Composite material easy-to-break cover with embedded microstructure of weak zone and preparation method thereof

Abstract

This invention discloses a composite material fracturing cap with an embedded weak zone microstructure and its preparation method. The fracturing cap includes a flange frame, a weak zone, and a separation body. The weak zone is an embedded adhesive structure based on a trapezoidal groove. The internal / external load-bearing capacity of the fracturing cap can be adjusted by changing the length and inclination angle of the trapezoidal groove slope in this weak zone. Under missile launch conditions, when the separation body undergoes significant deformation, the adhesive layer between the separation body and the weak zone inclination angle experiences shear and tensile failure, thereby achieving separation of the separation body from the flange and clearing the way for the missile's advance. This invention provides a compact fracturing cap that allows the ratio of the external to internal load-bearing extreme values ​​to be freely achievable within a certain range to the left and right of 1, making it suitable for situations where airtightness and opening performance indicators conflict and where there are strict requirements for equipment space.

Description

Technical Field

[0001] This invention relates to the field of missile launch and protection technology, specifically to a composite material easy-crack cover with an embedded weak area microstructure and its preparation method. Background Technology

[0002] The design of the missile launch canister cover is a crucial factor affecting the missile's rapid response capability. During missile storage, the launch canister is filled with an inert gas to prevent corrosion of the warhead's electronic components, and the cover must maintain airtightness under a certain pressure differential. During missile launch, it must meet rapid launch conditions. Traditional missile launch canister covers are mostly metal, opened mechanically or with explosive bolts. Metal covers are generally heavy, increasing overall weight and requiring specialized transmission and servo control mechanisms. Long-term storage can lead to malfunctions, and both opening methods have numerous problems, such as long opening times for mechanical covers and high maintenance costs and complex repairs for explosive bolt covers.

[0003] Composite materials possess advantages such as lightweight, high strength, good corrosion resistance, and high design flexibility, and have been widely used in aerospace, automotive, and medical fields. Using composite materials to manufacture missile launch canister covers can effectively solve the problems of traditional launch canister covers, such as large weight, long reaction time, and high maintenance costs.

[0004] To improve missile launch efficiency and meet the requirements of rapid military operations, other domestic scholars have conducted research. One domestically developed integral, impact-type composite membrane cover utilizes the airflow generated by the missile's engine before launch to impact the membrane cover, causing it to break along a predetermined trajectory. Another domestically developed directional-throw composite fragile cover uses separation and connection zones to allow the fragile cover to be directionally ejected under the impact of airflow.

[0005] The aforementioned domestically produced crackable covers can only achieve one of two conditions: the ratio of the external load-bearing extreme value to the internal load-bearing extreme value is greater than or equal to 1 or less than or equal to 1. However, the crackable cover of this invention allows the ratio of the external load-bearing extreme value to the internal load-bearing extreme value to be freely achievable within a certain range to the left and right of 1. Therefore, this invention greatly expands the achievable range of the ratio of the internal and external load-bearing extreme values ​​for crackable covers. Summary of the Invention

[0006] The purpose of this invention is to provide a composite material easy-crack cap with an embedded weak area microstructure and its preparation method. The easy-crack cap has a compact structure and can freely achieve the ratio of the external load-bearing extreme value to the internal load-bearing extreme value within a certain range to the left and right of 1. It is suitable for situations where the airtightness performance index and the opening performance index are contradictory and there are strict requirements for the space of the equipment.

[0007] To achieve the above objectives, the present invention provides a composite material easy-crack cover with an embedded weak area microstructure, comprising: a flange frame 1, a weak area 2, and a separation body 3; the separation body 3 is embedded in the flange frame 1 and bonded to the contact surface of the two with an adhesive; the embedded and bonded area of ​​the flange frame 1 and the separation body 3 is the weak area 2 of the easy-crack cover.

[0008] The aforementioned composite material easily crackable cover with an embedded weak area microstructure, wherein the flange frame 1 and the separator 3 are complementary in structure.

[0009] The aforementioned composite material crack-prone cover with an embedded weak area microstructure has a flange frame 1 and a separator 3 having a trapezoidal groove with slopes 6 and 7 on their contact surfaces, while the separator 3 and the flange frame 1 have complementary bosses. After assembly, the two form a combined connection of geometric topology, positioning, and bonding.

[0010] The aforementioned composite material easily crackable cover with an embedded weak area microstructure, wherein the strength of the weak area 2 is adjusted by setting the length of the bottom edge 5 of the trapezoidal groove, the length of the slope 67 of the trapezoidal groove, and the size of the slope angles 8 and 9 of the trapezoidal groove.

[0011] The aforementioned composite material easily crackable cover with an embedded weak area microstructure allows for the ratio of the external bearing capacity to the internal bearing capacity to be freely achieved within a certain range around 1 by individually setting the lengths 6 and 7 and the angles 8 and 9 of the slopes 6 and 7 on both sides of the trapezoidal groove in the weak area.

[0012] The aforementioned composite material easily crackable cap with an embedded weak area microstructure, wherein, under the open condition, the easily crackable cap causes large tensile and shear stresses in the slope area of ​​the adhesive layer 4 in the weak area due to the large deformation of the separated body 3, thereby damaging the adhesive layer and destroying the weak area.

[0013] The aforementioned composite material crack-prone cover with an embedded weak area microstructure includes a flange frame 1 that is a ring with a trapezoidal groove, a separator 3 that is a circular plate that forms a complementary structure with the groove of the flange frame 1, and a weak area 2 that is the area where the circular plate is embedded in the flange frame 1 and bonded together.

[0014] The aforementioned composite material easily crackable cover with an embedded weak area microstructure is made of a high-strength glass fiber plain weave fabric reinforced epoxy resin composite material.

[0015] A method for preparing a composite material cap with an embedded weak region microstructure, comprising the following steps:

[0016] Step 1: Cut out the required size and quantity of high-strength fiberglass plain weave fabric;

[0017] Step 2: Lay out the layers in an isotropic sequence, and lay out the required sizes of slabs A, B, C, and D.

[0018] Step 3: Cut plates A, B, and C into rings of the required size: ring A, ring B, and ring C;

[0019] Step 4: Cut plate D into a circular plate of the required size;

[0020] Step 5: Chamfer rings A and B at a specific angle, and chamfer the top and bottom edges of circular plate D with the same size.

[0021] Step 6: Stack and bond the chamfered ring A to the unchamfered ring C to form half of the flange groove structure;

[0022] Step 7: Complementarily bond the chamfered circular plate D to the structure completed in Step 6;

[0023] Step 8: Perform complementary bonding between ring B and the structure completed in step 7;

[0024] Step nine: Drill holes and polish. The product is now complete.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This invention presents a composite material fracturing cap with an embedded weak zone microstructure. The ratio of its external load-bearing extreme value to its internal load-bearing extreme value can be freely achieved within a certain range to the left and right of 1. This invention ensures that the fracturing cap does not suffer damage under large loads, guaranteeing airtight performance; and that damage does occur under smaller breaching loads, ensuring smooth opening of the cap, thereby protecting the precision components inside the warhead from damage under breaching conditions. Attached Figure Description

[0027] The following embodiments and figures illustrate a composite material crack-prone cap with an embedded weak region microstructure and its preparation method.

[0028] Figure 1 This is a top view of a composite material easily cracked cap with an embedded weak area microstructure according to the present invention;

[0029] Figure 2 This is a schematic diagram of the fine structure of the weak area of ​​the easily cracked cap of the present invention;

[0030] Among them: 1. Flange frame, 2. Weak area, 3. Separation body, 4. Weak area adhesive layer, 5. Vertical edge of trapezoidal groove in weak area, 6. Upper slope of trapezoidal groove in weak area, 7. Lower slope of trapezoidal groove in weak area, 8. Upper inclination angle of trapezoidal groove in weak area, 9. Lower inclination angle of trapezoidal groove in weak area. Detailed Implementation

[0031] The following provides a more detailed description of a composite material crack-prone cap with an embedded weak region microstructure and its preparation method, according to the present invention.

[0032] A composite material fracturing cap with an embedded weak zone microstructure includes: a flange frame, a weak zone, and a separation body. The material used is a high-strength glass fiber plain weave fabric reinforced epoxy resin composite material, and the layup is a quasi-isotropic layup of [(0 / 90) / (±45)]n. This layup sequence enables the overall structure of the fracturing cap to obtain quasi-isotropic performance characteristics, thereby obtaining uniform and stable load-bearing performance in the weak zone.

[0033] The weak zone of this invention is the area where the separator is embedded in the flange frame and bonded. The flange frame is a ring with a trapezoidal groove, and the separator is a circular plate forming a complementary structure with the flange frame groove. During the assembly of the fragile cover, the separator is embedded in the flange frame and bonded. The microscopic structure of this weak zone can be adjusted by changing the inclination angle and length of the trapezoidal groove's slope, allowing the ratio of the outer to inner load-bearing limits of the fragile cover to be freely achievable within a certain range to the left and right of 1. During missile launch, the deformation of the separator generates significant shear and tensile stresses in the adhesive layer of the weak zone, causing shear and tensile failure, thus separating the separator from the flange and clearing a path for the missile.

[0034] When the slope angles 8 and 9 of the trapezoidal groove are the same, if the length of the slope 6 is greater than that of 7, the ratio of the extreme external load that the easily crackable cover can withstand to the extreme internal load is less than 1; if the lengths of the slope 6 are less than that of 7, the ratio of the extreme external load that the easily crackable cover can withstand to the extreme internal load is greater than 1 (defined). Figure 2 The upper middle side is the outside, and the lower side is the inside.

[0035] Similarly, when the lengths of the trapezoidal groove slopes 6 and 7 are the same, when the slope angle 8 of the trapezoidal groove is greater than 9, the ratio of the extreme external load that the easily cracked cover can withstand to the extreme internal load is less than 1; when the slope angle 8 of the trapezoidal groove is less than 9, the ratio of the extreme external load that the easily cracked cover can withstand to the extreme internal load is greater than 1 (defined). Figure 2 The upper middle side is the outside, and the lower side is the inside.

[0036] This invention also discloses a method for preparing a composite material cap with an embedded weak region microstructure, the specific steps of which are as follows:

[0037] 1) Cut out the required size and quantity of high-strength fiberglass plain weave fabric;

[0038] 2) Lay out the required sizes of boards A, B, C and D in a quasi-isotropic sequence;

[0039] 3) Cut plates A, B and C into rings of the required size: ring A, ring B and ring C, wherein the radius of ring C is smaller than that of rings A and B, and the smaller radius value should be the same as the height of the preset trapezoidal groove;

[0040] 4) Plate D is cut into a circular plate with the same diameter as the inner diameter of ring C;

[0041] 5) Chamfer rings A and B at a preset angle, and chamfer the top and bottom edges of circular plate D with the same size.

[0042] 6) Stack and bond the chamfered ring A with the unchamfered ring C. During the bonding process, make sure that the inner edge of ring C is aligned with the inner edge of the chamfered ring A to form half of the trapezoidal groove structure of the flange frame.

[0043] 7) The chamfered circular plate D is bonded to the structure completed in step 6 in a complementary manner, that is, the chamfered bevel of the lower edge of the circular plate D is bonded to the chamfered bevel of the ring A.

[0044] 8) Perform complementary bonding between ring B and the structure completed in step 7, that is, bond the chamfered bevel of ring B to the chamfered bevel of circular plate D.

[0045] 9) Wait for the adhesive to fully cure;

[0046] 10) Drill holes and polish to complete the production.

Claims

1. A composite material cap with an embedded weak region microstructure prone to cracking, characterized in that, include: Flange frame (1), weak area (2), and separator (3); the separator (3) is embedded in the flange frame (1) and glued together with adhesive on the contact surface of the two; the embedded and glued area of ​​the flange frame (1) and the separator (3) is the weak area (2) of the easily cracked cover; the contact surface of the flange frame (1) and the separator (3) is a trapezoidal groove with slopes (6, 7), while the contact surface of the separator (3) and the flange frame (1) is a complementary boss. After assembly, the two form a comprehensive connection form of geometric topology positioning and glued connection; by setting the length and angle (8, 9) of the slopes (6, 7) on both sides of the trapezoidal groove in the weak area separately, the ratio of the external bearing extreme value to the internal bearing extreme value of the cover can be freely within a certain range around 1.

2. The composite material easily cracked cap with an embedded weak area microstructure as described in claim 1, characterized in that, The flange frame (1) and the separator (3) are complementary in structure.

3. The composite material easily cracked cap with an embedded weak area microstructure as described in claim 1, characterized in that, The strength of the weak area (2) is adjusted by setting the length of the bottom edge (5) of the trapezoidal groove, the length of the slope (6) and (7) of the trapezoidal groove, and the size of the slope angle (8, 9) of the trapezoidal groove.

4. The composite material easily cracked cap with an embedded weak area microstructure as described in claim 1, characterized in that, The flange frame (1) is a ring with a trapezoidal groove, the separator (3) is a circular plate that forms a complementary structure with the groove of the flange frame (1), and the weak area (2) is the area where the circular plate is embedded in the flange frame (1) and glued.

5. The composite material easily cracked cap with an embedded weak area microstructure as described in claim 1, characterized in that, The crackable cover is made of high-strength glass fiber plain weave fabric reinforced epoxy resin composite material.

6. A method for preparing a composite material cap with an embedded weak region microstructure as described in any one of claims 1-5, characterized in that, The steps include the following: Step 1: Cut out the required size and quantity of high-strength fiberglass plain weave fabric; Step 2: Lay out the layers in an isotropic sequence, and lay out the required sizes of slabs A, B, C, and D. Step 3: Cut plates A, B, and C into rings of the required size: ring A, ring B, and ring C; Step 4: Cut plate D into a circular plate of the required size; Step 5: Chamfer rings A and B at a specific angle, and chamfer the top and bottom edges of circular plate D with the same size. Step 6: Stack and bond the chamfered ring A to the unchamfered ring C to form half of the flange groove structure; Step 7: Complementarily bond the chamfered circular plate D to the structure completed in Step 6; Step 8: Perform complementary bonding between ring B and the structure completed in step 7; Step nine: Drill holes and polish. The product is now complete.

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