CN214150137U

CN214150137U - Centering device for three-dimensional woven composite material sample

Info

Publication number: CN214150137U
Application number: CN202022747073.0U
Authority: CN
Inventors: 黄剑进; 陆煦; 徐芳; 潘昕; 程瑞松
Original assignee: Shanghai Aeronautical Materials & Structures Testing Co ltd
Current assignee: Shanghai Aeronautical Materials & Structures Testing Co ltd
Priority date: 2020-11-24
Filing date: 2020-11-24
Publication date: 2021-09-07
Anticipated expiration: 2030-11-24

Abstract

The utility model discloses a centering device for three-dimensional weaving composite material sample, wherein two ends of the sample are bonded between two clamping tools; the centering device comprises a cylindrical inner sleeve body and a cylindrical outer sleeve body, wherein the inner sleeve body is divided into a plurality of parts and surrounds the outer side of the middle part of the sample; the inner diameter of the middle part of the outer sleeve body is larger, so that an annular groove is formed, and the outer sleeve body is divided into a plurality of parts; the inner diameter of the middle part of the outer sleeve body is matched with the outer diameter of the inner sleeve body, a plurality of parts of the outer sleeve body surround the outer side of the inner sleeve body, and the inner sleeve body is sleeved at the groove in the middle part of the outer sleeve body; the inner walls of the upper part and the lower part of the outer sleeve body are correspondingly attached to the virtual circumcircles of the outer walls of the two clamping tools; the outer side edges of all the parts of the outer sleeve body extend outwards to form connecting parts, and the adjacent parts are fixed together through the matching of the connecting parts and the fixing parts. The inner sleeve body, the outer sleeve body, the sample and the central axis of the clamping device are overlapped together, so that the centering degree is good, and the use is convenient.

Description

Centering device for three-dimensional woven composite material sample

Technical Field

The utility model belongs to an auxiliary test device field that is used for the three-dimensional combined material sample of weaving specifically is a centering device that is used for the three-dimensional combined material sample of weaving.

Background

The fatigue performance of the sample needs to be verified by a test, the requirement on the alignment degree of the sample and the clamping tool is high in the test process so as to ensure that no eccentric load is applied, otherwise, the test result is distorted, and the fatigue performance of the sample cannot be truly reflected, so that the alignment degree between the sample and the clamping tool is especially important to ensure. Particularly, in the case of a three-dimensional woven composite material, since the sample and the clamping tool cannot be fixed by simple clamping, the sample and the clamping tool can be fixed only by adhesion, so that the sample is prevented from being damaged by the clamping tool. Therefore, it is necessary to solve the problem of the alignment between the sample and the holding tool at the time of bonding. In addition, the adhesive used to bond the sample and the clamping tool also needs to be cured by heating to ensure that the two are firmly connected, so it is difficult to ensure the alignment before the two are cured.

For example, a chinese patent application with publication number CN111624100A discloses a testing device, and another chinese patent application with publication number CN111624066A discloses an auxiliary bonding tool. The problem that two above-mentioned patent applications mainly solved is how to guarantee the centering degree between three-dimensional weaving combined material's sample and corresponding clamping means.

SUMMERY OF THE UTILITY MODEL

Among the prior art, need use a plurality of mountings to carry on spacingly to the sample, lead to the operation complicacy, be unfavorable for improving the centering degree. In order to overcome the defects of the prior art, the utility model provides a centering device for three-dimensionally weaving composite material sample.

The utility model provides a technical scheme that its technical problem adopted is:

a centering device for three-dimensional weaving composite material samples, wherein,

the test sample is rotationally symmetrical around the central axis, the width of the two ends of the test sample is larger than that of the middle part of the test sample, and the two ends of the test sample are bonded between the two clamping tools;

the centering device comprises a cylindrical inner sleeve body and a cylindrical outer sleeve body, wherein:

the inner sleeve body is divided into a plurality of parts through the middle axis and is used for enclosing the outer side of the middle part of the sample, the outer diameter of the inner sleeve body is larger than the width of the widest part of the sample, and the inner diameter of the inner sleeve body is smaller than the width of the widest part of the sample;

the inner diameter of the middle part of the outer sleeve body is larger to form an annular groove, and the outer sleeve body is divided into a plurality of parts through the central axis of the outer sleeve body; the inner diameter of the middle part of the outer sleeve body is matched with the outer diameter of the inner sleeve body, and a plurality of parts of the outer sleeve body surround the outer side of the inner sleeve body so as to sleeve the inner sleeve body at the groove in the middle part of the outer sleeve body; the inner walls of the upper part and the lower part of the outer sleeve body are correspondingly attached to the virtual circumcircles of the outer walls of the two clamping tools; the outer side edges of all the parts of the outer sleeve body extend outwards to form connecting parts, and the adjacent parts are fixed together by means of the matching of the connecting parts and the fixing parts;

the inner sleeve body, the outer sleeve body, the sample and the central axis of the clamping device are overlapped together.

According to a preferred embodiment, the inner and outer sleeves are each divided into two symmetrical parts.

Furthermore, a plurality of fixing holes are formed in the connecting portions of the outer sleeve body and used for being matched with the fixing pieces to fix the adjacent connecting portions, so that the fixing assembly and the disassembly are facilitated.

According to a preferred embodiment, the length of the groove is greater than the length of the inner sheath.

According to a preferred embodiment, the inner diameter of the upper and lower parts of the outer casing is matched to the size and shape of the outer diameter of the clamping tool.

According to a preferred embodiment, the gripping tool comprises an integral head and tail, wherein: the width of the head part is larger, so that the outer wall of the head part is attached to the inner wall of the upper part or the lower part of the inner sleeve body; the tail part has smaller width and is used for being connected with a testing machine.

Furthermore, the edge of the inner side of the inner sleeve body is provided with a smooth chamfer.

Furthermore, the inner walls of the upper part and the lower part of the outer sleeve body are provided with threads, the outer side of the head part of the clamping tool is also provided with threads, and the head part of the clamping tool is matched with the inner wall of the outer sleeve body through threads to fix and adjust the position.

Compared with the prior art, the beneficial effects of the utility model are that:

1. after the inner sleeve body, the outer sleeve body, the sample and the clamping device are assembled together, the central axes of all the components are overlapped together, and the centering degree is very good.

2. The connection parts of the adjacent parts of the outer sleeve body can be fixed in various fixing modes, preferably fixing parts, so that the fixing assembly and the disassembly are convenient, and most importantly, the connection process does not directly fix the sample, so that the centering degree of the sample or the adverse effect on the sample is avoided.

3. The length of the groove on the outer sleeve body can be set to be longer, correspondingly, the length of the inner sleeve body is shorter, the test tube can be suitable for samples of various specifications, and the cost is greatly reduced.

4. The outer sleeve body upper portion and lower part further have the internal thread, the head of centre gripping instrument then has the external screw thread, carries out spacing fixed and position control through the screw-thread fit, and it is more convenient to use.

5. The edge of the inner side of the inner sleeve body is further provided with a smooth chamfer, so that the outer wall of the sample can be prevented from being damaged.

To sum up, the utility model discloses a centering device convenient to use, it is rational in infrastructure, and improved the centering degree between sample and the clamping device, can guarantee the fatigue performance of the true reaction sample of test result.

Drawings

FIG. 1 is a cross-sectional view of a centering device for a three-dimensional woven composite sample according to an embodiment, in which a dotted line X-X indicates a central axis where an inner sheath, an outer sheath, a sample and a clamping device coincide.

Fig. 2 is an exploded view of a centering device of a sample of an embodiment.

Fig. 3 is a front view of fig. 1.

FIG. 4 is a schematic view of the inner sheath, the sample and the clamping device moving downward with respect to the outer sheath.

FIG. 5 is a schematic view showing an embodiment in which a smooth chamfer is formed on the inner side edge of the inner jacket body.

Description of the figure numbers:

10. inner sleeve 10-a part of inner sleeve split, 10-b another part of inner sleeve split, 100 smooth chamfer.

20. The outer sleeve body, 20-a, one part of the split outer sleeve body, 20-b, the other part of the split outer sleeve body, 21, an annular groove, 210, limiting steps at the upper side and the lower side of the annular groove, 22, connecting parts at the outer side edges of the parts of the outer sleeve body, and 23, fixing holes in the connecting parts.

30. Sample, 40. holding tool, 41. head, 42. tail.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

As shown in fig. 1 and 2, the centering device for a three-dimensional braided composite material sample of the present embodiment includes a cylindrical inner sleeve 10 and an outer sleeve 20.

The width of the test piece 30 is greater at both ends than at the middle thereof, and the test piece 30 is adhered between the two holding tools 40 at both ends.

In order to facilitate the inner sleeve 10 to be sleeved on the outer side of the middle part of the sample 30, the inner sleeve 10 is divided into a plurality of parts through the central axis of the inner sleeve 10. Thus, portions of the inner housing 10 can be easily enclosed outside the middle portion of the test piece 30. In this embodiment, as a preferable mode, the inner sleeve 10 is divided into two symmetrical portions 10-a and 10-b, and the two portions 10-a and 10-b are enclosed at the outer side of the middle portion of the sample 30 from the two sides of the sample 30, so that the two portions 10-a and 10-b are spliced together to form the complete inner sleeve 10. The outer diameter of the inner sleeve 10 is larger than the width of the widest part of the sample 30, and the inner diameter of the inner sleeve 10 is smaller than the width of the widest part of the sample 30.

The inner diameter of the middle part of the outer sleeve body 20 is larger, and an annular groove 21 is formed. The outer diameters of the inner sleeve 10 and the sample 30 are different, and the outer sleeve 20 needs to be divided to fit the inner sleeve 10 and the sample 30 into the outer sleeve 10. Therefore, the outer casing 20 is divided into a plurality of parts through the central axis thereof, and in this embodiment, it is preferable to divide the outer casing 20 into two symmetrical parts 20-a and 20-b, which surround the inner casing 10 and the test specimen 30 from the two sides thereof, and then splice the two parts 20-a and 20-b together to form the complete outer casing 20.

In addition, the inner diameter of the middle part of the outer sleeve 20 is matched with the outer diameter of the inner sleeve 10, and the outer sleeve 20 surrounds the outer side of the inner sleeve 10, so that the inner sleeve 10 can be just sleeved in the annular groove 21 of the middle part of the outer sleeve 20, and the central axes of the inner sleeve 10 and the outer sleeve 20 are ensured to coincide. In this case, as long as the test piece 30 is rotationally symmetrical around its central axis (the cross section of the test piece is generally a circular or other rotationally symmetrical configuration, and is not generally made into an irregular configuration), after being sleeved in the inner sheath 10, the central axis of the test piece 30 coincides with the central axes of the inner sheath 10 and the outer sheath 20.

Meanwhile, the inner walls of the upper and lower portions of the outer casing 20 are correspondingly fitted to the virtual circumcircles of the outer walls of the two clamping tools 40, and preferably, the inner diameters of the upper and lower portions of the outer casing 20 are matched with the size and shape of the outer diameter of the clamping tools 40. When the clamping tool 40 is inserted into the outer sleeve 20, the central axis of the clamping tool 40 also coincides with the central axis of the outer sleeve 20.

The outer edges of the outer casing 20 extend outward to form connecting portions 22, and adjacent portions are fixed together by the connecting portions 22 and a fixing member (not shown).

In the present invention, after the inner housing 10, the outer housing 20, the sample 30, and the holding device 40 are assembled together, the central axes of the respective components are overlapped together, and the centering degree basically depends only on the system error between the respective components, so that the centering degree is very good. It is easy to understand that, in the present invention, the central axis is not an actual entity, but a virtual line in general mathematical sense.

The fixing means between the connecting portions 22 of the adjacent portions of the outer casing 20 is not limited, but preferably is a fixing means, which may be a bolt and a nut, for easy detachment. For this purpose, in this embodiment, the connecting portions 22 of the outer casing 20 are further provided with a plurality of fixing holes 23 for cooperating with fixing members to fix the adjacent connecting portions 22. The fasteners may also be other types of fasteners known in the art, such as rivets, snap-fit structures, and the like. Alternatively, other means of attachment, such as adhesive bonding, may be used.

Preferably, the gripping tool 40 comprises an integral head portion 41 and tail portion 42. Wherein, the width of the head 41 is larger, so that the outer wall of the head 41 is attached to the inner wall of the upper part or the lower part of the inner sleeve body 20, and is used for bonding with the end part of the sample 30; the tail 42 is of a small width for coupling to a testing machine (not shown) which is conventional in the art and will not be described further.

Since the center axes of the inner sleeve 10, the outer sleeve 20, the test sample 30 and the clamping device 40 are not coincident with each other, depending on the lengths of the groove 21 and the inner sleeve 10, the lengths of the groove 21 and the inner sleeve 10 can be selected as required. In this embodiment, however, it is preferable that the length of the groove 21 is greater than the length of the inner sheath 10. This makes it possible to adapt the inner sheath body 10 to samples 30 of different specifications. The conventional auxiliary test device for the sample is generally required to be matched with the sizes and specifications of different samples, so that the auxiliary test device with various specifications is required, the cost is high, and particularly the mold opening cost is high. And the utility model discloses a centering device just can be applicable to the sample of multiple specification under the condition of not making the adjustment, and the cost is reduced has especially practiced thrift a large amount of die sinking costs.

As shown in FIG. 3, the inner edge of the upper part and the inner edge of the lower part of the inner sheath 10 are both abutted against the outer wall of the middle part of the test specimen 30, and the central axes of the inner sheath 10 and the test specimen 30 are always coincident.

In contrast to the case where the inner periphery of the upper part and the inner periphery of the lower part of the inner housing 10 are both pressed against the outer periphery of the middle part of the test specimen 30, as shown in fig. 4: the length of the inner sleeve 10 is short, so that only the inner edge of the upper part of the inner sleeve abuts against the outer wall of the middle part of the sample 30, the clamping device 40 adhered to the upper side of the sample 30 and the sample 30 are pressed downwards, the inner sleeve 10 is sleeved in the groove 21 in the middle part of the outer sleeve 20, the lower side of the groove 21 forms a limiting step 210, at the moment, the lower part of the inner sleeve 10 abuts against the limiting step 210 at the lower side of the groove 21, the inner sleeve 10 can be ensured to coincide with the central axis of the sample 30, and the centering degree is further ensured.

Obviously, when at least one of the inner edge of the upper part and the inner edge of the lower part of the inner sheath 10 abuts against the outer wall of the middle part of the test sample 30, the positions of the inner sheath 10, the test sample 30 and the clamping device 40 can move up and down relative to the outer sheath 20, and have no influence on the centering degree. In addition, the limiting steps 210 at the upper and lower sides of the groove 20 can also play a limiting role, and can prevent the inner sheath 10 and the test sample 30 from falling out of the outer sheath 20.

In the above solution, only the improvement of the alignment degree is achieved, but during the heat curing process, the components in the outer sleeve 20 need to be limited up and down by other tools. For this purpose, in this embodiment, the outer casing 20 further has an internal thread (not shown) on the upper and lower portions thereof, the head 41 of the clamping tool 40 has an external thread (not shown), and the head 41 of the clamping tool 40 is screwed with the inner wall of the outer casing 10 for position-limiting and position-adjusting. Thus, the inner sheath 10, the outer sheath 20, the test specimen 30 and the clamping device 40 can be directly subjected to a thermosetting step after being assembled together, and the assembly is more convenient to use.

As shown in fig. 5, further, the inner edge of the inner sleeve 10 is provided with a smooth chamfer, so that the inner edge of the inner sleeve 10 can be prevented from damaging the outer wall of the sample 30. Wherein, the shape of sleek chamfer is in the utility model discloses in unrestricted, can be for example the fillet, with configurations such as arc chamfer that the outer wall at sample middle part matches completely.

The utility model discloses a centering device still has simple structure's advantage, during the assembly:

1) two parts 10-a and 10-b of the inner sleeve body 10 are sleeved on the outer side of the middle part of the sample 30, and the end faces of two sides of the sample 30 are coated with adhesive;

2) sleeving two parts 20-a and 20-b of the outer sleeve 20 on the outer side of the inner sleeve 10, so that the inner sleeve 10 is sleeved on the annular groove 21 in the middle of the outer sleeve 20; meanwhile, the connecting parts 22 of the two parts 20-a and 20-b of the outer sleeve 20 are fixed together by using fixing parts;

3) the heads 41 of the two clamping tools 40 are inserted from the two ends of the outer sleeve 20, so that the heads of the two clamping tools 40 are bonded to the two side end faces of the test piece 30.

The clamping tool 40 and the outer casing 20 can be fixed together by means of screw thread fit, and after the assembly is completed, heating and curing are carried out. The whole process can ensure that the central axes of the sample 30 and the clamping tool 40 are coincident, so that the centering degree is very good.

Before the test, the fixing members on the connecting portion 21 of the outer sleeve 20 are removed, and the outer sleeve 20 and the inner sleeve 10 are sequentially removed, so that the operation is simple. Finally, the clamping tools 40 at the two ends of the test sample 30 are fixed on the testing machine for testing.

The above embodiments describe in detail the structure of the centering device for three-dimensional weaving of composite material sample of the present invention, but should not be considered as limiting the present invention. It will be readily understood that modifications, substitutions and further improvements may be made by those skilled in the art based on the teachings of the present invention, but any modifications or equivalents will fall within the scope of the claims of the present invention.

Claims

1. A centering device for a three-dimensional woven composite specimen, said specimen being rotationally symmetric about its central axis and having a width at both ends greater than the width at its middle, the specimen being bonded at both ends between two clamping means, characterized in that said centering device comprises a cylindrical inner and outer sleeve, wherein:

2. The centering device of claim 1, wherein said inner and outer sleeves are each split into two symmetrical parts.

3. The centering device of claim 1, wherein the outer casing has a plurality of fixing holes formed on the connecting portions for cooperating with the fixing members to fix the adjacent connecting portions for easy fixing and disassembly.

4. The centering device of claim 1, wherein the length of said groove is greater than the length of said inner sheath.

5. The centering device of claim 1, wherein the inner diameters of the upper and lower portions of the outer housing match the size and shape of the outer diameter of the clamping tool.

6. The centering device as claimed in claim 5, wherein said holding means comprises a head portion and a tail portion which are integrated, the head portion having a width larger so that an outer wall of the head portion is fitted to an inner wall of an upper or lower portion of said inner housing; the tail part has smaller width and is used for being connected with a testing machine.

7. The centering device as claimed in claim 1, wherein an inner side edge of said inner sleeve body is provided with a rounded chamfer.

8. The centering device as claimed in any one of claims 1 to 7, wherein the inner walls of the upper and lower portions of the outer sleeve are threaded, the outer side of the head of the clamping means is also threaded, and the head of the clamping means and the inner wall of the outer sleeve are fixed and adjusted by threaded engagement.