A forming method of a structural and functional integration test machine cabinet skin

Abstract

The application discloses a kind of forming methods of structural function integration test machine cabinet skin in technical field, comprising the following steps: step 1) main skin forming, adopts negative mould laying, including outer skin layer, shock-absorbing layer, inner skin layer, the outer skin layer and inner skin layer are all used carbon fiber prepreg, shock-absorbing layer uses damping prepreg, from outside to inside laying, after laying is completed, it is cut into main skin after high temperature and high pressure solidification forming of heat pressure tank, demoulding;Step 2) the forming of mouth cover plate, adopts flat mould laying, its structure process is same with main skin, and installation hole is set up in the outer periphery of mouth cover plate using processing equipment;Step 3) cabinet skin is equipped with hole, and the hole is opened in the position needing to be opened in main skin using mouth cover plate to do rotating template;Step 4) mouth cover plate installation, mouth cover plate is installed to main skin using fastener, the application solves the problem that previous metal cabinet is relatively heavy, so that skin can have load-bearing structure strength while being able to itself play the role of shock absorption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite material products, in particular to a space station test machine cabinet. BACKGROUND

[0002] At present, various countries are developing space industry, especially the rocket recovery technology of SpaceX and the successful launch of Starlink, more and more private enterprises are developing space technology, which makes the unreachable space technology more and more popular in the public and on the commercial road. For the extreme environment in space, the construction raw materials of artificial celestial bodies and spacecraft launched into the earth's atmosphere have high requirements. According to the rocket, about 50 kg of energy is consumed for every 1 kg of weight launched, so the reduction of the weight of the material in the space launch process is very important for the use of launch energy. In addition, the vibration during the launch process has a great influence on the equipment launched, and the vibration reduction requirement of the equipment during the launch process is very high. A material that can reduce the weight of the equipment and itself is a material that is urgently needed in the field of aerospace.

[0003] The scientific test machine cabinet is a test machine cabinet opened for testing in the space station, a series of scientific tests can be carried out in it, and the cabinet exists in large quantities in the space station. The reduction of its own weight and the use of materials with vibration reduction function for manufacturing undoubtedly play a great role in the construction of the space station. SUMMARY

[0004] In view of the problems existing in the prior art, the present application provides a forming method of a structure and function integrated test machine cabinet skin, which solves the problem of the large weight of the metal cabinet in the prior art, and makes the skin have both load bearing structure strength and vibration reduction function.

[0005] The purpose of the present application is achieved by a forming method of a structure and function integrated test machine cabinet skin, comprising the following steps:

[0006] Step 1) forming the main skin, using negative mold laying, including an outer skin layer, a damping layer and an inner skin layer, the outer skin layer and the inner skin layer are made of carbon fiber prepreg, the damping layer is made of damping prepreg, and the laying is performed from outside to inside, after the laying is completed, the main skin is obtained by high temperature and high pressure curing in a heat press tank and cutting after demolding;

[0007] Step 2) forming the cover plate, using flat mold laying, which has the same structure as the main skin, including an outer skin layer, a damping layer and an inner skin layer, the outer skin layer and the inner skin layer are made of carbon fiber prepreg, the damping layer is made of damping prepreg, and the laying is performed from outside to inside, after the laying is completed, the cover plate is obtained by high temperature and high pressure curing in a heat press tank and demolding, and a mounting hole is formed on the outer periphery of the cover plate using a processing device;

[0008] Step 3) Cabinet skin hole, using the cover plate as a transfer template to open holes in the main body skin where needed;

[0009] Step 4) Cover plate installation, using fasteners to install the cover plate to the main body skin.

[0010] Further, the damping prepreg is composed of the following components: 45±2% of reinforcing carbon fiber, 10±2% of epoxy resin, and 45±2% of damping material.

[0011] Further, the manufacturing process of the damping prepreg is as follows: 9mm long T800 grade chopped carbon fiber is selected as the reinforcing carbon fiber, the chopped carbon fiber is added into the epoxy resin and stirred to diffuse uniformly, then added into the damping material and stirred again, and finally a film vulcanizing machine is used to make the damping prepreg with a thickness of 0.55±0.02mm.

[0012] Further, the forming process of the main body skin in step 1) includes:

[0013] a) Design and manufacture a corresponding size specification negative mold, and use the negative mold to make;

[0014] b) Use a full-automatic cutting machine to cut the prepreg and the damping prepreg;

[0015] c) The cabinet main body skin is a 5-face box structure with a uniform thickness of 1.5mm, which includes 0.5mm outer skin, 0.5mm damping prepreg, and 0.5mm inner skin. The outer skin and the inner skin are made of T800 grade carbon fiber reinforced epoxy resin unidirectional prepreg and T800 grade carbon fiber reinforced epoxy resin plain weave prepreg respectively, and the thickness of each single layer of the two kinds of prepreg is 0.125mm. The outer skin and the inner skin are both 4 layers of prepreg sheets;

[0016] d) Use the negative mold to lay up, first lay up the outer skin, the thickness of which is 0.5mm. The outermost layer is 1 layer of T800 grade carbon fiber reinforced epoxy resin plain weave prepreg, and the remaining 3 layers are all T800 grade carbon fiber reinforced epoxy resin unidirectional prepreg. The laying angle is designed as: 45°, 0°, 90°, 0°. After laying up 4 layers of prepreg sheets, a vacuum pre-exhaust bag is needed to pre-compact the prepreg sheets;

[0017] e) After the outer skin is laid up, a layer of structural adhesive film is laid on the surface of the prepreg sheets, and a vacuum pre-exhaust bag is made for pre-compaction after the laying up is completed;

[0018] f) Lay up the damping prepreg on the surface of the pre-compacted structural adhesive film, and lay up slowly. After the laying up is completed, a vacuum pre-exhaust bag is made for pre-compaction;

[0019] g) After the damping prepreg is laid up, a layer of structural adhesive film is laid on the surface of the prepreg, and a vacuum pre-exhaust bag is made for pre-compaction after the laying up is completed;

[0020] h) After the end of the structural adhesive film laying, the inner skin is laid, and the inner skin is also 0.5 mm. The laying of the inner skin is 3 layers of T800 grade carbon fiber reinforced epoxy resin unidirectional prepreg and 1 layer of T800 grade carbon fiber reinforced epoxy resin plain weave prepreg, and the laying angle is 0°, 90°, 0°, 45°. After laying 4 layers of sheets, a vacuum pre-evacuation bag is made for pre-compaction;

[0021] i) After all the sheets are laid, a final vacuum bag is made, and a hot press is used for high temperature and high pressure curing and forming, and the curing system is as follows: pressurized to 0.6 Mpa, 90℃ for 1 hour, 130℃ for 3 hours;

[0022] j) After curing and forming, the main skin is separated from the negative mold, and a cutting machine is used to cut the size allowance to the net size.

[0023] Further, in steps d) and e), the sheets of adjacent sections are laid with staggered butt joint, and the sheets in the same layer are laid with butt joint, and the butt joint gap is ≤1mm. The butt joint gap of adjacent two layers of sheets must be controlled between 15-20mm, and the butt joint seams of every 4 layers of sheets cannot be in the same position.

[0024] Further, in step a), when designing the negative mold, the expansion size of the mold material at the skin curing temperature is calculated by simulation software according to the linear expansion coefficient of the mold material, and the mold size at room temperature is obtained according to the size change of thermal expansion and cold contraction. Finally, the forming mold of the cabinet main skin is designed and processed according to this data, and the mold processing also needs to be processed under the condition of 25℃ constant temperature.

[0025] Further, in step a), after numerical control processing of the mold laying surface, foam polishing treatment is needed. 80 mesh sand, 2000 mesh sand, oil stone and polishing cotton are used for polishing in turn. The roughness of the mold surface is detected during the polishing process, and the precision of the laying surface needs to reach Rz≤0.4.

[0026] Compared with the prior art, the beneficial effects of the present application are as follows:

[0027] (1) The cabinet skin is made of carbon fiber composite material, which greatly reduces the weight of the skin and reduces the energy consumption of space launch;

[0028] (2) The present application adopts the mixed laying method of carbon fiber prepreg and self-designed damping prepreg, which not only ensures the structural strength of the cabinet skin, but also plays a damping role, reduces the use of dampers, reduces the energy consumption during space launch, optimizes the equipment placement space, and increases the space for carrying goods during single launch;

[0029] (3) The cabinet skin is made of composite material, the outer dimension is ensured by a mold, the cabinet skins produced by a single mold are completely consistent in size and can be interchanged, the space layout and installation precision in the space station are effectively ensured, and the maintenance difficulty of astronauts is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute a part of the embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on the provided drawings.

[0031] Figure 1 The flowchart of the present application.

[0032] Figure 2 The schematic diagram of the integrated test cabinet skin structure prepared by the present application.

[0033] Figure 3 The exploded view of the integrated test cabinet skin prepared by the present application.

[0034] Figure 4 The cross-sectional view of the integrated test cabinet skin prepared by the present application.

[0035] Among them, 101 is an outer skin layer, 102 is a shock absorption layer, 103 is an inner skin layer, 104 is a structural adhesive film, 200 is a composite skin, 300 is a skin side cover, 400 is a skin top cover, and 401 is a cross-shaped rib plate. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0037] As shown in the drawings, the present application needs to design an integrated test cabinet skin with structure and function, which comprises: Figures 2-4

[0038] The main skin 200 is in the shape of a box, the bottom is an open port, the two sides are provided with side openings, and the top is provided with a top opening;

[0039] The skin side cover 300 is in the shape of a flat plate and is installed on the side opening of the main skin 200;

[0040] The skin top cover 400 is in the shape of a flat plate and is installed on the top opening of the main skin 200.​

[0041] The main body skin 200, the skin side cover 300 and the skin top cover 400 are of the same structure and comprise an outer skin layer 101, a damping layer 102 and an inner skin layer 103, the outer skin layer 101 and the inner skin layer 103 are both formed by laying carbon fiber reinforced epoxy resin prepreg, the damping layer 102 is made of damping prepreg, and the top of the skin top cover 400 is provided with a cross-shaped rib plate 401.

[0042] Embodiment 1

[0043] As shown in the figure, a forming method of a structure and function integrated test main body skin 200 comprises the following steps: Figure 1

[0044] Step 1) forming the main body skin 200;

[0045] The cabinet main body skin 200 is the largest composite part, with a size of 1809mmx1043mmx780mm and a part thickness of 1.5mm. In order to ensure its outer size, a steel negative mold is laid. Its final size and equipment installation port size are ensured by cutting. The specific forming process is as follows:

[0046] a) Aviation equipment generally requires that the product surface must be smooth and sharp, therefore, the mold surface of the cabinet main body skin 200 must be smooth and defect-free, a negative mold is used to make the steel negative mold.

[0047] b) The weight control of space equipment is extremely strict, a detailed drawing is accurately made by using software, and the prepreg and damping prepreg are cut by using a full-automatic cutting machine.

[0048] c) The cabinet main body skin 200 is a 5-face box structure, with a uniform thickness of 1.5mm, including 0.5mm outer skin, 0.5mm damping prepreg and 0.5mm inner skin. The prepregs used are T800 carbon fiber reinforced epoxy resin unidirectional prepreg and T800 carbon fiber reinforced epoxy resin plain weave prepreg, with a single-layer thickness of 0.125mm, and the outer skin and the inner skin are both 4 layers of prepreg.

[0049] d) The negative mold is laid, the outer skin is laid first, according to the design, the outermost layer is one layer of T800 carbon fiber reinforced epoxy resin plain weave prepreg, and the remaining 3 layers are T800 carbon fiber reinforced epoxy resin unidirectional prepreg, with a laying design angle of (45°, 0°, 90°, 0°). In order to ensure that there is no bubble, gap or wrinkle between the prepreg layers, a vacuum pre-exhaust bag is made to pre-compact the prepreg after laying 4 layers of prepreg.

[0050] ​e) After the outer skin is laid, a layer of J-165 structural adhesive film 104 is laid on the surface of the patch, which serves to ensure the bonding strength of the damping pre-impregnated material and the pre-impregnated material. After laying, a vacuum pre-exhaust bag is made for pre-compaction.

[0051] f) After pre-compaction, the damping pre-impregnated material is laid on the surface of the structural adhesive film 104. The damping pre-impregnated material is soft and needs to be laid slowly to ensure quality. After laying, a vacuum pre-exhaust bag is made for pre-compaction. The damping pre-impregnated material is composed of the following components: 45±2% reinforced carbon fiber, 10±2% epoxy resin, and 45±2% damping material. The optimal selection is 45% reinforced carbon fiber, 10% epoxy resin, and 45% damping pre-impregnated material. The manufacturing process of the damping pre-impregnated material is as follows: select 9mm long T800 chopped carbon fiber as the reinforced carbon fiber, add the chopped carbon fiber into the epoxy resin and stir well to disperse evenly, then add it to the damping material and stir again to make it uniform. Finally, use a film vulcanizing machine to make a damping pre-impregnated material with a thickness of 0.55±0.02mm.

[0052] g) After laying the damping pre-impregnated material, a layer of J-165 structural adhesive film 104 is laid on its surface. After laying, a vacuum pre-exhaust bag is made for pre-compaction.

[0053] h) After the structural adhesive film 104 is laid, the inner skin is laid. The inner skin is also 0.5mm. The inner skin is laid with 3 layers of unidirectional pre-impregnated material and 1 layer of plain weave pre-impregnated material. The layup design angle is (0°, 90°, 0°, 45°). After laying the 4 layers of patches, a vacuum pre-exhaust bag is made for pre-compaction.

[0054] i) After all the patches are laid, a final vacuum bag is made, and the cabinet body skin 200 is cured and formed in a hot press at high temperature and high pressure. The curing system is to press to 0.6Mpa, 90℃ for 1 hour, and 130℃ for 3 hours.

[0055] j) After curing and forming, the cabinet body skin 200 is separated from the negative mold, and the cutting machine is used to cut the size allowance to the net size.

[0056] Step 2) Formation and manufacturing of the door cover plate (including the skin side cover 300 and the skin top cover 400).

[0057] The equipment installation door cover plate mainly includes two specifications, with sizes of 960mm×880m×1.5mm for the back equipment installation door cover plate and 650mm×340mm×1.5mm for the side equipment installation door cover plate. The thickness of both cover plates is 1.5mm. The layup design is consistent with that of the main body skin 200, which is also 0.5mm outer skin + 0.5mm damping pre-impregnated material + 0.5mm inner skin.

[0058] The equipment mounting port cover plate is a flat plate structure, which is formed by laying and pasting with a steel flat plate mold. It also has 4 layers of outer skin, 4 layers of inner skin, and one layer of damping prepreg in the middle. J-165 structural adhesive film 104 needs to be laid between the damping prepreg and the carbon fiber prepreg to increase the bonding performance. When laying and pasting the sheets, a vacuum pre-extraction bag is needed to pre-compact the sheets every 4 layers. After the laying and pasting of the structural adhesive film 104 and the damping prepreg is completed, it needs to be pre-compact separately. The laying angle design is (45°, 0°, 90°, 0°, adhesive film, damping, adhesive film, 0°, 90°, 0°, 45°). After all the sheets are laid and pasted, the final vacuum bag is made to enter the autoclave for high-temperature and high-pressure curing. The curing system is consistent with the cabinet main skin 200.

[0059] After the port cover plate is cured and formed, in order to ensure the dimensional accuracy and the opening accuracy of the bolt holes, the edge cutting and hole opening are directly processed by using a numerical control machining center.

[0060] Step 3) Main skin 200 hole matching installation

[0061] After all the composite parts are completed, the machined equipment mounting port cover plate is used as a transfer template to open holes in the positions where the bolt holes are needed on the cabinet main skin 200. The holes are opened to be seamlessly installed with the equipment mounting port cover plate.

[0062] It should be noted that the damping prepreg is a composite material composed of damping prepreg, epoxy resin, and reinforcing fiber. Since the main skin 200 is used in the space station, the weight requirement is extremely strict. If ordinary damping rubber is used, the total thickness of the main skin 200 will be more than 2mm according to simulation calculation. In order to control the thickness of the main skin 200 to be 1.5mm while meeting the structural strength requirements, the damping prepreg used in the present application has both damping and structural strength functions. According to a large number of calculations, tests, and tests, 9mm long T800 grade chopped carbon fiber is finally selected as the reinforcing material, with a carbon fiber content of 45%, an epoxy resin content of 10%, and a damping prepreg content of 45%. After the chopped carbon fiber is fully stirred and diffused in the epoxy resin, it is added to the damping material and stirred again. Finally, a coating vulcanizing machine is used to make the damping prepreg with a thickness of 0.55±0.02mm. (Since the damping prepreg has a certain elasticity, its thickness will be compressed after being processed into the main skin 200 and treated by the autoclave. According to a large number of tests, the thickness of the raw material needs to be made as 0.55mm, and the thickness after curing is about 0.5mm).

[0063] It should be noted that the cabinet main body skin 200 and the equipment installation port cover plate are mixed with T800 carbon fiber reinforced epoxy resin prepreg and self-designed damping prepreg to realize weight reduction and vibration reduction functions. The structural damping ratio G of the main body skin 200 and the equipment installation port cover plate is less than or equal to 0.3, and the dynamic amplification factor is less than or equal to 3.5.

[0064] According to the health considerations of astronauts on space stations, the total mass loss of volatile compounds of the composite material is required to be less than or equal to 1% (TML), and the collected condensable volatile matter is required to be less than or equal to 0.1% (CVCM).

[0065] The following is a list of main parts and materials of the main body skin 200:

[0066] Serial number Part name Material composition 1 Cabinet main body skin 200 T800 grade carbon fiber reinforced epoxy resin plain weave prepreg + T800 grade carbon fiber reinforced epoxy resin unidirectional prepreg + damping prepreg + J165 damping special structural adhesive film 2 Rear equipment mounting port cover plate T800 grade carbon fiber reinforced epoxy resin plain weave prepreg + T800 grade carbon fiber reinforced epoxy resin unidirectional prepreg + damping prepreg + J165 damping special structural adhesive film 3 Side equipment port mounting cover plate T800 grade carbon fiber reinforced epoxy resin plain weave prepreg + T800 grade carbon fiber reinforced epoxy resin unidirectional prepreg + damping prepreg + J165 damping special structural adhesive film

[0067] It should be noted that in order to ensure the interlaminar strength between the damping prepreg and the prepreg, a special J-165 epoxy structural adhesive film is used between the carbon fiber prepreg and the damping prepreg. The adhesive strength after curing is consistent with the interlaminar strength of the prepreg.

[0068] It should be noted that since the cabinet main body skin 200 is a 5-face box structure, the whole prepreg is pasted between every two adjacent faces, and in order to ensure that the thickness of the cabinet main body skin 200 is 1.5mm, the prepreg of adjacent sections is pasted by staggered butt joint method. In order to ensure the structural strength of the skin butt joint, the butt joint gap of adjacent two layers of prepreg must be controlled between 15-20mm, and the butt joint of every 4 layers of prepreg cannot be in the same position.

[0069] Specifically, the port cover plate and the main body skin 200 are connected by bolts. The port cover plate is cut and holed by a numerical control machining center, placed on the surface of the main body skin 200, and holed, and then connected by bolts to complete the installation. In order to ensure that the bolts do not loosen during the launch process, all high lock bolts are used.

[0070] It should be noted that the main body skin 200 is harsh in terms of weight requirements in terms of size, profile accuracy, skin thickness, etc. The main body skin 200 is a box-shaped five-face structure, and the size and profile accuracy of the outer shape are mainly guaranteed by the mold, so the precision of the molding mold of the cabinet main body skin 200 is required to be high.

[0071] According to the design requirements, the length, width, height dimensional tolerance of the main skin 200 is required to be ≤1mm, and the profile accuracy tolerance is within ±0.2mm. In order to achieve the requirements, at the initial stage of the mold design, the expansion size of the mold at the skin curing temperature needs to be calculated by simulation software according to the linear expansion coefficient of the mold material, and the mold size at room temperature (25℃) is obtained according to the size change of thermal expansion and cold shrinkage. Finally, the forming mold of the cabinet main skin 200 is designed and processed according to this data. Similarly, the mold processing needs to be processed under the condition of 25℃ constant temperature.

[0072] Considering the total mass loss requirement TML (total mass loss) ≤1% and CVCM (collected condensable volatile matter) ≤0.1% of the raw material used by the main skin 200, the outer surface cannot be painted, according to the design requirements, the surface of the main skin 200 directly uses carbon fiber surface, while ensuring the smoothest surface effect, the surface roughness Rz ≤0.4. Since the surface roughness of all composite parts of the main skin 200 is guaranteed by the mold, the mold laying surface precision needs to reach Rz ≤0.4. According to the processing requirements of the smoothest surface, the mold laying surface needs to be processed after numerical control processing, and 80 mesh sand, 2000 mesh sand, oil stone and polishing cotton are used for polishing and polishing in turn. The roughness of the mold surface is detected during the polishing process.

[0073] In order to ensure that the thickness tolerance of the main skin 200 composite part after curing and forming meets the requirements, the joint of the laying sheet is required to be extremely strict. The inner skin of T800 carbon fiber prepreg is 4 layers, and the outer skin is 4 layers. The same layer of sheet is laid by butt joint, and the butt joint gap is ≤1mm. The adjacent two layers of sheet are laid by staggered butt joint. In order to ensure the structural strength of the butt joint of the skin, the butt joint gap of the adjacent two layers of sheet must be controlled between 15-20mm, and the butt joint of every 4 layers of sheet cannot be in the same position. Because the damping prepreg has a certain elasticity, its thickness will be appropriately thinned after curing and forming, and the size will be appropriately increased. If the conventional sheet butt joint is used for laying, it is easy to form wrinkles after curing. Through a large number of tests, it is found that the butt joint of the damping prepreg sheet needs to reserve a gap of 3-4mm, so that the surface of the cured composite is smooth and wrinkle-free, and the thickness can be guaranteed to be about 1.5mm.

[0074] The above examples are only used to help understand the method of the present application and its core idea. It should be noted that for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A method for molding the skin of a structurally and functionally integrated test cabinet, characterized in that, Comprising the following steps: Step 1) The main body skin (200) is formed by using a negative mold laying, including an outer skin layer (101), a damping layer (102), and an inner skin layer (103), the outer skin layer (101) and the inner skin layer (103) are both made of carbon fiber prepreg, the damping layer (102) is made of damping prepreg, and the laying is performed from outside to inside, after the laying is completed, it is cut after being cured in a heat press tank to obtain the main body skin (200), the forming process of the main body skin (200) in step 1) comprises: a) Design and manufacture a negative mold with corresponding size specifications, and use the negative mold to manufacture; b) Cut the prepreg and damping prepreg by using a full-automatic cutting machine; c) The cabinet main body skin (200) is a 5-face box structure, with a uniform thickness of 1.5 mm, including 0.5 mm outer skin, 0.5 mm damping prepreg, and 0.5 mm inner skin, the outer skin and the inner skin are made of T800 carbon fiber reinforced epoxy resin unidirectional prepreg and T800 carbon fiber reinforced epoxy resin plain weave prepreg respectively, the thickness of a single layer of the two kinds of prepreg is 0.125 mm, and the outer skin and the inner skin are both 4 layers of prepreg; d) Laying by using a negative mold, first lay the outer skin, the thickness of the outer skin is 0.5 mm, the outermost layer is 1 layer of T800 carbon fiber reinforced epoxy resin plain weave prepreg, and the remaining 3 layers are all T800 carbon fiber reinforced epoxy resin unidirectional prepreg, the laying design angle is 45°, 0°, 90°, and 0°, after laying 4 layers of prepreg, a vacuum pre-exhaust bag is needed to pre-compact the prepreg; e) After the laying of the outer skin is completed, lay a layer of structural adhesive film (104) on the surface of the prepreg, and then pre-compact the prepreg by using a vacuum pre-exhaust bag; f) Lay the damping prepreg on the surface of the pre-compacted structural adhesive film (104), and slowly lay the prepreg, and then pre-compact the prepreg by using a vacuum pre-exhaust bag after the laying is completed; g) After laying the damping prepreg, lay a layer of structural adhesive film (104) on the surface of the prepreg, and then pre-compact the prepreg by using a vacuum pre-exhaust bag after the laying is completed; h) After the laying of the structural adhesive film (104) is completed, lay the inner skin, the thickness of the inner skin is also 0.5 mm, the laying of the inner skin is 3 layers of T800 carbon fiber reinforced epoxy resin unidirectional prepreg and 1 layer of T800 carbon fiber reinforced epoxy resin plain weave prepreg, the laying design angle is 0°, 90°, 0°, and 45°, and a vacuum pre-exhaust bag is needed to pre-compact the 4 layers of prepreg after the laying is completed; i) After the laying of all the prepregs is completed, a final vacuum bag is made, and the prepregs are cured in a heat press tank, the curing system is to press to 0.6 Mpa, 90℃ for 1 hour, and 130℃ for 3 hours; j) After the curing, the main body skin (200) is separated from the negative mold, and a cutting machine is used to cut the size allowance to the net size; Step 2) forming of the mouth cover plate, using flat mold paving, which has the same structure as the main body skin (200), including an outer skin layer (101), a shock absorbing layer (102), and an inner skin layer (103), the outer skin layer (101) and the inner skin layer (103) are made of carbon fiber prepreg, the shock absorbing layer (102) is made of damping prepreg, and the paving is performed from the outside to the inside, after paving, it is cured in a hot press tank at high temperature and high pressure, and after demolding, the mouth cover plate is obtained, and a processing equipment is used to open mounting holes on the periphery of the mouth cover plate; Step 3) cabinet skin hole matching, using the mouth cover plate as a transfer template to open holes on the main body skin (200) at the positions where holes are needed; Step 4) mouth cover plate installation, using fasteners to install the mouth cover plate on the main body skin (200).

2. The method of claim 1, wherein the method is a method of forming a skin for a structural functional test machine cabinet, and wherein the skin is formed from a single piece of material. The damping prepreg is composed of the following components: 45±2% reinforced carbon fiber, 10±2% epoxy resin, and 45±2% damping material.

3. The method of claim 2, wherein the method further comprises: The manufacturing process of the damping prepreg is as follows: select 9mm long T800 chopped carbon fiber as reinforced carbon fiber, add the chopped carbon fiber into the epoxy resin, stir and diffuse uniformly, then add it into the damping material and stir again, finally use a film coating vulcanizing machine to make a damping prepreg with a thickness of 0.55±0.02mm.

4. The method of claim 1, wherein the method further comprises the step of: 5 providing a plurality of structural members to the mold. In steps d) and e), the adjacent sections of the material sheet are laid with staggered butt joint, and the material sheets in the same layer are laid with butt joint, the butt joint gap is ≤1mm, the butt joint gap of adjacent two layers of material sheets must be controlled between 15-20mm, and the butt joint seams of every 4 layers of material sheets cannot appear at the same position.

5. The method of claim 1, wherein the method further comprises the step of: 5.

1. applying a coating to the surface of the skin of the test machine cabinet. In step a), when designing the female mold, according to the linear expansion coefficient of the mold material, the expansion size of the mold at the skin curing temperature is calculated by simulation software, and the mold size at room temperature is obtained according to the size change of thermal expansion and cold contraction, and finally the forming mold of the cabinet main body skin (200) is designed and processed according to this data, and the processing of the mold also needs to be processed under the condition of 25℃ constant temperature.

6. The method of claim 1, wherein the method further comprises the step of: 5 forming the skin of the structural-function integrated test machine cabinet by using a vacuum forming process. In step a), when preparing the female mold, the mold paving surface needs to be processed by foam polishing after numerical control processing, and 80 mesh sand, 2000 mesh sand, oil stone and polishing cotton are used for polishing and polishing in turn, the roughness of the mold surface is detected during the polishing process, and the paving surface precision needs to reach Rz≤0.4.

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