CN107907293B - Impact clamp for test - Google Patents

Abstract

An impact jig for testing relates to an impact testing device. The present invention solves the problem that the existing impact clamp cannot provide a curved structure clamping boundary. The invention includes a fixed base, an impact platform, an upper cover plate, two lower positioning plates and a plurality of uprights. The impact platform is arranged in parallel directly above the fixed base. A lower rectangular through hole is arranged in the middle of the platform, and a lower positioning plate is respectively fixed on both sides of the upper end of the lower rectangular through hole. The middle part of the lower end surface of the upper cover plate is provided with a circular arc groove, the middle part of the upper end surface of the upper cover plate is provided with an upper rectangular through hole, the lower positioning plate is arranged in the circular arc groove, and the circular arc groove and the lower positioning plate are formed. The arc surfaces are respectively in contact with the upper and lower arc surfaces of the surface shell to be measured. The present invention is used for impact testing.

Description

An impact jig for testing

technical field

The invention relates to an impact test device, in particular to an impact fixture for testing.

Background technique

At present, the impact clamp is the plane structure impact standard proposed by ASTM D7136/D7136-12. However, for the high-rigidity and high-strength composite plane structure subjected to medium and high-speed impact, the elbow clamps at the four corners cannot provide effective support boundaries and The constraint force cannot be measured, and it is impossible to effectively constrain the surface shell and the surface sandwich structure. Therefore, it is particularly urgent to improve the clamping effect of the composite material plane structure and the effective restraint of the curved surface structure.

SUMMARY OF THE INVENTION

In order to solve the problem that the existing impact fixture cannot provide a curved surface structural support boundary and the test cost is too high, the present invention further proposes an impact fixture for testing.

The technical scheme that the present invention takes for solving the above-mentioned technical problems is:

An impact fixture for testing includes a fixed base, an impact platform, an upper cover plate, two lower positioning plates and a plurality of vertical columns, the impact platform is arranged in parallel directly above the fixed base, and the impact platform passes through the plurality of vertical columns and the upper end surface of the fixed base Fixed connection, a lower rectangular through hole is arranged in the middle of the impact platform, and a lower positioning plate is respectively fixed on both sides of the upper end of the lower rectangular through hole. The upper end surface of the lower positioning plate is an arc surface, and the upper end surface of the impact platform is fixed The upper cover plate is connected, the middle part of the lower end surface of the upper cover plate is provided with a circular arc groove, the middle part of the end surface of the upper cover plate is provided with an upper rectangular through hole, the lower positioning plate is arranged in the circular arc groove, and the circular arc groove and The arc surfaces of the lower positioning plate are respectively in contact with the upper and lower arc surfaces of the curved surface shell to be measured.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention provides an impact fixture that can not only test the impact of a plane structure, but also test a curved shell and a curved sandwich structure, and can also perform impact testing on test pieces such as corrugated plates by changing the shape and size of the positioning plate 3 and the cover plate 4. Has good universality. The fixture can provide a solid support boundary for the specimen in the impact test, and its clamping force can be obtained by converting the bolt pre-tightening force measured by the torque wrench and the gravity of the cover plate, and can provide at least 25 standard atmospheric pressure and The error is reduced by at least 53%; at the same time, it has good versatility, and can be used for impact tests on plane structures, curved shells and curved sandwich structures, and different curvature surfaces can be performed by adjusting the size of the positioning plate 3 or washer 7 under the accessories. The impact test of shell and curved sandwich structure has simple structure, convenient operation and low test cost. Compared with processing a complete set of experimental fixtures, the detachable fixture processing small parts can effectively shorten the processing time and reduce the fixture processing cost by at least 90%.

Description of drawings

Fig. 1 is the axonometric view of the overall structure of the present invention;

Fig. 2 is the right side view of Fig. 1;

Fig. 3 is the front view of the upper cover plate 4 in the present invention;

Fig. 4 is the right side view of Fig. 3;

Fig. 5 is the front view of impact platform 2 in the present invention;

6 is a front view of the lower positioning plate 3 in the present invention;

FIG. 7 is a front view of the arc-shaped gasket 7 in the present invention.

Detailed ways

Embodiment 1: This embodiment is described with reference to FIGS. 1 to 7 . An impact fixture for testing described in this embodiment includes a fixed base 1 , an impact platform 2 , an upper cover plate 4 , two lower positioning plates 3 and a plurality of Column 5, the impact platform 2 is arranged in parallel directly above the fixed base 1, the impact platform 2 is fixedly connected with the upper end surface of the fixed base 1 through a plurality of columns 5, the middle of the impact platform 2 is provided with a lower rectangular through hole 2-1, the lower Two sides of the upper end of the rectangular through hole 2-1 are respectively fixed with a lower positioning plate 3, the upper end surface of the lower positioning plate 3 is an arc surface, and an upper cover plate 4 is fixed on the upper end surface of the impact platform 2. The middle part of the lower end surface of the plate 4 is provided with an arc groove 4-2, the middle part of the upper end surface of the upper cover plate 4 is provided with an upper rectangular through hole 4-1, and the lower positioning plate 3 is arranged in the arc groove 4-2. The arc grooves 4-2 and the arc surfaces of the lower positioning plate 3 are respectively in contact with the upper and lower arc surfaces of the curved surface shell to be measured.

In this embodiment, the fixed base 1 is provided with four through holes for fixing the fixed base 1 on the testing machine, and the dimensions of the uprights 5 are exactly the same to ensure that the impact platform 2 remains in a horizontal state after being assembled.

In this embodiment, the number of the plurality of uprights 5 is four.

The opening size of the lower rectangular through hole 2-1 in the middle of the impact platform 2 conforms to ASTM D7136/D7136-12, and the arc surface of the lower positioning plate 4 can be processed by itself according to the inner arc radius of the test piece, which has strong versatility. During positioning, the composite material sandwich shell test piece is completely attached to the arc surface of the lower positioning plate 4 after being placed, providing it with a clamping surface on the lower side, and the arc groove 4-2 at the lower end of the upper cover plate 4 corresponds to the composite The outer arc of the material sandwich shell is the clamping surface of the upper clamping boundary of the specimen. The gravity of the upper cover 4 and its screw connection with the impact platform 2 provide the clamping force of the clamping boundary of the specimen. The binding force is obtained by converting the bolt pre-tightening force measured by the wrench and the dead weight of the cover plate. When in use, the upper cover plate 4 can be turned over so that the upper end face faces downward, and the lower positioning plate 3 on the impact platform 2 can be removed at the same time, which is used to test the impact performance of the composite material sandwich plane structure, which has a wide range of general characteristics. suitability.

Embodiment 2: This embodiment is described with reference to FIGS. 1 to 2 and 5 to 6. The lower positioning plates 3 in this embodiment are arranged on both sides of the lower rectangular through hole 2-1 in the length direction, and each lower positioning plate 3 The plates 3 are respectively arranged in the width direction. Other compositions and connection methods are the same as those in the first embodiment.

Embodiment 3: This embodiment will be described with reference to FIG. 1 to FIG. 4 and FIG. 6 . The circular arc groove 4 - 2 in this embodiment is provided along the length direction of the upper rectangular through hole 4 - 1 . Other compositions and connection modes are the same as those in the second embodiment.

Embodiment 4: This embodiment will be described with reference to FIGS. 1 to 5 . The upper rectangular through hole 4 - 1 and the lower rectangular through hole 2 - 1 described in this embodiment have the same external dimensions. Other compositions and connection modes are the same as those in the first, second or third embodiment.

Embodiment 5: This embodiment will be described with reference to FIGS. 1 to 2 and 5 to 6 . The arc surface of the arc groove 4 - 2 in this embodiment has the same radian as the arc surface of the lower positioning plate 3 , and the curvature of the arc surface of the arc groove 4-2 is the same as the curvature of the upper end surface of the test piece, and the curvature of the arc surface of the lower positioning plate 3 is the same as the curvature of the lower end surface of the test piece. Other compositions and connection modes are the same as in the fourth embodiment.

Embodiment 6: This embodiment will be described with reference to FIG. 1 to FIG. 2 . In this embodiment, the fixing method between the lower positioning plate 3 and the impact platform 2 is detachable fixing, and the upper cover plate 4 is connected to the impact platform 2 . The fixing method between them is detachable fixing. Other compositions and connection manners are the same as in the first, second, third or fifth embodiment.

Such a design facilitates the disassembly and installation of the lower positioning plate 3 , and the removal and replacement of the lower positioning plate 3 .

Embodiment 7: This embodiment will be described with reference to FIGS. 1 to 2 . In this embodiment, the lower positioning plate 3 is fixed to the impact platform 2 through bolts, and the upper cover plate 4 is connected to the upper surface of the impact platform 2 through four connecting bolts 6 . End face fixed. Other components and connection modes are the same as those in the sixth embodiment.

Such a design facilitates the disassembly and installation of the upper cover plate 4 .

Embodiment 8: This embodiment will be described with reference to FIG. 1 to FIG. 2 and FIG. 7 . An arc-shaped gasket 7 is provided on the arc surface of the lower positioning plate 3 according to this embodiment. Other components and connection modes are the same as those in the seventh embodiment.

This is designed to test the impact properties of the upper side panels of composite sandwich shells.

Embodiment 9: This embodiment will be described with reference to FIGS. 1 to 2 and 7 . The curvature of the arc surface of the arc-shaped gasket 7 in this embodiment is the same as the curvature of the upper end surface of the test piece. The arc-shaped gasket 7 The curvature of the lower arc surface is the same as the curvature of the arc surface of the lower positioning plate 3 . Other compositions and connection modes are the same as those in the eighth embodiment.

In this embodiment, the material of the arc gasket 7 is a PTFE arc gasket. The performance of the arc gasket 7 produced in this way meets the test requirements, is convenient for production and installation, and can meet the impact test of panels with different curvatures. affect the accuracy of the test.

According to the difference between the inner arc and the outer arc of the test piece, replace the corresponding lower lower positioning plate 3 and process the upper PTFE gasket 7 and the arc groove 4-2 of the upper cover plate 4 to fix the different composite materials. The fixation of the sandwich shell is then subjected to the impact test. According to the curvature of the inner side panel and the outer side panel of the specimen, replace the corresponding lower lower positioning plate 3 and the processing upper side arc-shaped gasket 7 and fix the arc groove 4-2 of the upper cover plate 4 to realize the clamping of different composite materials. Fixing of the core shell for impact testing.

Embodiment 10: This embodiment will be described with reference to FIGS. 1 to 5. In this embodiment, the upper and lower ends of the column 5 are provided with threads, the lower end of the column 5 is vertically inserted on the fixed base 1, and the lower end of the column 5 The nut is screwed, and the nut is embedded in the fixed base 1. The impact platform 2 is symmetrically provided with a plurality of stepped through holes 2-2. The upper end of the column 5 is vertically inserted into the stepped through hole 2-2. The upper end of the column 5 The nut is screwed, and the nut is embedded in the stepped through hole 2-2. Other compositions and connection manners are the same as those of the specific embodiment one, two, three, five, seven, eight or nine.

In this way, the upper end of the upright column 5 and the nut are both sunk into the interior of the impact platform 2 to facilitate the installation and positioning of the upper cover plate 4 and prevent interference therewith.

Claims (7)

1. The utility model provides an experimental impact clamp who uses which characterized in that: the impact clamp for the test comprises a fixed base (1), an impact platform (2), an upper cover plate (4), two lower positioning plates (3) and a plurality of stand columns (5), wherein the impact platform (2) is arranged right above the fixed base (1) in parallel, the impact platform (2) is fixedly connected with the upper end face of the fixed base (1) through the stand columns (5), a lower rectangular through hole (2-1) is formed in the middle of the impact platform (2), two lower positioning plates (3) are respectively and fixedly connected to two sides of the upper end of the lower rectangular through hole (2-1), the upper end face of each lower positioning plate (3) is an arc face, an upper cover plate (4) is fixedly connected to the upper end face of the impact platform (2), an arc groove (4-2) is formed in the middle of the lower end face of the upper cover plate (4), an upper rectangular through hole (4-1) is formed in the middle of the upper end face, lower locating plate (3) sets up in circular arc recess (4-2), and the arc surface of circular arc recess (4-2) and lower locating plate (3) contacts with the upper and lower arc surface of being surveyed the curved surface shell respectively, the rigid coupling mode between lower locating plate (3) and impact platform (2) is detachable rigid coupling, and the rigid coupling mode between upper cover plate (4) and impact platform (2) is detachable rigid coupling, be equipped with arc gasket (7) on the arc surface of lower locating plate (3), the material of arc gasket (7) is for gathering tetrafluoro arc gasket, the camber of arc surface is the same with the camber of being surveyed a piece up end on arc gasket (7), the camber of arc surface under arc gasket (7) and the camber of lower locating plate (3) arc surface.

2. The impact clamp for testing as claimed in claim 1, wherein: the lower positioning plates (3) are arranged on two sides of the lower rectangular through hole (2-1) in the length direction, and each lower positioning plate (3) is arranged in the width direction.

3. The impact clamp for testing as claimed in claim 2, wherein: the arc-shaped groove (4-2) is arranged along the length direction of the upper rectangular through hole (4-1).

4. A test impact clamp according to claim 1, 2 or 3, wherein: the upper rectangular through hole (4-1) and the lower rectangular through hole (2-1) are identical in external dimension.

5. The impact clamp for testing as set forth in claim 4, wherein: the radian of the arc surface of the arc groove (4-2) is the same as that of the arc surface of the lower positioning plate (3), the curvature of the arc surface of the arc groove (4-2) is the same as that of the upper end surface of the tested piece, and the curvature of the arc surface of the lower positioning plate (3) is the same as that of the lower end surface of the tested piece.

6. The impact clamp for testing as claimed in claim 5, wherein: the lower positioning plate (3) is fixedly connected with the impact platform (2) through bolts, and the upper cover plate (4) is fixedly connected with the upper end face of the impact platform (2) through four connecting bolts (6).

7. The impact jig for testing as set forth in claim 1, 2, 3, 5 or 6, wherein: the upper end and the lower end of the upright post (5) are both provided with threads, the lower end of the upright post (5) is vertically inserted on the fixed base (1), the lower end of the upright post (5) is rotatably provided with a nut which is embedded in the fixed base (1), the impact platform (2) is symmetrically provided with a plurality of stepped through holes (2-2), the upper end of the upright post (5) is vertically inserted in the stepped through holes (2-2), the upper end of the upright post (5) is rotatably provided with a nut which is embedded in the stepped through holes (2-2).

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