Manufacturing method and device for test piece with wrinkle-pore coupling defect

Abstract

The present invention relates to a manufacturing method and device for a wrinkle-porosity coupling defect test piece, wherein the manufacturing method comprises: laying a first preset number of prepreg layers on a first surface provided with a convex portion on a male mold, demolding the prepreg after hot compaction to form a male mold hot compacted layer; laying a second preset number of prepreg layers on a second surface provided with a concave portion on a female mold, demolding the prepreg after hot compaction to form a female mold hot compacted layer; stacking the male mold hot compacted layer and the female mold hot compacted layer in a thickness direction, aligning the concave surface of the male mold hot compacted layer with the convex surface of the female mold hot compacted layer, and encapsulating them by connecting their respective film surfaces; placing the encapsulated wrinkled test piece in an autoclave, applying curing process conditions corresponding to the porosity in a preset interval for curing; demolding the test piece after curing to obtain a test piece with preset wrinkle positions and parameters and preset porosity.

Description

Technical Field

[0001] The present disclosure relates to the field of composite material structure forming technology, and in particular to a manufacturing method and device for a test piece with wrinkle-pore coupling defects. Background Art

[0002] There are two problems in the production, processing and application of composite materials that have a critical impact on the performance degradation of materials, including defects generated during production and manufacturing and damage caused during processing and use. Among them, pores and wrinkles are among the common defects of composite materials that have the greatest impact on compressive strength and fatigue life.

[0003] There are many reasons for wrinkles, such as mismatched thermal expansion coefficients of fibers, matrix and mold materials, unreasonable curing temperature and pressure control, errors in layer profile and position accuracy, unreasonable material layering sequence, etc., which can cause wrinkles in laminated composite materials; the cause of voids is usually due to resin moisture absorption or insufficient pressure.

[0004] In actual engineering, the formation of wrinkles often causes insufficient curing pressure on the curved surface of the laminate, resulting in accompanying porosity defects. In order to study the relationship between the effects of wrinkles and porosity defects on the performance of composite parts, especially the correlation between the effects on performance when the two types of defects are coupled, it is necessary to simultaneously and controllably manufacture the two types of defects with different content levels. Summary of the invention

[0005] The embodiments of the present disclosure provide a method and device for manufacturing a test piece with a wrinkle-pore coupling defect, which can simultaneously and controllably manufacture wrinkles and pore coupling defects in the test piece.

[0006] According to a first aspect of the present disclosure, there is provided a method for manufacturing a test piece with a wrinkle-pore coupling defect, comprising:

[0007] Laying a first preset number of prepreg layers on a first surface provided with a raised portion on the male mold, and after hot compaction, demoulding each layer of prepreg to form a male mold hot compaction layer;

[0008] Laying a second preset number of prepreg layers on the second surface of the female mold with the concave portion, and demolding each layer of the prepreg after hot compaction to form a female mold hot compaction layer; wherein, when the male mold and the female mold are relatively stacked with the first surface and the second surface, the convex portion and the concave portion are configured to cooperate with each other and the contact surface is consistent with the position and parameters of the preset folds;

[0009] The male mold hot compaction layer and the female mold hot compaction layer are stacked in the thickness direction, the concave surface of the male mold hot compaction layer is aligned with the convex surface of the female mold hot compaction layer, and they are connected through their respective film surfaces for packaging;

[0010] placing the packaged wrinkled test piece into an autoclave, applying a curing process condition corresponding to a porosity in a preset range, and curing; and

[0011] After curing, the test piece is demoulded to obtain a test piece with preset wrinkle positions and parameters and preset porosity.

[0012] In some embodiments, the preset wrinkle position and parameters include: at least one of the ply where the wrinkle is located in the test piece, the setting position in the ply, and the wrinkle angle.

[0013] In some embodiments, a plurality of protrusions are arranged at intervals along the first direction on the first surface of the male mold, and each protrusion extends along the second direction; a plurality of recessed portions are arranged at intervals along the first direction on the second surface of the female mold, and each recessed portion extends along the second direction, so as to form a plurality of wrinkles arranged at intervals along the first direction in the ply of the test piece, and each wrinkle extends along the second direction.

[0014] In some embodiments, the manufacturing method further comprises:

[0015] According to the preset fold positions and parameters, the positive mold and the negative mold are made.

[0016] In some embodiments, the step of laying a first preset number of layers of prepreg on the positive mold or laying a second preset number of layers of prepreg on the negative mold and performing hot compaction includes:

[0017] Laying a partial number of layers of prepreg on the first surface of the male mold or the second surface of the female mold;

[0018] Putting a part of the prepreg layers together with the mold into an autoclave, maintaining a first preset heating temperature for a first preset heating time under a first preset vacuum pressure to perform hot compaction;

[0019] After being taken out of the autoclave and cooled, the remaining layers of prepreg are laid on the compacted prepreg;

[0020] The remaining layers of prepreg are placed in an autoclave together with the mold, and maintained at a first preset heating temperature for a first preset heating time under a first preset vacuum pressure to perform thermal compaction again.

[0021] In some embodiments, the steps of placing the packaged wrinkled test piece into an autoclave and applying the curing process conditions corresponding to the porosity in the preset interval for curing include:

[0022] Pumping the packaged test piece to a second preset vacuum pressure;

[0023] The autoclave is pressurized to a first preset pressure, and the vacuum degree in the vacuum bag is reduced during the pressurization process. When the pressure in the autoclave reaches a second preset pressure, the vacuum degree in the vacuum bag reaches a third preset vacuum pressure. The second preset pressure is greater than the first preset pressure, and the absolute value of the third preset vacuum pressure is less than the absolute value of the second preset vacuum pressure.

[0024] The autoclave is heated to a second preset heating temperature at a preset heating rate;

[0025] Maintaining the temperature at a first preset pressure, a third preset vacuum pressure, and a second preset heating temperature for a second preset heating time;

[0026] After the heat preservation is completed, the temperature is lowered at a preset cooling rate, and the pressure in the autoclave is gradually released when the test piece reaches below the preset temperature.

[0027] In some embodiments, when the porosity in the preset interval is less than 1%, the second preset vacuum pressure is -1.0 bar, the third preset vacuum pressure is -0.2 bar, the first preset pressure is 7 bar, the second preset pressure is 1 bar, the preset heating rate is 1-2°C / min, the second preset heating temperature is 180°C±5°C, the second preset heating time is 120±5min, the preset cooling rate is 2-5°C / min, and the preset temperature is 60°C; or

[0028] When the porosity in the preset interval is between 1% and 3%, the second preset vacuum pressure is -0.6 bar, the third preset vacuum pressure is -0.2 bar, the first preset pressure is 2 bar, the second preset pressure is 1 bar, the preset heating rate is 1-2°C / min, the second preset heating temperature is 180°C±5°C, the second preset heating time is 120±5min, the preset cooling rate is 2-5°C / min, and the preset temperature is 60°C.

[0029] In some embodiments, after obtaining a test piece having a preset wrinkle position and parameters and a preset porosity, the manufacturing method further comprises:

[0030] Process the test pieces into corresponding test piece sizes according to different performance test standards;

[0031] The performance of the processed test pieces was tested and studied.

[0032] According to a second aspect of the present disclosure, there is provided a manufacturing device for a test piece with a wrinkle-pore coupling defect, comprising:

[0033] A male mold having a raised portion on its first surface, the first surface being configured to lay a first preset number of prepreg layers, and to demould each layer of prepreg by hot compaction to form a male mold hot compaction layer;

[0034] A female mold having a concave portion on its second surface, the second surface being configured to lay a second preset number of prepreg layers, and to demould each layer of prepreg by hot compaction to form a female mold hot compaction layer; and

[0035] The autoclave is configured to cure the test piece with wrinkles after the male mold hot compaction layer and the female mold hot compaction layer are stacked in the thickness direction, so as to obtain the test piece with preset wrinkle position and parameters and preset porosity after demolding;

[0036] Among them, when the male mold and the female mold are relatively superimposed with the first surface and the second surface, the raised portion and the recessed portion are configured to cooperate with each other and the contact surface is consistent with the position and parameters of the preset wrinkles; and the recessed surface of the male mold hot compaction layer and the raised surface of the female mold hot compaction layer are configured to be aligned when superimposed and packaged.

[0037] In some embodiments, a plurality of protrusions are arranged on the first surface of the male mold at intervals along the first direction, and each protrusion extends along the second direction; a plurality of recessed portions are arranged on the second surface of the female mold at intervals along the first direction, and each recessed portion extends along the second direction, so as to form a plurality of wrinkles arranged at intervals along the first direction in the ply of the test piece, and each wrinkle extends along the second direction.

[0038] The manufacturing method of the test piece with wrinkle-pore coupling defects of the embodiment of the present disclosure manufactures out-of-plane wrinkles in the composite material test piece through a mold, and the angle, direction and coverage of the wrinkles in the test piece can be accurately controlled by the mold design, and the pore percentage in the test piece can be accurately controlled by changing the process pressure. The test piece can be quickly and accurately manufactured, which contains wrinkle defects in any ply direction, any position, coverage range and angle, and pore coupling defects with different percentages, thereby realizing the controllable manufacturing of coupling defects in the test piece, reducing the manufacturing cost of the test piece, and improving the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present application. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure. In the drawings:

[0040] Figure 1 It is a schematic structural diagram of some embodiments of the tooling for forming a wrinkled test piece disclosed in the present invention;

[0041] Figure 2 A first layer formed by hot compaction of a male mold;

[0042] Figure 3 A second ply formed by hot compaction of a female mold;

[0043] Figure 4Curve of curing process conditions for forming a porosity of less than 1% in the test piece;

[0044] Figure 5 It is a schematic cross-sectional view of the fold-pore coupling test piece;

[0045] Figure 6 The present invention is a schematic flow chart of some embodiments of the method for manufacturing a test piece with fold-pore coupling defects disclosed in the present invention. DETAILED DESCRIPTION

[0046] The present disclosure is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Each aspect so defined can be combined with any other aspect or aspects, unless explicitly stated not to be combined. In particular, any feature that is considered to be preferred or advantageous can be combined with one or more other features that are considered to be preferred or advantageous.

[0047] The terms "first", "second", etc. that appear in the present disclosure are only for the convenience of description to distinguish different components with the same name, and do not indicate a sequence or a primary and secondary relationship.

[0048] In the description of the present invention, it is necessary to understand that the terms "inside", "outside", "up", "down", "left" and "right" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only used to facilitate the description of the present invention. They do not indicate or imply that the device referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0049] refer to Figure 1-Figure 5 In some embodiments, as Figure 6 As shown in the flow diagram, the present disclosure provides a method for manufacturing a test piece with a wrinkle-pore coupling defect, comprising:

[0050] Step 110: Lay a first preset number of prepreg layers on the first surface 11 of the male mold 1 provided with the raised portion 12, and after hot compaction, release each layer of prepreg from the mold to form a male mold hot compaction layer 10, such as Figure 2 shown.

[0051] Step 120: Lay a second preset number of prepreg layers on the second surface 21 of the female mold 2 provided with the concave portion 22, and after hot compaction, demould each layer of prepreg to form a female mold hot compaction layer 20. Figure 3 shown.

[0052] The male mold 1 and the female mold 2 can be formed by machining a metal plate, for example, an aluminum plate. When the male mold 1 and the female mold 2 are relatively stacked with the first surface 11 and the second surface 21, the protrusion 12 and the recessed portion 22 are configured to cooperate with each other, and the contact surface is consistent with the position and parameters of the preset wrinkles. The first preset number of layers and the second preset number of layers can be equal or unequal, depending on the ply of the wrinkles in the test piece. In order to facilitate the laying of prepreg, the male mold 1 or the female mold 2 can be placed on the support table 3.

[0053] Step 130, stack the male mold hot compacted ply 10 and the female mold hot compacted ply 20 in the thickness direction, align the concave surface 101 of the male mold hot compacted ply 10 with the convex surface 201 of the female mold hot compacted ply 20, and package them by connecting them through their respective film surfaces.

[0054] When the male mold hot compacted ply 10 and the female mold hot compacted ply 20 are stacked, the concave surface 101 of the male mold hot compacted ply 10 is opposite to the convex surface 201 of the female mold hot compacted ply 20. If the test piece is preset with multiple wrinkles, the concave surface 101 and the convex surface 201 corresponding to the same wrinkle are aligned. Both the male mold hot compacted ply 10 and the female mold hot compacted ply 20 are provided with film-applying surfaces. The film-applying surface of the male mold hot compacted ply 10 is laid on the top of the film-applying surface of the female mold hot compacted ply 20, and the concave surfaces 101 and the convex surfaces 201 of different wrinkles are aligned. After the laying is completed, it is packaged according to the packaging system, for example, it can be packaged in a vacuum bag.

[0055] Step 140: Place the packaged wrinkled test piece into an autoclave, apply curing process conditions corresponding to the porosity in the preset range, and perform curing.

[0056] Among them, the porosity in different ranges can be obtained in the test piece by changing the curing process conditions. For example, the porosity can be changed by adjusting the vacuum degree of the package and the pressure in the autoclave.

[0057] Step 150: After curing, the test piece is demoulded to obtain a test piece with a preset wrinkle position and parameters and a preset porosity, such as Figure 5 As shown, the wrinkles are represented by S.

[0058] The embodiments of the present disclosure use a mold to manufacture out-of-plane wrinkles in a composite material test piece. The angle, direction and coverage of the wrinkles in the test piece can be accurately controlled through the mold design, and the pore percentage in the test piece can be accurately controlled by changing the process pressure. The test piece can be quickly and accurately manufactured to contain wrinkle defects in any ply direction, any position, coverage range and angle, and pore coupling defects with different percentages, thereby achieving controllable manufacturing of coupling defects in the test piece, reducing the manufacturing cost of the test piece, and improving production efficiency.

[0059] This kind of test piece can be used for nondestructive testing research and defect tolerance design. It can be used as a comparison test block to study the influence of different coupling comparison performance and nondestructive testing signal characteristics of these two defects, and to formulate more reasonable defect tolerance and detection standards, so as to solve the problems of unclear mechanism of influence of coupling defects on performance and unavailable test data in engineering.

[0060] This type of test piece can be used to simulate composite parts such as fan blades made of composite materials in aircraft engines. By prefabricating wrinkles and gap defects in the test piece, the performance of fan blade parts under these prefabricated defects can be analyzed, as well as their impact on the working performance and safety of aircraft engines.

[0061] In some embodiments, the preset wrinkle position and parameters include: at least one of the ply where the wrinkle is located in the test piece, the setting position in the ply, and the wrinkle angle. The ply where the wrinkle is located in the test piece refers to the ply in which the wrinkle is formed; for a rectangular ply, the setting position in the ply refers to the position of the wrinkle in the ply along the first direction or the second direction; the wrinkle angle refers to the bending angle of the wrinkle relative to the ply plane.

[0062] According to the preset wrinkle positions and parameters in this embodiment, various information of the preset wrinkles in the test piece can be determined, so as to produce a male mold 1 and a female mold 2 with matching sizes, thereby accurately controlling the positions and parameters of the wrinkles in the test piece.

[0063] In some embodiments, a plurality of raised portions 12 are arranged at intervals along the first direction on the first surface 11 of the male mold 1, and each raised portion 12 extends along the second direction; a plurality of recessed portions 22 are arranged at intervals along the first direction on the second surface 21 of the female mold 2, and each recessed portion 22 extends along the second direction, so as to form a plurality of wrinkles arranged at intervals along the first direction in the ply of the test piece, and each wrinkle extends along the second direction. The wrinkle angles of the plurality of wrinkles may be the same or different, and the sizes of the plurality of raised portions 12 and the plurality of recessed portions 22 are set accordingly.

[0064] This embodiment can set a plurality of wrinkles according to the test requirements of the test piece, and the plurality of wrinkles can be precisely controlled by the male mold 1 and the female mold 2 to quickly and accurately manufacture wrinkles along any ply direction, at any position, and in any coverage range.

[0065] In some embodiments, before step 110, the manufacturing method of the present disclosure further includes:

[0066] According to the preset fold positions and parameters, a positive mold 1 and a negative mold 2 are produced.

[0067] The positions, parameter sizes and numbers of the raised portions 12 and the recessed portions 22 are determined by the positions and parameters of the wrinkles in the test piece. If different wrinkles are to be made in the test piece, the male mold 1 and the female mold 2 need to be remade.

[0068] In some embodiments, step 110 of laying a first preset number of prepreg layers on the male mold 1 and performing hot compaction comprises:

[0069] Step 111, laying a portion of the first preset number of layers of prepreg on the first surface 11 of the male mold 1;

[0070] Step 112, placing a portion of the prepreg layers together with the male mold 1 into an autoclave, and maintaining the first preset heating temperature for a first preset heating time under a first preset vacuum pressure to perform hot compaction;

[0071] Step 113, after taking out from the autoclave and cooling, laying the remaining number of prepreg layers in the first preset number of layers on the compacted prepreg;

[0072] Step 114 , placing the remaining layers of prepreg together with the male mold 1 into an autoclave, maintaining the first preset heating time at a first preset heating temperature under a first preset vacuum pressure, and performing hot compaction again.

[0073] In some embodiments, step 120 of laying a second preset number of prepreg layers on the female mold 2 and performing hot compaction comprises:

[0074] Step 121, laying a portion of the second preset number of layers of prepreg on the second surface 21 of the female mold 2;

[0075] Step 122, placing a part of the prepreg layers together with the female mold 2 into an autoclave, maintaining a first preset heating time at a first preset heating temperature under a first preset vacuum pressure to perform hot compaction;

[0076] Step 123, after taking out from the autoclave and cooling, laying the remaining number of prepreg layers in the second preset number of layers on the compacted prepreg;

[0077] Step 124 , placing the remaining layers of prepreg together with the female mold 2 into an autoclave, maintaining the first preset heating time at a first preset heating temperature under a first preset vacuum pressure, and performing hot compaction again.

[0078] Among them, steps 111-114 and 121-124 are not shown in the figure. This embodiment adopts the method of laying prepreg on the male mold 1 or the female mold 2 in batches, which can improve the compaction degree of each layer. Vacuum hot compaction can make the prepreg undergo low-density cross-linking reaction at a lower temperature and maintain a surface that is relatively consistent with the mold, so as to prepare for the formation and maintenance of wrinkles during subsequent high-temperature curing.

[0079] In some embodiments, Figure 4 The curing process condition curve shown in FIG. 1 includes the following steps: step 140 of placing the packaged wrinkled test piece into an autoclave and applying the curing process conditions corresponding to the porosity in the preset interval for curing:

[0080] Step 141, pumping the packaged test piece to a second preset vacuum pressure;

[0081] Step 142: pressurize the autoclave to a first preset pressure, and reduce the vacuum degree in the vacuum bag during the pressurization process. When the pressure in the autoclave reaches a second preset pressure, the vacuum degree in the vacuum bag reaches a third preset vacuum pressure. The second preset pressure is greater than the first preset pressure, and the absolute value of the third preset vacuum pressure is less than the absolute value of the second preset vacuum pressure.

[0082] Step 143, heating the autoclave to a second preset heating temperature at a preset heating rate;

[0083] Step 144, maintaining the temperature at the first preset pressure, the third preset vacuum pressure, and the second preset heating temperature for a second preset heating time;

[0084] Step 145, after the heat preservation is completed, the temperature is reduced at a preset cooling rate, and the pressure in the autoclave is gradually released when the test piece reaches below the preset temperature.

[0085] Among them, steps 141-144 are not shown in the figure. Steps 142 and 143 can be performed simultaneously to heat the autoclave while adjusting the pressure in the autoclave and the vacuum bag, which can improve the curing efficiency. This embodiment can accurately control the porosity in the test piece by controlling the vacuum pressure of the test piece after packaging, as well as the temperature and pressure parameters in the autoclave. Porosity control principle: by reducing the vacuum degree, the saturated vapor pressure of the hygroscopic moisture and other volatile substances in the prepreg ply is increased, thereby increasing the temperature of its gasification and overflow. Before the prepreg is heated to the state with the lowest viscosity, more moisture and volatile substances can remain in the ply in a non-gaseous state. After the prepreg is heated to the state with the lowest viscosity, the gas overflow channel is gradually closed. At this time, the reduced curing pressure is lower than the saturated vapor pressure of moisture and volatile substances at the corresponding temperature. The moisture and volatile substances in the prepreg ply cannot escape to form pores when they are gasified at high temperature and low pressure. The porosity can be adjusted by adjusting the vacuum degree and curing pressure.

[0086] In some embodiments, when the porosity in the preset interval is less than 1%, the second preset vacuum pressure is -1.0 bar, the third preset vacuum pressure is -0.2 bar, the first preset pressure is 7 bar, the second preset pressure is 1 bar, the preset heating rate is 1-2°C / min, the second preset heating temperature is 180°C±5°C, the second preset heating time is 120±5min, the preset cooling rate is 2-5°C / min, and the preset temperature is 60°C.

[0087] In some embodiments, when the porosity in the preset interval is in the range of 1% to 3%, the second preset vacuum pressure is -0.6 bar, the third preset vacuum pressure is -0.2 bar, the first preset pressure is 2 bar, the second preset pressure is 1 bar, the preset heating rate is 1-2°C / min, the second preset heating temperature is 180°C±5°C, the second preset heating time is 120±5min, the preset cooling rate is 2-5°C / min, and the preset temperature is 60°C.

[0088] In some embodiments, after obtaining the test piece with preset wrinkle positions and parameters and preset porosity in step 150, the manufacturing apparatus of the present disclosure further includes:

[0089] Process the test pieces into corresponding test piece sizes according to different performance test standards;

[0090] The performance of the processed test pieces was tested and studied.

[0091] Secondly, the present disclosure also provides a manufacturing device for a test piece with a wrinkle-pore coupling defect, such as Figure 1 As shown, in some embodiments, including:

[0092] A male mold 1, a first surface 11 of which is provided with a protrusion 12, the first surface 11 being configured to lay a first preset number of layers of prepreg, and to demould each layer of prepreg by hot compaction to form a male mold hot compaction layer 10;

[0093] A female mold 2, a second surface 21 of which is provided with a recessed portion 22, the second surface 21 being configured to lay a second preset number of prepreg layers, and to demould each layer of prepreg by hot compaction to form a female mold hot compaction layer 20; and

[0094] The autoclave is configured to cure the test piece with wrinkles after the male mold hot compaction layer 10 and the female mold hot compaction layer 20 are stacked in the thickness direction, so as to obtain the test piece with preset wrinkle position and parameters and preset porosity after demolding;

[0095] Among them, when the male mold 1 and the female mold 2 are relatively stacked with the first surface 11 and the second surface 21, the raised portion 12 and the recessed portion 22 are configured to cooperate with each other and the contact surface is consistent with the position and parameters of the preset wrinkles; and the recessed surface 101 of the male mold hot compaction layer 10 and the raised surface 201 of the female mold hot compaction layer 20 are configured to be aligned when stacked and packaged.

[0096] This embodiment uses a mold to manufacture out-of-plane wrinkles in a composite material test piece. The angle, direction and coverage of the wrinkles in the test piece can be accurately controlled by the mold design, and the pore percentage in the test piece can be accurately controlled by changing the process pressure. The test piece can be quickly and accurately manufactured to contain wrinkle defects in any ply direction, any position, coverage and angle, and pore coupling defects with different percentages, thereby achieving controllable manufacturing of coupling defects in the test piece, reducing the manufacturing cost of the test piece, and improving production efficiency.

[0097] In some embodiments, Figure 1 As shown, a plurality of raised portions 12 are arranged on the first surface 11 of the male mold 1 at intervals along the first direction, and each raised portion 12 extends along the second direction; a plurality of recessed portions 22 are arranged on the second surface 21 of the female mold 2 at intervals along the first direction, and each recessed portion 22 extends along the second direction, so as to form a plurality of wrinkles arranged at intervals along the first direction in the ply of the test piece, and each wrinkle extends along the second direction.

[0098] This embodiment can set a plurality of wrinkles according to the test requirements of the test piece, and the plurality of wrinkles can be precisely controlled by the male mold 1 and the female mold 2 to quickly and accurately manufacture wrinkles along any ply direction, at any position, and in any coverage range.

[0099] In a specific embodiment, taking the coupled defects of pores with different percentages and in-plane and out-of-plane wrinkles with different angles as an example, the specific operation steps are described as follows:

[0100] 1. Test piece design:

[0101] Use [0] 20 Laying, the size of the test piece is 300mm×300mm, and 5°, 10° and 20° folds are designed at the 9th, 10th and 11th layer positions in the middle of the test piece;

[0102] 2. Mold design: design the machine on the aluminum plate Figure 1 The male mold 1 and the female mold 2 are shown as a set of mutually fitting. The male mold 1 has three arc convex parts 12 with different protrusion angles to simulate different wrinkle angles, and the female mold 2 has a concave arc concave part 22 with the same angle at the position corresponding to the male mold 1 to cooperate.

[0103] 3. Pleated paving:

[0104] Five layers of prepreg are manually laid on the positive mold 1 according to the laying requirements, and the five layers of prepreg are vacuumed and compacted together with the aluminum positive mold 1 and placed in the autoclave for hot compaction. The heating temperature is 60°C, the heating time is 15 minutes, and the vacuum pressure is sufficient. After being taken out of the autoclave and cooled, five more layers of prepreg are laid on the compacted prepreg, and the above steps are repeated for vacuum hot compaction. Finally, the ten layers of prepreg are demoulded and set aside to form a Figure 2 The male mold shown heat compacts the ply 10. The purpose of laying 5 layers on the male mold 1 is to better ensure the formation of wrinkle angles, so as to avoid flattening wrinkles during the later curing due to too few layers, or wrinkles in the thickness direction of the entire ply 20 due to too many layers.

[0105] Follow [0] 20 The ply requirements are to manually lay five layers of 0° prepreg on the female mold 2, and then put the five layers of prepreg into the autoclave together with the aluminum female mold 2 for hot compaction after vacuum compaction. The heating temperature is 60℃, the heating time is 15min, and the vacuum pressure is sufficient. After being taken out of the autoclave and cooled, five more layers of prepreg are laid on the compacted prepreg, and the above steps are repeated for vacuum hot compaction. Finally, the ten layers of prepreg are demoulded and set aside for use. Figure 3 The female mold shown hot compacts the layup 20 .

[0106] 4. Packaging:

[0107] The film surface of the ten layers of prepregs hot-pressed by the male mold 1 is laid on the film surface of the ten layers of prepregs hot-pressed by the female mold 2, and the concave surface 101 and the convex surface 201 with different angles of wrinkles are aligned. After laying, it is packaged according to the packaging system, such as putting it into a vacuum bag.

[0108] 5. Curing:

[0109] The packaged vacuum bag with wrinkled test pieces is placed in an autoclave for curing, and test pieces with different porosity contents are obtained by changing the curing system. For example, for the IM7 / M91 material system, the curing process conditions corresponding to two porosities are given below.

[0110] (1) In order to obtain a porosity of less than 1%, the curing curve is as follows Figure 4 As shown, the curing process is:

[0111] The test piece with wrinkles was subjected to vacuum treatment (-1.0 bar);

[0112] Use an autoclave to pressurize to 7 bar. During the pressurization process, when the pressure in the autoclave reaches 1 bar, reduce the vacuum to -0.2 bar;

[0113] Set the heating rate of the autoclave to 1-2℃ / min, and raise the temperature inside the autoclave to 180℃±5℃;

[0114] Keep warm at 180℃±5℃ for 120±5min;

[0115] The cooling rate is 2-5℃ / min;

[0116] When the temperature of the test piece reaches below 60°C, release the autoclave pressure.

[0117] (2) In order to obtain a porosity of 1% < 3%, the curing process is:

[0118] The test piece with wrinkles was subjected to vacuum treatment (-0.6 bar);

[0119] Use an autoclave to pressurize to 2 bar. During the pressurization process, when the pressure in the autoclave reaches 1 bar, reduce the vacuum to -0.2 bar;

[0120] Set the heating rate of the autoclave to 1-2℃ / min, and raise the temperature inside the autoclave to 180℃±5℃;

[0121] Keep warm at 180℃±5℃ for 120±5min;

[0122] The cooling rate is 2-5℃ / min;

[0123] When the temperature of the part reaches below 60°C, release the autoclave pressure.

[0124] 6. Demolding:

[0125] After curing, the test piece is demoulded, and test pieces with different porosities and different out-of-plane bending wrinkle angles are obtained, such as Figure 5 shown.

[0126] 7. Performance test: The formed 300mm×300mm pore and wrinkle coupling test piece is processed into the corresponding test piece size according to different performance test standards to study the effect of defect coupling on performance. The common tensile test piece size is 250mm×325mm, and the compression test piece size is 140x12mm. The test piece size of 300x300mm can meet the corresponding processing requirements.

[0127] The above is a detailed introduction to the manufacturing method and device of a test piece with fold-pore coupling defects provided by the present disclosure. Specific embodiments are used in this article to illustrate the principles and implementation methods of the present disclosure. The description of the above embodiments is only used to help understand the method and core ideas of the present disclosure. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present disclosure, several improvements and modifications can be made to the present disclosure, and these improvements and modifications also fall within the scope of protection of the claims of the present disclosure.

Claims

1. A method for manufacturing a test piece with wrinkle-pore coupling defects, characterized in that: include: Laying a first preset number of prepreg layers on a first surface provided with a raised portion on the male mold, and after hot compaction, demoulding each layer of prepreg to form a male mold hot compaction layer; Laying a second preset number of prepreg layers on the second surface of the female mold with the concave portion, and demolding each layer of prepreg after hot compaction to form a female mold hot compaction layer; wherein, when the male mold and the female mold are relatively superimposed with the first surface and the second surface, the convex portion and the concave portion are configured to cooperate with each other and the contact surface is consistent with the position and parameters of the preset folds; The male mold hot compaction layer and the female mold hot compaction layer are stacked in the thickness direction, the concave surface of the male mold hot compaction layer is aligned with the convex surface of the female mold hot compaction layer, and they are connected through their respective film surfaces for packaging; The packaged test piece with wrinkles is placed in an autoclave, and the curing process conditions corresponding to the porosity in the preset interval are applied to perform curing; and After curing, the test piece is demoulded to obtain a test piece with preset wrinkle positions and parameters and preset porosity.

2. The method for manufacturing a test piece with wrinkle-pore coupling defects according to claim 1, characterized in that: The preset wrinkle position and parameters include: at least one of the ply where the preset wrinkle is located in the test piece, the setting position in the ply, and the wrinkle angle.

3. The method for manufacturing a test piece with wrinkle-pore coupling defects according to claim 1, characterized in that: A plurality of the protrusions are arranged on the first surface of the male mold at intervals along the first direction, and each of the protrusions extends along the second direction; a plurality of the concave portions are arranged on the second surface of the female mold at intervals along the first direction, and each of the concave portions extends along the second direction, so as to form a plurality of wrinkles arranged at intervals along the first direction in the ply of the test piece, and each wrinkle extends along the second direction.

4. The method for manufacturing a test piece with wrinkle-pore coupling defects according to claim 1, characterized in that: Also includes: The positive mold and the negative mold are manufactured according to the positions and parameters of the preset wrinkles.

5. The method for manufacturing a test piece with wrinkle-pore coupling defects according to claim 1, characterized in that: The steps of laying a first preset number of layers of prepreg on the positive mold or laying a second preset number of layers of prepreg on the negative mold and performing hot compaction include: Laying a partial number of layers of prepreg on the first surface of the male mold or the second surface of the female mold; Putting the partial number of layers of prepreg together with the mold into an autoclave, maintaining a first preset heating time at a first preset heating temperature under a first preset vacuum pressure to perform hot compaction; After being taken out from the autoclave and cooled, the remaining number of prepreg layers are laid on the compacted prepreg; The remaining number of layers of prepreg are placed together with the mold into an autoclave, and the first preset heating time is maintained at the first preset heating temperature under the first preset vacuum pressure to perform thermal compaction again.

6. The method for manufacturing a test piece with wrinkle-pore coupling defects according to claim 1, characterized in that: The steps of placing the packaged wrinkled test piece into an autoclave and applying the curing process conditions corresponding to the porosity in the preset interval for curing include: Pumping the packaged test piece to a second preset vacuum pressure; The autoclave is pressurized to a first preset pressure, and the vacuum degree in the vacuum bag is reduced during the pressurization process. When the pressure in the autoclave reaches a second preset pressure, the vacuum degree in the vacuum bag reaches a third preset vacuum pressure. The second preset pressure is greater than the first preset pressure, and the absolute value of the third preset vacuum pressure is less than the absolute value of the second preset vacuum pressure. The autoclave is heated to a second preset heating temperature at a preset heating rate; Maintaining the temperature at the first preset pressure, the third preset vacuum pressure, and the second preset heating temperature for a second preset heating time; After the heat preservation is completed, the temperature is lowered at a preset cooling rate, and the pressure in the autoclave is gradually released when the test piece reaches below the preset temperature.

7. The method for manufacturing a test piece with fold-pore coupling defects according to claim 6, characterized in that: When the porosity in the preset interval is less than 1%, the second preset vacuum pressure is -1.0 bar, the third preset vacuum pressure is -0.2 bar, the first preset pressure is 7 bar, the second preset pressure is 1 bar, the preset heating rate is 1-2°C / min, the second preset heating temperature is 180°C±5°C, the second preset heating time is 120±5min, the preset cooling rate is 2-5°C / min, and the preset temperature is 60°C; or When the porosity in the preset interval is in the range of 1% to 3%, the second preset vacuum pressure is -0.6 bar, the third preset vacuum pressure is -0.2 bar, the first preset pressure is 2 bar, the second preset pressure is 1 bar, the preset heating rate is 1-2°C / min, the second preset heating temperature is 180°C±5°C, the second preset heating time is 120±5min, the preset cooling rate is 2-5°C / min, and the preset temperature is 60°C.

8. The method for manufacturing a test piece with wrinkle-pore coupling defects according to claim 1, characterized in that: After obtaining the test piece with the preset fold position and parameters and the preset porosity, it also includes: Processing the test piece into corresponding test piece sizes according to different performance test standards; The performance of the processed test pieces was tested and studied.

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