CN114112737B - A drop hammer impact fixture with variable sample size, variable impact point and variable boundary conditions - Google Patents

Abstract

The present invention is a drop hammer impact fixture with variable sample size, variable impact point and variable boundary conditions, which belongs to the field of impact test fixtures; it includes an upper seat, a position slider, a boundary slider, a T-shaped slider, a pillar and a base; four The upper seat is fixed directly above the base through pillars, and is located at the four corners of the space rectangle; the base is used to connect the drop weight impact testing machine; the upper seat is provided with guide rails along the horizontal direction on the two adjacent sides on the inner side; The four position sliders are respectively installed on the guide rails of the four upper seats through the slide rails to form the sides of the space rectangle; the four boundary sliders are respectively installed on the guide rails of the four position sliders through the slide rails; the T-shaped sliders are installed on the boundary In the T-shaped guide rail of the slider, it can slide in the T-shaped guide rail. There is a threaded hole on the top, which cooperates with the bolt to press and position the edge of the sample. The invention can realize the impact of samples of the same size under the same position and different boundary conditions and the impact of different positions and different boundary conditions.

Description

A drop hammer impact fixture with variable sample size, variable impact point and variable boundary conditions

technical field

The invention belongs to the field of impact test fixtures, in particular to a dropping weight impact fixture with variable sample size, variable impact point and variable boundary conditions.

Background technique

Composite materials have been widely used in the fields of aviation, aerospace, ships and automobiles because of their excellent performance. In actual use, composite laminates and composite sandwich structures are easily damaged under low-velocity impact loads. In order to evaluate the impact resistance of composite laminates and composite sandwich structures, study the impact response of structures and materials under different low-speed impact loads and determine their damage tolerance, drop weight impact tests are usually required.

The current impact test fixtures are usually designed according to the standard sample size (150mm×100mm) stipulated in ASTM D7136 and other standards. When the sample size changes, different positions need to be impacted, or impact tests need to be performed under different boundary conditions, the fixtures are often unusable. . In response to the above problems, researchers have continuously improved the fixture. For example: Invention patent CN112504824A discloses an impact-resistant fixture for composite laminates with variable thickness. A non-single impact point impact test fixture realizes the impact of different positions of the sample, but it cannot be used for impact tests of different size samples and different boundary conditions; the invention CN110864981A discloses a modular non-single impact position The point impact fixture realizes the variable impact point impact and can impact samples of different sizes at the same time, but its size changing function must be realized by customizing the support plate 7, that is, samples of different sizes need to customize different support plates 7, which undoubtedly increases The test cost is reduced, and the boundary conditions of the impact cannot be changed.

To sum up, it is necessary to design a drop weight impact test fixture with variable sample size, variable impact position and variable boundary conditions, which is economical and practical.

Contents of the invention

Technical problem to be solved:

The existing drop weight impact fixtures for composite laminates and sandwich structures have fixed dimensions, which cannot be applied to the impact of composite laminates and sandwich structures of different sizes, resulting in difficulty in sample preparation and waste of materials. In order to avoid the deficiencies of the prior art, the present invention proposes a drop hammer impact fixture with variable sample size, variable impact point and variable boundary conditions. Position sliders and boundary sliders are set in the X and Y directions. By adjusting The position of the two sliders and the clamping position of the sample can realize the impact of the same size sample at the same position and different boundary conditions and the impact of different positions and different boundary conditions; the manufacturing cost is low, the application range is wide, and it is practical Strong.

The technical solution of the present invention is: a drop hammer impact fixture with variable sample size, variable impact point and variable boundary conditions, which is characterized in that it includes an upper seat, a position slider, a boundary slider, a T-shaped slider 7, and a pillar 9 and the base 10; the four upper seats are respectively fixed directly above the base through pillars to form a rectangular space, and are located at the four corners of the rectangular space; the base is used to connect to the drop weight impact testing machine;

The upper seat is a cuboid structure, the two adjacent sides on the outside coincide with the right-angled sides of the space rectangle, and the two adjacent sides on the inside are provided with guide rails along the horizontal direction;

The position slider is a flat plate structure, both ends of which are slide rail structures that cooperate with the guide rails of the upper base, and can slide horizontally along the guide rails of the adjacent upper base; the four position sliders are respectively installed on the guide rails of the four upper bases through the slide rails On the side of the space rectangle; there is a guide rail along the horizontal direction on the inner wall surface of the position slider;

The boundary slider is a flat plate structure, one end of which is a slide rail structure matched with the guide rail of the position slider, and can slide horizontally along the guide rail of the position slider; the four boundary sliders are respectively installed on the four position sliders through the slide rails On the guide rail; there is a T-shaped guide rail on the upper end of the boundary slider, and the T-shaped guide rail is perpendicular to the sliding direction of the boundary slider;

The T-shaped slider is installed in the T-shaped guide rail of the boundary slider, and can slide in the T-shaped guide rail. There are threaded holes on the top, and cooperate with bolts to press and position the edge of the sample.

A further technical solution of the present invention is: the upper seat includes a first upper seat and a second upper seat, the two first upper seats are arranged diagonally, and the two second upper seats are arranged diagonally; one side guide rail of the first upper seat is Through groove structure, the inner end of the guide rail on the other side is closed; the second upper seat and the first upper seat are symmetrical structures.

A further technical solution of the present invention is: the first upper seat is provided with a scale on the upper surface of the through-slot guide rail, and the second upper seat is provided with a scale on the upper surface of the guide rail whose inner end is closed.

A further technical solution of the present invention is: the position slider includes a Y-direction position slider 3 and an X-direction position slider 4, and the two Y-direction position sliders are symmetrically arranged on two opposite sides of the space rectangle, and the two X The position slider 4 is symmetrically arranged on the other two opposite sides of the space rectangle; the Y direction position slider 3 slides along the upper seat to the Y direction of the space rectangle, and the X direction position slider 4 slides along the upper seat to the space rectangle. the X direction.

A further technical solution of the present invention is: scales are provided on the upper surfaces of the guide rails of the Y-direction position slider 3 and the X-direction position slider 4 .

A further technical solution of the present invention is: the boundary slider includes an X-directional boundary slider 5 and a Y-directional boundary slider 6, the slide rails of the two X-directional boundary sliders 5 are respectively connected with the two Y-directional position sliders 3 The guide rails are installed in cooperation, and the slide rails of the two Y-direction boundary sliders 6 are respectively installed with the guide rails of the two X-direction position sliders 4; the X-direction boundary slider 5 slides in the X direction along the long space, and the Y-direction boundary slides Block 6 slides along the Y direction of the spatial rectangular row.

A further technical solution of the present invention is: a scale is provided on the upper surface of the T-shaped guide rail of the boundary slider.

A further technical solution of the present invention is: the upper surface of the upper seat and the position slider are provided with threaded holes on the upper surface of the guide rail. Press the positioning.

A further technical solution of the present invention is: the screws are M4 screws.

Beneficial effect

The beneficial effect of the present invention is that: the present invention adopts four upper seats and four position sliders to form a rectangular space structure, and the four position sliders slide along the X and Y directions with respect to the guide rails of the upper seat through the slide rail structures at both ends respectively, which can satisfy Clamping of samples of any size; four boundary sliders are respectively installed inside the four position sliders, which can slide along the X and Y directions relative to the position sliders, and different positions can be realized under the condition of ensuring the same boundary conditions Impact: T-shaped sliders are installed in the T-shaped guide rails of the boundary sliders, and the samples are accurately positioned and pressed through the screws installed on the T-shaped sliders, and can meet the clamping of samples of different thicknesses.

In the present invention, a position slider and a boundary slider are respectively arranged in the X and Y directions, and by adjusting the positions of the two sliders and the clamping position of the sample, the impact of the same size sample under the same position and different boundary conditions can be realized. and impacts at different positions and under different boundary conditions; the fixture has a simple structure, is easy to manufacture and use, can reduce the number of samples and reduce the difficulty of sample preparation, and at the same time enriches the types of drop weight impact tests, which has strong practicability.

In the embodiment, the clamping of samples of any size within the range of 75mm×50mm-255mm×250mm can be satisfied.

Description of drawings

Figure 1 is an isometric view of the fixture;

Fig. 2 is a schematic structural view of the first upper seat 1;

Fig. 3 is a schematic structural view of the Y-direction position slider 3;

Fig. 4 is a schematic structural view of the X-boundary slider 5;

Fig. 5 is the structural representation of T-shaped slide block 7;

Figure 6 is a schematic diagram of impacts at different positions with the same boundary conditions;

Fig. 7 is a schematic diagram of impact at the same position with different boundary conditions;

Fig. 8 is a schematic diagram of impacts at different positions with different boundary conditions.

Explanation of reference signs: 1-the first upper seat, 2-the second upper seat, 3-Y-direction position slider, 4-X-direction position slider, 5-X-direction boundary slider, 6-Y-direction boundary slider, 7 -T-slider, 8-M4 screw, 9-pillar, 10-base, 11-M10 screw.

Detailed ways

The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Orientation indicated by rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc. The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as limiting the invention.

Referring to Fig. 1, the test fixture of the present invention consists of a first upper seat 1, a second upper seat 2, a Y-direction position slider 3, an X-direction position slider 4, an X-direction boundary slider 5, a Y-direction boundary slider 6, T Type slider 7, positioning compression screw 8, pillar 9, base 10 and M10 screw 11. The four upper seats are respectively fixed directly above the base 10 through the pillars 9 to form a rectangular space, and are respectively located at the four corners of the rectangular space; the base 10 is used to connect the drop weight impact testing machine;

As shown in Fig. 2, the upper seat is a cuboid structure, two adjacent sides on the outside coincide with the right-angled sides of the space rectangle, and two adjacent side surfaces on the inner side are provided with guide rails along the horizontal direction; the upper seat includes the first upper seat 1 and The second upper seat 2, the two first upper seats 1 are arranged diagonally, and the two second upper seats 2 are arranged diagonally; the guide rail on one side of the first upper seat 1 is a through-slot structure, and the inner end of the guide rail on the other side is closed; and A scale is arranged on the upper surface of the through-slot guide rail; the second upper seat 2 and the first upper seat 1 have a symmetrical structure, and a scale is arranged on the upper surface of the guide rail whose inner end is closed.

Referring to Figure 3, the position slider is a flat plate structure, both ends of which are slide rail structures that cooperate with the guide rails of the upper seat, and can slide horizontally along the guide rails of the adjacent upper seat; the four position sliders are respectively installed through the slide rails On the guide rails of the four upper seats, the sides of the rectangular space are formed; there are guide rails along the horizontal direction on the inner wall surface of the position slider; the position slider includes a Y-direction position slider 3 and an X-direction position slider 4, two Y The position sliders 4 are symmetrically arranged on two opposite sides of the space rectangle, and the two X direction position sliders 4 are symmetrically arranged on the other two opposite sides of the space rectangle; the Y direction position slider 3 slides along the direction of the upper seat. In the Y direction of the rectangle, the direction in which the position slide block 4 slides along the upper seat in the X direction is the X direction of the space rectangle. Both the upper surfaces of the guide rails of the Y-direction position slider 3 and the X-direction position slider 4 are provided with scales.

Referring to Fig. 4, the boundary slider is a flat plate structure, one end of which is a slide rail structure that cooperates with the guide rail of the position slider, and can slide horizontally along the guide rail of the position slider; the four boundary sliders are respectively installed through the slide rails On the guide rails of the four position sliders; there is a T-shaped guide rail on the upper end of the boundary slider, and the T-shaped guide rail is perpendicular to the sliding direction of the boundary slider; the boundary slider includes X-direction boundary slider 5 and Y-direction The boundary slider 6, the slide rails of the two X-direction boundary sliders 5 are respectively installed with the guide rails of the two Y-direction position sliders 3, and the slide rails of the two Y-direction boundary sliders 6 are respectively connected with the two X-direction position slides. The guide rails of the block 4 are installed in cooperation; the X-boundary slider 5 slides along the X direction of the space rectangular row, and the Y-boundary slider 6 slides along the Y direction of the space rectangular row. A ruler is provided on the upper surface of the T-shaped guide rail of the boundary slider.

Referring to Fig. 5, the T-shaped slider 7 is installed in the T-shaped guide rail of the boundary slider, and can slide in the T-shaped guide rail. There are threaded holes on the top, and cooperate with bolts to press and position the edge of the sample.

Both the upper seat and the position slider have threaded holes on the upper surface of the guide rail. When the position of the sample is determined, the position slider and the boundary slider are pressed and positioned through the cooperation of the screw and the threaded hole.

Example:

A drop hammer impact fixture with variable size, variable thickness, and variable impact point according to the present invention includes: the first upper base 1, on which there are 75mm×15mm×10mm guide rails, 65mm×15mm×10mm guide rails, 70mm scales, and M4 threaded holes and M10 threaded holes are used to provide support, guidance and positioning for the Y-direction position slider 3 and the X-direction position slider 4; the second upper seat 2 has a 75mm×15mm×10mm guide rail, a 65mm×15mm×10mm guide rail, 60mm scale, M4 threaded hole and M10 threaded hole, used to provide support, guidance and positioning for Y-direction position slider 3 and X-direction position slider 4; Y-direction position slider 3 has a 65mm×15mm×10mm slider Rail, 130mm×5mm×65mm guide rail, 30mm bidirectional scale and M4 threaded hole, used to cooperate with the first upper seat 1 and the second upper seat 2 to slide along the Y direction and provide support, guidance and positioning for the X-direction boundary slider 5, so that Meet the Y-direction size of the sample and adjust the impact position; X-direction position slider 4, on which there are 75mm×15mm×10mm slide rails, 115mm×5mm×75mm guide rails, 20mm bidirectional scales and M4 threaded holes for use with 1 and 2 Cooperate with sliding along the X direction and provide support, guidance and positioning for 6, so as to meet the size of the sample in the X direction and adjust the impact position; X-direction boundary slider 5, on which there are 70mm×10mm×5mm slide rails, T-shaped guide rails and 50mm The scale is used to cooperate with the Y-direction position slider 3 to move along the X direction, and at the same time provide support, guidance and positioning for the T-shaped slider 7, so as to meet the impact of different sizes of samples and different positions; the Y-direction boundary slider, its There are 75mm×10mm×5mm slide rails, T-shaped guide rails and 30mm scales, which are used to cooperate with the X-direction position slider 4 to move along the Y direction, and provide support, guidance and positioning for the T-type slider 7 to meet different sizes. Impact of the sample and different positions; T-shaped slider 7, with M4 threaded holes on it, for sample positioning; M4 screw 8, for positioning and compressing the sample; pillar 9, for supporting the workbench; base 10, for connecting the drop weight impact testing machine.

Since the position of the punch remains unchanged during the impact process, the center of the hemispherical surface of the punch is taken as the origin in the schematic diagram, and the positive directions of X and Y are shown in Figure 1 to establish a coordinate system. The following introduces the use of the fixture by briefly describing three different impact tests of 125mm×90m×10mm samples.

1. Impact at different positions under the same boundary conditions

1.1. The distance between the edge of the sample and the edge of 5 and 6 is 2.5mm, and the impact position is (0, 0)

Move 4 on both sides so that its edge is flush with the 25mm scale line on the scale of 2 and tighten the set screw 8; move 3 on both sides so that its edge is flush with the 20mm scale line on the scale of 1 and tighten the set screw 8; move 5 And 7 and 8 on 6, make the axis of 8 parallel to the 0 scale line of scale 5 and 6, rotate 8 to position and compress the sample; start the test.

1.2. The distance between the edge of the sample and the edge of 5 and 6 is 2.5mm, and the impact position is (-20, 20)

After test 1.1, operate as follows: move 4 and 5 on both sides 20mm along the positive direction of the X axis; move 3 and 6 on both sides 20mm along the negative direction of the Y axis; turn 8 on 7 to compress the pattern and start the test.

2. Impact at the same position with different boundary conditions

2.1. The distance between the edge of the sample and the edge of 5 and 6 is 22.5mm, and the impact position is (0, 0)

After the end of 1.1, test 2.1 by the following operations: move the 0 scale on both sides of the 3 to 2 scale; move 5mm on the 4 to 1 scale on both sides; move 7 and 8 on 5 and 6 respectively to make the axis of 8 It is flush with the 20mm engraved line on the ruler; press the sample to start the test.

3. Different boundary conditions and different positions impact

After test 1.2, carry out test 2.1 through the following operations: move the 0 reticle on the 3 to 2 scale on both sides; move the 4 to 1 scale on both sides by 5mm; move the 5 on both sides so that its edge is level with the 0 reticle on 3 Align; move 6 on both sides to make its edge flush with the 0 reticle on 4; move 7 and 8 on 5 and 6 respectively, so that the axis of 8 is flush with the 20mm reticle on the scale; press the sample to start the test.

It can be seen from the above examples that by adjusting the relative positions of 1, 2, 3, 4, 5, 6, and 7, the drop weight impact test with variable sample size, variable impact position and variable boundary conditions can be realized. The experimental process is easy to operate and feasible. high.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations to the present invention. Variations, modifications, substitutions, and modifications to the above-described embodiments are possible within the scope of the present invention.

Claims (9)

1. A drop hammer impact fixture with variable sample size, variable impact point and variable boundary conditions, which is characterized in that: comprises an upper seat, a position slide block, a boundary slide block, a T-shaped slide block (7), a support column (9) and a base (10); the four upper seats are respectively fixed right above the base through the support posts to form a space rectangle and are respectively positioned at four corners of the space rectangle; the base (10) is used for being connected with a drop hammer impact tester;

the upper seat is of a cuboid structure, two adjacent side surfaces on the outer side of the upper seat are overlapped with right-angle sides of the space rectangle, and guide rails are arranged on two adjacent side surfaces on the inner side along the horizontal direction;

the sliding blocks are of flat plate structures, and two ends of the sliding blocks are of sliding rail structures matched with the guide rails of the upper seats and can horizontally slide along the guide rails of the adjacent upper seats; the four position sliding blocks are respectively arranged on the guide rails of the four upper seats through sliding rails to form sides of a space rectangle; the inner side wall surface of the position slide block is provided with a guide rail along the horizontal direction;

the boundary sliding block is of a flat plate structure, one end of the boundary sliding block is of a sliding rail structure matched with the guide rail of the position sliding block, and the boundary sliding block can horizontally slide along the guide rail of the position sliding block; the four boundary sliding blocks are respectively arranged on the guide rails of the four position sliding blocks through sliding rails; the upper end face of the boundary sliding block is provided with a T-shaped guide rail which is perpendicular to the sliding direction of the boundary sliding block;

the T-shaped sliding block is arranged in a T-shaped guide rail of the boundary sliding block and can slide in the T-shaped guide rail, a threaded hole is formed in the top of the T-shaped sliding block, and the T-shaped sliding block is matched with a bolt to compress and position the edge of a sample.

2. The drop hammer impact fixture of varying specimen size, varying impact point and varying boundary conditions as set forth in claim 1 wherein: the upper seats comprise a first upper seat (1) and a second upper seat (2), wherein the two first upper seats (1) are arranged in a pair angle manner, and the two second upper seats (2) are arranged in a pair angle manner; the guide rail on one side of the first upper seat is of a through groove structure, and the inner end of the guide rail on the other side is closed; the second upper seat (2) and the first upper seat (1) are of symmetrical structures.

3. The drop hammer impact fixture of varying specimen size, varying impact point and varying boundary conditions as set forth in claim 2 wherein: the first upper seat (1) is provided with a scale on the upper surface of the through groove guide rail, and the second upper seat (2) is provided with a scale on the upper surface of the guide rail with the inner end closed.

4. The drop hammer impact fixture of varying specimen size, varying impact point and varying boundary conditions as set forth in claim 1 wherein: the position sliding blocks comprise Y-position sliding blocks (3) and X-position sliding blocks (4), the two Y-position sliding blocks are symmetrically arranged on two opposite sides of the space rectangle, and the two X-position sliding blocks (4) are symmetrically arranged on the other two opposite sides of the space rectangle; the sliding direction of the Y-position sliding block (3) along the upper seat is the Y direction of the space rectangle, and the sliding direction of the X-position sliding block (4) along the upper seat is the X direction of the space rectangle.

5. The drop hammer impact fixture of varying specimen size, varying impact point and varying boundary conditions as set forth in claim 4, wherein: the upper surfaces of the guide rails of the Y-position sliding block (3) and the X-position sliding block (4) are respectively provided with a scale.

6. The drop hammer impact fixture of varying specimen size, varying impact point and varying boundary conditions as set forth in claim 1 wherein: the boundary sliding blocks comprise X-direction boundary sliding blocks (5) and Y-direction boundary sliding blocks (6), sliding rails of the two X-direction boundary sliding blocks (5) are respectively matched with guide rails of the two Y-position sliding blocks (3), and sliding rails of the two Y-direction boundary sliding blocks (6) are respectively matched with guide rails of the two X-position sliding blocks (4); the X-direction boundary slide block (5) slides along the X direction of the space rectangular row, and the Y-direction boundary slide block (6) slides along the Y direction of the space rectangular row.

7. The drop hammer impact fixture of varying sample size, varying impact point and varying boundary conditions as defined in claim 6, wherein: and a scale is arranged on the surface above the T-shaped guide rail of the boundary sliding block.

8. The drop hammer impact fixture of varying specimen size, varying impact point and varying boundary conditions as set forth in claim 1 wherein: the upper seat and the position slide block are respectively provided with a threaded hole on the surface above the guide rail, and after the position of the sample is determined, the position slide block and the boundary slide block are pressed and positioned through the matched installation of the screw and the threaded holes.

9. The drop hammer impact fixture of varying sample size, varying impact point and varying boundary conditions as set forth in claim 8, wherein: the screw is an M4 screw.