Test method for anti-delamination performance of prepreg

Abstract

The present disclosure relates to a method for testing the anti-delamination performance of prepregs. The method for testing the anti-delamination performance of prepregs includes: obtaining a plurality of prepreg samples; paving a plurality of prepreg samples to form a prepreg sample; peeling off a first target prepreg sample of the prepreg sample to obtain a target sample; determining the anti-delamination performance of the prepreg according to the target height of the second target prepreg sample remaining on the surface of the target sample; wherein, before peeling off the first target prepreg sample, the first target prepreg sample is paved on the surface of the second target prepreg sample, and the remaining part of the prepreg sample after peeling off the first target prepreg sample is the target sample. The anti-delamination performance of the prepreg is determined according to the target height that can characterize the delamination phenomenon of the prepreg sample, thereby improving the accuracy of determining the anti-delamination performance of the prepreg. After completing various anti-delamination performance tests of prepregs, a prepreg with stronger anti-delamination performance is selected to prepare the prepreg to improve the preparation efficiency of the composite material.

Description

Technical Field

[0001] The present invention relates to the field of testing technology, and in particular to a method for testing the anti-delamination performance of a prepreg. Background Art

[0002] Prepreg is a composite of a resin matrix and a reinforcement made by impregnating continuous fibers or fabrics with a resin matrix under strictly controlled conditions. Unidirectional prepreg is a type of prepreg. Since composite materials made of unidirectional prepreg have the advantage of a stable resin-fiber ratio, they are widely used in fields with high precision requirements such as the aerospace and automotive industries. However, when part of the unidirectional prepreg needs to be removed during the laying process, the unidirectional prepreg is prone to damage, resulting in a reduction in the preparation efficiency of the composite material. Summary of the invention

[0003] In order to overcome the problems existing in the related art, the present disclosure provides a method for testing the anti-delamination performance of prepreg.

[0004] The present disclosure provides a method for testing the anti-delamination performance of a prepreg, and the method comprises:

[0005] obtaining a plurality of prepreg specimens;

[0006] Laying out a plurality of the prepreg specimens to form a prepreg sample;

[0007] peeling off a first target prepreg specimen of the prepreg sample to obtain a target sample;

[0008] determining the anti-delamination performance of the prepreg according to a target height of a second target prepreg sample remaining on the surface of the target sample;

[0009] Before peeling off the first target prepreg sample, the first target prepreg sample is laid on the surface of the second target prepreg sample, and the remaining part of the prepreg sample after peeling off the first target prepreg sample is the target sample.

[0010] In some embodiments of the present disclosure, the plurality of prepreg specimens include a first prepreg specimen, a second prepreg specimen, and a third prepreg specimen, wherein the second prepreg specimen includes a first surface and a second surface that are opposite to each other;

[0011] The step of laying out a plurality of the prepreg specimens to form a prepreg sample comprises:

[0012] removing the protective film from the first region of the first prepreg sample;

[0013] removing the protective films on the first surface and the second surface of the second prepreg sample;

[0014] Laying the first surface on the first area;

[0015] removing the protective film from the second region of the third prepreg sample;

[0016] Laying the second region of the third prepreg sample on the second surface to form the prepreg sample;

[0017] Among them, the length of the first region is greater than or equal to the length of the first surface, and the length of the second region is greater than or equal to the length of the second surface; the length of the third prepreg sample is greater than the length of the first prepreg sample, and the length of the first prepreg sample is greater than the length of the second prepreg sample.

[0018] In some embodiments of the present disclosure, the first prepreg sample includes a third surface and a fourth surface that are opposite to each other, the first area is located on the fourth surface, and before removing the protective film of the first area of ​​the first prepreg sample, the method further includes:

[0019] removing the protective film on the third surface of the first prepreg sample;

[0020] The third surface is adhered to the fixing plate.

[0021] In some embodiments of the present disclosure, before peeling off the first target prepreg specimen of the prepreg sample, the method further includes:

[0022] A preset pressure is applied to the prepreg sample.

[0023] In some embodiments of the present disclosure, applying a preset pressure to the prepreg sample comprises:

[0024] placing the prepreg sample between a first pressing roller and a second pressing roller;

[0025] Determining a target distance that the second pressing roller needs to move toward the first pressing roller according to the preset pressure;

[0026] The second pressing roller is controlled to move toward the first pressing roller by the target distance.

[0027] In some embodiments of the present disclosure, determining the anti-delamination performance of the prepreg according to the target height of the second target prepreg sample remaining on the surface of the target sample includes:

[0028] Acquiring fiber heights of a plurality of fibers of the second target prepreg sample remaining on the surface of the target sample as a plurality of the target heights;

[0029] According to the number of the target heights, determining each target length corresponding to each of the target heights;

[0030] Determining an anti-delamination index of the prepreg according to the plurality of target heights and the plurality of target lengths;

[0031] The anti-delamination performance of the prepreg is determined according to the anti-delamination index of the prepreg.

[0032] In some embodiments of the present disclosure, determining each target length corresponding to each target height according to the number of the target heights includes:

[0033] Sorting the plurality of target heights in ascending order;

[0034] According to the order from small to large, each of the target lengths corresponding to each of the target heights is determined.

[0035] In some embodiments of the present disclosure, determining the prepreg anti-delamination index according to the plurality of target heights and the plurality of target lengths includes:

[0036] Get the preset height;

[0037] According to the preset height, the plurality of target heights are divided into a plurality of first target heights smaller than the preset height and a plurality of second target heights larger than the preset height;

[0038] The prepreg anti-delamination index is determined according to a plurality of the first target heights, a plurality of the second target heights, the preset height, and a plurality of the target lengths.

[0039] In some embodiments of the present disclosure, determining the prepreg anti-delamination index according to the plurality of first target heights, the plurality of second target heights, the preset height, and the plurality of target lengths includes:

[0040] According to the plurality of the first target heights and the plurality of the second target heights, respectively determining a plurality of corresponding first target lengths and a plurality of corresponding second target lengths;

[0041] Determining a first prepreg anti-delamination index according to a plurality of the first target heights, a plurality of the first target lengths, and the preset height;

[0042] Determining a second prepreg anti-delamination index according to a plurality of the second target heights, a plurality of the second target lengths, and the preset height;

[0043] The prepreg anti-delamination index is determined according to the first prepreg anti-delamination index and the second prepreg anti-delamination index.

[0044] In some embodiments of the present disclosure, after peeling off the target prepreg specimen of the prepreg sample to obtain the target sample, the method further includes:

[0045] spraying a first coating onto the surface of the target sample;

[0046] Spraying a second coating onto the surface of the target sample, wherein the color of the second coating is different from the color of the first coating;

[0047] photographing the target sample to obtain image information of the target sample;

[0048] transmitting the image information to a digital image correlation system;

[0049] determining a target height of the second target prepreg sample remaining on the surface of the target sample according to output data of the digital image correlation system;

[0050] Wherein, the area of ​​the target sample sprayed with the first coating is larger than the area of ​​the target sample sprayed with the second coating.

[0051] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0052] Acquire multiple prepreg samples, and lay multiple prepreg samples to form a prepreg sample to simulate the plying process of the prepreg. Peel off the first target prepreg sample of the prepreg sample to obtain the target sample, thereby removing part of the plying of the prepreg. According to the target height of the second target prepreg sample remaining on the surface of the target sample, determine the anti-delamination performance of the prepreg, and determine the anti-delamination performance according to the delamination phenomenon of the second target prepreg sample. By determining the anti-delamination performance of the prepreg according to the target height that can characterize the delamination phenomenon of the prepreg sample, the accuracy of determining the anti-delamination performance of the prepreg is improved. Moreover, after completing the test of the anti-delamination performance of various prepregs, prepregs with strong anti-delamination performance can be selected to prepare prepregs in large quantities, thereby improving the anti-delamination performance of the prepreg used to prepare composite materials, thereby improving the preparation efficiency of composite materials.

[0053] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0055] Figure 1 It is a schematic diagram of the structure of a prepreg for plying;

[0056] Figure 2 is a schematic flow chart of a method for testing the anti-delamination performance of prepreg according to an exemplary embodiment;

[0057] Figure 3 is a schematic flow chart of a method for testing the anti-delamination performance of prepreg according to another exemplary embodiment;

[0058] Figure 4 is a schematic diagram of an exploded structure of a prepreg sample according to an exemplary embodiment;

[0059] Figure 5 is a schematic structural diagram of a prepreg sample after peeling off a first target prepreg sample according to an exemplary embodiment;

[0060] Figure 6 is a schematic top view of a target sample according to an exemplary embodiment;

[0061] Figure 7 is a schematic flow chart of a method for testing the anti-delamination performance of prepreg according to another exemplary embodiment;

[0062] Figure 8 is a schematic structural diagram of a stripping device according to an exemplary embodiment;

[0063] Fig. 9 is a schematic flow chart of a method for testing the anti-delamination performance of prepreg according to another exemplary embodiment;

[0064] Fig.10 is a schematic flow chart of a method for testing the anti-delamination performance of prepreg according to another exemplary embodiment;

[0065] Fig.11 is a schematic flow chart of a method for testing the anti-delamination performance of prepreg according to another exemplary embodiment;

[0066] Fig.12 is a schematic diagram showing a curve relationship between a target length and a target height according to another exemplary embodiment;

[0067] Fig.13 is a schematic flow chart of a method for testing the anti-delamination performance of prepreg according to another exemplary embodiment;

[0068] Fig.14 is a schematic flow chart of a method for testing the anti-delamination performance of prepreg according to another exemplary embodiment;

[0069] Fig.15 is a block diagram of a testing device according to an exemplary embodiment.

[0070] In the figure:

[0071] 1. first prepreg; 2. second prepreg; 3. third prepreg; 4. fourth prepreg; 10. first prepreg sample; 11. third surface; 12. first area; 20. fixing plate; 30. second prepreg sample; 40. third prepreg sample; 41. second area; 50-first fixture; 51. first pressure roller; 52. second pressure roller; 53. conveying roller; 54. first connector; 55. second connector; 100. test equipment; 101. computing unit; 102. ROM; 103. RAM; 104. bus; 105. input / output interface; 106. input unit; 107. output unit; 108. storage unit; 109. communication unit. DETAILED DESCRIPTION

[0072] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0073] Prepreg is a composite of a resin matrix and a reinforcement made by impregnating continuous fibers or fabrics with a resin matrix under strictly controlled conditions. Unidirectional prepreg is a type of prepreg. Composite materials made of unidirectional prepreg have the advantage of a stable resin-fiber ratio, so they are widely used in aerospace, automotive and other fields with high precision requirements. During the laying process of unidirectional prepregs, operational errors or equipment deviations may cause wrinkles in the laid unidirectional prepregs, or foreign matter may be mixed between the laid unidirectional prepregs. In order to ensure the quality of the prepared composite materials, some unidirectional prepregs need to be removed for re-laying. However, if the anti-delamination performance of the unidirectional prepreg is poor, delamination may occur when it is removed. Such as Figure 1 As shown, the prepregs for the plying include a first prepreg 1, a second prepreg 2, a third prepreg 3 and a fourth prepreg 4. The second prepreg 2 is laid between the first prepreg 1 and the third prepreg 3, and the third prepreg 3 is laid between the second prepreg 2 and the fourth prepreg 4. When wrinkles exist in the fourth prepreg 4, the fourth prepreg 4 needs to be removed. When the fourth prepreg 4 is removed, the third prepreg 3 may be delaminated, that is, a part of the third prepreg 3 exists on the second prepreg 2, and a part of the third prepreg 3 exists on the fourth prepreg 4. As a result, the prepregs that have been laid cannot be used, which reduces the preparation efficiency of the composite material and increases the production cost.

[0074] Based on this, the present disclosure provides a method for testing the anti-delamination performance of prepregs, by simulating the laying and removal process of prepregs, and determining the target height of the second target prepreg sample remaining on the surface of the target sample, so as to determine whether the second target prepreg sample is delaminated and the strength of the delamination phenomenon according to the target height, thereby improving the accuracy of determining the anti-delamination performance of the prepreg. Moreover, after completing the test of the anti-delamination performance of various prepregs, prepregs with strong anti-delamination performance can be selected to prepare prepregs in large quantities, thereby improving the anti-delamination performance of the prepregs used to prepare composite materials, thereby improving the preparation efficiency of composite materials.

[0075] The present disclosure provides a method for testing the anti-delamination performance of prepregs. Figure 2 As shown, the method includes:

[0076] S100, obtaining a plurality of prepreg samples.

[0077] S200, laying out a plurality of prepreg test specimens to form a prepreg sample.

[0078] S300 , peeling off a first target prepreg specimen of a prepreg sample to obtain a target sample.

[0079] S400, determining the anti-delamination performance of the prepreg according to the target height of the second target prepreg sample remaining on the surface of the target sample.

[0080] Before the first target prepreg sample is peeled off, the first target prepreg sample is laid on the surface of the second target prepreg sample, and the remaining part of the prepreg sample after the first target prepreg sample is peeled off is the target sample.

[0081] In the present embodiment, a plurality of prepreg samples are obtained, and a plurality of prepreg samples are laid to form a prepreg sample to simulate the plying process of the prepreg. The first target prepreg sample of the prepreg sample is peeled off to obtain the target sample, thereby partially removing the plying of the prepreg. According to the target height of the second target prepreg sample remaining on the surface of the target sample, the anti-delamination performance of the prepreg is determined, and the anti-delamination performance is determined according to the delamination phenomenon of the second target prepreg sample. By determining the anti-delamination performance of the prepreg according to the target height that can characterize the delamination phenomenon of the prepreg sample, the accuracy of determining the anti-delamination performance of the prepreg is improved. Moreover, after completing the test of the anti-delamination performance of various prepregs, a prepreg with strong anti-delamination performance can be selected to prepare a large number of prepregs, which improves the anti-delamination performance of the prepreg used to prepare the composite material, thereby improving the preparation efficiency of the composite material.

[0082] Exemplarily, obtaining a plurality of prepreg samples in step S100 includes cutting a plurality of prepreg samples from a prepreg mother roll.

[0083] Exemplarily, the prepreg anti-delamination performance may also be determined according to a target height of a second target prepreg sample remaining on the surface of the first target prepreg sample.

[0084] In one embodiment, if Figure 3 As shown, the plurality of prepreg samples include a first prepreg sample, a second prepreg sample and a third prepreg sample, and the second prepreg sample includes a first surface and a second surface that are separated from each other. The laying of the plurality of prepreg samples in step S200 to form a prepreg sample is formed by:

[0085] S210, removing the protective film of the first region of the first prepreg sample.

[0086] S220, removing the protective films on the first surface and the second surface of the second prepreg sample.

[0087] S230, laying the first surface on the first area.

[0088] S240, removing the protective film of the second area of ​​the third prepreg sample

[0089] S250, laying the second region of the third prepreg sample on the second surface to form a prepreg sample.

[0090] The length of the first region is greater than or equal to the length of the first surface, the length of the second region is greater than or equal to the length of the second surface, the length of the third prepreg sample is greater than the length of the first prepreg sample, and the length of the first prepreg sample is greater than the length of the second prepreg sample.

[0091] In this embodiment, the protective films of the first prepreg sample, the second prepreg sample and the third prepreg sample are removed, so that the second prepreg sample can be laid on the surface of the first prepreg sample, and the third prepreg sample can be laid on the surface of the second prepreg sample. At the same time, since the length of the second prepreg sample is the smallest, the second prepreg sample can be completely laid between the first prepreg sample and the third prepreg sample, thereby improving the reliability of laying multiple prepreg samples. In addition, since the protective films of the first prepreg sample and the third prepreg sample are partially removed, the prepreg sample with the protective film not removed can be used for stripping in subsequent steps, thereby improving the reliability of the stripping process.

[0092] Exemplarily, the protective film includes a PE film.

[0093] It is understandable that during the paving process, it is necessary to avoid using a large force to prevent external forces from affecting the subsequent peeling process of the prepreg sample.

[0094] In one embodiment, the first prepreg sample includes a third surface and a fourth surface that are opposite to each other, and the first area is located on the fourth surface. Before removing the protective film of the first area of ​​the first prepreg sample in step S210, the prepreg anti-delamination performance testing method further includes:

[0095] The protective film on the third surface of the first prepreg sample was removed.

[0096] The third surface is adhered to the fixed plate.

[0097] In this embodiment, since the first prepreg sample is at the bottom layer of the prepreg samples, pasting the first prepreg sample on the fixed plate can improve the stability of the first prepreg sample, so that in the process of paving the second prepreg sample and the third prepreg sample, the flatness and reliability of paving can be improved.

[0098] For example, Figure 4 As shown, the protective film on the third surface 11 of the first prepreg sample 10 is removed, and the third surface of the first prepreg sample is pasted on the fixing plate 20. The protective film on the first area 12 of the fourth surface of the first prepreg sample 10 is removed, and the protective film on the first surface of the second prepreg sample 30 is removed, and the first surface of the second prepreg sample 30 is laid on the first area 12 of the first prepreg sample 10, and the second prepreg sample 30 and the first prepreg sample 10 are laid together. The protective film on the second surface of the second prepreg sample 30 is removed, and the protective film on the second area 41 of the third prepreg sample 40 is removed, and the second area 41 of the third prepreg sample 40 is laid on the second surface of the second prepreg sample 30, and the third prepreg sample 40 and the second prepreg sample 30 are laid together to form a prepreg sample.

[0099] Exemplarily, the fixing plate 20 comprises a steel plate. After removing the protective film on the third surface 11 of the first prepreg sample 10, a double-sided tape is adhered to the third surface 11, and the first prepreg sample 10 is adhered to the fixing plate 20 by the double-sided tape.

[0100] For example, Figure 4 , Figure 5 and Figure 6 As shown, the third prepreg sample 40 is the first target prepreg sample, and the second prepreg sample 30 is the second target prepreg sample. After the third prepreg sample 40 is peeled off, the first prepreg sample 10, the fixing plate 20, and the second prepreg sample 30 remaining on the fourth surface of the first prepreg sample 10 are the target samples. The height of the second prepreg sample 30 remaining on the fourth surface is the target height.

[0101] Exemplarily, after the third prepreg sample 40 is peeled off, the third prepreg sample 40 and the second prepreg sample 30 remaining on the surface of the third prepreg sample 40 are target samples. The height of the second prepreg sample 30 remaining on the surface of the third prepreg sample 40 is the target height.

[0102] In one embodiment, before peeling off the first target prepreg specimen of the prepreg sample in step S300, the method further includes:

[0103] A preset pressure is applied to the prepreg sample.

[0104] In this embodiment, since the prepregs that have been completed in the plying have mutual forces, during the process of peeling the first target prepreg sample, the prepreg located below the first target prepreg sample will apply pressure to the first target prepreg sample. By applying a preset pressure to the prepreg sample before peeling the first target prepreg sample, the prepreg below the first target prepreg sample will also apply pressure to the first target prepreg sample during the peeling process, thereby improving the reliability of the obtained target sample, thereby improving the accuracy of determining the anti-delamination performance. Moreover, the more plies there are, the greater the mutual force between the prepregs. By applying a preset pressure, the delamination phenomenon of the prepregs with multiple layers in the peeling process can be determined with fewer plies, saving costs.

[0105] In one embodiment, if Figure 7 As shown, applying a preset pressure to the prepreg sample in the step is achieved by:

[0106] S500, placing the prepreg sample between the first pressing roller and the second pressing roller.

[0107] S510: Determine a target distance that the second pressing roller needs to move toward the first pressing roller according to a preset pressure.

[0108] S520, controlling the second pressing roller to move toward the first pressing roller by a target distance.

[0109] In this embodiment, the prepreg sample is placed between the first pressing roller and the second pressing roller, and a preset pressure is applied to the prepreg sample by adjusting the distance between the second pressing roller and the first pressing roller, which reduces the complexity of applying the preset pressure to the prepreg sample and also avoids the risk of the prepreg sample being damaged. Moreover, when the prepreg sample is placed between the first pressing roller and the second pressing roller, the first target prepreg sample can be pulled in the direction of the second pressing roller away from the first pressing roller, so that when the prepreg sample passes between the first pressing roller and the second pressing roller, it can be subjected to the preset pressure and the first target prepreg sample can be peeled off, which improves the reliability of the obtained target sample, thereby improving the accuracy of determining the anti-delamination performance.

[0110] For example, Figure 8 As shown, the stripping device includes: a computer (not shown in the figure), a first clamp 50, a second clamp (not shown in the figure), a first pressure roller 51, a second pressure roller 52, two conveying rollers 53, a tensile machine (not shown in the figure), a first connector 54 and a second connector 55. The first clamp 50 is provided with a first pressure roller 51, a second pressure roller 52 and two conveying rollers 53, the first pressure roller 51 and the second pressure roller 52 are parallel to the two conveying rollers 53, respectively, and the first pressure roller 51 is arranged directly above the second pressure roller 52. The distance between the second pressure roller 52 and the first pressure roller 51 can be adjusted. The tensile machine includes a first connector 54 and a second connector 55, and the computer is electrically connected to the second pressure roller 52 and the tensile machine. The prepreg sample is placed between the two conveying rollers 53, the second clamp clamps the first target prepreg sample, and the second clamp is connected to the second connector 55 of the tensile machine, and the first clamp 50 is connected to the first connector 54 of the tensile machine. A preset pressure is input to the computer, and the computer controls the second pressing roller 52 to move the target distance toward the first pressing roller 51. The computer controls the tensile testing machine to start, and the tensile testing machine controls the second connecting head 55 to pull the first target prepreg sample along the gap between the first pressing roller 51 and the second pressing roller 52 at a preset rate. Under the traction of the second connecting head 55, the first target prepreg sample will move along the direction of the first pressing roller 51 away from the second pressing roller 52, so that the first target prepreg sample is gradually peeled off from the prepreg sample, and the remaining target sample continues to move along the gap between the first pressing roller 51 and the second pressing roller 52 until the first target prepreg sample is completely peeled off from the prepreg sample.

[0111] For example, the computer can control the pneumatic device to push the second pressing roller 52 to approach and move away from the first pressing roller 51. The computer can also control the pneumatic device to push the first pressing roller 51 to approach and move away from the second pressing roller 52. The first pressing roller 51, the second pressing roller 52, and the two conveying rollers 53 are all rollers with smooth surfaces.

[0112] In one embodiment, if Fig. 9 As shown, in step S300, the anti-delamination performance of the prepreg is determined according to the target height of the second target prepreg sample remaining on the surface of the target sample by:

[0113] S310, obtaining fiber heights of a plurality of fibers of a second target prepreg sample remaining on a surface of the target sample as a plurality of target heights.

[0114] S320: Determine target lengths corresponding to target heights according to the number of target heights.

[0115] S330. Determine the anti-delamination index of the prepreg according to the target height and the target length.

[0116] S340. Determine the anti-delamination performance of the prepreg according to the anti-delamination index of the prepreg.

[0117] In this embodiment, since the delamination area and delamination height of the prepreg can characterize the anti-delamination index of the prepreg to a certain extent, the target length of the fiber is determined according to the number of target heights of the fiber to determine the number of delaminated fibers, thereby determining the delamination area of ​​the prepreg. By comprehensively determining the anti-delamination index of the prepreg according to the delamination area and delamination depth, the reliability of determining the anti-delamination performance of the prepreg is improved.

[0118] In one embodiment, in step S320, the target lengths corresponding to the target heights are determined according to the number of target heights by:

[0119] Sort multiple target heights in ascending order.

[0120] According to the order from small to large, the target lengths corresponding to the target heights are determined.

[0121] In this embodiment, the target length is determined according to the order of the target heights, and the delamination areas of fibers at different heights can be determined, thereby improving the reliability of determining the delamination area and thus improving the reliability of determining the anti-delamination index of the prepreg.

[0122] For example, if the multiple target heights include H1, H5, H4, H3, and H2, the multiple target heights are sorted in ascending order: H1, H2, H3, H4, and H5. The target lengths corresponding to the target heights are determined to be: L1, L2, L3, L4, and L5.

[0123] Exemplarily, the prepreg anti-delamination index can be determined by the following formula:

[0124]

[0125] Wherein, F is the anti-delamination index of the prepreg, A is the minimum value of the target length, B is the maximum value of the target length, and Z is the target height. The target length between A and B includes the target lengths corresponding to all target heights.

[0126] Exemplarily, the smaller the anti-delamination index is, the stronger the anti-delamination performance of the prepreg is.

[0127] In one embodiment, if Fig.10 As shown, in step S330, the anti-delamination index of the prepreg is determined according to the multiple target heights and the multiple target lengths in the following manner:

[0128] S331. Obtain a preset height.

[0129] S332. According to a preset height, divide the multiple target heights into a plurality of first target heights greater than the preset height and a plurality of second target heights less than the preset height.

[0130] S333, determining the prepreg anti-delamination index according to the multiple first target heights, the multiple second target heights, the preset height and the multiple target lengths.

[0131] In this embodiment, when the first target prepreg sample is peeled off, the second target prepreg sample may be partially located at the target sample and partially located at the first target prepreg sample. Then when the target height is less than the preset height, the anti-delamination index will increase as the target height increases. When the target height is greater than the preset height, the anti-delamination index will decrease as the target height increases. By setting the preset height, the anti-delamination index of the prepreg is comprehensively judged according to the preset height, thereby improving the reliability of the anti-delamination index of the prepreg.

[0132] Exemplarily, the preset height is half of the height of the second target prepreg sample.

[0133] In one embodiment, if Fig.11 As shown, in step S333, determining the prepreg anti-delamination index according to the multiple first target heights, the multiple second target heights, the preset height, and the multiple target lengths includes:

[0134] S3331. Determine a corresponding plurality of first target lengths and a corresponding plurality of second target lengths according to a plurality of first target heights and a plurality of second target heights.

[0135] S3332. Determine the first prepreg anti-delamination index according to the multiple first target heights, the multiple first target lengths and the preset height.

[0136] S3333. Determine the second prepreg anti-delamination index according to the multiple second target heights, the multiple second target lengths and the preset height.

[0137] S3334. Determine the prepreg anti-delamination index according to the first prepreg anti-delamination index and the second prepreg anti-delamination index.

[0138] In this embodiment, since the first prepreg anti-delamination index increases with the increase of the first target height, and the second prepreg anti-delamination index decreases with the increase of the second target height, the anti-delamination index of the prepreg is comprehensively determined by respectively determining the first prepreg anti-delamination index corresponding to the first target heights and the second prepreg anti-delamination index corresponding to the second target heights, thereby improving the reliability of the anti-delamination index of the prepreg.

[0139] Exemplarily, the prepreg anti-delamination index can be determined by the following formula:

[0140]

[0141] F=F1+F2; (4)

[0142] Wherein, F is the anti-delamination index of the prepreg, F1 is the anti-delamination index of the first prepreg, and F2 is the anti-delamination index of the second prepreg. A is the minimum value of the target length, B is the maximum value of the target length, and Z is the target height. The target length between A and B includes the target lengths corresponding to all target heights. a is the preset height, 2a is the height (thickness) of the second target prepreg sample, and M is the target length corresponding to the target height a.

[0143] For example, Fig.12 As shown, the anti-delamination index of the prepreg is determined by area integration, such as can be determined by MATLAB. Wherein, the ordinate is the target height Z, and the abscissa is the target length S. The target length corresponding to the target height is the interval from A to B. When the target length is less than A, the second target prepreg samples representing the area are all located on the first target prepreg, and no delamination occurs. When the target length is greater than B, the second target prepreg samples representing the area are all located on the target sample, and no delamination occurs. When the target length is in the interval from A to B, the second target prepreg sample delaminates.

[0144] For example, multiple target samples can be formed during the laying and peeling process. The average prepreg anti-delamination index and the coefficient of variation are determined according to the prepreg anti-delamination indexes of the multiple target samples. The smaller the coefficient of variation, the more reliable the prepreg anti-delamination index.

[0145] Exemplarily, the prepreg preparation process can be optimized based on the average prepreg anti-delamination index and coefficient of variation to reduce the prepreg anti-delamination index and coefficient of variation, thereby improving the prepreg anti-delamination performance, so that when the unidirectional prepreg is removed, the problems of reduced preparation efficiency and increased cost of the composite material caused by poor prepreg anti-delamination performance can be avoided.

[0146] In one embodiment, if Fig.13 As shown, after the target prepreg specimen of the prepreg sample is stripped in step S300 to obtain the target sample, the prepreg anti-delamination performance testing method further includes:

[0147] S600: spraying a first coating onto the surface of the target sample.

[0148] S610, spraying a second coating onto the surface of the target sample, wherein the color of the second coating is different from the color of the first coating.

[0149] S620: Photograph the target sample to obtain image information of the target sample.

[0150] S630: Transmit the image information to a digital image correlation system.

[0151] S640: Determine a target height of the second target prepreg sample remaining on the surface of the target sample according to the output data of the digital image correlation system.

[0152] The area of ​​the target sample sprayed with the first coating is larger than the area of ​​the target sample sprayed with the second coating.

[0153] In this embodiment, a speckle image can be formed on the surface of the target sample by spraying the first coating and the second coating, and the image information is then transmitted to the digital image correlation system by shooting. The digital image correlation system can then output relevant data of the target height based on the image information, thereby improving the reliability of determining the target height.

[0154] Exemplarily, the target sample can also be photographed before spraying the first coating, and the image information before and after spraying can be obtained and transmitted to the digital image correlation system, thereby improving the accuracy of the target height.

[0155] Exemplarily, the first coating and the second coating have different colors, which facilitates the digital image correlation system to process the image information. The digital image correlation system can establish a model based on the contrast between the first coating and the second coating, and can determine the target height based on the size of the actual sample and the size in the model.

[0156] It is understood that Digital Image Correlation (DIC) technology is a device that uses optical measurement technology to analyze the deformation and strain of the surface of materials or structures. It compares the speckle images of the surface before and after deformation of the object, and uses image matching algorithms to calculate the displacement field and strain field of the surface of the object, thereby obtaining the deformation information of the object under the influence of force or other factors.

[0157] Exemplarily, the digital image correlation technology may include a camera for shooting. The first coating may be white paint, and the second coating may be black paint.

[0158] The present disclosure provides a method for testing the anti-delamination performance of prepregs. Fig.14 As shown, the method includes:

[0159] S700: Obtain a plurality of prepreg samples.

[0160] S710, laying out a plurality of prepreg test specimens to form a prepreg sample.

[0161] S720 , peeling off the first target prepreg specimen of the prepreg sample to obtain a target sample.

[0162] S730, obtaining fiber heights of a plurality of fibers of the second target prepreg sample remaining on the surface of the target sample as a plurality of target heights.

[0163] S740: Determine target lengths corresponding to target heights according to the number of target heights.

[0164] S750: Obtain a preset height.

[0165] S760. According to a preset height, divide the multiple target heights into a plurality of first target heights that are smaller than the preset height and a plurality of second target heights that are larger than the preset height.

[0166] S770: Determine a corresponding plurality of first target lengths and a corresponding plurality of second target lengths according to the plurality of first target heights and the plurality of second target heights.

[0167] S780, determining a first prepreg anti-delamination index according to a plurality of first target heights, a plurality of first target lengths, and a preset height.

[0168] S790, determining a second prepreg anti-delamination index according to the plurality of second target heights, the plurality of second target lengths, and the preset height.

[0169] S800: Determine a prepreg anti-delamination index according to the first prepreg anti-delamination index and the second prepreg anti-delamination index.

[0170] In the present embodiment, a plurality of prepreg samples are obtained, and a plurality of prepreg samples are laid to form a prepreg sample to simulate the plying process of the prepreg. The first target prepreg sample of the prepreg sample is peeled off to obtain the target sample, thereby partially removing the plying of the prepreg. According to the target height of the second target prepreg sample remaining on the surface of the target sample, the anti-delamination performance of the prepreg is determined, and the anti-delamination performance is determined according to the delamination phenomenon of the second target prepreg sample. By determining the anti-delamination performance of the prepreg according to the target height that can characterize the delamination phenomenon of the prepreg sample, the accuracy of determining the anti-delamination performance of the prepreg is improved. Moreover, after completing the test of the anti-delamination performance of various prepregs, a prepreg with strong anti-delamination performance can be selected to prepare a large number of prepregs, which improves the anti-delamination performance of the prepreg used to prepare the composite material, thereby improving the preparation efficiency of the composite material.

[0171] Embodiment 1:

[0172] Sample preparation process: The first prepreg sample, the second prepreg sample and the third prepreg sample are cut from the carbon fiber mother roll produced by manufacturing process 1. The size of the first prepreg sample is 100mm×60mm, the size of the second prepreg sample is 80mm×60mm, and the size of the third prepreg sample is 150mm×60mm. The lengths of the first prepreg sample, the second prepreg sample and the third prepreg sample are all parallel to the direction of the fiber.

[0173] Stripping process: remove the PE film on the third surface of the first prepreg sample, and paste the third surface on a steel flat plate. Remove the PE film in the middle area of ​​the first prepreg sample, the length of the PE removed is 80mm, and the length of the remaining PE film at both ends of the first prepreg sample is 10mm each. Remove the PE film on the first surface of the second prepreg sample, and lay the first surface of the second prepreg sample on the middle area of ​​the first prepreg sample. Remove the PE film on the second surface of the second prepreg sample, and remove the PE film in the middle area of ​​the third prepreg sample. The length of the PE film removed from the third prepreg sample is 80mm, the length of the PE film remaining at one end of the third prepreg sample is 70mm, and the length of the PE film remaining at the other end of the third prepreg sample is 10mm, so as to form a prepreg sample. The first clamp 50 and the second clamp of the stripping device are installed on the tensile machine, and the prepreg sample is placed between the two conveying rollers 53, and the second clamp clamps the third prepreg sample of the prepreg sample. The preset pressure of 150N is input through the computer device to control the second pressing roller 52 to move the target distance toward the first pressing roller 51. The computer controls the second clamp to pull the third prepreg sample upward at a speed of 2mm / min. The third prepreg sample is pulled by the second clamp so that the prepreg sample can pass through the gap between the two conveying rollers 53 and the gap between the first pressing roller 51 and the second pressing roller 52 at a uniform speed until the third prepreg sample is peeled off. The second prepreg sample is partially present in the third prepreg sample and partially present in the first prepreg sample.

[0174] Test process: The target height of the second prepreg sample on the surface of the first prepreg sample is determined by digital image correlation technology. 200 data are collected within the effective area of ​​80mm×60mm. The thickness of the second prepreg sample is 0.2mm. There are three cases for the 200 data collected, namely ①z value = 0; ②0<z value<0.2mm; ③z value = 0.2mm. The 200 collected target heights are sorted in order from small to large, and assigned target lengths of 1-200 respectively. The target length is between 1-10, and the target height is 0. The target length is between 11-35, and the target height is between 0 and 0.1mm. The target length is between 36-50, and the target height is between 0.1mm and 0.2mm. The target length is between 51-200, and the target height is 0. Substitute the above data into formula (2)(3)(4) to obtain:

[0175]

[0176] F=F1+F2; (4)

[0177] The above test process was repeated for 5 times, and the unidirectional prepreg of manufacturing process 1 was tested 5 times, and the anti-delamination performance indexes of the 5 prepregs were 4.12, 4.09, 3.89, 4.34, and 4.22 respectively. The mean value was 4.12, and the coefficient of variation CV was 0.149.

[0178] Embodiment 2:

[0179] The difference between this embodiment and the first embodiment is that:

[0180] Sample preparation process: The first prepreg sample, the second prepreg sample and the third prepreg sample are cut from the carbon fiber mother roll produced by production process 2 respectively.

[0181] Test process: The target height of the second prepreg sample on the surface of the first prepreg sample is determined by digital image correlation technology. 200 data are collected within the effective area of ​​80mm×60mm. The thickness of the second prepreg sample is 0.2mm. For the 200 data collected, there is one situation, 0<z value<0.2mm. Sort the 200 collected target heights in order from small to large, and assign 1-200 target lengths respectively. The target length is between 1-85, and the target height is between 0.02mm and 0.1mm. The target length is between 86-200, and the target height is between 0.1 and 0.189mm. Substitute the above data into formula (2)(3)(4) to obtain:

[0182]

[0183] F=F1+F2; (4)

[0184] The above test process was repeated for 5 times, and the unidirectional prepreg of manufacturing process 2 was tested 5 times, and the anti-delamination performance indexes of the 5 prepregs were 19.85, 17.33, 17.43, 18.11, and 16.22 respectively. The mean value was 17.85, and the coefficient of variation CV was 1.12.

[0185] In summary, under the same process conditions such as preset pressure and peeling speed, the anti-delamination performance index and coefficient of variation of the prepreg master roll produced by production process 1 are lower than the anti-delamination performance index of the prepreg master roll produced by production process 2. This shows that the prepreg produced by production process 1 has stronger anti-delamination performance. Using production process 1 to produce prepreg can improve the anti-delamination performance, thereby improving the preparation efficiency of composite materials.

[0186] In an exemplary embodiment, a testing device is provided, including a processor and a memory, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of any of the above-mentioned prepreg anti-delamination performance testing methods are implemented.

[0187] In an exemplary embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the above-mentioned prepreg anti-delamination performance testing methods are implemented. The computer readable storage medium can be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0188] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps of any of the above-mentioned methods for testing the anti-delamination performance of prepregs are implemented.

[0189] Reference Fig.15 , a structural block diagram of a test device 100 that can be used as the present disclosure will now be described. The test device 100 includes a computing unit 101, which can perform various appropriate actions and processes according to a computer program stored in a ROM 102 or a computer program loaded from a storage unit 108 to a RAM 103. In the RAM 103, various programs and data required for the operation of the test device 100 can also be stored. The computing unit 101, the ROM 102, and the RAM 103 are connected to each other via a bus 104. An input / output (I / O) interface 105 is also connected to the bus 104.

[0190] A plurality of components in the test device 100 are connected to the I / O interface 105, including: an input unit 106, an output unit 107, a storage unit 108, and a communication unit 109. The input unit 106 may be any type of device capable of inputting information to the test device 100, the input unit 106 may receive input digital or character information, and generate key signal inputs related to user settings and / or function control of the test device 100, and may include but is not limited to a mouse, a keyboard, a touch screen, a track pad, a track ball, a joystick, a microphone, and / or a remote controller. The output unit 107 may be any type of device capable of presenting information, and may include but is not limited to a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 108 may include but is not limited to a disk, an optical disk. The communication unit 109 allows the test device 100 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks, and may include but is not limited to a modem, a network card, an infrared communication device, a wireless communication transceiver, and / or a chipset, such as a Bluetooth™ device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0191] The computing unit 101 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 101 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 101 performs the various methods and processes described above, such as a prepreg anti-delamination performance test method. For example, in some embodiments, the prepreg anti-delamination performance test method may be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as a storage unit 108. In some embodiments, part or all of the computer program may be loaded and / or installed on the test device 100 via ROM 102 and / or a communication unit 109. When the computer program is loaded into RAM 103 and executed by the computing unit 101, one or more steps of the prepreg anti-delamination performance test method described above may be performed. Alternatively, in other embodiments, the computing unit 101 may be configured to execute the prepreg anti-delamination performance testing method in any other appropriate manner (for example, by means of firmware).

[0192] The test device 100 can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components to perform the above-mentioned prepreg anti-delamination performance test method.

[0193] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed in this disclosure. The specification and examples are to be considered as exemplary only, and the true scope and spirit of the present invention are indicated by the claims.

[0194] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for testing the anti-delamination performance of prepreg, characterized in that: The prepreg anti-delamination performance testing method comprises: obtaining a plurality of prepreg specimens; Laying out a plurality of the prepreg specimens to form a prepreg sample; peeling off a first target prepreg specimen of the prepreg sample to obtain a target sample; determining the anti-delamination performance of the prepreg according to a target height of a second target prepreg sample remaining on the surface of the target sample; Before peeling off the first target prepreg sample, the first target prepreg sample is laid on the surface of the second target prepreg sample, and the remaining part of the prepreg sample after peeling off the first target prepreg sample is the target sample.

2. The method for testing the anti-delamination performance of prepreg according to claim 1, characterized in that: The plurality of prepreg samples include a first prepreg sample, a second prepreg sample and a third prepreg sample, wherein the second prepreg sample includes a first surface and a second surface facing away from each other; The step of laying out a plurality of the prepreg specimens to form a prepreg sample comprises: removing the protective film from the first region of the first prepreg sample; removing the protective films on the first surface and the second surface of the second prepreg sample; Laying the first surface on the first area; removing the protective film from the second region of the third prepreg sample; Laying the second region of the third prepreg sample on the second surface to form the prepreg sample; Among them, the length of the first region is greater than or equal to the length of the first surface, and the length of the second region is greater than or equal to the length of the second surface; the length of the third prepreg sample is greater than the length of the first prepreg sample, and the length of the first prepreg sample is greater than the length of the second prepreg sample.

3. The method for testing the anti-delamination performance of prepreg according to claim 2, characterized in that: The first prepreg sample comprises a third surface and a fourth surface which are opposite to each other, the first area is located on the fourth surface, and before removing the protective film of the first area of ​​the first prepreg sample, the method further comprises: removing the protective film on the third surface of the first prepreg sample; The third surface is adhered to the fixing plate.

4. The method for testing the anti-delamination performance of prepreg according to claim 1, characterized in that: Prior to the stripping of the first target prepreg specimen of the prepreg sample, the method further comprises: A preset pressure is applied to the prepreg sample.

5. The method for testing the anti-delamination performance of prepreg according to claim 4, characterized in that: The applying a preset pressure to the prepreg sample comprises: placing the prepreg sample between a first pressing roller and a second pressing roller; Determining a target distance that the second pressing roller needs to move toward the first pressing roller according to the preset pressure; The second pressing roller is controlled to move toward the first pressing roller by the target distance.

6. The method for testing the anti-delamination performance of prepreg according to claim 1, characterized in that: The step of determining the anti-delamination performance of the prepreg according to the target height of the second target prepreg sample remaining on the surface of the target sample comprises: Acquiring fiber heights of a plurality of fibers of the second target prepreg sample remaining on the surface of the target sample as a plurality of the target heights; According to the number of the target heights, determining each target length corresponding to each of the target heights; Determining an anti-delamination index of the prepreg according to the plurality of target heights and the plurality of target lengths; The anti-delamination performance of the prepreg is determined according to the anti-delamination index of the prepreg.

7. The method for testing the anti-delamination performance of prepreg according to claim 6, characterized in that: Determining, according to the number of the target heights, each target length corresponding to each of the target heights comprises: Sorting the plurality of target heights in ascending order; According to the order from small to large, each of the target lengths corresponding to each of the target heights is determined.

8. The method for testing the anti-delamination performance of prepreg according to claim 6, characterized in that: Determining the prepreg anti-delamination index according to the plurality of target heights and the plurality of target lengths comprises: Get the preset height; According to the preset height, the plurality of target heights are divided into a plurality of first target heights smaller than the preset height and a plurality of second target heights larger than the preset height; The prepreg anti-delamination index is determined according to a plurality of the first target heights, a plurality of the second target heights, the preset height, and a plurality of the target lengths.

9. The method for testing the anti-delamination performance of prepreg according to claim 8, characterized in that: The step of determining the prepreg anti-delamination index according to the plurality of the first target heights, the plurality of the second target heights, the preset height, and the plurality of the target lengths comprises: According to the plurality of the first target heights and the plurality of the second target heights, respectively determining a plurality of corresponding first target lengths and a plurality of corresponding second target lengths; Determining a first prepreg anti-delamination index according to a plurality of the first target heights, a plurality of the first target lengths, and the preset height; Determining a second prepreg anti-delamination index according to a plurality of the second target heights, a plurality of the second target lengths, and the preset height; The prepreg anti-delamination index is determined according to the first prepreg anti-delamination index and the second prepreg anti-delamination index.

10. The method for testing the anti-delamination performance of prepreg according to any one of claims 1 to 9, characterized in that: After peeling off the target prepreg specimen of the prepreg sample to obtain the target sample, the method further comprises: spraying a first coating onto the surface of the target sample; Spraying a second coating onto the surface of the target sample, wherein the color of the second coating is different from the color of the first coating; photographing the target sample to obtain image information of the target sample; transmitting the image information to a digital image correlation system; determining a target height of the second target prepreg sample remaining on the surface of the target sample according to output data of the digital image correlation system; Wherein, the area of ​​the target sample sprayed with the first coating is larger than the area of ​​the target sample sprayed with the second coating.

Images