Glue joint tool for composite material compression sample and manufacturing method of glue joint tool

Abstract

The invention discloses a gluing tool for a composite material compression sample and a manufacturing method of the gluing tool, and relates to the technical field of composite material manufacturing. The gluing tool for the composite material compression test sample is used for gluing a composite material compression test plate and a reinforcing sheet and comprises a bottom plate, a supporting assembly is arranged on the bottom plate, at least one glue overflowing groove is formed in the bottom plate, and the glue overflowing grooves are located in the periphery of the composite material compression test plate placed on the bottom plate; the pressurizing assembly comprises a pressurizing plate and a pressurizing part, the fixed end of the pressurizing part is connected with the supporting assembly, and the free end of the pressurizing part is connected with the pressurizing plate. According to the gluing tool for the composite material compression test sample, the pressurization assembly pushes the pressurization plate to pressurize the composite material compression test plate and the reinforcing piece, the gluing quality of the composite material compression test plate and the reinforcing piece is guaranteed, extruded residual glue is contained in the glue overflowing groove, and the cleanliness of the periphery of the composite material compression test plate is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material manufacturing, and more particularly to a bonding tool for a composite material compression specimen and a manufacturing method thereof. Background Art

[0002] Composite materials, due to their high strength, high modulus, lightweight, and corrosion resistance, are widely used in aerospace, rail transit, and marine applications. Compression performance directly impacts the load-bearing efficiency and failure resistance of composite components under complex loads and is a core mechanical performance indicator. The compression performance of carbon fiber composites is influenced by a variety of factors, including fiber buckling, reinforcement bonding quality, curing process, process benchmark selection, and machining accuracy.

[0003] Currently, the most common method for preparing composite compression test pieces is manual scribing. A flat jig is used to control the spacing between reinforcements on the same side and the relative position of the reinforcements on the front and back sides. Four reinforcements are bonded to the front and back sides of the compression test plate, which is then secured with a fixture. After curing and demolding, the compression test specimen is processed. Manual measurement and control of the reinforcement position and accuracy can easily lead to asymmetry between the upper and lower reinforcements, poor consistency, and high dispersion in the test data. This can also result in uneven compression of the specimen, leading to the shedding of reinforcements during testing.

[0004] In response to existing problems, the industry has designed a variety of gluing tools for optimization and upgrading. However, most of the existing reinforcement sheet gluing tools only consider the gluing process, and do not keep the prepreg laying benchmark, the test plate and reinforcement sheet gluing benchmark, and the two machining benchmarks consistent. The prepared compression specimen fibers have poor parallelism with the test direction, which greatly reduces the test data. At the same time, the existing reinforcement sheet gluing tool cannot clean up the overflowed residual glue during the reinforcement sheet gluing process. This not only increases the polishing process for removing the residual glue, but also brings great difficulty to the positioning of the subsequent machining benchmark, which easily leads to an angular deviation between the processed sample and the fiber axis, resulting in low test data. At the same time, the clamping device of the reinforcement sheet during the bonding process mostly uses nuts to tighten, which greatly reduces the positioning accuracy and makes the clamping force uncontrollable, which easily causes excessive outflow of adhesive and glue starvation. The tooling structure and process are complex, not only inefficient, but also requires high quality of operators. Summary of the Invention

[0005] In view of this, the present invention provides a bonding tool for composite material compression specimens and a manufacturing method thereof to ensure the bonding quality of the composite material compression test plate and the reinforcement sheet. In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a bonding tool for composite material compression specimens, which is used for bonding composite material compression test plates and reinforcement sheets, comprising:

[0007] A bottom plate, wherein a support assembly is provided on the bottom plate, and at least one glue overflow groove is provided on the bottom plate, wherein the glue overflow groove is located around the composite material compression test plate placed on the bottom plate;

[0008] The pressurizing assembly includes a pressurizing plate and a pressurizing member. The fixed end of the pressurizing member is connected to the supporting assembly, and the free end of the pressurizing member is connected to the pressurizing plate. The composite material compression test plate on the bottom plate is pressurized by the pressurizing plate.

[0009] Furthermore, the bottom plate is provided with a prying opening, and there are multiple prying openings, which are arranged around the composite material compression test plate placed on the bottom plate.

[0010] Furthermore, the reinforcing sheet is provided with a groove, and both the bottom plate and the pressure plate are provided with a boss adapted to the groove of the reinforcing sheet, and glue overflow grooves are provided around the boss.

[0011] Furthermore, both the bottom plate and the pressure plate are provided with pin holes for pins to pass through.

[0012] In another aspect, the present invention provides a method for manufacturing a composite material compression specimen, wherein the method uses the above-mentioned bonding fixture for the composite material compression specimen, and the method comprises the following steps:

[0013] S10: Machining composite compression test panels

[0014] S110: Use anhydrous ethanol or detergent to clean the curing platform and L-shaped positioning ribs, and apply 3-5 coats of release agent in a "cross" pattern on the working surface of the tooling;

[0015] S120: Fix the L-shaped positioning rib on the curing platform and lay the carbon fiber prepreg layer by layer based on the L-shaped positioning rib;

[0016] S130: laying auxiliary materials in sequence for packaging to form a composite material blank, placing the composite material blank together with the forming tooling into an autoclave, curing the composite material blank using a stepwise temperature increase method according to the curing parameters of the prepreg, and after curing, cooling the temperature to room temperature in the oven and demolding to obtain a composite material compression test plate blank;

[0017] S140: Fixing the composite material compression test plate blank on a work surface, using a long side aligned with a long side of the L-shaped positioning rib as a machining X-direction reference, and a short side aligned with a short side of the L-shaped positioning rib as a machining Y-direction reference, and machining the composite material compression test plate blank to obtain a composite material compression test plate;

[0018] S20: Bond the composite compression test plate to the reinforcement sheet

[0019] S210: Pour an appropriate amount of anhydrous ethanol or detergent onto a clean, lint-free cotton cloth and wipe the bottom plate of the bonding tool clean; apply 3-5 coats of release agent in a cross pattern on the bottom plate of the bonding tool;

[0020] S220: A layer of single-sided adhesive release cloth is laid on the non-adhesive surface of the reinforcement sheet, and a layer of single-sided adhesive release cloth is laid on the composite material compression test plate below the groove of the reinforcement sheet;

[0021] S230: Apply the prepared adhesive evenly to the bonding surface of the reinforcement sheet and the composite material compression test plate, the thickness of the adhesive layer is 0.2-0.3mm, and let it stand for 5 minutes to defoam.

[0022] S240: Place the lower reinforcement sheet, the composite material compression test plate, the upper reinforcement sheet, and the pressure plate on the bottom plate in sequence, with the upper reinforcement sheet, the composite material compression test plate, and the lower reinforcement sheet aligned on all sides;

[0023] S250: Install the support column, support plate and pressure piece. The pressure piece pressurizes the composite material compression test plate and reinforcement sheet through the pressure plate. Use anhydrous ethanol or acetone to clean the residual glue that escapes from the surrounding area.

[0024] S260: Curing is performed according to the curing parameters of the selected adhesive. After curing is completed, the pressure plate is removed and the part is removed to obtain a composite material test piece;

[0025] S30: Processing composite compression specimens

[0026] S310: The composite material test piece is attached to a backing plate, and the long side of the composite material test piece is aligned with the X reference side of the backing plate, and the short side is aligned with the Y reference side of the backing plate. The backing plate is clamped on a workbench of a cutting and grinding machine for positioning, and the cutting and grinding machine is used to perform cutting and grinding according to the size and accuracy required by the composite material compression specimen drawing using a grinding wheel.

[0027] S320: Remove the double-sided tape on the back of the composite material test piece, clean the oil and dust on the surface of the composite material test piece with anhydrous ethanol or acetone, place it in an oven to dry, and obtain a composite material compression specimen.

[0028] Furthermore, in the process of laying the prepreg, the 0° edge line of the first layer of material is aligned with the long side of the L-shaped positioning rib, and the 90° edge line is aligned with the short side of the L-shaped positioning rib. It is gradually rolled out from one side to the other and laid layer by layer. The vacuum pre-compaction time is ≥5 minutes for every 3 to 8 layers laid, and the vacuum degree is not lower than -0.085Mpa. An equalizing plate is placed during pre-compaction.

[0029] Furthermore, a pin hole is provided on the reinforcing plate, and the position of the pin hole of the reinforcing plate corresponds to the position of the pin hole of the base plate. During the processing of the composite material compression test plate blank, pin holes corresponding to the positions of the pin holes of the reinforcing plate are processed at both ends of the composite material compression test plate blank. During the installation of the pressure piece, the pins are inserted into the pin holes of the reinforcing plate, the composite material compression test plate, the base and the pressure plate.

[0030] Furthermore, during the auxiliary material packaging process, pressure is applied near the gel point of the prepreg resin, and the molding pressure is controlled between 0.3 and 0.6 MPa.

[0031] Furthermore, 3M double-sided tape was used to bond the composite test piece to the backing plate, and the thickness of the grinding wheel was taken into account when the composite test piece was cut according to size.

[0032] Furthermore, during the drying process of the composite material test piece in the oven, the temperature in the oven is 60-80° C., and the composite material test piece is kept warm in the oven for 1.5-2 hours.

[0033] It can be seen from the above technical solution that compared with the prior art, the present invention discloses a bonding tool for composite material compression specimens, which pushes the pressure plate through the pressure component to pressurize the composite material compression test plate and the reinforcement sheet to ensure the bonding quality of the composite material compression test plate and the reinforcement sheet. The overflow glue groove is used to hold the squeezed residual glue, which makes it easy to clean the residual glue, thereby ensuring the cleanliness around the composite material compression test plate, ensuring the bonding quality of the composite material compression test plate and the reinforcement sheet, improving work efficiency, and at the same time ensuring the accuracy of the positioning of subsequent benchmarks, thereby ensuring that the machined benchmark is consistent with the direction of the fiber, thereby ensuring the accuracy of the test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0035] Figure 1 A schematic structural diagram of a bonding tool for composite material compression specimens provided by the present invention;

[0036] Figure 2 A schematic structural diagram of the support assembly provided by the present invention;

[0037] Figure 3 A schematic structural diagram of a pressurizing assembly provided by the present invention;

[0038] Figure 4 This is a schematic structural diagram of the composite material compression test plate and the reinforcement sheet provided by the present invention;

[0039] Figure 5 A schematic structural diagram of the pad provided by the present invention;

[0040] Figure 6 This is a comparison chart of compression performance test results of the composite material compression specimen provided by the present invention and the composite material compression specimen of the prior art.

[0041] In the figure: 1. Base plate; 2. Support assembly; 101. Handle; 102. Connecting bolt; 201. Support plate; 202. Connecting nut; 203. Support column; 3. Pressurizing assembly; 301. Pressurizing cylinder; 302. Controller; 303. Pressurizing plate; 4. Pin; 5. Composite material compression test plate; 6. Reinforcement sheet; 7. Curing platform; 8. L-shaped positioning rib; 9. Prepreg; 10. Lamination coordinate system. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] See also Figure 1-6 On the one hand, an embodiment of the present invention discloses a bonding tool for a composite material compression specimen, which is used to bond a composite material compression test plate and a reinforcement sheet 6, comprising:

[0044] A bottom plate, on which a support assembly 2 is provided, and at least one glue overflow groove is provided on the bottom plate, and the glue overflow groove is located around the composite material compression test plate placed on the bottom plate;

[0045] The pressurizing assembly includes a pressurizing plate 303 and a pressurizing member. The fixed end of the pressurizing member is connected to the supporting assembly 2 , and the free end of the pressurizing member is connected to the pressurizing plate 303 . The composite material compression test plate 5 on the bottom plate 1 is pressurized through the pressurizing plate 303 .

[0046] In some embodiments, the support assembly 2 includes a support column 203 and a support plate 201. The support column 203 is arranged on the base plate 1. The end of the support column 203 away from the base plate 1 is connected to the support plate 201, and the fixed end of the pressure piece is connected to the support plate 201.

[0047] During the process of gluing the composite material compression test plate 5 and the reinforcing sheet 6, the pressurizing assembly 3 drives the pressurizing plate 303 to extrude the composite material compression test plate 5 and the reinforcing sheet 6. At this time, the excess glue between the composite material compression test plate 5 and the reinforcing sheet 6 flows out into the glue overflow groove under the action of the extrusion force.

[0048] In some embodiments, two glue overflow grooves are provided on the bottom plate 1 , and the two glue overflow grooves are respectively provided on both sides of the composite material compression test plate 5 placed on the bottom plate 1 .

[0049] The setting of the overflow glue groove can ensure that the residual glue flowing out can be cleaned at any time during the process of bonding the composite material compression test plate 5 and the reinforcement sheet 6. There is no need to grind the residual glue after the composite material compression test plate 5 and the reinforcement sheet 6 are bonded, which speeds up the work efficiency. At the same time, it ensures that there is no residual glue around the composite material test piece after bonding, and ensures that the composite material test piece can be fitted with the reference edge on the pad, thereby ensuring that the reference direction is consistent with the fiber direction.

[0050] In some embodiments, a handle 101 is provided on the side wall of the base plate 1 , and the handle 101 is mounted on the side wall of the base plate via connecting bolts 101 .

[0051] In some embodiments, the bottom plate 1 and the pressure plate 303 are provided with prying openings, and there are multiple prying openings, which are arranged around the composite material compression test plate 5 placed on the bottom plate 1.

[0052] In some embodiments, the film prying openings are provided at both ends of the bottom plate 1 where no glue overflow groove is provided, and two film prying openings are provided at each end.

[0053] The provision of the prying opening facilitates demoulding of the composite material test piece obtained by gluing the composite material compression test plate 5 and the reinforcement sheet 6 .

[0054] In some embodiments, a groove is provided on the reinforcing sheet 6 , and both the bottom plate 1 and the pressure plate 303 are provided with bosses adapted to the groove of the reinforcing sheet 6 , and glue overflow grooves are provided around the bosses.

[0055] The alignment of the upper and lower reinforcing sheets is ensured by the cooperation of the bosses on the pressure plate 303 and the bottom plate 1 with the grooves on the upper and lower reinforcing sheets respectively.

[0056] The setting of the glue overflow groove makes it convenient to clean up the residual glue flowing out during the gluing process.

[0057] In some embodiments, the pressurizing member is a pressurizing cylinder 301 , which is fixed on the support plate 201 , and the pressurizing plate 303 is connected to the moving end of the pressurizing cylinder 301 .

[0058] In some embodiments, multiple through holes are provided on the base plate 1 and the support plate 201, and threads are provided at both ends of the support column 203. The support column 203 is fixed between the base plate 1 and the support plate 201 by connecting the connecting nut 202 with the threads on the support column 203.

[0059] In some embodiments, both the bottom plate 1 and the pressure plate 303 are provided with pin holes for the pins 4 to pass through.

[0060] Before gluing the composite material compression test plate 5 to the reinforcement plate 6, the lower reinforcement plate, composite material compression test plate 5, upper reinforcement plate and pressure plate 303 to be glued are stacked in sequence on the base plate 1 between the two overflow grooves, and the boss on the base plate 1 is located in the groove on the lower reinforcement plate, and the boss on the pressure plate 303 is located in the groove on the upper reinforcement plate to ensure the parallelism of the upper reinforcement plate and the lower reinforcement plate. The edge line of the composite material compression test plate 5 is aligned with the edge line of the upper reinforcement plate and the lower reinforcement plate, and the pin 4 is inserted into the pin hole to fix the composite material compression test plate 5 and the reinforcement plate 6. The support column 203, the support plate 201 and the pressure cylinder 301 are connected in sequence, and the pressure plate 303 and the pressure cylinder 301 are connected to complete the installation of the pressure component 3.

[0061] During the process of the pressurizing cylinder 301 squeezing the composite material compression test plate 5 and the reinforcing sheet 6 through the pressurizing plate 303, the movement of the pressurizing plate 303 is constrained by the pin 4 to ensure that the pressurizing plate 303 uniformly squeezes the composite material compression test plate 5 and the reinforcing sheet 6, thereby ensuring the squeezing effect.

[0062] In some embodiments, the pressurizing assembly 3 further includes a controller 302 , which is electrically connected to the pressurizing cylinder 301 .

[0063] On the other hand, an embodiment of the present invention discloses a method for manufacturing a composite material compression specimen, the manufacturing method using the above-mentioned bonding tool for the composite material compression specimen, and the manufacturing method comprising the following steps:

[0064] S10: Processing composite compression test plate 5

[0065] S110: Use anhydrous ethanol or a cleaning agent to clean the curing platform 7 and the L-shaped positioning rib 8, and apply 3-5 coats of release agent on the working surface of the tooling in a "cross" pattern;

[0066] S120: Fix the L-shaped positioning rib 8 on the curing platform 7, and lay the carbon fiber prepreg 9 layer by layer based on the L-shaped positioning rib 8;

[0067] S130: Auxiliary materials are laid out in sequence for packaging to form a composite material blank. The composite material blank is placed together with the forming tooling into an autoclave. The composite material blank is cured in a stepwise heating manner according to the curing parameters of the prepreg 9. After curing, the temperature is lowered to room temperature in the oven and then demolded to obtain a composite material compression test plate blank.

[0068] S140: Fixing the composite material compression test plate blank on a work surface, using a long side aligned with the long side of the L-shaped positioning rib 8 as a machining X-direction reference, and a short side aligned with the short side of the L-shaped positioning rib 8 as a machining Y-direction reference, and machining the composite material compression test plate blank to obtain a composite material compression test plate 5;

[0069] S20: Bonding the composite material compression test plate 5 to the reinforcement sheet 6

[0070] S210: Pour an appropriate amount of anhydrous ethanol or detergent onto a clean lint-free cotton cloth and wipe the bottom plate 1 of the bonding tool clean; apply 3-5 coats of release agent on the bottom plate 1 of the bonding tool in a cross pattern;

[0071] S220: A layer of single-sided adhesive release cloth is laid on the non-adhesive surface of the reinforcing sheet 6, and a layer of single-sided adhesive release cloth is laid on the composite material compression test plate 5 below the groove of the reinforcing sheet 6;

[0072] S230: evenly apply the prepared adhesive to the bonding surface of the reinforcement sheet 6 and the composite material compression test plate 5, the surface of which has been roughened, with the adhesive layer thickness of 0.2 to 0.3 mm, and let it stand for 5 minutes to defoam;

[0073] S240: placing the lower reinforcing sheet, the composite material compression test plate 5, the upper reinforcing sheet and the pressure plate 303 on the bottom plate 1 in sequence, with the upper reinforcing sheet, the composite material compression test plate 5 and the lower reinforcing sheet aligned on all sides;

[0074] S250: Install the support column 203, the support plate 201 and the pressure piece. The pressure piece presses the composite material compression test plate 5 and the reinforcement sheet 6 through the pressure plate 303. Clean the residual glue around with anhydrous ethanol or acetone.

[0075] S260: Curing is performed according to the curing parameters of the selected adhesive. After curing is completed, the pressure plate is removed and the part is removed to obtain a high-precision composite test piece;

[0076] S30: Processing high-precision composite compression specimens

[0077] S310: The composite material test piece is attached to the backing plate, and the long side of the composite material test piece is aligned with the X reference side of the backing plate, and the short side is aligned with the Y reference side of the backing plate. The backing plate is clamped on the workbench of the cutting and grinding machine to position the backing plate, and the cutting and grinding machine is used to perform cutting and grinding according to the size and accuracy required by the composite material compression specimen drawing using the grinding wheel of the cutting and grinding machine;

[0078] S320: Remove the double-sided tape on the back of the composite test piece, clean the oil and dust on the surface of the composite test piece with anhydrous ethanol or acetone, place it in an oven to dry, and obtain a high-precision composite compression specimen.

[0079] During the process of laying the carbon fiber prepreg 9, the prepreg 9 is laid in the same fiber direction, and the fiber direction is aligned with the X-direction reference or the Y-direction reference in the layup coordinate system 10 of the curing platform 7 to ensure the consistency of the fiber direction in the composite material sample, improve the straightness of the fiber, and thus improve the preparation accuracy of the composite material compression sample.

[0080] In some embodiments, during the process of laying the prepreg 9, the 0° edge line of the first layer of material is aligned with the long side of the L-shaped positioning retaining edge 8, and the 90° edge line is aligned with the short side of the L-shaped positioning retaining edge 8. The material is gradually rolled and laid from one side to the other, layer by layer, to prevent stacking defects such as air entrapment and fiber wrinkles. The vacuum pre-compaction time is ≥5 minutes for every 3 to 8 layers laid, and the vacuum degree is not lower than -0.085 MPa. An equalizing plate is placed during pre-compacting to ensure uniform pressure on the surface of the prepreg 9.

[0081] In some embodiments, the curing parameters of the prepreg 9 in the autoclave are:

[0082] a. Maintain vacuum, increase the temperature at a rate of 1°C / min, hold the temperature at 100±5°C for 15 minutes, and pressurize to 0.3±0.03MPa;

[0083] b. Raise the temperature at a rate of 1°C / min, hold at 102±5°C for 20 minutes, and pressurize to 0.5±0.03MPa;

[0084] c. Raise the temperature at a rate of 1°C / min, and when the temperature reaches 105±5°C, keep the temperature and pressure for 25 minutes;

[0085] d. Raise the temperature at a rate of 1°C / min, and when the temperature reaches 140±5°C, keep the temperature and pressure for 120 minutes.

[0086] e. Cool down to below 60℃ at a cooling rate of 1℃ / min, and release the pressure to remove the product from the tank.

[0087] In some embodiments, a pin hole is provided on the reinforcing sheet 6, and the position of the pin hole of the reinforcing sheet 6 corresponds to the position of the pin hole of the base plate 1. During the processing of the composite material compression test plate blank, pin holes corresponding to the positions of the pin holes of the reinforcing sheet 6 are processed at both ends of the composite material compression test plate blank. During the installation of the pressure piece, the pin 4 is inserted into the pin holes of the reinforcing sheet 6, the composite material compression test plate 5, the base plate 1 and the pressure plate 303.

[0088] By cooperating with the pin hole and the pin 4, the composite material compression test plate 5 and the reinforcement sheet 6 are prevented from moving during the bonding process, the parallelism of the upper reinforcement sheet and the lower reinforcement sheet is ensured, the bonding quality is ensured, and thus the preparation accuracy of the composite material compression specimen is ensured.

[0089] In some embodiments, during the auxiliary material packaging process, pressure is applied near the gel point of the prepreg 9, and the molding pressure is controlled between 0.3 and 0.6 MPa.

[0090] By controlling the timing of pressurization and molding pressure, the resin can further flow and fill under the distribution of the force field, expelling bubbles and volatiles in the material, making the composite material compression test plate 5 laminated and dense, ensuring that the composite material compression test plate 5 has no internal defects such as delamination, foreign matter, inclusions, and pores.

[0091] In some embodiments, the composite material test piece is bonded to the backing plate using 3M double-sided tape, and the thickness of the grinding wheel is taken into consideration when calculating the size of the composite material test piece.

[0092] In some embodiments, during the drying of the composite material test piece in the oven, the temperature in the oven is 60-80° C., and the composite material test piece is kept warm in the oven for 1.5-2 hours.

[0093] In some embodiments, the reinforcing sheet 6 is bonded and cured with the composite material compression test plate 5 using epoxy adhesive 3M DP460, Blackstone J-133, or Langbowan 660-X. The curing system is determined by the type of adhesive used.

[0094] In some embodiments, a dial indicator is required to ensure that the deviation in the X-axis direction is controlled within 0.1 mm when determining the machining datum.

[0095] In some embodiments, the ejection pressure set by the small pressurized cylinder 301 is calculated based on the contact area between the pressurized plate 303 and the reinforcing sheet 6, and the ejection pressure F = P*S, where P is the contact pressure (generally, the molding pressure of the liquid adhesive is controlled at 0.02-0.05 MPa), and S is the area of ​​the contact surface between the pressurized plate 303 and the reinforcing sheet 6 projected in the horizontal direction.

[0096] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0097] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bonding tool for composite material compression specimens, used for bonding composite material compression test plates and reinforcement sheets, characterized in that: include: A bottom plate, wherein a support assembly is provided on the bottom plate, and at least one glue overflow groove is provided on the bottom plate, wherein the glue overflow groove is located around the composite material compression test plate placed on the bottom plate; The pressurizing assembly includes a pressurizing plate and a pressurizing member. The fixed end of the pressurizing member is connected to the supporting assembly, and the free end of the pressurizing member is connected to the pressurizing plate. The composite material compression test plate on the bottom plate is pressurized by the pressurizing plate.

2. The bonding tool for composite material compression specimens according to claim 1, characterized in that: The bottom plate is provided with a prying opening, and a plurality of the prying openings are provided. The plurality of the prying openings are arranged around the composite material compression test plate placed on the bottom plate.

3. The bonding tool for composite material compression specimens according to claim 1, characterized in that: The reinforcing sheet is provided with a groove, and both the bottom plate and the pressure plate are provided with a boss adapted to the groove of the reinforcing sheet, and glue overflow grooves are provided around the boss.

4. The bonding tool for composite material compression specimens according to claim 1, characterized in that: The bottom plate and the pressure plate are both provided with pin holes for pins to pass through.

5. A method for manufacturing a composite material compression specimen, characterized in that: The manufacturing method uses the bonding tool for composite material compression specimens according to any one of claims 1 to 4, and the manufacturing method comprises the following steps: S10: Machining composite compression test panels S110: Use anhydrous ethanol or detergent to clean the curing platform and L-shaped positioning ribs, and apply 3-5 coats of release agent in a "cross" pattern on the working surface of the tooling; S120: Fix the L-shaped positioning rib on the curing platform and lay the carbon fiber prepreg layer by layer based on the L-shaped positioning rib; S130: laying auxiliary materials in sequence for packaging to form a composite material blank, placing the composite material blank together with the forming tooling into an autoclave, curing the composite material blank using a stepwise temperature increase method according to the curing parameters of the prepreg, and after curing, cooling the temperature to room temperature in the oven and demolding to obtain a composite material compression test plate blank; S140: Fixing the composite material compression test plate blank on a work surface, using a long side aligned with a long side of the L-shaped positioning rib as a machining X-direction reference, and a short side aligned with a short side of the L-shaped positioning rib as a machining Y-direction reference, and machining the composite material compression test plate blank to obtain a composite material compression test plate; S20: Bond the composite compression test plate to the reinforcement sheet S210: Pour an appropriate amount of anhydrous ethanol or detergent onto a clean, lint-free cotton cloth and wipe the bottom plate of the bonding tool clean; apply 3-5 coats of release agent in a cross pattern on the bottom plate of the bonding tool; S220: A layer of single-sided adhesive release cloth is laid on the non-adhesive surface of the reinforcement sheet, and a layer of single-sided adhesive release cloth is laid on the composite material compression test plate below the groove of the reinforcement sheet; S230: Apply the prepared adhesive evenly to the bonding surface of the reinforcement sheet and the composite material compression test plate, the thickness of the adhesive layer is 0.2-0.3mm, and let it stand for 5 minutes to defoam. S240: Place the lower reinforcement sheet, the composite material compression test plate, the upper reinforcement sheet, and the pressure plate on the bottom plate in sequence, with the upper reinforcement sheet, the composite material compression test plate, and the lower reinforcement sheet aligned on all sides; S250: Install the support column, support plate and pressure piece. The pressure piece pressurizes the composite material compression test plate and reinforcement sheet through the pressure plate. Use anhydrous ethanol or acetone to clean the residual glue that escapes from the surrounding area. S260: Curing is performed according to the curing parameters of the selected adhesive. After curing is completed, the pressure plate is removed and the part is removed to obtain a composite material test piece; S30: Processing composite compression specimens S310: The composite material test piece is attached to a backing plate, and the long side of the composite material test piece is aligned with the X reference side of the backing plate, and the short side is aligned with the Y reference side of the backing plate. The backing plate is clamped on a workbench of a cutting and grinding machine for positioning, and the cutting and grinding machine is used to perform cutting and grinding according to the size and accuracy required by the composite material compression specimen drawing using a grinding wheel. S320: Remove the double-sided tape on the back of the composite material test piece, clean the oil and dust on the surface of the composite material test piece with anhydrous ethanol or acetone, place it in an oven to dry, and obtain a composite material compression specimen.

6. The method for manufacturing a composite material compression specimen according to claim 5, characterized in that: During the process of laying prepreg, align the 0° edge line of the first layer of material with the long side of the L-shaped positioning rib, and align the 90° edge line with the short side of the L-shaped positioning rib. Gradually roll it out from one side to the other and lay it layer by layer. For every 3 to 8 layers laid, the vacuum pre-compaction time should be ≥5 minutes, and the vacuum degree should not be lower than -0.085Mpa. Place a pressure equalizing plate during pre-compaction.

7. The method for manufacturing a composite material compression specimen according to claim 5, characterized in that: A pin hole is provided on the reinforcing plate, and the position of the pin hole of the reinforcing plate corresponds to the position of the pin hole of the base plate. During the processing of the composite material compression test plate blank, pin holes corresponding to the positions of the pin holes of the reinforcing plate are processed at both ends of the composite material compression test plate blank. During the installation of the pressure piece, the pins are inserted into the pin holes of the reinforcing plate, the composite material compression test plate, the base and the pressure plate.

8. The method for manufacturing a composite material compression specimen according to claim 5, characterized in that: During the auxiliary material packaging process, pressure is applied near the gel point of the prepreg resin, and the molding pressure is controlled between 0.3 and 0.6 MPa.

9. The method for manufacturing a composite material compression specimen according to claim 5, characterized in that: The composite test piece and the backing plate were bonded using 3M double-sided tape, and the thickness of the grinding wheel was taken into account when the composite test piece was cut according to size.

10. The method for manufacturing a composite material compression specimen according to claim 5, characterized in that: During the drying process of the composite material test piece in the oven, the temperature in the oven is 60 to 80° C., and the composite material test piece is kept warm in the oven for 1.5 to 2 hours.

Images