Composite material interface performance test sample preparation device and method based on fiber multifilament

Abstract

The invention discloses a fiber multifilament-based composite material interface performance test sample preparation device and method, and belongs to the technical field of composite material interface characterization. The sample preparation device comprises a wire winding plate, a bottom plate, a multifilament fixing plate, compactors, a rod type pressure head and a rubber strip, the compactors are arranged at four corners of the bottom plate, the wire winding plate is placed on the bottom plate, the multifilament fixing plate is arranged on the wire winding plate in a matched mode, the rod type pressure head is installed on the compactors through a duplex structure, and the rubber strip is arranged on the lower portion of the rod type pressure head. Wire clamping grooves are formed in the two ends of the wire winding plate in the length direction. The sample preparation method comprises the following steps: respectively adhering a single-sided adhesive release cloth and a pressure-sensitive adhesive tape to the front and back surfaces of a wire winding plate, winding a first bundle of fibers, adhering the pressure-sensitive adhesive tape, then pressing and impregnating the resin on the first bundle of fibers, repeating the operation, and winding a second bundle of fibers and impregnating the resin; and fully infiltrating and compounding the two bundles of fibers, and separating the sample group to obtain the test sample after curing of the resin is completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material interface characterization, and in particular relates to a device and method for preparing composite material interface performance test samples based on fiber multifilaments. Background Art

[0002] Fiber-reinforced resin-based composite materials are widely used as load-bearing structures in aviation, aerospace, new energy vehicles, wind turbine blades and other fields due to their light weight and high strength. Compared with traditional metal and other engineering materials, fiber-reinforced resin-based composite materials are composed of a reinforcing phase (fiber), a matrix phase (resin) and an interface phase. The interface phase acts as a "bridge" and "heart" between the fiber and the resin, and can transfer loads and inhibit damage expansion. It can be said that the quality of the interface performance is one of the key factors affecting the mechanical properties of composite materials. At present, there are two main methods for characterizing interface performance: microscopic and macroscopic. The former tests the interface shear strength between the fiber and the resin by micro-debonding and single-filament pull-out methods, while the latter characterizes the quality of its interface performance by testing the interlaminar shear strength of the composite laminate.

[0003] However, for micro-interface performance characterization methods such as micro-debonding and single-filament pull-out, the test specimens are fiber monofilaments, the sample preparation process is relatively complicated and inconvenient to operate, and the fiber multifilaments are often composed of thousands or tens of thousands of single filaments. The micro-testing methods have problems such as large performance dispersion and low data reliability, and it is difficult to objectively show the interface performance between the fiber and the resin; compared with the micro-testing methods, macro-interface performance characterization methods such as interlaminar shear strength and transverse tensile strength tests can be used to reliably evaluate the interface performance between the resin and the fiber and are widely used in the engineering field. However, considering that the test specimens are composite laminate structures, the sample preparation process is more complicated, and the manufacturing cycle and manufacturing cost are higher than the micro-testing methods.

[0004] In response to the above problems, the present invention provides a device and method for preparing sample for composite interface performance test based on fiber multifilament, which is suitable for the interface performance evaluation process between fiber multifilament and resin matrix. It can effectively characterize the interface performance on the basis of rapid sample preparation while reducing the test cycle and cost. Summary of the Invention

[0005] In response to the shortcomings of the prior art, the present invention provides a device and method for preparing test samples for composite interface properties based on fiber multifilaments. On the one hand, compared with the characterization method of interface shear strength, this method can avoid the influence of fiber discreteness on test data, and the test data is closer to the interface performance of real composite materials; on the other hand, compared with the sample preparation method for testing interlaminar shear strength, this method has the advantages of less material usage, short sample preparation cycle, low material consumption cost and manufacturing cost. This method forms an infiltration composite effect between the fiber multifilament and the resin that is between the microscopic and macroscopic, and realizes a reliable evaluation of the interface performance of the composite material through a fast and simple sample preparation and testing method. The present invention can improve the reliability of interface performance evaluation while reducing sample preparation cycle and cost, and is suitable for the evaluation process of interface performance between different fiber bundles and different resin matrices.

[0006] A device for preparing sample for testing interface properties of composite materials based on fiber multifilaments comprises a wire winding plate, a base plate, a multifilament fixing plate, a compactor, a rod-type pressing head and a rubber strip. Compactors are provided at the four corners of the base plate, the wire winding plate is placed on the base plate, and the multifilament fixing plate is provided in conjunction with the wire winding plate; the rod-type pressing head is installed on the compactor in a double-linked structure, and a rubber strip is provided at the lower part of the rod-type pressing head.

[0007] The wire winding plate is a rectangular plate, and wire-clamping grooves are provided at both ends of the length direction of the plate.

[0008] A method for preparing a sample for testing the interface properties of a composite material based on fiber multifilaments is implemented using the above-mentioned device and specifically comprises the following steps:

[0009] (1) The left end of the front length direction of the wire wrapping plate is defined as A, the right end of the front length direction of the wire wrapping plate is defined as B, the position of the rod-type pressure head on the left side of the front of the wire wrapping plate is defined as C, and the position of the rod-type pressure head on the right side of the front of the wire wrapping plate is defined as D; the left end of the back length direction of the wire wrapping plate is defined as E, the right end of the back length direction of the wire wrapping plate is defined as F, the position of the rod-type pressure head on the left side of the back of the wire wrapping plate is defined as G, and the position of the rod-type pressure head on the right side of the back of the wire wrapping plate is defined as H;

[0010] (2) Affix a single-sided adhesive release cloth to positions C and H of the wire wrapping plate along the width direction, and affix a first layer of pressure-sensitive tape to positions A, B, E, F and positions C, D, G, H of the wire wrapping plate along the width direction;

[0011] (3) After fixing one end of the first bundle of fibers to the edge of the winding plate, the first bundle of fibers is wound in the grooves of the winding plate in sequence, and then a second layer of pressure-sensitive tape is attached to the surface of the first bundle of fibers near the positions of the first layer of pressure-sensitive tape at positions C, D, G, and H;

[0012] (4) Place the winding plate on the bottom plate and use pins to fix the two multifilament fixing plates on both sides of the winding plate at point C. Use a glue spreading tool to evenly apply the resin on the rubber strip of the rod-type press head. Use a compactor to press the resin along point C and impregnate it on the first bundle of fibers.

[0013] After the resin impregnation is completed, remove the pins and the multifilament fixing plate and turn over the winding plate. Then use the pins to fix the two multifilament fixing plates on both sides of the H point of the winding plate. Repeat the above operation to press the resin along the H point to impregnate the first bundle of fibers.

[0014] (5) Separate the wire wrapping plate from the base plate, fix one end of the second fiber bundle to the edge of the wire wrapping plate, and then wind the second fiber bundle in the wire-binding groove of the wire wrapping plate in sequence. Then, adhere a third layer of pressure-sensitive tape to the surface of the second fiber bundle near the positions of the first layer of pressure-sensitive tape at positions A, B, E, and F.

[0015] (6) Place the wire wrapping plate on the bottom plate again, clean the residual resin on the rubber strip, and press the glue pressing positions at C and H in turn with a presser to promote good resin infiltration and compounding between the two bundles of fibers;

[0016] (7) After the wire wrapping plate is removed and the resin is cured, all fiber bundles are cut at both ends of the front side A and B of the wire wrapping plate, and the first layer of pressure-sensitive tape is peeled off to obtain a sample group. The sample group is separated from the wire wrapping plate, and the first and second fiber bundles are cut at the AC and CD sides of the wire wrapping plate C, respectively. The pressure-sensitive tape is then cut along the direction of the fiber bundle to complete the separation of the first group of samples.

[0017] Cut all fiber bundles at both ends E and F on the reverse side of the wire wrapping plate, peel off the first layer of pressure-sensitive tape to obtain a sample group, separate the sample group from the wire wrapping plate, cut the first and second fiber bundles on the FH and GH sides of the wire wrapping plate H, respectively, and then cut the pressure-sensitive tape along the direction of the fiber bundle to complete the separation of the second group of samples;

[0018] (8) Use pressure-sensitive tape to fix the two ends of the sample to be clamped, clamp the sample and test it in a straightened state to obtain the load value.

[0019] in:

[0020] In the step (3), the fiber type is selected from carbon fiber, aramid fiber, glass fiber, ultra-high molecular weight polyethylene fiber, quartz fiber, basalt fiber, poly(p-phenylene phenylene propanedioxazole) fiber or various natural fibers, the number of fiber roots is selected from 1k, 3k, 12k, 24k or 48k, and the fiber tow is in the form of twisted or untwisted.

[0021] In the step (3), bending and twisting of the fiber bundle should be avoided during the fiber winding process to prevent the fibers from bundling or breaking.

[0022] In the step (4), the glue application tools include brushes, droppers, syringes and cotton swabs. Brushes and cotton swabs are suitable for resins with a viscosity of ≤1 Pa·s, while droppers and syringes are suitable for resins with a viscosity of >1 Pa·s.

[0023] In the step (4), the resin is selected from epoxy resin, bismaleimide resin, unsaturated polyester resin, phenolic resin and polyimide resin.

[0024] In the step (4), the width of the rubber strip is preferably in the range of 0.5 mm to 3 mm.

[0025] In the step (8), the sample is fixed by pasting 2 to 3 layers of pressure-sensitive tape on the position of the sample to be clamped.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. Compared with microscopic characterization methods such as interface shear strength, the present invention uses multifilament to characterize the interface properties of composite materials, which can avoid the influence of fiber discreteness on the test data, and the test data is closer to the interface properties of real composite materials.

[0028] 2. Compared with macroscopic characterization methods such as interlaminar shear strength, the present invention uses multifilament to prepare composite material interface performance characterization samples, which uses less material, has a shorter sample preparation cycle, and has lower material consumption and manufacturing costs.

[0029] 3. Compared with traditional characterization methods such as interface shear strength and interlaminar shear strength, the present invention directly uses multifilaments to prepare samples and conduct composite material interface performance tests. There is no need to use single-filament samples or molded laminate samples, which effectively simplifies the sample preparation and characterization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A three-dimensional diagram of the structure of a composite material sample preparation device based on fiber multifilament of the present invention;

[0031] Figure 2 A front view of the structure of a composite material sample preparation device based on fiber multifilament of the present invention;

[0032] In the figure: 1-wire winding plate, 2-wire groove, 3-bottom plate, 4-multifilament fixing plate, 5-rod type pressure head, 6-rubber strip, 7-presser; A is the left end of the front length direction of the wire winding plate, B is the right end of the front length direction of the wire winding plate, C is the position of the rod type pressure head on the left side of the front of the wire winding plate, D is the position of the rod type pressure head on the right side of the front of the wire winding plate, E is the left end of the back length direction of the wire winding plate, F is the right end of the back length direction of the wire winding plate, G is the position of the rod type pressure head on the left side of the back of the wire winding plate, and H is the position of the rod type pressure head on the right side of the back of the wire winding plate. DETAILED DESCRIPTION

[0033] The contents disclosed in the present invention, including key technical points such as changes in fiber types, changes in fiber numbers, changes in resin types, etc., should be regarded as the protection scope of the present invention.

[0034] The present invention will be further described below with reference to specific implementation cases, but the present invention is not limited to these embodiments.

[0035] Taking the CS series fibers provided by Changsheng (Langfang) Technology Co., Ltd. as an example, CS-1 and CS-2 are 3k carbon fibers, CS-3 and CS-4 are 24k carbon fibers, and the fiber tows are in the form of untwisted fibers; the resin selected is bismaleimide resin QY8911-I, whose viscosity is less than 1Pa·s.

[0036] In the embodiment of the present invention, the width of the rubber strip in the composite material interface performance test sample preparation device is 2 mm.

[0037] Example 1

[0038] A fiber multifilament-based composite material interface performance test sample preparation device, the three-dimensional diagram of its structure is as follows Figure 1 As shown, the front view is as Figure 2 As shown, it includes a wire winding plate 1, a base plate 3, a multifilament fixing plate 4, a compressor 7, a rod-type pressure head 5 and a rubber strip 6. Compressors 7 are provided at the four corners of the base plate 3. The wire winding plate 1 is placed on the base plate 3, and a multifilament fixing plate 4 is provided on the wire winding plate 1. The rod-type pressure head 5 is installed on the compressor 7 in a double-linked structure, and a rubber strip 6 is provided at the lower part of the rod-type pressure head 5.

[0039] The wire wrapping plate 1 is a rectangular plate, and wire-clamping grooves 2 are provided at both ends in the length direction thereof.

[0040] Example 2

[0041] A method for preparing a sample for testing the interface properties of a fiber multifilament composite material is implemented using the apparatus described in Example 1, and specifically comprises the following steps:

[0042] (1) The left end of the front length direction of the wire winding plate 1 is defined as A, the right end of the front length direction of the wire winding plate 1 is defined as B, the position of the rod-type pressure head 5 on the left side of the front of the wire winding plate 1 is defined as C, and the position of the rod-type pressure head 5 on the right side of the front of the wire winding plate 1 is defined as D; the left end of the back length direction of the wire winding plate 1 is defined as E, the right end of the back length direction of the wire winding plate 1 is defined as F, the position of the rod-type pressure head 5 on the left side of the back of the wire winding plate 1 is defined as G, and the position of the rod-type pressure head 5 on the right side of the back of the wire winding plate 1 is defined as H.

[0043] (2) A single-sided adhesive release cloth is attached to the wire wrapping plate 1 at positions C and H along the width direction. The attachment position is an area 10 mm wide on both sides of the central axis of the rubber strip 6. A first layer of pressure-sensitive tape is attached to the wire wrapping plate 1 near positions A, B, E, F and near positions C, D, G, and H (with a distance greater than 25.4 mm from the wire-binding groove 2) along the width direction. The purpose of attaching the first layer of pressure-sensitive tape is to facilitate the detachment of the fiber bundle from the surface of the wire wrapping plate 1. The wire wrapping plate 1 cooperates with the rod-type pressure head 5 and the bottom plate 3 on both sides to achieve the preparation of twice the number of test specimens.

[0044] (3) After fixing one end of the first bundle of carbon fiber filaments on the edge of the winding plate 1, the first bundle of carbon fiber filaments is wound in the wire-clamping groove 2 of the winding plate 1 in sequence. During the fiber winding process, it is necessary to avoid bending and twisting of the fiber bundle to prevent the fibers from bundling or breaking. Then, a second layer of pressure-sensitive tape is attached to the surface of the first bundle of fibers near the positions of the first layer of pressure-sensitive tape at C, D, G, and H.

[0045] (4) Place the winding plate 1 on the base plate 3 and use pins to fix the two multifilament fixing plates 4 on both sides of the winding plate 1 at point C. Use a brush to evenly apply QY8911-I resin to the rubber strip 6 of the rod-type pressing head 5. Use the pressing device 7 to press the resin along point C and impregnate it into the first bundle of fibers. Use a cotton swab to remove excess resin from the winding structure. The function of the multifilament fixing plates is to prevent the multifilament fibers from moving and deforming during the gluing process.

[0046] After the resin impregnation is completed, remove the pins and the multifilament fixing plate 4 and turn over the winding plate 1. Then use the pins to fix the two multifilament fixing plates 4 on both sides of the H of the winding plate 1. Repeat the above operation, press the QY8911-I resin along the H to impregnate it on the first bundle of fibers, and use a cotton swab to clean the excess resin.

[0047] (5) Separate the wire wrapping plate 1 from the base plate 3, fix one end of the second bundle of carbon fiber tow to the edge of the wire wrapping plate 1, and then wind the second bundle of carbon fiber tow in the wire-card groove 2 of the wire wrapping plate 1 in sequence, and then stick the third layer of pressure-sensitive tape on the surface of the second bundle of fibers near the positions of the first layer of pressure-sensitive tape at A, B, E, and F.

[0048] (6) Place the wire wrapping plate 1 on the bottom plate 3 again, clean the residual resin on the rubber strip 6, and press the glue pressing positions at C and H in turn through the pressing device 7 to promote good resin infiltration and compounding between the two bundles of fibers.

[0049] (7) After the wire wrapping plate 1 is taken out and placed in a vacuum oven to complete the curing of the resin, all fiber bundles are cut at both ends A and B of the front surface of the wire wrapping plate 1, and the first layer of pressure-sensitive tape is peeled off to obtain a sample group. The sample group is separated from the wire wrapping plate, and the first and second fiber bundles are cut at 10 mm from the AC side and CD side of the wire wrapping plate 1C, respectively. The pressure-sensitive tape is then cut along the direction of the fiber bundle to complete the separation of the first group of samples.

[0050] Cut off all fiber bundles at both ends E and F on the back side of the wire-wound plate 1, peel off the first layer of pressure-sensitive tape to obtain a sample group, separate the sample group from the wire-wound plate 1, cut the first bundle of fibers and the second bundle of fibers 10 mm away from the FH side and the GH side of the wire-wound plate 1H, respectively, and then cut the pressure-sensitive tape along the direction of the fiber bundle to complete the separation between the second group of samples, thereby producing multiple samples formed by overlapping two bundles of fibers.

[0051] (8) Use pressure-sensitive tape to stick three layers of pressure-sensitive tape on the clamping positions of the two ends of the sample to prevent the sample from slipping during the stretching process. Clamp the sample and keep it in a straightened state to test and obtain the load value.

[0052] By comparing and analyzing the X-ray photoelectron spectroscopy and scanning electron microscope images of the surfaces of CS-1, CS-2, CS-3 and CS-4 samples, it can be seen that the interface performance of the small-tow carbon fiber CS-1 is better than that of CS-2, and the interface performance of the large-tow carbon fiber CS-4 is greater than that of CS-3. This is consistent with the tensile peeling load per unit area of 3.169 N / mm2 of CS-1, CS-2, CS-3 and CS-4 samples obtained by the method of the present invention. 2 , 3.128N / mm 2 , 0.971N / mm 2 and 1.716N / mm 2 The trends are consistent, which proves that the present invention can effectively characterize the interface properties between fiber multifilaments and resin.

Claims

1. A device for preparing sample for testing interface properties of composite materials based on fiber multifilament, characterized in that: It includes a wire winding plate, a base plate, a multifilament fixing plate, a compressor, a rod-type pressure head and a rubber strip. Compressors are provided at the four corners of the base plate. The wire winding plate is placed on the base plate, and a multifilament fixing plate is provided in conjunction with the wire winding plate. The rod-type pressure head is installed on the compressor in a double-linked structure, and a rubber strip is provided at the lower part of the rod-type pressure head.

2. The device for preparing sample for testing interface properties of composite materials based on fiber multifilament according to claim 1, characterized in that: The wire winding plate is a rectangular plate, and wire-clamping grooves are provided at both ends of the length direction of the plate.

3. A method for preparing a sample for testing the interface properties of a composite material based on fiber multifilaments, implemented using the device described in claim 1, characterized in that: The specific steps include: (1) The left end of the front length direction of the wire wrapping plate is defined as A, the right end of the front length direction of the wire wrapping plate is defined as B, the position of the rod-type pressure head on the left side of the front of the wire wrapping plate is defined as C, and the position of the rod-type pressure head on the right side of the front of the wire wrapping plate is defined as D; the left end of the back length direction of the wire wrapping plate is defined as E, the right end of the back length direction of the wire wrapping plate is defined as F, the position of the rod-type pressure head on the left side of the back of the wire wrapping plate is defined as G, and the position of the rod-type pressure head on the right side of the back of the wire wrapping plate is defined as H; (2) Affix a single-sided adhesive release cloth to positions C and H of the wire wrapping plate along the width direction, and affix a first layer of pressure-sensitive tape to positions A, B, E, F and positions C, D, G, H of the wire wrapping plate along the width direction; (3) After fixing one end of the first bundle of fibers to the edge of the winding plate, the first bundle of fibers is wound in the grooves of the winding plate in sequence, and then a second layer of pressure-sensitive tape is attached to the surface of the first bundle of fibers near the positions of the first layer of pressure-sensitive tape at positions C, D, G, and H; (4) Place the winding plate on the bottom plate and use pins to fix the two multifilament fixing plates on both sides of the winding plate at point C. Use a glue spreading tool to evenly apply the resin on the rubber strip of the rod-type press head. Use a compactor to press the resin along point C and impregnate it on the first bundle of fibers. After the resin impregnation is completed, remove the pins and the multifilament fixing plate and turn over the winding plate. Then use the pins to fix the two multifilament fixing plates on both sides of the H point of the winding plate. Repeat the above operation to press the resin along the H point to impregnate the first bundle of fibers. (5) Separate the wire wrapping plate from the base plate, fix one end of the second fiber bundle to the edge of the wire wrapping plate, and then wind the second fiber bundle in the wire-binding groove of the wire wrapping plate in sequence. Then, adhere a third layer of pressure-sensitive tape to the surface of the second fiber bundle near the positions of the first layer of pressure-sensitive tape at positions A, B, E, and F. (6) Place the wire wrapping plate on the bottom plate again, clean the residual resin on the rubber strip, and press the glue pressing positions at C and H in turn with a presser to promote good resin infiltration and compounding between the two bundles of fibers; (7) After the wire wrapping plate is removed and the resin is cured, all fiber bundles are cut at both ends of the front side A and B of the wire wrapping plate, and the first layer of pressure-sensitive tape is peeled off to obtain a sample group. The sample group is separated from the wire wrapping plate, and the first and second fiber bundles are cut at the AC and CD sides of the wire wrapping plate C, respectively. The pressure-sensitive tape is then cut along the direction of the fiber bundle to complete the separation of the first group of samples. Cut all fiber bundles at both ends E and F on the reverse side of the wire wrapping plate, peel off the first layer of pressure-sensitive tape to obtain a sample group, separate the sample group from the wire wrapping plate, cut the first and second fiber bundles on the FH and GH sides of the wire wrapping plate H, respectively, and then cut the pressure-sensitive tape along the direction of the fiber bundle to complete the separation of the second group of samples; (8) Use pressure-sensitive tape to fix the two ends of the sample to be clamped, clamp the sample and test it in a straightened state to obtain the load value.

4. The method for preparing a sample for testing the interface properties of a fiber multifilament composite material according to claim 3, wherein: In the step (3), the fiber type is selected from carbon fiber, aramid fiber, glass fiber, ultra-high molecular weight polyethylene fiber, quartz fiber, basalt fiber, poly(p-phenylene phenylene propanedioxazole) fiber or various natural fibers, the number of fiber roots is selected from 1k, 3k, 12k, 24k or 48k, and the fiber tow is in the form of twisted or untwisted.

5. The method for preparing a sample for testing the interface properties of a composite material based on fiber multifilament according to claim 3, characterized in that: In the step (3), bending and twisting of the fiber bundle should be avoided during the fiber winding process to prevent the fibers from bundling or breaking.

6. The method for preparing a sample for testing the interface properties of a fiber multifilament composite material according to claim 3, wherein: In the step (4), the glue application tools include brushes, droppers, syringes and cotton swabs. Brushes and cotton swabs are suitable for resins with a viscosity of ≤1 Pa·s, while droppers and syringes are suitable for resins with a viscosity of >1 Pa·s.

7. The method for preparing a sample for testing the interface properties of a fiber multifilament composite material according to claim 3, wherein: In the step (4), the resin is selected from epoxy resin, bismaleimide resin, unsaturated polyester resin, phenolic resin and polyimide resin.

8. The method for preparing a sample for testing interface properties of a fiber multifilament composite material according to claim 3, characterized in that: In the step (4), the width of the rubber strip is preferably in the range of 0.5 mm to 3 mm.

9. The method for preparing a sample for testing interface properties of a fiber multifilament composite material according to claim 3, wherein: In the step (8), the sample is fixed by pasting 2 to 3 layers of pressure-sensitive tape on the position of the sample to be clamped.

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