinson bar clamp capable of adjusting impact position and clamping thickness of plate-shaped test piece

Abstract

The invention discloses a Hopkinson bar clamp with adjustable impact position and clamping thickness of a plate-shaped test piece, and belongs to the field of impact test clamps. The Hopkinson bar clamp comprises a base, an L-shaped plate, a lower clamping plate and an upper clamping plate, the base is fixed on a Hopkinson bar sliding rail through a bolt; the L-shaped plate is composed of a bottom surface flat plate, a side surface flat plate and reinforcing ribs, and the bottom surface flat plate is provided with a large through groove parallel to the side surface flat plate and small through grooves which are symmetrical based on the large through groove and used for moving left and right; the middle of the side flat plate is hollowed to form a U-shaped structure, reinforcing ribs are arranged in the side flat plate, and side through grooves used for moving up and down are formed in the two sides of the U-shaped face. The lower clamping plate and the upper clamping plate are of flat plate structures, rectangular impact areas are arranged between the lower clamping plate and the upper clamping plate, and bolts penetrate through unthreaded holes of the upper clamping plate to be matched with threads of the lower clamping plate to clamp a plate-shaped test piece and adjust clamping thickness. According to the invention, the impact test of plate-shaped test pieces with different thicknesses at different impact positions by using the Hopkinson bar can be realized.

Description

Technical Field

[0001] The invention belongs to the field of Hopkinson bar test fixtures, and in particular relates to a Hopkinson bar fixture with adjustable impact position and clamping thickness of a plate-shaped test piece. Background Art

[0002] In fields such as aerospace, automobiles, and armor, the impact resistance of plate specimens similar to laminates and structural parts has always been the focus of research. In order to evaluate the impact response and damage tolerance of plate specimens, impact tests are usually required.

[0003] Currently, impact tests on plate-like specimens can only be performed using drop hammer impact testers, while the Hopkinson bar is mainly used to test block-like specimens. Although it is called a high-speed impact, it actually uses an incident rod and a transmission rod to clamp the specimen. The more standard experimental name is a high strain rate compression test, so strictly speaking, it does not fall into the category of high-speed impact. Currently, many patents have invented special fixture devices, which enable the Hopkinson bar to achieve different uses: Patent CN202010290323.4 discloses a separate Hopkinson rod thin sheet specimen tensile fixture and experimental method, which realizes the use of Hopkinson rods for tensile tests of thin sheet specimens; Patent CN202310983751.9 discloses a Hopkinson rod three-dimensional fabric composite material dynamic shear test device, which realizes shear tests on composite materials; Patent CN201911407398.X discloses a separate Hopkinson rod compression-torsion load composite loading device and its use method, which realizes the use of Hopkinson rods for compression-torsion composite loading tests; Patent CN202310701557.7 discloses a mold device for horizontal plate specimen impact forming experimental research used on a Hopkinson rod, which realizes impact forming experiments under high strain rates for difficult-to-deform plate materials. Therefore, the impact test on the plate specimen can be realized by making a Hopkinson bar fixture. At the same time, the fixture can be further designed and optimized according to the thickness of the specimen and the impact position.

[0004] In summary, it is necessary to design a Hopkinson bar fixture with adjustable impact position and clamping thickness of plate specimens. Summary of the Invention

[0005] Technical issues to be solved:

[0006] Existing Hopkinson bar devices are unable to perform impact tests on plate-like specimens. To overcome the shortcomings of the existing technology, the present invention proposes a Hopkinson bar fixture with adjustable impact position and clamping thickness for plate-like specimens. The fixture separates the base, L-shaped plate, and upper and lower clamping plates. By adjusting the impact position and clamping thickness in conjunction with each other, the Hopkinson bar can be used to perform impact tests on plate-like specimens of varying thicknesses at different impact positions. This fixture features a simple structure, wide applicability, and strong practicality.

[0007] The technical solution of the present invention is: a Hopkinson bar clamp with adjustable impact position and clamping thickness of a plate-shaped specimen, characterized by comprising a base, an L-shaped plate, a lower clamping plate and an upper clamping plate;

[0008] The base is used to fix the fixture on the Hopkinson bar slide and can cooperate with the L-shaped plate;

[0009] The side plates of the L-shaped plate are hollowed out in the middle to form a U-shaped structure, and reinforcement ribs are provided inside. Side through slots for up and down movement are provided on both sides of the U-shaped surface. A large through slot parallel to the side plates is provided in the middle of the bottom plate to avoid interference with the bolts fixing the base. Small through slots for left and right movement are provided on both sides of the large through slot, which are symmetrical to the large through slot.

[0010] The lower clamping plate and the upper clamping plate are flat plate structures with a rectangular impact area in the middle. Bolts pass through the threads of the upper clamping plate and the lower clamping plate to clamp the plate-shaped specimen; the lower clamping plate can cooperate with the L-shaped plate.

[0011] A further technical solution of the present invention is that the base is provided with a base light hole matched with the Hopkinson bar slide rail, and the upper surface is provided with six base threaded holes matched with the two small through grooves of the bottom flat plate of the L-shaped plate.

[0012] A further technical solution of the present invention is that the L-shaped plate as a whole is composed of a bottom plate, side plates and reinforcing ribs; the middle of the side plates is hollowed out to form a U-shaped structure, and the inner side of the reinforcing ribs coincides with the inner side of the U-shaped structure.

[0013] A further technical solution of the present invention is: a large through-slot parallel to the U-shaped flat plate is provided in the middle of the bottom flat plate of the L-shaped plate, and small through-slots cooperating with the threaded holes of the base are provided on both sides of the large through-slot, and bolts pass through the small through-slots and cooperate with the threaded holes of the base to fix the L-shaped plate to the base, and the two ends of the small through-slot and the threaded holes of the base are provided with a margin for left and right movement; the two ends of the large through-slot and the light hole of the base are provided with a margin for left and right movement.

[0014] A further technical solution of the present invention is: the middle of the side plate of the L-shaped plate is hollowed out to form a U-shaped structure, and side through grooves are provided on both sides of the U-shaped surface to cooperate with the countersunk threaded holes of the lower clamping plate; bolts pass through the side through grooves and cooperate with the countersunk threaded holes of the lower clamping plate to fix the lower clamping plate on the L-shaped plate, and the two ends of the side through grooves and the countersunk threaded holes of the lower clamping plate are provided with a margin for up and down movement.

[0015] A further technical solution of the present invention is that a groove is provided at the bottom of the reinforcing rib of the L-shaped plate, so that the bolts fixing the base to the Hopkinson bar slide rail are not interfered when moving left and right.

[0016] A further technical solution of the present invention is: a rectangular impact area is set in the middle of the lower splint, countersunk threaded holes are opened on the left and right sides to match the side grooves of the L-shaped plate, and two through-hole threaded holes are opened on the upper and lower sides respectively for fixing the test piece.

[0017] A further technical solution of the present invention is that pin holes for assisting in positioning the test piece are provided on the left, right and bottom of the rectangular impact area.

[0018] A further technical solution of the present invention is: an impact area identical to that of the lower splint is provided in the middle of the upper splint, and light holes are provided on the upper and lower sides to match the threaded holes of the lower splint, and bolts pass through the light holes to match the threaded holes of the lower splint to fix the specimen.

[0019] Beneficial effects

[0020] The beneficial effects of the present invention are as follows: the present invention adopts a method of separating the base, L-shaped plate, and upper and lower clamping plates, and realizes left and right movement through the cooperation of the threaded hole of the base and the small through groove of the L-shaped plate, and realizes up and down movement through the cooperation of the lower clamping plate and the through groove on the side of the L-shaped plate, which can make the specimen move in different directions, thereby realizing the adjustment of the impact position; the plate-shaped specimen is fixed by the cooperation between the upper and lower clamping plates, and the specimen is accurately positioned and pressed, which can meet the clamping needs of specimens of different thicknesses.

[0021] While achieving adjustment of the impact position and clamping thickness, the present invention further designs strength and interference. Reinforcing ribs are designed on the L-shaped plate to ensure the stability of the clamp when subjected to impact, and the affected area during movement is processed to avoid interference. The clamp has a simple structure and is easy to manufacture and use. At the same time, it enriches the types of Hopkinson bar tests, makes up for the vacancy that the Hopkinson bar cannot perform impact tests on plate-shaped specimens, and has strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the fixture provided in this embodiment;

[0023] Figure 2 A schematic diagram of the base provided in this embodiment;

[0024] Figure 3 Schematic diagram of the L-shaped plate provided in this embodiment;

[0025] Figure 4 A schematic diagram of the lower splint provided in this embodiment;

[0026] Figure 5 A schematic diagram of the upper splint provided in this embodiment;

[0027] Figure 6 Schematic diagram of the upper and lower clamps clamping the test piece provided in this embodiment;

[0028] Figure 7 A schematic diagram of an eccentric impact provided in this embodiment;

[0029] In the figure: base 1, base smooth hole 101, base threaded hole 102, L-shaped plate 2, bottom plate 201, side plate 202, reinforcing rib 203, large through slot 204, small through slot 205, side through slot 206, lower splint 3, countersunk threaded hole 301, through hole threaded hole 302, pin hole 303, upper splint 4. DETAILED DESCRIPTION

[0030] The embodiments described below with reference to the accompanying drawings are all exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0031] In the description of the present invention, it should be understood that terms such as "side", "bottom", "middle", "inside", "both sides", "up", "down", "left", "right", "two ends", and "bottom" indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operate in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0032] refer to Figure 1 As shown, the test fixture of the present invention consists of a base 1, an L-shaped plate 2, a lower clamping plate 3 and an upper clamping plate 4; the base 1 is used to fix the clamp on the Hopkinson bar slide rail and can cooperate with the L-shaped plate 2; the side plate 202 of the L-shaped plate 2 is hollowed out in the middle to form a U-shaped structure, and a reinforcing rib 203 is arranged inside, and side through grooves 206 for up and down movement are opened on both sides of the U-shaped surface, and a large through groove 204 parallel to the side plate 202 is arranged in the middle of the bottom plate 201 to avoid interference with the bolts fixing the base 1, and small through grooves 205 for left and right movement are opened on both sides of the large through groove 204 based on the large through groove 204; the lower clamping plate 3 and the upper clamping plate 4 are flat plate structures, and a rectangular impact area is arranged in the middle, and the bolts pass through the threads of the upper clamping plate 3 and the lower clamping plate 4 to clamp the plate-shaped specimen; the lower clamping plate 3 can cooperate with the L-shaped plate 2.

[0033] refer to Figure 2 As shown, the base 1 is provided with a base light hole 101 that cooperates with the Hopkinson bar slide rail, and the upper surface is provided with six base threaded holes 102 that cooperate with the two small through grooves 205 of the bottom plate 201 of the L-shaped plate.

[0034] refer to Figure 3As shown, the L-shaped plate 2 is composed of a bottom plate 201, a side plate 202 and a reinforcing rib 203; the middle of the side plate 202 is hollowed out to form a U-shaped structure, and the inner side of the reinforcing rib 203 coincides with the inner side of the U-shaped structure; a large through groove 204 parallel to the U-shaped plate is provided in the middle of the bottom plate 201 of the L-shaped plate 2, and small through grooves 205 that cooperate with the base threaded holes 102 are provided on both sides of the large through groove 204. Bolts pass through the small through grooves 205 and cooperate with the base threaded holes 102 to fix the L-shaped plate 2 on the base 1, and the two ends of the small through groove 205 and the base threaded holes 102 are provided with a margin for left and right movement; the large through groove 2 04, the two ends and the base light hole 101 are provided with a margin for left and right movement; the side flat plate 202 of the L-shaped plate 2 is hollowed out in the middle to form a U-shaped structure, and the two sides of the U-shaped surface are provided with side through grooves 206 that cooperate with the countersunk threaded holes 301 of the lower clamping plate 3; the bolts pass through the side through grooves 206 and cooperate with the countersunk threaded holes 301 of the lower clamping plate to fix the lower clamping plate 3 on the L-shaped plate 2, and the two ends of the side through grooves 206 and the lower clamping plate countersunk threaded holes 301 are provided with a margin for up and down movement; the bottom of the reinforcement rib 203 of the L-shaped plate 2 is provided with a groove, which can prevent the bolts fixing the base 1 on the Hopkinson bar slide rail from being interfered when moving left and right.

[0035] refer to Figure 4 As shown, a rectangular impact area is provided in the middle of the lower splint 3, and countersunk threaded holes 301 are provided on the left and right sides to cooperate with the side grooves 206 of the L-shaped plate, and two through-hole threaded holes 302 are provided on the upper and lower sides for fixing the specimen; pin holes 303 for assisting the positioning of the specimen are provided on the left, right and bottom of the rectangular impact area.

[0036] refer to Figure 5 As shown, the upper clamping plate 4 is provided with the same impact area as the lower clamping plate 3 in the middle, and light holes are opened on the upper and lower sides to match the threaded holes 302 of the lower clamping plate. Bolts pass through the light holes and match the threaded holes 302 of the lower clamping plate to fix the specimen.

[0037] Example:

[0038] The present invention discloses a Hopkinson bar clamp with adjustable impact position and clamping thickness for a plate-shaped specimen, comprising: a base 1 having a φ20 base aperture 101 and an M10 base threaded hole 102 for fixing the clamp on a Hopkinson bar slide rail and connecting the base 1 with an L-shaped plate 2; the L-shaped plate 2 comprising a bottom plate 201, side plates 202, and reinforcing ribs 203; the bottom plate 201 having a 20mm×240mm large through slot 204 and an 11mm×141mm small through slot 206; 05, used to avoid interference with the bolts of the fixed base 1 and to achieve left and right movement to meet the adjustment of the impact position of the test piece in the left and right directions; the side plate 202, which has an 11mm×61mm side through groove 206, is used to achieve up and down movement to meet the adjustment of the impact position of the test piece in the up and down directions; the reinforcing rib 203, which has a 40mm×10mm groove, is used to strengthen the stability of the fixture and avoid interference with the bolts of the fixed base 1; the lower clamping plate 3, which has an M10 countersunk thread Hole 301 and M10 through-hole threaded hole 302 are used to connect the lower clamping plate 3 with the L-shaped plate 2 and the lower clamping plate 3 with the upper clamping plate 4; the upper clamping plate 4 has a φ11 light hole on it, which is used to cooperate with the through-hole threaded hole 302 of the lower clamping plate and the M10×120mm bolt to clamp the specimen to meet the clamping thickness of the adjusted specimen; and there are pin holes 303 on the left and right and bottom of the lower clamping plate 3 for auxiliary positioning of 180mm×120mm and 150mm×100mm specimens; the lower clamping plate 3 and the upper clamping plate are provided with a plurality of holes 301 and 302 respectively. There is a 125mm×75mm rectangular impact area in the center of each of the four parts; the base light hole 101 requires an M16×60mm bolt to cooperate with the threaded hole on the Hopkinson bar slide rail, and the base threaded hole 102 requires an M10×40mm bolt to pass through the small through slot 205 for cooperation; the lower splint countersunk threaded hole 301 requires an M10×30mm bolt to pass through the side through slot 206 for cooperation; the lower splint through hole threaded hole 302 requires an M10×120mm bolt to pass through the upper splint light hole for cooperation.

[0039] The following describes how to use the fixture by briefly describing impact tests on 180mm×120mm specimens at the center, eccentric positions, and specimens of different thicknesses.

[0040] 1. Center impact

[0041] 1.1. Place base 1 on the Hopkinson bar slide with the side without rounded corners facing the impact head. Align the base's smooth hole 101 with the threaded hole on the slide and tighten using M16×60mm bolts.

[0042] 1.2. Place L-shaped plate 2 on base 1, with bottom plate 201 aligned with the side of base 1, and then tighten using M10×40mm bolts.

[0043] 1.3. Place the specimen on lower clamping plate 3 and position it using the 180 mm × 120 mm pin hole. Position it by using a pin shorter than the specimen thickness to press against the side of the specimen. Align the open hole in upper clamping plate 4 with the threaded hole 302 in the lower clamping plate and tighten it using an M10 × 120 mm bolt.

[0044] 1.4. Place the lower clamping plate 3, which has secured the specimen, on the side plate 202 of the L-shaped plate, so that the upper surface of the lower clamping plate coincides with the upper surface of the side plate. Tighten it using M10×30mm bolts. At this point, the countersunk bolt hole 301 is exactly at the midpoint of the side slot 206, and the impact rod is facing the center of the specimen. Start the test.

[0045] 2. Eccentric impact

[0046] Based on step 1, perform eccentric impact through the following operations:

[0047] 2.1. Loosen the M10 x 40 mm bolts that pass through the bottom plate 201 of the L-shaped plate and mate with the threaded holes 102 of the base. Then move the L-shaped plate 2 65 mm to the right.

[0048] 2.2. Loosen the M10×30mm bolt that passes through the side slot 206 and fits into the countersunk threaded hole 301 of the lower clamping plate, and then move the lower clamping plate 3 upward by 25mm. At this time, the impact position of the impact rod is (65, 25).

[0049] 3. Impact of specimens of different thicknesses

[0050] Based on 1, the impact of specimens with different thicknesses is carried out through the following operations:

[0051] 3.1. Loosen the M10 × 120 mm bolts that pass through the smooth hole 4 in the upper clamping plate and fit into the threaded hole 302 in the lower clamping plate to increase the distance between the upper and lower clamping plates. Replace the test piece and retighten the bolts; begin the test.

[0052] As can be seen from the above example, by adjusting the relative positions of the base 1, L-shaped plate 2, lower clamping plate 3, and upper clamping plate 4, a Hopkinson bar impact test with adjustable impact position and clamping thickness of the plate specimen can be achieved. The test process is simple to operate and has high feasibility.

[0053] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limiting the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the present invention without departing from the principles and purpose of the present invention.

Claims

1. A Hopkinson bar clamp with adjustable impact position and clamping thickness for a plate-shaped specimen, characterized by: It comprises a base (1), an L-shaped plate (2), a lower clamping plate (3) and an upper clamping plate (4); The base (1) is used to fix the clamp on the Hopkinson bar slide rail and can cooperate with the L-shaped plate (2); The side plate (202) of the L-shaped plate (2) is hollowed out in the middle to form a U-shaped structure, and a reinforcing rib (203) is provided inside. Side through grooves (206) for upward and downward movement are provided on both sides of the U-shaped surface. A large through groove (204) parallel to the side plate (202) is provided in the middle of the bottom plate (201) to avoid interference with the bolts fixing the base (1). Small through grooves (205) for left and right movement are provided on both sides of the large through groove (204) and are symmetrical to the large through groove (204). The lower clamping plate (3) and the upper clamping plate (4) are flat plate structures with a rectangular impact area set in the middle. Bolts pass through the threads of the upper clamping plate (4) and the lower clamping plate (3) to clamp the plate-shaped test piece; the lower clamping plate (3) can cooperate with the L-shaped plate (2).

2. The Hopkinson bar clamp with adjustable impact position and clamping thickness for plate-shaped specimens according to claim 1, characterized in that: The base (1) is provided with a base light hole (101) that matches the Hopkinson rod slide rail, and the upper surface is provided with six base threaded holes (102) that match the two small through grooves (205) of the L-shaped plate bottom surface flat plate (201).

3. The Hopkinson bar clamp with adjustable impact position and clamping thickness for plate-shaped specimens according to claim 1, characterized in that: The L-shaped plate (2) as a whole is composed of a bottom plate (201), a side plate (202) and a reinforcing rib (203); the middle of the side plate (202) is hollowed out to form a U-shaped structure, and the inner side of the reinforcing rib (203) coincides with the inner side of the U-shaped structure.

4. The Hopkinson bar clamp with adjustable impact position and clamping thickness for plate-shaped specimens according to claim 3, characterized in that: A large through slot (204) parallel to the U-shaped flat plate is provided in the middle of the bottom flat plate (201) of the L-shaped plate (2); small through slots (205) cooperating with the base threaded hole (102) are provided on both sides of the large through slot (204); bolts pass through the small through slots (205) and cooperate with the base threaded hole (102) to fix the L-shaped plate (2) on the base (1); two ends of the small through slot (205) and the base threaded hole (102) are provided with a margin for left and right movement; two ends of the large through slot (204) and the base light hole (101) are provided with a margin for left and right movement.

5. The Hopkinson bar clamp with adjustable impact position and clamping thickness for plate-shaped specimens according to claim 3, characterized in that: The middle of the side plate (202) of the L-shaped plate (2) is hollowed out to form a U-shaped structure, and side through grooves (206) are provided on both sides of the U-shaped surface to cooperate with the countersunk threaded holes (301) of the lower clamping plate (3); bolts pass through the side through grooves (206) and cooperate with the countersunk threaded holes (301) of the lower clamping plate to fix the lower clamping plate (3) on the L-shaped plate (2), and the two ends of the side through grooves (206) and the countersunk threaded holes (301) of the lower clamping plate are provided with margins for upward and downward movement.

6. The Hopkinson bar clamp with adjustable impact position and clamping thickness for plate-shaped specimens according to claim 3, characterized in that: The bottom of the reinforcing rib (203) of the L-shaped plate (2) is provided with a groove, which enables the bolts fixing the base (1) to the Hopkinson bar slide rail to move left and right without interference.

7. The Hopkinson bar clamp with adjustable impact position and clamping thickness for plate-shaped specimens according to claim 1, characterized in that: A rectangular impact area is provided in the middle of the lower clamping plate (3), and countersunk threaded holes (301) are provided on the left and right sides to match the through grooves (206) on the side of the L-shaped plate, and two through-hole threaded holes (302) are provided on the upper and lower sides respectively for fixing the test piece.

8. The Hopkinson bar clamp with adjustable impact position and clamping thickness for plate-shaped specimens according to claim 7, characterized in that: Pin holes (303) for assisting the positioning of the test piece are provided on the left, right and bottom of the rectangular impact area.

9. The Hopkinson bar clamp with adjustable impact position and clamping thickness for plate-shaped specimens according to claim 1, characterized in that: The upper clamping plate (4) is provided with an impact area in the middle that is the same as the lower clamping plate (3), and light holes are provided on the upper and lower sides to match the threaded holes (302) of the lower clamping plate through holes. Bolts pass through the light holes and match the threaded holes (302) of the lower clamping plate through holes to fix the specimen.

Images