Resin matrix composite box reinforcing rib and rapid layering method

Abstract

The invention discloses a resin-based composite material box reinforcing rib which comprises a circle of foam layer adhered to the four side walls of a box, and inverted U-shaped prepregs are laid on the straight plane in the middle of the foam layer and the vertical faces on the two sides of the middle of the foam layer and recorded as D prepregs; laying L-shaped prepreg on vertical surfaces on two sides of the middle part and straight planes at two ends, and recording the L-shaped prepreg as prepreg B; laying the prepreg which is lapped in an annular L shape on the side vertical surfaces at the two ends, and recording the prepreg as E; laying line-shaped prepregs on the line-shaped planes at the two ends, and recording the line-shaped prepregs as A prepregs; laying a line-shaped prepreg on the middle line-shaped plane, and recording the line-shaped prepreg as C prepreg; the laying sequence of the prepregs on the foam layer is as follows: the prepreg D, the prepreg E and the prepreg B are laid in a staggered manner, and after all the prepregs D, E and B are laid, the prepreg A and the prepreg C are laid in an annular winding manner. The manufacturing efficiency is improved, the labor cost is reduced, meanwhile, the strength and performance of the box body are effectively improved, and good application prospects are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of manufacturing resin-based composite material boxes, and relates to a resin-based composite material box reinforcement rib and a rapid laying method for polygonal structures such as quadrilaterals or hexagons. The present invention aims to propose a rapid laying method without losing the structural strength of the composite material box reinforcement rib, so as to improve its laying efficiency and improve its appearance. The present invention is suitable for the fields of composite material packaging boxes, launch boxes, etc. Background Art

[0002] With the development of modern industry, composite materials have been widely used in various industrial fields due to their excellent mechanical properties and lightweight characteristics. Single-layer carbon fiber composite skin reinforced structural boxes are commonly found in composite packaging boxes and launch boxes. In order to increase the rigidity of the box and reduce deformation during use, several composite reinforcement ribs are usually laid on the outer surface of the box. These reinforcement ribs are usually in the shape of a "J", filled with rigid polyurethane foam, PMI foam, etc., and the outer surface is layered with glass fiber or carbon fiber prepreg, such as Figures 1 to 4 The existing lamination process is usually an integral lamination process, which has the problems of large workload and low efficiency. In addition, the prepreg needs to be cut at the corners of the box, resulting in fiber breakage and reduced rib structural strength. Summary of the invention

[0003] (I) Purpose of the invention

[0004] The purpose of the present invention is to provide a resin-based composite material box reinforcement rib and a rapid laying method, which improves the laying efficiency by optimizing the laying process, enhances the structural strength of the reinforcement rib, and improves the surface quality of the reinforcement rib.

[0005] (II) Technical solution

[0006] In order to solve the above technical problems, the present invention provides a resin-based composite box reinforcement rib, which includes: a circle of foam layer bonded to the four side walls of the box, the thickness of the middle area of ​​the foam layer is greater than the thickness of the two side areas, and the surface of the foam layer exposed to the outside is recorded from the middle to the two sides in sequence: a middle straight plane, a middle two side vertical surfaces, a two end straight plane and a two end side vertical surfaces; an inverted U-shaped prepreg is laid on the middle straight plane and the middle two side vertical surfaces, which is recorded as D prepreg; the middle two side vertical surfaces and the two side vertical surfaces are L-shaped prepreg is laid on the straight plane at the end, recorded as B prepreg; circumferential L-shaped overlapping prepreg is laid on the side facades at both ends, recorded as E prepreg; I-shaped prepreg is laid on the straight plane at both ends, recorded as A prepreg; I-shaped prepreg is laid on the middle I-shaped plane, recorded as C prepreg; the laying order of prepreg on the foam layer is: D prepreg, E prepreg, B prepreg are laid alternately, and after all D, E, B prepreg layers are completed, A and C prepregs are finally laid in a circumferential manner.

[0007] Each layer of E prepreg includes four circumferential L-shaped prepregs, each circumferential L-shaped prepreg includes a long side and a short side, and the four circumferential L-shaped prepregs form a complete circle of circumferential reinforcement rib facades.

[0008] Among them, the inner corner of each annular L-shaped prepreg is chamfered.

[0009] When the E prepreg is laid, the long sides and short sides of the circumferential L-shaped prepreg are overlapped alternately, and the overlap width is 20 mm.

[0010] Among them, the long sides and short sides of the circumferential L-shaped prepreg are alternately layered at the same corner of the reinforcement rib.

[0011] The foam layer is made of rigid polyurethane foam or PMI foam; the prepreg is made of glass fiber or carbon fiber fabric prepreg.

[0012] The present invention also provides a method for quickly laying layers of resin-based composite material box reinforcement ribs, which comprises the following steps:

[0013] 1) Material preparation

[0014] Prepare resin-based composite box skin, stiffener foam layer and carbon fiber or glass fiber fabric prepreg;

[0015] 2) Foam bonding

[0016] On the four sides of the composite box skin, the foam layer is bonded and fixed to the skin according to the size requirements of the drawing using room temperature curing structural adhesive;

[0017] 3) Prepreg cutting

[0018] According to the composite material thickness of the reinforcement, the laying thickness of each of the E prepreg, D prepreg, B prepreg, C prepreg and A prepreg is designed; according to the size of the foam layer, the size of each layer of E prepreg, D prepreg, B prepreg, C prepreg and A prepreg is determined, and the prepreg is cut using an automatic cloth cutting machine;

[0019] 4) Reinforcement layer

[0020] The prepregs are laid in a cyclic staggered laying method. After the D prepreg is laid, the E prepreg is laid vertically, and then the B prepreg is laid. After all the B, D, and E prepregs are laid, the A and C prepregs are laid in a hoop-shaped winding manner. Vacuum compaction is performed every 5 to 8 layers. The vacuum degree of vacuum compaction is not less than -0.09MPa, and the maintenance time is 4 to 6 minutes.

[0021] 5) Autoclave curing

[0022] The box body is formed by autoclave molding process. After the laying is completed, the release cloth, non-porous isolation film, guide net and vacuum bag film material are laid on the surface of the box in turn as required; the vacuum bag is bonded and sealed with the high-temperature clay bag, and the airtightness is checked by vacuuming. The vacuum degree shall not be lower than -0.090MPa. The vacuum degree shall not drop by more than 0.02Mpa within 10 minutes after the vacuuming is stopped. After the vacuum inspection is completed, the box body is placed in an autoclave with a curing system of 85℃ / 60min+125℃ / 120min and a pressure of 0.5MPa.

[0023] Among them, in step 3), when the thickness of the reinforcement rib is 8 mm, the designed laying thickness of the E prepreg on the side facades at both ends is 5 mm, the laying thickness of the D prepreg and the B prepreg is 1.5 mm, and the "I"-shaped laying thickness of the C prepreg and the A prepreg is 6.5 mm.

[0024] Wherein, in step 3), E prepreg is cut into 20 layers, D prepreg is cut into 6 layers, B prepreg is cut into 6 layers, C prepreg is cut into 26 layers, and A prepreg is cut into 26 layers.

[0025] Wherein, in step 4), the order of laying the prepreg is:

[0026] 1 layer of D prepreg, 4 layers of E prepreg, 1 layer of B prepreg, 5 layers of A prepreg, 5 layers of C prepreg, vacuum compaction;

[0027] 1 layer of D prepreg, 4 layers of E prepreg, 1 layer of B prepreg, 5 layers of A prepreg, 5 layers of C prepreg, vacuum compaction;

[0028] 1 layer of D prepreg, 4 layers of E prepreg, 1 layer of B prepreg, 5 layers of A prepreg, 5 layers of C prepreg, vacuum compaction;

[0029] 1 layer of D prepreg, 4 layers of E prepreg, 1 layer of B prepreg, 5 layers of A prepreg, 5 layers of C prepreg, vacuum compaction;

[0030] 2 layers of D prepreg, 4 layers of E prepreg, 2 layers of B prepreg, 6 layers of A prepreg, 6 layers of C prepreg, vacuum compacted.

[0031] (III) Beneficial effects

[0032] The resin-based composite box reinforcement ribs and rapid laying method provided by the above technical solution improve the traditional laying process of composite box reinforcement ribs, which not only improves manufacturing efficiency and reduces labor costs, but also effectively improves the strength and performance of the box, and has good application prospects. This technology can be widely used in aviation, aerospace, packaging and other fields, and will help promote the development of related industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figures 1 to 4They are the main view, AA section view, partial enlarged view and side view of the reinforcement ribs laid on the box.

[0034] Figure 5 This is a schematic diagram of laying reinforcing bars according to an embodiment of the present invention.

[0035] Figure 6 for Figure 5 Side view of.

[0036] Figure 7 It is a schematic diagram of cutting the annular L-shaped prepreg according to an embodiment of the present invention.

[0037] Figure 8 and Fig. 9 The following are two examples of circumferential L-shaped prepreg laying. DETAILED DESCRIPTION

[0038] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0039] Reference Figures 5 to 9 As shown, the resin-based composite material box reinforcement ribs of this embodiment include a circle of foam layers bonded to the four side walls of the box, the thickness of the middle area of ​​the foam layer is greater than the thickness of the two side areas, and the surface of the foam layer exposed to the outside is recorded from the middle to the two sides in sequence: the middle straight plane, the middle two side vertical surfaces, the two end straight planes and the two end side vertical surfaces; the middle straight plane and the middle two side vertical surfaces are paved with inverted U-shaped prepreg, which is recorded as D prepreg; the middle two side vertical surfaces and the two end straight planes are paved with Suppose an L-shaped prepreg is marked as B prepreg; a prepreg with an L-shaped overlap is laid on the side elevations at both ends, which is marked as E prepreg; a straight-line prepreg is laid on the straight-line planes at both ends, which is marked as A prepreg; a straight-line prepreg is laid on the straight-line plane in the middle, which is marked as C prepreg; the laying order of the prepreg on the foam layer is: D prepreg, E prepreg, B prepreg are laid alternately, and after all D, E, and B prepreg layers are laid, A and C prepregs are finally laid in a circumferential manner.

[0040] In this embodiment, each layer of E prepreg includes four annular L-shaped prepregs, each of which includes a long side and a short side, and the four annular L-shaped prepregs form a complete circle of annular reinforcement rib vertical surface.

[0041] The inner corner of each annular L-shaped prepreg is chamfered.

[0042] To ensure the vertical strength of the reinforcement, when laying the E prepreg, the long and short sides of the circumferential L-shaped prepreg are overlapped alternately with an overlap width of 20 mm.

[0043] In order to prevent the overlap positions of the prepregs from being the same, the long and short sides of the L-shaped prepregs are laid alternately at the same corner of the reinforcement, such as Figure 8 and 9 shown.

[0044] In this embodiment, the foam layer is made of rigid polyurethane foam or PMI foam; the prepreg is made of glass fiber or carbon fiber fabric prepreg.

[0045] Taking the example of a reinforcement rib with an inner cross-sectional dimension of 940 mm × 940 mm, a reinforcement rib with a width of 60 mm on both sides and a thickness of 8 mm, and a foam layer with a width and height of 300 mm × 30 mm, the rapid laying method of the reinforcement rib of a resin-based composite material box of this embodiment is introduced, which specifically includes the following steps:

[0046] 1) Material preparation

[0047] Prepare resin-based composite box skin, reinforced PMI foam and carbon fiber fabric prepreg, and the single-layer thickness of the prepreg is 0.25mm.

[0048] 2) Foam bonding

[0049] On the four sides of the composite box skin, J-133 room temperature curing structural adhesive is used to bond and fix the foam layer to the skin according to the size requirements of the drawing. It is left at room temperature for 24 hours and surface treatment is performed after curing.

[0050] 3) Prepreg cutting

[0051] For the reinforcement ribs with a composite material thickness of 8mm, the designed laying thickness of the E prepreg on the side facades at both ends is 5mm, the laying thickness of the D prepreg and the B prepreg is 1.5mm, and the "I"-shaped laying thickness of the C prepreg and the A prepreg is 6.5mm.

[0052] For easy identification, they are divided into A ("I" shape), B ("L" shape), C ("I" shape), D ("U" shape) and E (circular "L" shape). The cutting dimensions, layer thickness and number of layers are shown in Table 1; the outer dimensions of the circular "L" shaped cutting are shown in Table Figure 3 .

[0053] According to the requirements of Table 1, an automatic cloth cutting machine is used to cut "U"-shaped, "L"-shaped, circumferential "L"-shaped, and "I"-shaped carbon fiber fabric prepregs.

[0054] Table 1 Fabric cutting dimensions

[0055] Fabric cutting type Thickness / mm Number of layers Size and quantity specifications A 6.5 26 60mm×105000mm×2(both sides) B 1.5 6 360mm×24000mm×2(both sides) C 6.5 26 300mm×109200mm D 1.5 6 360mm×25200mm E 5 20 20×4×2=80 pieces (on both sides), see the cutting size Figure 3

[0056] 4) Reinforcement layer

[0057] The carbon fiber fabric prepreg is laid in a cyclic staggered ply method. After the D prepreg is laid, the E prepreg is laid vertically. To ensure the vertical strength of the reinforcement ribs, the long and short sides of the E prepreg are laid in an alternating overlap, with an overlap width of 20mm. Next, the B prepreg is laid; after all the B, D, and E prepregs are laid, the A and C prepregs are finally laid in a hoop-wrap manner (can be done at the same time), and vacuum compaction is performed every 5 to 8 layers, and the vacuum degree of vacuum compaction is not less than -0.09MPa, and the maintenance time is 4min to 6min. See the ply table 2 for details.

[0058] Table 2 Reinforcement layer table

[0059]

[0060]

[0061] 5) Autoclave curing

[0062] The box body adopts the autoclave molding process. After the layering is completed, the demoulding cloth, non-porous isolation film, guide net and vacuum bag film material are laid on the surface of the box body in turn as required; the vacuum bag is bonded and sealed with the high-temperature clay bag, and the airtightness is checked by vacuuming. The vacuum degree is required to be no less than -0.090MPa, and the vacuum degree should not drop by more than 0.02MPa within 10 minutes after stopping the vacuuming. After the vacuum inspection is completed, the box body is placed in the autoclave, and the curing system is 85℃ / 60min+125℃ / 120min, and the pressure is 0.5MPa.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A resin-based composite material box reinforcement rib, characterized in that: include: A circle of foam layer is bonded to the four side walls of the box body, the thickness of the middle area of ​​the foam layer is greater than the thickness of the two side areas, and the exposed surface of the foam layer is recorded from the middle to the two sides in sequence: the middle straight plane, the middle two side vertical surfaces, the two end straight planes and the two end side vertical surfaces; the middle straight plane and the middle two side vertical surfaces are laid with inverted U-shaped prepreg, which is recorded as D prepreg; the two side vertical surfaces in the middle and the two end straight planes are laid with L-shaped prepreg, which is recorded as B prepreg; the two end side vertical surfaces are laid with circumferential L-shaped overlapping prepreg, which is recorded as E prepreg; the two end straight planes are laid with straight prepreg, which is recorded as A prepreg; the middle straight plane is laid with straight prepreg, which is recorded as C prepreg; the laying order of prepreg on the foam layer is: D prepreg, E prepreg, B prepreg are laid alternately, and after all D, E, B prepreg layers are laid, A and C prepregs are finally laid in a circumferential winding manner.

2. The resin-based composite material box reinforcement rib according to claim 1, characterized in that: Each layer of E prepreg includes four circumferential L-shaped prepregs, each of which includes a long side and a short side, and the four circumferential L-shaped prepregs form a complete circle of circumferential reinforcement rib facades.

3. The resin-based composite material box reinforcement rib according to claim 2, characterized in that: The inner corner of each annular L-shaped prepreg is chamfered.

4. The resin-based composite material box reinforcement rib according to claim 3, characterized in that: When E prepreg is laid, the long and short sides of the circumferential L-shaped prepreg are overlapped alternately with an overlap width of 20 mm.

5. The resin-based composite material box reinforcement rib according to claim 4, characterized in that: At the same corner of the stiffener, the long and short sides of the L-shaped prepreg are alternately laid.

6. The resin-based composite material box reinforcement rib according to claim 5, characterized in that: The foam layer is made of rigid polyurethane foam or PMI foam; the prepreg is made of glass fiber or carbon fiber fabric prepreg.

7. A rapid laying method for a box reinforcement made of a resin-based composite material according to claim 6, characterized in that: The following steps are involved: 1) Material preparation Prepare resin-based composite box skin, stiffener foam layer and carbon fiber or glass fiber fabric prepreg; 2) Foam bonding On the four sides of the composite box skin, the foam layer is bonded and fixed to the skin according to the size requirements of the drawing using room temperature curing structural adhesive; 3) Prepreg cutting According to the composite material thickness of the reinforcement, the laying thickness of each of the E prepreg, D prepreg, B prepreg, C prepreg and A prepreg is designed; according to the size of the foam layer, the size of each layer of E prepreg, D prepreg, B prepreg, C prepreg and A prepreg is determined, and the prepreg is cut using an automatic cloth cutting machine; 4) Reinforcement layer The prepregs are laid in a cyclic staggered laying method. After the D prepreg is laid, the E prepreg is laid vertically, and then the B prepreg is laid. After all the B, D, and E prepregs are laid, the A and C prepregs are laid in a hoop-shaped winding manner. Vacuum compaction is performed every 5 to 8 layers. The vacuum degree of vacuum compaction is not less than -0.09MPa, and the maintenance time is 4 to 6 minutes. 5) Autoclave curing The box body is formed by autoclave molding process. After the laying is completed, the release cloth, non-porous isolation film, guide net and vacuum bag film material are laid on the surface of the box in turn as required; the vacuum bag is bonded and sealed with the high-temperature clay bag, and the airtightness is checked by vacuuming. The vacuum degree shall not be lower than -0.090MPa. The vacuum degree shall not drop by more than 0.02Mpa within 10 minutes after the vacuuming is stopped. After the vacuum inspection is completed, the box body is placed in an autoclave with a curing system of 85℃ / 60min+125℃ / 120min and a pressure of 0.5MPa.

8. The method for rapid laying of resin-based composite material box reinforcement ribs according to claim 7, characterized in that: In step 3), when the thickness of the reinforcement is 8 mm, the design thickness of the E prepreg on the side elevations at both ends is 5 mm, the thickness of the D prepreg and the B prepreg is 1.5 mm, and the "I"-shaped thickness of the C prepreg and the A prepreg is 6.5 mm.

9. The method for rapid laying of resin-based composite material box reinforcement ribs according to claim 8, characterized in that: In step 3), the E prepreg is cut into 20 layers, the D prepreg is cut into 6 layers, the B prepreg is cut into 6 layers, the C prepreg is cut into 26 layers, and the A prepreg is cut into 26 layers.

10. The method for rapid laying of resin-based composite material box reinforcement ribs according to claim 9, characterized in that: In step 4), the order of laying the prepreg is: 1 layer of D prepreg, 4 layers of E prepreg, 1 layer of B prepreg, 5 layers of A prepreg, 5 layers of C prepreg, vacuum compaction; 1 layer of D prepreg, 4 layers of E prepreg, 1 layer of B prepreg, 5 layers of A prepreg, 5 layers of C prepreg, vacuum compaction; 1 layer of D prepreg, 4 layers of E prepreg, 1 layer of B prepreg, 5 layers of A prepreg, 5 layers of C prepreg, vacuum compaction; 1 layer of D prepreg, 4 layers of E prepreg, 1 layer of B prepreg, 5 layers of A prepreg, 5 layers of C prepreg, vacuum compaction; 2 layers of D prepreg, 4 layers of E prepreg, 2 layers of B prepreg, 6 layers of A prepreg, 6 layers of C prepreg, vacuum compacted.

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