Air-drop pod with carbon fiber twill prepreg sandwich structure and preparation method of air-drop pod

Abstract

The invention belongs to the field of military transportation aircraft nacelles, and particularly relates to an air-drop nacelle with a carbon fiber twill prepreg sandwich structure and a preparation method of the air-drop nacelle. The head cover, the cabin cover, the cabin body and the tail cover all adopt polyurethane foam reinforcing ribs / plates as skeletons, the skeletons are internally and externally wrapped with carbon fiber twill prepregs to form a prepreg interlayer structure, and the cabin cover and the hanging structure are integrally formed. The polyurethane foam reinforcing rib / plate is subjected to scabbling treatment or is provided with a plurality of grooves in the surface, and the scabbling polyurethane foam can improve the roughness of the surface of the polyurethane foam, so that the polyurethane foam can be better combined with the prepregs on the two sides, and the layering phenomenon is avoided; the polyurethane foam reinforcing rib adopting the slotted hole structure and the carbon fiber twill prepreg form an interlayer structure, the wettability between the polyurethane foam reinforcing rib and the carbon fiber twill prepreg is better, and the strength and tear resistance of the pod are remarkably improved. Compared with a traditional air-drop pod made of wood, the air-drop pod has the advantages of being light in weight, large in rigidity, high in strength, high in impact resistance, large in load capacity and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of military transport aircraft pod, and particularly relates to an air-drop pod with a carbon fiber twill prepreg sandwich structure and a preparation method thereof. BACKGROUND

[0002] The existing air-drop pods at home and abroad mainly include wood, metal and composite materials.

[0003] Wooden air-drop pods are eliminated due to poor strength, sealing, moisture resistance and water resistance, and are prone to rot in the natural environment. Metal is heavy and bulky, and is prone to corrosion and rust, which is inconvenient for maintenance and durability. Composite materials such as glass fiber composite materials are light in quality, high in specific strength, good in fatigue resistance, corrosion resistance and designability, and are widely used, but the rigidity is small, and in production, aluminum alloy profiles or galvanized steel plates are pre-buried at the cabin cover part to meet the hoisting requirements. The pre-buried metal parts undoubtedly increase the weight of the product itself, and the load capacity is also affected.

[0004] Chinese patent document CN116080905A discloses a delivery pod mounted on the wing of a transport aircraft, comprising a suspension joint assembly and a pod body assembly; the pod body assembly comprises a pod body, a front fairing and a rear fairing; the pod body comprises a framework, an outer skin and an inner skin assembly; the suspension joint assembly comprises a suspension joint seat, a suspension joint and a timer; the inner skin assembly comprises an inner skin cylinder, a skin front cover and a skin rear cover; a parachute is placed in the rear fairing. However, the inner and outer skins are riveted with the framework, and the partition frame and the longitudinal beam are fixedly connected through bolts and nuts, resulting in a relatively weak structure at the connection point and prone to breakage under impact; the cabin frame is made of aluminum alloy metal material, which is relatively heavy in overall quality, and the specific strength and specific stiffness of aluminum alloy are relatively low, resulting in low load capacity and deformation resistance, and the fatigue performance of aluminum alloy is also poor, and the pod is prone to deformation; the suspension joint assembly of the pod is bolted with the body, which generates extremely high stress at the hole edge, reduces the static strength and fatigue strength of the connecting piece, and is prone to fatigue cracks, which can cause connection failure, abnormal noise, looseness and even catastrophic accidents during repeated use. The pod skin is made of glass fiber, which is low in strength and prone to deformation, and has a small load capacity.

[0005] Therefore, light-weight and high-strength air-drop pods are increasingly valued. Under the premise of ensuring the strength, the reduction of the quality means the increase of the load capacity, which can better meet the needs of the military transport field. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides an air-drop pod with a carbon fiber twill prepreg sandwich structure and a preparation method thereof, to solve the problems of small load capacity, low strength, heavy quality and poor durability of traditional pods.

[0007] In order to achieve the above object, the present application adopts the following technical solutions: The air-drop pod with the carbon fiber twill prepreg sandwich structure, the main body of the air-drop pod is composed of a head cover, a pod cover, a pod body and a tail cover, the pod cover, the head cover and the tail cover are connected with the pod body through buckles, the main body is a conical structure, the head cover is a sharp conical type, and a deceleration parachute system is embedded in the tail cover; a hanging structure is arranged on the top of the pod cover, and the pod cover and the hanging structure are integrally formed; the pod body, the pod cover, the head cover and the tail cover are all made of a skin, a reinforcing framework is arranged in the skin, the reinforcing framework is polyurethane foam, the skin is made of carbon fiber twill prepreg, and the reinforcing framework and the carbon fiber twill prepreg wrapped thereon form a sandwich structure.

[0008] Preferably, the surface of the reinforcing framework is roughened or provided with a plurality of grooves.

[0009] Further preferably, the roughened surface of the reinforcing framework is uniformly distributed with a plurality of roughening points, the roughening density is 200-500 / ㎡, the roughening point diameter is 2-5mm, and the roughening depth is 2-3mm.

[0010] Further preferably, the grooves are arranged on the surface of the reinforcing framework, the groove depth is 1 / 5-1 / 4 of the thickness of the reinforcing framework, and the groove width is 1-3mm, so that the reinforcing framework and the prepreg are combined, the resin filling is improved, and the adhesion is improved to avoid delamination.

[0011] Preferably, the reinforcing framework is a polyurethane foam reinforcing rib and / or a polyurethane foam reinforcing plate, and the reinforcing framework can increase the strength, high and low temperature resistance, corrosion resistance, impact resistance and environmental adaptability of the main body.

[0012] Preferably, the angle of the carbon fiber twill prepreg pattern is 45° or -45°, and the twill weaving usually adopts a 2x2 or 4x4 weaving mode, wherein 2x2 means that two weft yarns are inserted between every two warp yarns, and then the process is repeated; 4x4 increases the weaving density on this basis to form a more compact structure; the weaving rule of the carbon fiber twill prepreg makes the surface of the carbon fiber twill prepreg have a certain angle with the arrangement direction of the carbon fiber, so that the carbon fiber twill prepreg has excellent tear resistance; at the same time, the twill carbon fiber cloth has better strength and rigidity than the plain carbon fiber cloth under the same weight and thickness; these characteristics make the twill prepreg better resist the damage of external force and maintain the integrity and carrying capacity of the material when impacted.

[0013] Preferably, the upper ends of the tail cover and the head cover are connected with the pod cover through buckles.

[0014] Preferably, the hanging structure comprises a hanging lug, a parachute lug, a support and a lug fixing carbon plate.

[0015] Preferably, the head cover is a tetrahedron-like pyramidal cavity, and the polyurethane foam stiffeners are arranged in the middle of each face.

[0016] Further preferably, the polyurethane foam stiffeners of the head cover are isosceles trapezoids, and the projection of the stiffeners in a vertical section when the head cover is vertically placed is an isosceles trapezoid.

[0017] Preferably, the stiffening framework of the hatch cover is polyurethane foam stiffeners and polyurethane foam stiffening plates.

[0018] Preferably, the stiffening framework of the cabin is polyurethane foam stiffeners.

[0019] Preferably, the stiffening framework of the tail cover is polyurethane foam stiffening plates.

[0020] The application also provides a method for preparing a headless nacelle with a carbon fiber twill prepreg sandwich structure, comprising the following steps: (1) preparing polyurethane foam stiffening frameworks according to the sizes of the head cover, the hatch cover, the cabin, and the tail cover; (2) preparing the head cover, the hatch cover, the cabin, and the tail cover with the stiffening frameworks by using an integrated molding method; (3) assembling the head cover, the hatch cover, the cabin, and the tail cover into a headless nacelle.

[0021] Preferably, step (2) comprises: manually laying the outer carbon fiber twill prepreg, laying the stiffening frameworks, manually laying the inner carbon fiber twill prepreg, and performing vacuum extraction and high-temperature curing treatment after the laying is completed, and then demolding to obtain the head cover, the hatch cover, the cabin, and the tail cover with the stiffening frameworks by integrated molding. The number of layers of the outer carbon fiber twill prepreg and the inner carbon fiber twill prepreg is calculated according to the thickness of the product.

[0022] Further preferably, in step (2), a positioning galvanized steel plate is pre-buried at the buckle installation position before the inner carbon fiber twill prepreg is laid.

[0023] Further preferably, in step (2), the curing temperature is 140°C, and the curing time is 3h.

[0024] Further preferably, in the preparation process of the hatch cover in step (2), a carbon plate is laid for fixing the lifting lug before the positioning galvanized steel plate is pre-buried at the buckle installation position.

[0025] Further preferably, in the preparation process of the hatch cover in step (2), after demolding, a hole is positioned and opened on the hatch cover, a base is installed, a lifting lug and a parachute lifting lug are hung, and a cut carbon fiber twill prepreg is used to locally reinforce the connection part, and then the hatch cover is placed into a curing furnace for high-temperature curing, so that the lifting structure and the hatch cover are truly integrated.

[0026] Preferably, in step (2), the thickness of the carbon fiber twill pre-impregnated material on the inner and outer sides is equal, and the number of layers is the same.

[0027] Further preferably, in step (2), the number of layers on one side is 1-5 layers, and the thickness of a single layer is 0.1-0.5mm.

[0028] Compared with the prior art, the present application has the following beneficial effects: (1) The present application provides an air-drop pod with light weight, large rigidity, high strength, strong impact resistance, and large loading capacity.

[0029] (2) The present application uses carbon fiber twill pre-impregnated material for the head cover, the pod cover, the pod body, and the tail cover, replacing the traditional plain cloth, to effectively improve the impact resistance.

[0030] (3) The present application uses a sandwich structure formed by the chiseled polyurethane foam and the carbon fiber twill pre-impregnated material to replace the original steel material framework, reducing the weight. The chiseled polyurethane foam improves the roughness of the polyurethane foam surface, thereby better combining it with the pre-impregnated material on both sides and avoiding delamination.

[0031] (4) The pod cover and the suspension joint device of the present application are integrally formed, having strong integrity, which can increase the durability of the pod, avoid the loosening of the original bolt structure during long-term use, and prevent the wear of the circumference, thereby ensuring safety.

[0032] (5) The present application uses a slot hole structure polyurethane foam reinforcing rib and a carbon fiber twill pre-impregnated material to form a sandwich structure, with better infiltration between the two, significantly improving the strength and tear resistance of the pod.

[0033] (6) The total weight of the carbon fiber twill pre-impregnated material, the head cover, the pod cover, the pod body, the tail cover, and the metal elements of the present application is about 28kg, which is about 10kg lighter than that of the glass fiber composite material. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The figure is a schematic diagram of the overall structure of the air-drop pod. Figure 2 The figure is a schematic diagram of the polyurethane foam reinforcing rib structure of the head cover. Figure 3 The figure is a schematic diagram of the head cover structure. Figure 4 The figure is a schematic diagram of the polyurethane foam reinforcing rib structure of the pod cover. Figure 5 The figure is a schematic diagram of the external structure of the pod cover. Figure 6 The figure is a schematic diagram of the internal structure of the pod cover. Figure 7The structure diagram of the cabin body polyurethane foam ribbing; Figure 8 The structure diagram of the cabin body; Figure 9 The structure diagram of the tail cover polyurethane foam ribbing; Figure 10 The structure diagram of the tail cover external structure; Figure 11 The structure diagram of the tail cover internal structure; Figure 12 The structure diagram of the polyurethane foam ribbing sandwich structure; Figure 13 The structure diagram of the hanging structure; Figure 14 The structure diagram of the cabin cover bottom hanging structure; Figure 15 The three-dimensional diagram of the roughened polyurethane foam; Figure 16 The three-dimensional diagram of the polyurethane foam ribbing with upper and lower slot structures; Figure 17 The installation position diagram of the deceleration parachute.

[0035] The signs are as follows: 1 head cover, 2 cabin cover, 3 cabin body, 4 tail cover; 1-1 head cover outer skin; 1-2 head cover inner skin; 1-3 head cover butterfly buckle; 1-4 head cover positioning pin hole; 2-1 cabin cover outer skin; 2-2 cabin cover inner skin; 2-3 base; 2-4 hanging lug; 2-5 parachute lug; 2-6 cabin cover self-locking buckle; 2-7 cabin cover butterfly buckle; 2-8 lug fixed carbon plate; 2-9 cabin cover positioning pin hole; 3-1 cabin body outer skin; 3-2 cabin body inner skin; 3-3 cabin body butterfly buckle; 3-4 cabin body self-locking buckle; 3-5 D-shaped pull ring; 3-6 cabin body positioning pin hole; 4-1 tail cover outer skin; 4-2 tail cover inner skin; 4-3 tail cover butterfly buckle; 4-4 tail cover positioning pin hole; 4-5 landing device fixed hole; 4-6 landing device fixed hole; 5-1 external carbon fiber twill prepreg (outer skin); 5-2 polyurethane foam ribbing and / or polyurethane foam reinforcing plate; 5-3 internal carbon fiber twill prepreg (inner skin). DETAILED DESCRIPTION

[0036] The preferred embodiments of the present application are described below, and the described preferred embodiments are only used for description and explanation of the present application, and are not used for limiting the present application.

[0037] Test standard: the sample is determined according to the standard GB / T3354-2014 “Tensile properties test method of directional fiber reinforced polymer matrix composite”.

[0038] The sample was a sandwich structure made from the sheet metal of the product that came with the furnace, with dimensions of 250*25*8 mm. 8 mm is the thickness of the sandwich structure. The dimensions of the sample in the example and the comparative example were the same.

[0039] Example 1 like Figure 1 As shown, the present invention provides an airdrop pod with a carbon fiber twill prepreg sandwich structure. The main body of the airdrop pod consists of a head cover 1, a canopy 2, a pod body 3, and a tail cover 4. The canopy 2, head cover 1, and tail cover 4 are all connected to the pod body 3 via buckles. The main body has a conical structure, the head cover 1 is a pointed cone, and the tail cover 4 has an embedded deceleration parachute system. The top of the canopy has a hanging structure, and the canopy and the hanging structure are integrally formed. The pod body 2, canopy 3, head cover 1, and tail cover 4 are all made of skin, and a reinforcing skeleton is provided inside the skin. The reinforcing skeleton is polyurethane foam, and the skin is made of carbon fiber twill prepreg. The reinforcing skeleton and the carbon fiber twill prepreg that wraps it form a sandwich structure.

[0040] Specifically, such as Figure 15 As shown, the surface of the polyurethane foam reinforcing ribs and / or polyurethane foam reinforcing boards is roughened by chiseling. Multiple chisel marks are evenly distributed on the roughened surface, with a chisel density of 300-500 marks / m². 2 The chisel diameter is 3-5mm and the chisel depth is 2-3mm to form a rough surface, which improves the bonding strength, increases the contact area between the polyurethane foam and the prepreg, and provides better adhesion, thereby improving the bonding force between the two.

[0041] Specifically, T300 400g carbon fiber twill prepreg is used, with a single layer thickness of approximately 0.5mm. The angle of the carbon fiber twill prepreg's weave is 45°. This structure not only increases the fabric's three-dimensionality but also improves its strength and uniformity. Twill weaving typically uses a 2x2 weave pattern, where 2x2 means that two weft yarns are interlaced between every two warp yarns, and this process is repeated.

[0042] Specifically, such as Figure 1As shown, the hatch cover 2 and the cabin body 3 are connected by the hatch self-locking buckle 2-6 and the cabin body self-locking buckle 3-4, the head cover 1 and the hatch cover 2 are connected by the head cover butterfly buckle 1-3 and the hatch cover butterfly buckle 2-7, the head cover 1 and the cabin body 3 are connected by the head cover butterfly buckle 1-3 and the cabin body butterfly buckle 3-3, the tail cover 4 is connected with the hatch cover butterfly buckle 2-7 of the hatch cover 2 and the cabin body butterfly buckle 3-3 of the cabin body 3 through the tail cover butterfly buckle 4-3, and the head cover and the hatch cover are also inserted through the hatch cover positioning pin hole 2-9 and the head cover positioning pin hole 1-4, the head cover and the cabin body are inserted through the cabin body positioning pin hole 3-6 and the head cover positioning pin hole 1-4, the hatch cover and the tail cover are inserted through the hatch cover positioning pin hole 2-9 and the tail cover positioning pin hole 4-6, and the cabin body and the tail cover are inserted through the cabin body positioning pin hole 3-6 and the tail cover positioning pin hole 4-4, so that the head cover 1 and the tail cover 4 are fixedly connected with the cabin body 3 and the hatch cover 2.

[0043] Specifically, as shown in the figure, Figure 12 The polyurethane foam reinforcing rib and / or the polyurethane foam reinforcing plate 5-2 are wrapped with carbon fiber twill prepreg on the inside and outside, the thickness of the carbon fiber twill prepreg on both sides is equal, forming a prepreg sandwich structure, the carbon fiber twill prepreg wrapped inside the framework is called internal carbon fiber twill prepreg (inner skin) 5-3, and the carbon fiber twill prepreg wrapped outside the framework is called external carbon fiber twill prepreg (outer skin) 5-1.

[0044] Specifically, as shown in the figure, Figure 2 The head cover is a tetrahedron-like sharp cone-shaped cavity made of a head cover outer skin 1-1 and a head cover inner skin 1-2, and a reinforcing framework polyurethane foam reinforcing rib is arranged in the sandwich formed by the head cover outer skin 1-1 and the head cover inner skin 1-2 at the middle position of each face, which increases the bearing capacity and stiffness to effectively improve the bending strength and compression resistance, so as to ensure that the packaging box will not be easily deformed or damaged during transportation and use. At the same time, the polyurethane material itself has a certain elasticity and can absorb impact energy, thereby improving the impact resistance of the packaging box. This is particularly important for collisions and vibrations that may occur during transportation, which can effectively protect the internal items from damage.

[0045] Specifically, as shown in the figure, Figure 3 The head cover polyurethane foam reinforcing rib is isosceles trapezoidal, and the isosceles trapezoidal is the projection of the reinforcing rib in the vertical section when the head cover is vertically placed. The upper part refers to the side close to the head cover end, and the bottom part refers to the side close to the tail end of the head cover. This design is because the head cover is the front end of the pod and receives the largest wind load during the journey, and the corresponding bearing capacity is the strongest. The isosceles trapezoidal section has a large moment of inertia, which can disperse stress more evenly, reduce stress concentration, have strong bending resistance, excellent fatigue resistance, delay crack propagation, and prolong service life. The stress distribution of a square or rectangular shape is not as uniform as that of an isosceles trapezoidal shape in terms of bending and compression resistance.

[0046] Specifically, as shown in Figure 5 and Figure 6 , the hatch cover 2 is made of a hatch cover outer skin 2-1 and a hatch cover inner skin 2-2, and a polyurethane foam reinforcing rib and a polyurethane foam reinforcing plate are arranged in the interlayer formed by the hatch cover outer skin 2-1 and the hatch cover inner skin 2-2. Specifically, as shown in Figure 4 , the polyurethane foam reinforcing rib is located around the hatch cover, and the polyurethane foam reinforcing plate is arranged on the top surface of the hatch cover, avoiding the installation area of the mounting base, the hanging lug, the parachute lug, and the lug fixing carbon plate.

[0047] Specifically, as shown in Figure 13 , the hanging structure includes a hanging lug 2-4, a parachute lug 2-5, a base 2-3, and a lug fixing carbon plate 2-8. The hanging lug 2-4 is connected to the aircraft hanging device, and the base 2-3 is provided to balance the front and rear of the hanging device.

[0048] Specifically, the hanging lug 2-4, the parachute lug 2-5, and the base 2-3 are all made of carbon fiber pultruded rods.

[0049] Specifically, as shown in Figure 8 , the cabin body 3 is composed of a cabin body outer skin 3-1 and a cabin body inner skin 3-2, and a cabin body polyurethane foam reinforcing rib is uniformly arranged in the interlayer formed by the cabin body outer skin 3-1 and the cabin body inner skin 3-2. The cabin body 3 is also provided with a D-shaped pull ring 3-5 for fixing the materials inside the cabin body.

[0050] Specifically, as shown in Figure 7 , the cabin body polyurethane foam reinforcing rib is located around the cabin body and at the bottom.

[0051] Specifically, as shown in Figures 9-11 , 17, the tail cover 4 is made of a tail cover outer skin 4-1 and a tail cover inner skin 4-2, and a polyurethane foam reinforcing plate is arranged in the interlayer inside the tail cover outer skin 4-1 and the tail cover inner skin 4-2. The tail cover is also provided with a landing device fixing hole 4-5 and 4-6 for connecting with the deceleration parachute.

[0052] The preparation method of the above-mentioned air-drop hanging cabin with carbon fiber twill prepreg interlayer structure is as follows: (1) Prepare a polyurethane foam reinforcing framework according to the sizes of the head cover 1, the hatch cover 2, the cabin body 3, and the tail cover 4; (2) Use an integrated molding method to prepare the head cover 1, the hatch cover 2, the cabin body 3, and the tail cover 4 with reinforcing frameworks; Specifically, step (2) comprises: sequentially manually laying the outer carbon fiber twill prepreg 5-1, laying the polyurethane foam stiffener and / or polyurethane foam stiffening plate 5-2, pre-burying the positioning galvanized steel plate at the buckle installation position, pasting the galvanized steel plate with double-sided adhesive film, manually laying the inner carbon fiber twill prepreg 5-3, and bonding the galvanized steel plate with the outer and inner carbon fiber twill prepregs 5-1 and 5-3. After the laying is completed, vacuumizing and high-temperature curing at 140 DEG C for 3 hours are performed, and the head cover 1, the hatch cover 2, the cabin body 3 and the tail cover 4 with the integrated reinforcing framework are obtained after the mold is removed. The outer carbon fiber twill prepreg 5-1 and the inner carbon fiber twill prepreg 5-3 have the same number of layers and thickness, and the number of layers is 3 and the thickness of a single layer is 0.5 mm.

[0053] Specifically, in the process of step (2), before the positioning galvanized steel plate is pre-buried at the buckle installation position, the lug fixing carbon plate 2-8 is laid. Figure 14 As shown in the drawing, after the mold is removed, the lug fixing carbon plate 2-8 is laid on the hatch cover 2, the base 2-3 is installed, the hanging lug 2-4 and the umbrella lug 2-5 are hung, the carbon fiber twill prepreg cut is used to locally reinforce the connection part, and the high-temperature curing is performed in the curing furnace. The hanging structure is truly integrated with the hatch cover, and the traditional process of embedding aluminum alloy or galvanized steel plate is changed.

[0054] (3) Assembling the head cover, the hatch cover, the cabin body and the tail cover into the empty head hanging cabin.

[0055] After testing, the failure load of the sample is 70268.00 N, the tensile strength is 668.00 MPa, the elastic modulus is 35.2 GPa, and the failure strain is 16.08%.

[0056] Example 2 The other conditions are the same as in Example 1, except that the gouging density of the polyurethane foam is 200-300 / ㎡, the gouging point diameter is 2-3 mm, and the gouging depth is 2-3 mm.

[0057] After testing, the failure load of the sample is 68352.00 N, the tensile strength is 632.00 MPa, the elastic modulus is 32.5 GPa, and the failure strain is 12.5%.

[0058] Example 3 The other conditions are the same as in Example 1, except that: The head cover 1, the hatch cover 2, the cabin body 3 and the tail cover 4 all use polyurethane foam with multiple grooves on the surface as the framework, the grooves are arranged on the surface of the reinforcing framework, the groove depth is 1 / 5 of the thickness of the reinforcing framework, and the width is 1 mm, as shown in the drawing. Figure 16

[0059] ​The test shows that the failure load of the sample is 60158.00 N, the tensile strength is 542.00 MPa, the elastic modulus is 27.8 GPa, and the failure strain is 10.24%.

[0060] Example 4 Other than Example 3, except that: The groove depth is 1 / 4 of the thickness of the reinforcing framework, and the width is 2 mm.

[0061] The test shows that the failure load of the sample is 58952.00 N, the tensile strength is 530.00 MPa, the elastic modulus is 23.4 GPa, and the failure strain is 9.5%.

[0062] Comparative Example 1 Other than Example 1, except that: the skin is made of carbon fiber plain weave prepreg, and the reinforcing framework and the carbon fiber plain weave prepreg wrapped around it form a sandwich structure.

[0063] The test shows that the failure load of the sample is 65308.00 N, the tensile strength is 606.00 MPa, the elastic modulus is 28.9 GPa, and the failure strain is 14.02%.

[0064] Comparative Example 2 Other than Example 1, except that: the head cover 1, the hatch cover 2, the cabin body 3, and the tail cover 4 all use polyurethane foam with no chiseling treatment on the surface as the framework.

[0065] The test shows that the failure load of the sample is 54384.00 N, the tensile strength is 480.00 MPa, the elastic modulus is 18.6 GPa, and the failure strain is 7.4%. And in the test, the sample has delamination phenomenon.

Claims

1. An air delivery pod having a carbon fiber twill prepreg sandwich structure, characterized by, The main body of the air-drop pod is composed of a head cover, a pod cover, a pod body and a tail cover, the pod cover, the head cover and the tail cover are connected with the pod body through buckles, the main body is a conical structure, the head cover is a sharp conical type, and the tail cover is embedded with a deceleration parachute system; the pod cover is provided with a hanging structure at the top, and the pod cover and the hanging structure are integrally formed; the pod body, the pod cover, the head cover and the tail cover are all made of a skin, the skin is internally provided with a reinforcing framework, the reinforcing framework is polyurethane foam, the skin is made of carbon fiber twill prepreg, and the reinforcing framework and the carbon fiber twill prepreg wrapped therearound form a sandwich structure.

2. The airfoil satchet of claim 1, wherein, The surface of the reinforcing framework is subjected to chiseling treatment, or is provided with a plurality of grooves; preferably, the surface of the reinforcing framework subjected to chiseling treatment is uniformly distributed with a plurality of chiseling points, the chiseling density is 200-500 / ㎡, the chiseling point diameter is 2-5mm, and the chiseling depth is 2-3mm; the grooves are arranged on the surface of the reinforcing framework, the groove depth is 1 / 5-1 / 4 of the thickness of the reinforcing framework, and the groove width is 1-3mm.

3. The airfoil satchet of claim 1, wherein, The reinforcing framework is polyurethane foam reinforcing rib and / or polyurethane foam reinforcing plate, the reinforcing framework of the pod cover is polyurethane foam reinforcing rib and polyurethane foam reinforcing plate, the reinforcing framework of the tail cover is polyurethane foam reinforcing plate, the reinforcing framework of the pod body is polyurethane foam reinforcing rib, and the head cover is a tetrahedron-like sharp conical cavity, and the polyurethane foam reinforcing rib is arranged at the middle position of each face; preferably, the polyurethane foam reinforcing rib of the head cover is isosceles trapezoidal.

4. The airfoil satchet of claim 1, wherein, The hanging structure comprises a hanging lug, a parachute lug, a support and a lug fixing carbon plate.

5. A method of manufacturing a headless pod according to any one of claims 1-4, wherein, The method comprises the following steps: (1) preparing polyurethane foam reinforcing frameworks according to the sizes of the head cover, the pod cover, the pod body and the tail cover; (2) preparing the head cover, the pod cover, the pod body and the tail cover with reinforcing frameworks by using an integral molding method; (3) assembling the head cover, the pod cover, the pod body and the tail cover into an air-drop pod.

6. The production method according to claim 5, wherein Step (2) comprises: sequentially manually laying external carbon fiber twill prepreg, laying reinforcing frameworks, manually laying internal carbon fiber twill prepreg, performing vacuumizing and high-temperature curing treatment after the laying is completed, and demolding to obtain the integrally-molded head cover, the pod cover, the pod body and the tail cover with reinforcing frameworks; the number of layers of the external carbon fiber twill prepreg and the internal carbon fiber twill prepreg is calculated according to the product thickness.

7. The production method according to claim 6, wherein In step (2), a positioning galvanized steel plate is embedded at the buckle installation position before the internal carbon fiber twill prepreg is laid.

8. The production method according to claim 7, wherein In the process of preparing the pod cover in step (2), a positioning galvanized steel plate is embedded at the buckle installation position before the lug fixing carbon plate is laid.

9. The production method according to claim 6, wherein In step (2), the thicknesses of the carbon fiber twill prepreg on the inner side and the outer side are equal, and the number of layers is the same.

10. The production method according to claim 9, wherein In step (2), the number of layers on a single side is 1-5 layers, and the thickness of a single layer is 0.1-0.5mm.

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