Composite material mechanical connection test clamp and test device
By designing a composite mechanical connection test fixture including removable live blocks, the problem that existing fixtures are only suitable for single-size test pieces is solved, and flexible adjustment of fixture size is achieved, reducing manufacturing costs and working cycles.
Patent Information
- Application Number
- CN202421605274.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-09
- Publication Date
- 2025-05-06
- Estimated Expiration
- 2034-07-09
AI Technical Summary
The existing anti-instability fixtures are only suitable for single-size test pieces, which leads to the need to design different size fixtures when the test pieces change, resulting in high manufacturing costs and long working cycles.
A composite material mechanical connection test fixture is designed, including two relatively long clamps and four live blocks. By installing detachable live blocks of different sizes, the clamp size can be clamped with different sizes and the fixture size can be adjusted.
It realizes flexible adjustment of fixture size, adapts to test parts of different sizes, reduces manufacturing costs and working cycles, and avoids the risk of instability.
Smart Images
Figure CN222831635U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of fixtures, and in particular to a composite material mechanical connection test fixture and a test device. Background Art
[0002] In the field of aviation structures, carbon fiber composite materials are increasingly widely used in important load-bearing structures due to their high specific strength and high specific stiffness. The mechanical connection parts of composite structures generate nail hole extrusion and bypass loads, which are concentrated and complex load transfer and are an important risk source of potential structural failure. Therefore, it is necessary to conduct research on the failure modes and analysis methods of composite materials under extrusion / bypass loads. Among them, the 75% bypass / extrusion coupling performance test of composite materials (hereinafter referred to as the "BP75 test") is an important test under the combined characteristics of high bypass and low extrusion loads. The BP75 test under compression load requires the use of an anti-instability fixture to ensure that no instability occurs and does not affect the expected failure mode.
[0003] At present, when the aviation industry conducts BP75 tests on mechanical connections of composite materials, it generally refers to ASTM D7248 "Test Method for Extrusion Bypass Response of Polymer Matrix Composite Laminates". The geometric dimensions of the test piece are related to the fasteners used. When using different fasteners, the dimensions of the test piece need to be changed accordingly. The size of the anti-instability fixture must match the size of the test piece to which it is assembled.
[0004] However, the existing anti-instability fixture is only suitable for a single-size test piece and has the risk of instability. When the size of the test piece changes, it is necessary to design anti-instability fixtures of different sizes, resulting in high manufacturing costs and long working cycles. Utility Model Content
[0005] The present application provides a composite material mechanical connection test fixture and a test device, which can effectively solve the above or other potential technical problems.
[0006] The first aspect of the present application is to provide a composite material mechanical connection test fixture, which includes two relatively arranged long clamps and four loose blocks, each of the long clamps has two connecting bosses relatively arranged; the connecting bosses of each of the long clamps are respectively connected to the loose blocks; the two long clamps are relatively arranged on one side to which the loose blocks are connected, and a clamping space is formed; the workpiece to be tested is placed in the clamping space between the two long clamps, and the cover plate in the middle of the workpiece to be tested is limited between the loose blocks at both ends.
[0007] The composite material mechanical connection test fixture provided by the present application includes two long clamping plates arranged opposite to each other and four loose blocks, each of the long clamping plates is arranged opposite to each other with two connecting bosses; the connecting bosses of each long clamping plate are respectively connected to the loose blocks; the two long clamping plates are arranged opposite to each other on one side connected to the loose blocks, and a clamping space is formed; the test piece is placed in the clamping space between the two long clamping plates, and the cover plate in the middle of the test piece is limited between the loose blocks at both ends. By installing detachable loose blocks of different sizes, the test pieces of different sizes can be clamped, thereby achieving the purpose of adjusting the size of the fixture.
[0008] In an optional embodiment according to the first aspect, the composite material mechanical connection test fixture also includes two short clamps, each of which is provided with a clamping protrusion, and a first step-type structure is provided on the short clamp; the long clamp has a clamping end and a fixed end, and the clamping end is provided with a second step-type structure that matches the first step-type structure and forms the clamping space for accommodating the test piece; the fixed end is provided with a clamping notch that is adapted to the shape of the clamping protrusion; the two long clamps are arranged opposite to each other, the clamping end of one long clamp corresponds to the fixed end of the other long clamp, the short clamp is clamped to the fixed end, and the short clamp is fixedly connected to the clamping end of the other long clamp.
[0009] In an optional embodiment according to the first aspect, the composite material mechanical connection test fixture further includes two support plates, and the support plates are fixedly connected to the short clamping plates.
[0010] In an optional embodiment according to the first aspect, the composite material mechanical connection test fixture further includes fastening bolts, wherein the fastening bolts penetrate the corresponding support plate, the short clamping plate, and the long clamping plate.
[0011] In an optional embodiment according to the first aspect, the clamping protrusion is in a pointed shape, and the clamping notch is in a V shape that matches the pointed shape.
[0012] In an optional embodiment according to the first aspect, two open slots are arranged at intervals on the long clamping plate, and two screws on the test piece are respectively placed in the open slots.
[0013] In an optional embodiment according to the first aspect, a connecting groove is provided on the connecting boss, and a connecting protrusion which is adapted to the shape of the connecting groove is correspondingly provided on the movable block.
[0014] In an optional embodiment according to the first aspect, the connecting groove is a trapezoidal groove, and the connecting protrusion is a trapezoidal protrusion.
[0015] In an optional embodiment according to the first aspect, the composite material mechanical connection test fixture includes a plurality of groups of loose blocks of different sizes, and the number of the loose blocks in each group is four.
[0016] The second aspect of the present application also provides a testing device, comprising the above-mentioned composite material mechanical connection test fixture.
[0017] The testing device provided in the present application includes the above-mentioned composite material mechanical connection test fixture, and therefore also has the above-mentioned technical effect of being able to clamp test pieces of different sizes, thereby achieving the purpose of adjusting the fixture size.
[0018] Advantages of additional aspects of the present application will be given in part in the following description, and in part will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and other purposes, features and advantages of the embodiments of the present application will become more easily understood through the following detailed description with reference to the accompanying drawings. In the accompanying drawings, multiple embodiments of the present application will be described in an exemplary and non-limiting manner, wherein:
[0020] Figure 1 A schematic diagram of the overall structure of the composite material mechanical connection test fixture in an assembled state provided in an embodiment of the present application;
[0021] Figure 2 A schematic diagram of the overall structure of the composite material mechanical connection test fixture provided in an embodiment of the present application in a disassembled state;
[0022] Figure 3 A schematic structural diagram of a long clamping plate of a composite material mechanical connection test fixture provided in an embodiment of the present application;
[0023] Figure 4 A schematic diagram of the structure of a movable block of a composite material mechanical connection test fixture provided in an embodiment of the present application;
[0024] Figure 5 A schematic structural diagram of a short clamping plate of a composite material mechanical connection test fixture provided in an embodiment of the present application;
[0025] Figure 6 A schematic structural diagram of a test piece for testing using a composite material mechanical connection test fixture provided in an embodiment of the present application.
[0026] Description of reference numerals:
[0027] 10. Composite material mechanical connection test fixture; 11. Long clamping plate; 111. Connecting boss; 112. Clamping end; 113. Fixed end; 114. Snap-fit notch; 115. Opening groove; 116. Connecting groove; 117. Second stepped structure; 12. Loose block; 121. Connecting protrusion; 13. Short clamping plate; 131. Snap-fit protrusion; 132. First stepped structure; 14. Support plate; 141. Fastening bolt; 20. Part to be tested; 21. Bolt fastener; 22. Cover plate. DETAILED DESCRIPTION
[0028] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.
[0029] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0031] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0032] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0033] In the field of aviation structures, carbon fiber composite materials are increasingly widely used in important load-bearing structures due to their high specific strength and high specific stiffness. The mechanical connection parts of composite structures generate nail hole extrusion and bypass loads, which are concentrated and complex, and are important sources of potential structural failure. Therefore, it is necessary to study the failure mode and analysis method of composite materials under extrusion / bypass loads. Among them, the composite material 75% bypass / extrusion coupling performance test (hereinafter referred to as "BP75 test") is an important test under the combined characteristics of high bypass and low extrusion loads. The BP75 test under compression load requires the use of an anti-instability fixture to ensure that no instability occurs and does not affect the expected failure mode. At present, when the aviation industry conducts BP75 tests on mechanical connections of composite materials, it generally refers to ASTM D7248 "Test Method for Extrusion Bypass Response of Polymer Matrix Composite Laminates". The geometric dimensions of the test piece are related to the fasteners used. When using different fasteners, the size of the test piece needs to be changed accordingly. The size of the anti-instability fixture must match the size of the test piece assembled with it. However, the existing anti-instability fixture is only suitable for single-size test pieces and there is a risk of instability. When the size of the test piece changes, it is necessary to design anti-instability fixtures of different sizes, which leads to high manufacturing costs and long working cycles.
[0034] In view of this, the composite material mechanical connection test fixture provided by the present application includes two long clamping plates arranged opposite to each other and four loose blocks, each of the long clamping plates is arranged opposite to each other with two connecting bosses; the connecting bosses of each long clamping plate are respectively connected to the loose blocks; the two long clamping plates are arranged opposite to each other on one side connected to the loose blocks, and a clamping space is formed; the test piece is placed in the clamping space between the two long clamping plates, and the cover plate in the middle of the test piece is limited between the loose blocks at both ends. By installing detachable loose blocks of different sizes, the test pieces of different sizes can be clamped, thereby achieving the purpose of adjusting the size of the fixture.
[0035] Please refer to Figures 1 to 6The composite material mechanical connection test fixture 10 provided in the embodiment of the present application includes two oppositely arranged long clamps 11 and four loose blocks 12, each of the long clamps 11 is oppositely provided with two connecting bosses 111; the connecting bosses 111 of each of the long clamps 11 are respectively connected to the loose blocks 12; the two sides of the two long clamps 11 connected to the loose blocks 12 are oppositely arranged to form a clamping space; the workpiece 20 to be tested is placed in the clamping space between the two long clamps 11, and the cover plate 22 in the middle of the workpiece 20 to be tested is limited between the loose blocks 12 at both ends.
[0036] The composite material mechanical connection test fixture 10 provided in the present application comprises two long clamping plates 11 and four loose blocks 12 arranged opposite to each other, and two connecting bosses 111 are arranged opposite to each other on each of the long clamping plates 11; the loose blocks 12 are connected to the connecting bosses 111 of each of the long clamping plates 11; the two sides of the two long clamping plates 11 connected to the loose blocks 12 are arranged opposite to each other and form a clamping space; the workpiece 20 to be tested is placed in the clamping space between the two long clamping plates 11, and the cover plate 22 in the middle of the workpiece 20 to be tested is limited between the loose blocks 12 at both ends. By installing removable loose blocks 12 of different sizes, the workpieces 20 to be tested of different sizes can be clamped, thereby achieving the purpose of adjusting the size of the fixture.
[0037] Specifically, an extrusion reserved gap is provided between the cover plate 22 in the middle of the test piece 20 and the movable block 12 .
[0038] In an optional exemplary embodiment, the composite material mechanical connection test fixture 10 also includes two short clamps 13, each of which is provided with a clamping protrusion 131, and a first step-type structure 132 is provided on the short clamps 13; the long clamp 11 has a clamping end 112 and a fixed end 113, and the clamping end 112 is provided with a second step-type structure 117 that matches the first step-type structure 132 and forms the clamping space for accommodating the test piece 20; the fixed end 113 is provided with a clamping notch 114 that is adapted to the shape of the clamping protrusion 131; the two long clamps 11 are arranged opposite to each other, the clamping end 112 of one long clamp 11 corresponds to the fixed end 113 of the other long clamp 11, the short clamp 13 is clamped to the fixed end 113, and the short clamp 13 is fixedly connected to the clamping end 112 of the other long clamp 11.
[0039] It should be noted that, specifically, in the present embodiment, a short clamping plate 13 is provided, on which a clamping protrusion 131 is provided, and on which a first step-type structure 132 is provided; the long clamping plate 11 has a clamping end 112 and a fixed end 113, and the clamping end 112 is provided with a second step-type structure 117 which matches the first step-type structure 132, and forms the clamping space for accommodating the test piece 20; the fixed end 113 is provided with a clamping notch 114 which is adapted to the shape of the clamping protrusion 131; the two long clamping plates 11 are arranged opposite to each other, and the clamping end 112 of one long clamping plate 11 corresponds to the fixed end 113 of the other long clamping plate 11, and the short clamping plate 13 is clamped at the fixed end 113, and the short clamping plate 13 is fixedly connected to the clamping end 112 of the other long clamping plate 11. The short clamping plate 13 can realize the fixed connection of the two long clamping plates 11 after being arranged relative to each other, thereby ensuring the stability of the clamping space; at the same time, the first stepped structure 132 and the second stepped structure 117 form a clamping space, which is specifically used to accommodate the long plate structures at both ends of the test piece 20.
[0040] In an optional exemplary embodiment, the composite material mechanical connection test fixture 10 further includes two support plates 14 , and the support plates 14 are fixedly connected to the short clamping plates 13 .
[0041] It should be noted that, specifically, in this embodiment, two support plates 14 are provided, and the support plates 14 are fixedly connected to the short clamping plates 13 . Such a configuration further ensures the stability of the overall structure of the composite material mechanical connection test fixture 10 .
[0042] In an optional exemplary embodiment, the composite material mechanical connection test fixture 10 further includes a fastening bolt 141 , and the fastening bolt 141 passes through the corresponding support plate 14 , the short clamping plate 13 , and the long clamping plate 11 .
[0043] It should be noted that, specifically, in this embodiment, it also includes a fastening bolt 141, and the fastening bolt 141 passes through the corresponding support plate 14, the short clamping plate 13 and the long clamping plate 11, and the three are fastened and connected by the fastening bolt 141, thereby ensuring the connection stability of the overall structure.
[0044] In an optional exemplary embodiment, the engaging protrusion 131 is in a pointed shape, and the engaging notch 114 is in a V-shape that matches the pointed shape.
[0045] It should be noted that, specifically, in this embodiment, the clamping protrusion 131 is pointed, and the clamping notch 114 is V-shaped to match the pointed shape. This arrangement facilitates the clamping and separation of the two, while ensuring the stability of the clamping and avoiding the phenomenon of clamping deviation.
[0046] In an optional exemplary embodiment, two open slots 115 are spaced apart on the long clamping plate 11 , and two bolt fasteners 21 on the test piece 20 are respectively placed in the open slots 115 .
[0047] It should be noted that, specifically, in this embodiment, two opening slots 115 are provided at intervals on the long clamping plate 11, and two bolt fasteners 21 on the test piece 20 are respectively placed in the opening slots 115. The anti-instability capability of the fixture is enhanced by providing the segmented opening slots 115.
[0048] In an optional exemplary embodiment, a connecting groove 116 is provided on the connecting boss 111 , and a connecting protrusion 121 whose shape matches that of the connecting groove 116 is correspondingly provided on the movable block 12 .
[0049] It should be noted that, specifically, in this embodiment, the connecting boss 111 is provided with a connecting groove 116, and the movable block 12 is correspondingly provided with a connecting protrusion 121 that matches the shape of the connecting groove 116. Such a configuration facilitates the quick disassembly and assembly of the movable block 12 and the connecting boss 111.
[0050] Exemplarily, the connection groove 116 is a trapezoidal groove, and the connection protrusion 121 is a trapezoidal protrusion.
[0051] In an optional exemplary embodiment, the composite material mechanical connection test fixture 10 includes a plurality of groups of loose blocks 12 of different sizes, and each group of the loose blocks 12 includes four loose blocks 12 .
[0052] It should be noted that, specifically, in this embodiment, multiple groups of movable blocks 12 of different sizes are included, and each group of movable blocks 12 has four movable blocks 12. Providing movable blocks 12 of different sizes can adapt to test pieces 20 of different sizes.
[0053] The composite material mechanical connection test fixture 10 provided in the present application, during the installation process, two of the movable blocks 12 are horizontally placed in the connection groove 116 of the connection boss 111 on the long clamping plate 11, and then the test piece 20 is horizontally placed thereon, so that one end of it is in contact with the second stepped structure 117 of the long clamping plate 11, so that the two bolt fasteners 21 on the test piece 20 pass through the two opening grooves 115 of the long clamping plate 11 respectively, and the test piece can be aligned by marking on the long clamping plate 11. Then, the short clamping plate 13 and the support plate 14 are placed in sequence at one end of the second stepped structure 117 of the long clamping plate 11, and the fastening bolts 141 are inserted to fix it, and then the other end of the test piece 20 is set in the same way. The assembled composite laminate BP75 compression composite material mechanical connection test fixture 10 is clamped in the chuck of the testing machine so that the long axis of the clamping fixture is consistent with the direction of the test piece. The load is applied to the test piece at a specified rate, and the load-strain curve is recorded at the same time.
[0054] The present application also provides a testing device, including the composite material mechanical connection test fixture 10 mentioned above.
[0055] The testing device provided in the present application includes the above-mentioned composite material mechanical connection test fixture 10, and therefore also has the above-mentioned technical effect of being able to clamp the test pieces 20 of different sizes, thereby achieving the purpose of adjusting the size of the fixture.
[0056] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned implementation modes, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned implementation modes can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the implementation modes of the present application.
[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not further describe various possible combinations.
Claims
1. A composite material mechanical connection test fixture, characterized in that: It comprises two long clamping plates arranged opposite to each other and four loose blocks, each of the long clamping plates is provided with two connecting bosses opposite to each other; the connecting bosses of each long clamping plate are respectively connected to the loose blocks; the two sides of the two long clamping plates connected to the loose blocks are arranged opposite to each other and form a clamping space; The workpiece to be tested is placed in the clamping space between the two long clamping plates, and the cover plate in the middle of the workpiece to be tested is limited between the movable blocks at both ends.
2. The composite material mechanical connection test fixture according to claim 1, characterized in that: The composite material mechanical connection test fixture further comprises two short clamping plates, each of which is provided with a clamping protrusion and a first stepped structure; The long clamping plate has a clamping end and a fixed end, the clamping end is provided with a second stepped structure matched with the first stepped structure and forms the clamping space for accommodating the test piece; the fixed end is provided with a clamping notch adapted to the shape of the clamping protrusion; The two long clamps are arranged opposite to each other, the clamping end of one long clamp corresponds to the fixed end of the other long clamp, the short clamp is clamped to the fixed end, and the short clamp is fixedly connected to the clamping end of the other long clamp.
3. The composite material mechanical connection test fixture according to claim 2, characterized in that: It also includes two support plates, which are fixedly connected to the short clamping plate.
4. The composite material mechanical connection test fixture according to claim 3, characterized in that: It also includes fastening bolts, which penetrate the corresponding support plates, the short clamping plates and the long clamping plates.
5. The composite material mechanical connection test fixture according to claim 2, characterized in that: The clamping protrusion is in a pointed shape, and the clamping notch is in a V shape that matches the pointed shape.
6. The composite material mechanical connection test fixture according to any one of claims 1 to 5, characterized in that: The long clamping plate is provided with two open slots at intervals, and two bolt fasteners on the test piece are respectively placed in the open slots.
7. The composite material mechanical connection test fixture according to any one of claims 1 to 5, characterized in that: The connecting boss is provided with a connecting groove, and the movable block is correspondingly provided with a connecting protrusion which is adapted to the shape of the connecting groove.
8. The composite material mechanical connection test fixture according to claim 7, characterized in that: The connecting groove is a trapezoidal groove, and the connecting protrusion is a trapezoidal protrusion.
9. The composite material mechanical connection test fixture according to any one of claims 1 to 5, characterized in that: It comprises a plurality of groups of movable blocks of different sizes, and each group of movable blocks has four movable blocks.
10. A testing device, characterized in that: A composite material mechanical connection test fixture comprising any one of claims 1 to 9.