Method for processing composite material mechanical test piece
Through the method of cutting reinforcement sheets by co-curing molding and precise processing equipment, the problem of unstable test data in the manufacturing of composite mechanical test pieces is solved, the accuracy and reliability of the test pieces are improved, and the manufacturing cost is reduced.
Patent Information
- Application Number
- CN202510558581.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2025-08-19
AI Technical Summary
During the manufacturing process of composite material mechanical testing, factors such as the distance, parallelism, perpendicularity and overflow of adhesive tapes affect the accuracy of the test results, resulting in poor repeatability of the mechanical test data. It is difficult for existing methods to ensure that the test pieces are not damaged under thermal shock, which affects the real performance of the material.
The co-curing molding method is adopted to co-cure the mechanical test piece and the reinforcement sheet through the film layer, and the reinforcement sheet is cut to the film layer with precise processing equipment to ensure the cutting accuracy and reference, avoid secondary molding damage, and use special equipment for cutting and processing.
It improves the dimensional accuracy of the mechanical test piece and the stability of the test data, reduces manufacturing costs, enhances the repeatability and manufacturing efficiency of the test piece, and ensures the true performance of the material.
Smart Images
Figure CN120503267A_ABST
Abstract
Description
Technical Field
[0001] The present invention discloses a method for processing composite material mechanical test pieces, which is applicable to the manufacturing process of composite material mechanical test reinforcement test pieces, can improve the processing accuracy of mechanical test reinforcement test pieces, and ensure the stability of mechanical test piece test data. Background Art
[0002] Mechanical property testing is an indispensable means of characterizing the performance of composite materials. It is necessary to use composite materials to manufacture typical test pieces, process them according to specific dimensions, and use relevant equipment to conduct tests to obtain corresponding data. Usually mechanical property tests include: tensile strength / modulus, compressive strength / modulus, flexural strength / modulus, layer shear strength, in-plane shear strength, peel strength, etc. For adhesive structures, they also include crack propagation resistance, tensile shear strength, etc. In order to accurately test the mechanical properties of composite materials, the distribution of test results is required to be relatively convergent, the range of average values is relatively concentrated, and the difference between the average value and the minimum value is small. Therefore, the mechanical testing of composite materials has extremely stringent requirements for the material itself, the manufacturing process of composite material test pieces, and the testing process. Problems in any process will lead to unqualified experimental results. Because the manufacture of composite material mechanical test pieces is a relatively complex process, it requires processes such as layer-by-layer stacking, autoclave curing, and the pasting of reinforcement sheets, which has a particularly obvious impact on the results. Especially for mechanical property test pieces that need to be pasted with reinforcement sheets, the distance, parallelism, verticality, and glue overflow at the edge of the reinforcement sheets will all affect the test results. At the same time, pasting the reinforcement sheets generally requires heating and curing the adhesive film, which will cause thermal shock to the mechanical test piece, resulting in poor repeatability of the mechanical test piece test data and leading to failure of the mechanical test. Summary of the Invention
[0003] The purpose of the present invention is to design a manufacturing method to address the above-mentioned problem of manufacturing reinforced test pieces for mechanical testing of composite materials. By changing the manufacturing method of reinforced test pieces for mechanical testing of composite materials and using designed precise processing equipment, the dimensional accuracy of mechanical performance test pieces is improved, the distribution of mechanical test piece test results is made more convergent, the influence of the mechanical performance test piece manufacturing process on the results is reduced, and the success rate of mechanical testing of composite materials is improved.
[0004] A manufacturing method designed to address the manufacturing issues of reinforced test pieces for mechanical testing of composite materials involves co-curing the mechanical test piece and the reinforcement sheet. A film is added to the mechanical test piece and reinforcement sheet to ensure a baseline for subsequent processing. Co-curing ensures that the resin and fiber of the mechanical test piece are not damaged by secondary molding, thereby maximizing the material's true performance. After co-curing, the test piece is processed using specially designed processing equipment with precision machining capabilities. This equipment has the ability to accurately cut the reinforcement sheet down to the film layer, ensuring both the dimensional accuracy and gap accuracy of the reinforcement sheet and completely cutting the reinforcement sheet to prevent it from affecting the mechanical test piece. This manufacturing method is simple, easy to operate, highly repeatable, and improves manufacturing efficiency while reducing manufacturing costs.
[0005] According to one aspect of the present application, a method for processing a composite material mechanical test piece is provided, wherein the composite material mechanical test piece comprises, from one side to the other, a reinforcement sheet layer, a film layer, a mechanical test piece layer, a film layer, and a reinforcement sheet layer;
[0006] The thickness of the composite material mechanical test piece is 4 to 10.5 mm;
[0007] There are two symmetrical areas on the composite mechanical test piece. There is no reinforcement layer in this area. From one side to the other, there is a film layer, a mechanical test piece layer, and a film layer. The thickness of this area is 2 to 4 mm.
[0008] The method adopts a device for processing a composite material mechanical test piece, which is composed of a motor 9, a cutting tool 10, an X-axis movement controller 11, a Y-axis movement controller 12, a Z-axis movement controller 13, a clamping platform 14, a clamping platform movement controller 15, and a pressing device 16;
[0009] The method comprises the following steps:
[0010] The test piece 7 to be processed is installed on the test piece clamping platform 14. During installation, one end of the test piece 7 to be processed is pressed against the clamping platform 14. The clamping device 16 is adjusted to hold the test piece 7 to be processed for cutting. The Y-axis movement controller 12 is adjusted to move the cutting tool 10 to the position where cutting is required. After checking that the Y-axis movement controller 12 reaches the theoretical position, the Y-axis movement controller 12 is locked. The Z-axis movement controller 13 is adjusted so that the cutting tool 10 can cut the test piece 7 to be processed. After the adjustment is completed, the Z-axis movement controller 13 is locked. The clamping platform movement controller 15 is adjusted, the motor 9 is started, and the X-axis movement controller 11 is controlled to enable the cutting tool 10 to cut the test piece 7 to be processed.
[0011] After the first cut, use a depth gauge to measure the actual cutting depth and evaluate the subsequent processing feed rate and number according to this depth;
[0012] Adjust the clamping platform movement controller 15 to continuously increase the cutting depth. According to the evaluation, when the remaining cutting depth of the test piece 7 to be processed is about 0.2 mm, the adjustment amount of the clamping platform movement controller 15 is reduced to 0.05 mm each time until the reinforcing sheet 2 of the test piece 7 to be processed is completely removed and the adhesive film 5 appears.
[0013] The test piece 7 to be processed is removed and then flipped over and clamped, and the above steps are repeated until the reinforcing sheet 2 of the test piece 7 to be processed on the other side is completely removed, and the adhesive film 5 appears, thereby obtaining the composite material mechanical test piece.
[0014] The Y-axis movement controller 12 has a scale and can achieve a movement accuracy of 0.01 mm.
[0015] The adjustment of the clamping platform movement controller 15 requires accurate confirmation of the cutting depth, and the initial adjustment depth is generally about 0.5 mm.
[0016] The mechanical test piece layer is made of carbon fiber prepreg material with a thickness of 2 to 4 mm;
[0017] The reinforcing sheet is made of carbon fiber prepreg with a thickness of 1 to 3 mm;
[0018] The adhesive film layer is selected from at least one of epoxy adhesive film, bismaleimide adhesive film and polyimide adhesive film, and has a thickness of 0.05 to 0.2 mm.
[0019] The adhesive film layer has color, which is convenient for identification during processing.
[0020] The test piece 7 to be processed is obtained by stacking a mechanical test piece 1 and a reinforcing sheet 2. A layer of adhesive film 5 is stacked between the mechanical test piece 1 and the reinforcing sheet 2. During the stacking process, the positions of the mechanical test piece 1 and the reinforcing sheet 2 are determined by a reference ruler 3. After the stacking is completed, the test piece 7 to be processed is cured.
[0021] The reference ruler 3 and the test piece 7 to be processed are cured together.
[0022] The thickness of the reference ruler 3 is the same as that of the test piece 7 to be processed.
[0023] The test piece to be processed 7 can be processed into multiple composite material mechanical test pieces;
[0024] When the same piece of test piece 7 to be processed is to be processed into multiple composite material mechanical test pieces, multiple composite material mechanical test pieces can be cut out first and then a specific area of each composite material mechanical test piece can be processed, or a specific area can be processed first and then multiple composite material mechanical test pieces can be cut out.
[0025] Optionally, the following steps are included:
[0026] When stacking the mechanical test piece 1 and the reinforcement sheet 2, a reference ruler 3 is aligned. A layer of adhesive film 5 is laid between the two sheets. The reference ruler 3, along with the mechanical test piece 1 and the reinforcement sheet 2, is cured together, providing the mechanical test piece 1 and the reinforcement sheet 2 with a processing reference edge 6. The mechanical test piece 1 is then cut to remove excess material based on the processing reference edge 6, resulting in multiple test pieces 7 to be processed. The reinforcement sheet 2 is processed using specially designed test piece processing equipment 8, which comprises a motor 9, a cutting tool 10, an X-axis motion controller 11, a Y-axis motion controller 12, a Z-axis motion controller 13, a test piece clamping platform 14, and a clamping platform motion controller 15. When using the test piece processing equipment 8, the test piece to be processed 7 is mounted on the test piece clamping platform 14, the Y-axis movement controller 12 and the Z-axis movement controller 13 are adjusted so that the cutting tool 10 is located at the processing position of the test piece to be processed 7, the clamping platform movement controller 15 is accurately adjusted, the cutting depth is confirmed, and then the motor 9 is started, and the X-axis movement controller 11 is moved so that the cutting tool 10 processes the reinforcement sheet 2 of the test piece to be processed 7. After each back and forth processing, the clamping platform movement controller 15 is adjusted to make the test piece to be processed 7 rise to a certain position until the reinforcement sheet 2 is completely removed and the adhesive film 5 appears.
[0027] The mechanical test piece 1 and reinforcement sheet 2 are manufactured by laying up carbon fiber prepreg. The carbon fiber prepreg is cut to the same size using a CNC blanking machine. During the tooling, the prepreg reference edge must be aligned with the reference ruler 3, which is usually made of metal and has a thickness comparable to that of the test piece and reinforcement sheet. After all the layers are laid up, a composite laminate 4 is obtained. A metal plate is placed on top of the composite laminate 4 to ensure the overall flatness of the test piece. The test piece 7 to be processed is then manufactured and packaged in a vacuum bag in the tooling and placed in an autoclave for curing.
[0028] The cured composite laminate 4 is transferred to the cutting site and cut according to the processing reference edge 6. According to the external dimensions required for mechanical testing, the external dimensions are cut into test pieces 7 to be processed that are consistent with the final dimensions.
[0029] The test piece 7 to be processed is transferred to the test piece processing equipment 8 and installed on the test piece clamping platform 14. During installation, one end of the test piece 7 to be processed is pressed against the clamping platform 14, and the clamping device 16 is adjusted to hold the test piece 7 to be processed for cutting.
[0030] Adjust the Y-axis motion controller 12 of the test piece processing equipment 8 to move the cutting tool 10 to the position where cutting is required. The Y-axis motion controller 12 has a scale that can achieve a motion accuracy of 0.01mm. After checking that the Y-axis motion controller 12 has reached the theoretical position, lock the Y-axis motion controller 12.
[0031] Adjust the Z-axis motion controller 13 of the specimen processing equipment 8 so that the cutting tool 10 can cut the specimen 7 to be processed. After adjustment, lock the Z-axis motion controller 13. Accurately adjust the clamping platform motion controller 15 to confirm the cutting depth. The initial adjustment depth is generally about 0.5mm.
[0032] Start the motor 9 and control the X-axis motion controller 11, causing the cutting tool 10 to cut the test piece 7. After the first cut, use a depth gauge to measure the reinforcement sheet 2 of the test piece 7 to determine the actual cutting depth. This depth is used to estimate the feed rate and number of subsequent processing times.
[0033] The clamping platform movement controller 15 is repeatedly adjusted to continuously increase the cutting depth. According to the evaluation, when there is about 0.2mm of cutting amount left for the test piece 7 to be processed, the adjustment amount of the clamping platform movement controller 15 is reduced to 0.05mm each time until the reinforcing sheet 2 of the test piece 7 to be processed is completely removed and the adhesive film 5 appears.
[0034] The test piece 7 to be processed is removed and then flipped over and clamped, and step 3) of processing the composite material test piece reinforcement sheet is repeated until the reinforcement sheet 2 of the other side of the test piece 7 to be processed is completely removed, and the adhesive film 5 appears, thereby obtaining the composite material mechanical test piece 1.
[0035] Advantages of the solution of the present invention:
[0036] The present invention improves the dimensional accuracy of mechanical property test pieces by changing the manufacturing method of reinforced test pieces for mechanical testing of composite materials and using designed precise processing equipment. The mechanical test piece and the reinforcement sheet of the present invention are co-cured and formed, and a film is added to the mechanical test piece and the reinforcement sheet to ensure the benchmark for subsequent processing. The co-curing molding can ensure that the resin and fiber of the mechanical test piece are not damaged by secondary molding, and the true performance of the material is guaranteed to the greatest extent. The processing of the test piece is achieved by specially designed processing equipment, which can accurately cut the reinforcement sheet to the film layer, ensuring both the dimensional accuracy and gap accuracy of the reinforcement sheet, and can also completely cut the reinforcement sheet to prevent the reinforcement sheet from affecting the mechanical test piece. The manufacturing method is simple, easy to operate, highly repeatable, improves manufacturing efficiency, and reduces manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 Schematic diagram of the composite material mechanical test piece, where a is the main view and b is the side view;
[0038] Figure 2 Schematic diagram of the stacking of composite material mechanical test specimens.
[0039] Figure 3 Schematic diagram of the use of the benchmark ruler.
[0040] Figure 4Schematic diagram of cutting multiple composite mechanical test specimens from a composite laminate.
[0041] Figure 5 Schematic diagram of the device for processing composite material mechanical test pieces.
[0042] Among them: 1 mechanical test piece, 2 reinforcement piece, 3 reference ruler, 4 composite material laminate, 5 adhesive film, 6 processing reference edge, 7 test piece to be processed, 8 test piece processing equipment, 9 motor, 10 cutting tool, 11X-axis movement controller, 12Y-axis movement controller, 13Z-axis movement controller, 14 clamping platform, 15 clamping platform movement controller, 16 clamping device. DETAILED DESCRIPTION
[0043] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.
[0044] Example 1
[0045] Figures 1 to 5 The method for manufacturing a mechanical test piece 1 for composite material compression testing is shown as a technical solution of the present invention. The mechanical test piece 1 for composite material compression testing includes a reinforcement sheet 2. During manufacturing, a composite laminate 4 is first fabricated as a whole, which is then cut into test pieces 7 to be processed. These test pieces 7 are then processed using test piece processing equipment 8, ultimately resulting in a qualified composite mechanical test piece 1. The test piece is 80 mm long, 15 mm wide, and 2 mm thick. The reinforcement sheet is 38 mm long and 2 mm thick, and the gap between the two reinforcement sheets is 4.75 mm wide.
[0046] The process scheme includes the following steps:
[0047] 1) Composite material test piece manufacturing
[0048] The composite mechanical test piece 1 and its included reinforcement sheet 2 are manufactured by laying up carbon fiber prepregs. The carbon fiber prepregs are cut to uniform size using a CNC blanking machine. During the layup process, the prepreg reference edges must be aligned with a reference ruler 3, which is typically made of metal and has a thickness comparable to that of the test piece and reinforcement sheet. After all the layers are laid up, a metal plate is placed over the composite laminate 4 to ensure the overall flatness of the test piece. The test piece is then packaged in a vacuum bag in the manufacturing tooling and cured in an autoclave.
[0049] 2) Composite material test piece cutting
[0050] The cured composite laminate 4 is transferred to the cutting site, and cut according to the processing reference edge 6 of the composite laminate 4 formed during the curing process, and cut into test pieces 7 with the same external dimensions as the final dimensions required for mechanical testing.
[0051] 3) Composite material test piece reinforcement processing
[0052] The test piece 7 to be processed is transferred to the test piece processing equipment 8 and installed on the test piece clamping platform 14. During installation, one end of the test piece 7 to be processed is pressed against the clamping platform 14, and the clamping device 16 is adjusted to hold the test piece 7 to be processed for cutting.
[0053] Adjust the Y-axis motion controller 12 of the test piece processing equipment 8 to move the cutting tool 10 to the position where cutting is required. The Y-axis motion controller 12 has a scale that can achieve a motion accuracy of 0.01mm. After checking that the Y-axis motion controller 12 has reached the theoretical position, lock the Y-axis motion controller 12.
[0054] Adjust the Z-axis motion controller 13 of the specimen processing equipment 8 so that the cutting tool 10 can cut the specimen 7 to be processed. After adjustment, lock the Z-axis motion controller 13. Accurately adjust the clamping platform motion controller 15 to confirm the cutting depth. The initial adjustment depth is generally about 0.5mm.
[0055] Start the motor 9 and control the X-axis motion controller 11, causing the cutting tool 10 to cut the test piece 7. After the first cut, use a depth gauge to measure the reinforcement sheet 2 of the test piece 7 to determine the actual cutting depth. This depth is used to estimate the feed rate and number of subsequent processing times.
[0056] The clamping platform movement controller 15 is repeatedly adjusted to continuously increase the cutting depth. According to the evaluation, when there is about 0.2mm of cutting amount left for the test piece 7 to be processed, the adjustment amount of the clamping platform movement controller 15 is reduced to 0.05mm each time until the reinforcing sheet 2 of the test piece 7 to be processed is completely removed and the adhesive film 5 appears.
[0057] Remove the test piece 7 to be processed and flip it over and clamp it, repeat 3) the composite material test piece reinforcement sheet processing step until the reinforcement sheet 2 of the other side of the test piece 7 to be processed is completely removed and the adhesive film 5 appears, and the composite material mechanical test piece 1 is obtained.
[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art may make various modifications or substitutions within the technical scope disclosed in the present invention, and all such modifications or substitutions shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.
Claims
1. A method for processing a composite material mechanical test piece, characterized in that: The composite material mechanical test piece comprises, from one side to the other, a reinforcement sheet layer, a film layer, a mechanical test piece layer, a film layer, and a reinforcement sheet layer; The thickness of the composite material mechanical test piece is 4 to 10.5 mm; There are two symmetrical areas on the composite mechanical test piece. There is no reinforcement layer in this area. From one side to the other, there is a film layer, a mechanical test piece layer, and a film layer. The thickness of this area is 2 to 4 mm. The method adopts a device for processing a composite material mechanical test piece, the device comprising a motor (9), a cutting tool (10), an X-axis movement controller (11), a Y-axis movement controller (12), a Z-axis movement controller (13), a clamping platform (14), a clamping platform movement controller (15), and a pressing device (16); The method comprises the following steps: The test piece (7) to be processed is mounted on the test piece clamping platform (14). During the mounting process, one end of the test piece (7) to be processed is pressed against the clamping platform (14). The pressing device (16) is adjusted to fix the test piece (7) to be processed for cutting. The Y-axis movement controller (12) is adjusted to move the cutting tool (10) to the position where cutting is required. After checking that the Y-axis movement controller (12) reaches the theoretical position, the Y-axis movement controller (12) is locked. The Z-axis movement controller (13) is adjusted to enable the cutting tool (10) to cut the test piece (7) to be processed. After the adjustment is completed, the Z-axis movement controller (13) is locked. The clamping platform movement controller (15) is adjusted to start the motor (9). The X-axis movement controller (11) is controlled to enable the cutting tool (10) to cut the test piece (7) to be processed. After the first cut, use a depth gauge to measure the actual cutting depth and evaluate the subsequent processing feed rate and number according to this depth; Adjust the clamping platform movement controller (15) to continuously increase the cutting depth. When the remaining cutting amount of the test piece (7) to be processed is about 0.2 mm, the adjustment amount of the clamping platform movement controller (15) is reduced to 0.05 mm each time until the reinforcing sheet (2) of the test piece (7) to be processed is completely removed and the adhesive film (5) appears. The test piece (7) to be processed is removed and then flipped over and clamped, and the above steps are repeated until the reinforcing sheet (2) of the test piece (7) to be processed on the other side is completely removed, and the adhesive film (5) appears, thereby obtaining the composite material mechanical test piece.
2. The method for processing a composite material mechanical test piece according to claim 1, characterized in that: The Y-axis movement controller (12) has a scale and can achieve a movement accuracy of 0.01 mm.
3. The method for processing a composite material mechanical test piece according to claim 1, characterized in that: The adjustment of the clamping platform movement controller (15) requires accurate confirmation of the cutting depth, and the initial adjustment depth is generally about 0.5 mm.
4. The method for processing a composite material mechanical test piece according to claim 1, characterized in that: The mechanical test piece layer is made of carbon fiber prepreg material with a thickness of 2 to 4 mm; The reinforcing sheet is made of carbon fiber prepreg with a thickness of 1 to 3 mm; The adhesive film layer is selected from at least one of epoxy adhesive film, bismaleimide adhesive film and polyimide adhesive film, and has a thickness of 0.05 to 0.2 mm.
5. The method for processing a composite material mechanical test piece according to claim 1, characterized in that: The adhesive film layer has color, which is convenient for identification during processing.
6. The method for processing a composite material mechanical test piece according to claim 1, characterized in that: The test piece (7) to be processed is obtained by stacking a mechanical test piece (1) and a reinforcing piece (2), and a layer of adhesive film (5) is stacked between the mechanical test piece (1) and the reinforcing piece (2). During the stacking process, the positions of the mechanical test piece (1) and the reinforcing piece (2) are determined by a reference ruler (3); after the stacking is completed, the test piece (7) to be processed is cured; The reference ruler (3) and the test piece (7) to be processed are cured together.
7. The method for processing a composite material mechanical test piece according to claim 1, characterized in that: The thickness of the reference ruler (3) is the same as that of the test piece (7) to be processed.
8. The method for processing a composite material mechanical test piece according to claim 1, characterized in that: The test piece to be processed (7) can be processed into a plurality of composite material mechanical test pieces; When a plurality of composite material mechanical test pieces are to be processed from the same test piece to be processed (7), the plurality of composite material mechanical test pieces can be cut out first and then a specific area of each composite material mechanical test piece is processed, or the specific area is processed first and then a plurality of composite material mechanical test pieces are cut out.