Manufacturing method of carbon fiber modified and patch wound reinforced solid rocket engine shell

Abstract

The invention relates to a manufacturing method of a carbon fiber modified and patch winding reinforced solid rocket engine shell. Comprising the following steps: preparing a basic sizing agent; preparing a crystalline polyether-ether-ketone grafted carbon nano tube; preparing a final sizing agent: dispersing the original carbon nano tube, the carboxylated carbon nano tube or the polyether-ether-ketone grafted carbon nano tube in NM under an ultrasonic condition, and then pouring the basic sizing agent for ultrasonic dispersion to obtain the final sizing agent; modifying the carbon fibers by adopting the final sizing agent; the shell is spirally wound firstly and then annularly wound to form a step-shaped structure with the height gradually reduced from a cylinder body to an end socket section, and primary curing is carried out; and the step-shaped height difference is supplemented through two-section type fan-shaped two-layer patch reinforcement, the whole shell is spirally wound, and the solid rocket engine shell is obtained through secondary curing. Stress distribution of the shell can be improved, stress concentration is reduced, heat resistance is improved, and therefore safety and reliability of the rocket engine are improved.

Description

Technical Field

[0001] The invention belongs to the field of solid rocket engine casings, and specifically relates to a method for manufacturing a solid rocket engine casing through carbon fiber modification and patch winding reinforcement. Background Art

[0002] Carbon fiber composite rocket engine shells are usually prepared using a winding process, which is done by winding a pre-impregnated epoxy resin carbon fiber tape on a core mold. During the fiber winding process, a large number of spiral layers are concentrated in the cylindrical part. The existence of these spiral layers leads to an unreasonable distribution of fiber materials in this area. Many fibers do not fully exert their load-bearing capacity, and stress cannot be evenly dispersed. It is easy to generate excessive stress locally, affecting the safety of the shell. In addition, since the utilization efficiency of fiber materials in the cylindrical part is not high, in order to achieve the required performance requirements, not only the material cost is increased, but also the overall weight of the container is increased.

[0003] The above problems can be effectively solved by adopting a reasonable winding patch reinforcement method, but the problem of how to cure it will arise. If it is only cured once, the internal spiral and circumferential layers will not be completely cured, which will seriously affect the mechanical properties and air tightness of the shell. Therefore, a two-time curing method is used to improve this problem. Traditional carbon fiber epoxy resin composite materials meet the requirements of rocket engine shells for high strength and high modulus to a certain extent, but the lack of heat resistance also affects the safety and reliability of the structure. Since the two-time curing has higher requirements for temperature, the traditional carbon fiber epoxy resin material does not meet the requirements of secondary curing, and the carbon fiber matrix material needs to be modified to improve its heat resistance.

[0004] Therefore, it is of great significance to carry out more effective winding and reinforcement in the head section to improve its safety and to effectively modify the carbon fiber composite materials to improve their heat resistance. Summary of the invention

[0005] The object of the present invention is to provide a method for manufacturing a carbon fiber modified and patch-wound reinforced solid rocket engine casing.

[0006] The technical solution to achieve the purpose of the present invention is: a method for manufacturing a carbon fiber modified and patch-wound reinforced solid rocket engine casing, comprising the following steps:

[0007] Step (1): preparing a base sizing agent;

[0008] Step (2): preparing crystalline polyetheretherketone grafted carbon nanotubes;

[0009] Step (3): preparing the final sizing agent: dispersing the original carbon nanotubes, carboxylated carbon nanotubes or carbon nanotubes grafted with polyetheretherketone in NM under ultrasonic conditions, then pouring the base sizing agent prepared in step (1), and dispersing again by ultrasonication to obtain the final sizing agent;

[0010] Step (4): modifying the carbon fiber using the final sizing agent prepared in step (3) to obtain modified carbon fiber;

[0011] Step (5): The shell is first spirally wound and then circumferentially wound to form a stepped structure with a gradually decreasing height from the barrel to the head section, and solidified once; a two-stage fan-shaped two-layer patch is used to reinforce the stepped height difference, and the entire shell is spirally wound, and a solid rocket engine shell is obtained after secondary solidification.

[0012] Furthermore, step (1) is specifically as follows: polyetheretherketone-1,3-dithiocyclopentane PEEKDith of different molecular weights and carbonyl contents is synthesized by protecting the carbonyl group to prevent it from undergoing unnecessary reactions, PEEKDith-2.5-100 is subjected to a substitution reaction to synthesize polyetheretherketone-1,3-dioxolane, which is dissolved in N-methylpyrrolidone and reacted at room temperature for 2±0.2h under magnetic stirring to prepare a base sizing agent.

[0013] Furthermore, step (2) specifically includes the following steps:

[0014] Step (21): PEEKDith-2.0-20 is dissolved in tetrahydrofuran (THF) under magnetic stirring, and then NaBH4 and anhydrous methanol are added in sequence, and the mixture is reacted at room temperature for 10±1h to obtain a mixture, and the mixture is poured into ethanol to produce a white precipitate; the precipitate is boiled and washed in ethanol for multiple times, and then dried at 100±5°C to obtain a white PEEKDith-2.0-20-OH powder, and PEEKDith-2.0-144-OH powder is obtained in the same way;

[0015] Step (22): performing an oxidation reaction on CNT to obtain carboxylated carbon nanotubes CNT-COOH; adding the carboxylated carbon nanotubes CNT-COOH to anhydrous N-methylpyrrolidone NMP to obtain a CNT-COOH suspension, adding DCC and DMAC after ultrasonic dispersion, and then ultrasonically treating at 40±2° C. for 2±0.2 h to obtain a CNT-COOH suspension after ultrasonication;

[0016] Step (23): dissolving the PEEKDith-2.0-20-OH powder or PEEKDith-2.0-144-OH powder prepared in step (21) in THF, then adding DCC and pouring it into the CNT-COOH suspension after ultrasonic stirring, and reacting it under an ultrasonic environment of 50-60°C for 70±5h, heating to reflux for 24±2h, and filtering to obtain a crude product of CNT grafted with PEEK-1,3-dithiolane; washing the crude product of CNT grafted with PEEK-1,3-dithiolane with NMP, THF and DMF under reflux conditions to remove excess polymer, and drying to obtain CNT grafted with PEEK-1,3-dithiolane;

[0017] Step (24): under 400W ultrasonic conditions, adding the PEEK-1,3-dithiocyclopentane grafted CNT to chloroform, ultrasonically dispersing for 2±0.2 hours, adding dimethyl sulfoxide DMSO and 2-iodo-2-methylpropane in sequence, and then ultrasonically treating at 60±2°C for 24±2 hours; after ultrasonic treatment, heating to 65±1°C and maintaining for 48±1 hours to obtain a crystalline PEEK grafted CNT crude product, washing the crystalline PEEK grafted CNT crude product with methanol for multiple times and drying at 80±2°C to obtain a crystalline PEEK grafted CNT, i.e., CNT-gPEEK-20 or CNT-gPEEK-144;

[0018] Step (25): Disperse the original carbon nanotubes Raw-CNT, CNT-COOH and CNT-gPEEK-20 or CNT-gPEEK-144 in NMP under ultrasonic conditions for 2 hours, then slowly pour the base sizing agent into the above suspension, followed by ultrasonic dispersion for another 2 hours to obtain the final sizing agent.

[0019] Furthermore, step (4) is specifically as follows: the unsized carbon fiber passes through a sizing tank containing a final sizing agent at a speed of 0.1±0.02 m / min, and then is vacuum dried at 160±5° C.; the sized carbon fiber passes through a 1 mol / L hydrogen chloride solution and deionized water in turn, and finally is vacuum dried at 80±2° C. to obtain modified carbon fiber.

[0020] Furthermore, step (5) is specifically as follows:

[0021] Step (51): using a wet winding process, unfolding the modified carbon fiber bundle obtained in step (4), mixing it with a liquid polyetheretherketone matrix resin by dipping it through a resin tank, and directly winding it on a core mold installed on a winding machine tool; applying a constant tension of 2.5N to the fiber bundle during the winding process, and setting the heating temperature to 120-180°C;

[0022] Step (52): Calculate the winding angle of the spiral winding, calculate the thickness of the spiral winding layer of the barrel section, the thickness of the circumferential winding layer, and determine the layer laying sequence; perform winding of the innermost complete spiral layer and winding of the circumferential layer of the middle barrel section to obtain a semi-finished shell;

[0023] Step (53): placing the semi-finished shell into a curing chamber for vacuuming and first curing treatment;

[0024] Step (54): After the first curing is completed, the area of ​​the head section to be patched is polished and shot peened, and two layers of patch reinforcement are performed on the head section. Each layer of patch reinforcement is two-stage, and each stage is composed of a plurality of fan-shaped patches. After the patch reinforcement, the shell is spirally wound with carbon fiber epoxy resin material as a whole;

[0025] Step (55): After the final spiral winding is completed, a second curing treatment is performed.

[0026] Furthermore, in step (52), the thickness of the spiral winding layer of the barrel section is 1.5±0.1 mm, and the thickness of the hoop winding layer is 2.2±0.1 mm; the spiral winding layer is determined to be 2 layers and the hoop winding layer is determined to be 2 layers, and the ply laying sequence is determined to be {[(15.1°), (-15.1°)], (90°)2}.

[0027] Furthermore, the curing of step (53) is specifically as follows: heating from room temperature to 250±10°C at a heating rate of 40-50°C / h, keeping warm for 2-4 hours, and naturally cooling to room temperature after curing; and during the curing process, the shell is kept rotating uniformly at a speed of 2±0.1r / min.

[0028] Furthermore, in step (54), the surface is polished using sandpaper with a fine grain size of 320 mesh, and the speed of the polishing machine is 800-1200 rpm;

[0029] When sandblasting, choose plastic particle sandblasting media, set the sandblasting distance to 15-20 cm, and the sandblasting pressure to 0.2-0.4MPa;

[0030] The overall spiral winding angle is 40±2°, the winding layer is 2 layers, and the winding thickness is 1.5±0.1mm.

[0031] Furthermore, the curing step (55) is specifically as follows: the entire shell is placed in a curing chamber, and the temperature is increased from room temperature to 90°C-120°C at a heating rate of 25°C-30°C / h, and kept warm for 2-4 hours. After the curing is completed, the shell is naturally cooled to room temperature and then demolded.

[0032] A method for manufacturing a carbon fiber modified and patch-wound reinforced solid rocket engine casing is prepared using the above method.

[0033] Compared with the prior art, the present invention has the following significant advantages:

[0034] (1) Improved performance of carbon fiber / polyetheretherketone after modification: Compared with the traditional method, the new chemical grafting method proposed in the present invention overcomes the problem that crystalline polyetheretherketone is difficult to directly graft onto carbon nanotubes at room temperature, and provides a new approach for nano-reinforced carbon fiber / polyetheretherketone composite materials. Compared with traditional epoxy resin-based composite materials, the heat resistance of the composite material in this way is improved from about 120° to about 250°, which meets the temperature requirements of secondary curing and has an outstanding curing effect.

[0035] (2) Uniform strength distribution: Compared with the circumferential spiral alternating winding in the conventional technology, the circumferential-spiral alternation times in the fiber winding and patch process of the present invention are less, the stress on the composite layer is reduced, the container can withstand greater pressure in the circumferential direction, and the bursting pressure of the head section is effectively improved. In addition, the two-stage fan-shaped patch layout of the present invention effectively reduces the stress concentration problem existing at the critical point of the circumferential winding and spiral winding. Under this winding method, the bursting pressure of the shell is increased from 18MPa to 21Mpa, which is about 16% and is quite significant. In addition, the use of patch reinforcement reduces the mass of the container by 15% while keeping the bursting pressure unchanged.

[0036] (3) High air tightness and high material utilization: The mechanical properties of the shell are improved through secondary curing, and the porosity inside the shell is reduced. At the same time, reasonable layering and patch design also reduce the winding cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a fiber modification flow chart of the present invention.

[0038] Figure 2 The schematic diagram of the formation process of the polyetheretherketone sizing agent in the present invention; (1) the PEEK-CNT sizing agent is obtained by the reaction of soluble polyetheretherketone and carbon nanotubes; (2) the PEEK-aCNT sizing agent is obtained by the reaction of soluble polyetheretherketone and carbon nanotubes; (3) the intermediate product is further reacted to obtain PEEK-gCNT.

[0039] FIG. 3( a ) is a schematic diagram of the shell winding and patch reinforcement of the present invention. FIG.

[0040] Figure 3(b) is a side view of the patch layer.

[0041] Figure 3(c) is a schematic diagram of wet winding.

[0042] Description of reference numerals:

[0043] 3-1- spirally wound layer, 3-2- hoop-wound layer, 3-3- spirally wound layer, 3-4- patch layer, 3-5- connector. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0045] A method for manufacturing a carbon fiber modified and patch-wound reinforced solid rocket engine casing comprises the following steps:

[0046] Step 1): Preparation of soluble polyetheretherketone and grafting of crystalline polyetheretherketone onto carbon nanotubes (CNTs):

[0047] Polyetheretherketone-1,3-dithiolane (PEEKDith) with different molecular weights and carbonyl contents were synthesized by protecting the carbonyl group to avoid unnecessary reactions. The naming basis is PEEKDith-2.5-100, which means that the content of 1,2-ethanedithiol is 0.25 mol and the melt flow index of polyetheretherketone is 100. PEEKDith-2.5-100 is synthesized into polyetheretherketone-1,3-dioxolane by substitution reaction, dissolved in N-methylpyrrolidone, and reacted at room temperature for 2 hours under magnetic stirring to prepare a basic sizing agent. The sizing agent with a solid content of 0.75wt% is selected for subsequent modification operations.

[0048] The synthesized PEEKDith-2.0-20 and PEEKDith-2.0-144 were used as raw materials to synthesize hydroxyl-containing PEEKDith. The operation is to first dissolve PEEKDith-2.0-20 in tetrahydrofuran (THF) under magnetic stirring. Then NaBH4 and anhydrous methanol were added to the solution in sequence. After reacting at room temperature for 10 hours, the mixture was poured into ethanol to produce a white precipitate. Finally, the precipitate was boiled and washed in ethanol 3 times, and then dried at 100°C overnight to obtain white PEEKDith-2.0-20-OH powder. PEEKDith-2.0-144-OH was obtained in the same way.

[0049] Carboxylated carbon nanotubes (CNT-COOH) were obtained by oxidation reaction of CNT. CNT-COOH was slowly added to anhydrous N-methylpyrrolidone (NMP) to obtain a CNT-COOH suspension. After ultrasonic dispersion for 2 hours, DCC and DMAC were added, and then ultrasonic treatment was performed at 40°C for 2 hours. PEEKDith-2.0-20-OH / PEEKDith-2.0-144-OH was dissolved in THF, and then DCC was added and quickly poured into the CNT-COOH suspension under ultrasonic stirring, and reacted for about 70 hours under an ultrasonic environment of 50-60°C, and the polymer solution was heated to reflux for 24 hours. The crude product was obtained after filtration. The crude product was washed with NMP, THF and DMF under reflux conditions to remove excess polymer. After drying, PEEK-1,3-dithiocyclopentane-grafted CNTs were obtained. Under 400W ultrasonic conditions, the PEEK-1,3-dithiolane grafted CNTs were slowly added to chloroform. After ultrasonic dispersion for 2 hours, dimethyl sulfoxide (DMSO) and 2-iodo-2-methylpropane were added in sequence, and then ultrasonicated at 60 ° C for 24 hours. After ultrasonic treatment, the flask was heated to 65 ° C and kept for 48 hours. The mixture was poured into methanol. The crude product was washed three times with methanol and dried at 80 ° C to obtain crystalline PEEK grafted CNTs. The samples were named CNT-gPEEK-20 and CNT-gPEEK-144.

[0050] Step 2): Preparation of sizing agent and sizing treatment:

[0051] Raw carbon nanotubes (Raw-CNT), CNT-COOH or CNT-gPEEK-20 were dispersed in NMP under ultrasonic conditions for 2 hours, and then the base sizing agent was slowly poured into the above suspension, followed by ultrasonic dispersion for another 2 hours to obtain the final sizing agent. The schematic diagram of this chemical reaction is shown in Figure 2 shown.

[0052] The unsized carbon fiber passes through the sizing agent at a low speed of about 0.1m / min (the length of the sizing tank is 1.0m), and then is vacuum dried at 160℃. The sized carbon fiber passes through 1mol / L hydrogen chloride solution and deionized water in turn, and finally is vacuum dried at 80℃ to obtain modified carbon fiber. The flow chart is as follows Figure 1 shown.

[0053] Step 3) Fiber composite material winding patch and curing process

[0054] The present invention adopts a wet winding process, and the modified polyetheretherketone / carbon fiber unidirectional fiber bundle is unfolded by a fiber unwinding device, and mixed with the liquid polyetheretherketone matrix resin by impregnation through a resin tank, and then directly drawn out from the impregnation device and wound on the core mold installed on the winding machine tooling through a winding nozzle, and the winding speed is set to 0.8m / min. The winding molding device is specifically shown in Figure 3(c). In the tension control and heating device, the constant tension is set to 2.5N and the temperature is set to 120-180°C. This is the tension applied to the fiber bundle during the winding process to ensure that the fiber bundle can be evenly impregnated with the polyetheretherketone resin and tightly wound on the core mold. The function of the wire nozzle is to control the direction of the carbon fiber tape and ensure the accuracy and consistency of the winding process.

[0055] The winding process of the rocket engine casing includes accurately calculated annular winding and spiral winding, and the winding angle calculation: according to the isopolar hole structure according to the geodesic winding formula The calculation results in α = 15.1°, where r0 is the polar aperture radius and r is the radius of the circle at any latitude;

[0056] Using the improved grid theory, we calculated that the thickness of the spiral winding layer of the barrel section is 1.5mm, and the thickness of the circumferential winding layer is 2.2mm. The optimal laying sequence of 2 spiral winding layers and 2 circumferential winding layers was determined by combining the cubic spline function method and the geometric method with MATLAB software. And according to the finite element simulation, it was determined to be the laying sequence of {[(15.1°), (-15.1°)], (90°)2}. Then, before the patch reinforcement, the modified winding shell was placed in the curing chamber for the first vacuum curing treatment. The specific parameters of the curing process were: from room temperature to 250°C at a heating rate of 40-50°C / h, and kept warm for 2 to 4 hours. After the curing was completed, it was naturally reduced to room temperature. During the entire curing process, the composite shell was kept rotating evenly at a speed of 2 revolutions / min to ensure the curing effect.

[0057] After the first curing is completed, the patch area needs to be polished before patching. When polishing, use fine-grained sandpaper with a mesh size of 320 to gently polish the surface, and reduce the speed of the grinder to 800-1200 rpm. When sandblasting, choose plastic particle sandblasting media, increase the sandblasting distance to 15-20 cm, and reduce the sandblasting pressure to 0.2-0.4MPa. In the head section, a two-stage fan-shaped two-layer patch with a thickness of 2.2mm is reinforced as shown in Figures 3(a) and 3(b), and then the shell is reinforced with overall spiral winding using carbon fiber epoxy resin material. The spiral winding angle is 40°, the winding layer is 2 layers, and the winding thickness is 1.5mm.

[0058] After the final spiral winding is completed, a second curing treatment is carried out, and the entire shell is placed in a curing chamber. The specific parameters of this curing are to increase the temperature from room temperature to 90°C to 120°C at a heating rate of 25°C to 30°C / h, and keep it warm for 2 to 4 hours. After the curing is completed, it is naturally cooled to room temperature and then demolded.

[0059] This method makes the strength of the barrel section after winding equal to or greater than the traditional winding method. On the other hand, it can be fitted after multi-layer patch reinforcement, reducing the gap generated at the transition between the head and the barrel section during the process production, reducing stress concentration, and then the whole is spirally wound again to reinforce the entire shell and enhance the mechanical properties of the shell. And the shell burst pressure under this patch winding and curing process is increased from 18MPa to 21Mpa. The improvement effect is about 16%, which is quite significant. And the use of patch reinforcement reduces the mass of the container by 15% while the burst pressure remains unchanged.

Claims

1. A method for manufacturing a carbon fiber modified and patch-wound reinforced solid rocket engine casing, characterized in that: The steps include: Step (1): preparing a base sizing agent; Step (2): preparing crystalline polyetheretherketone grafted carbon nanotubes; Step (3): preparing the final sizing agent: dispersing the original carbon nanotubes, carboxylated carbon nanotubes or carbon nanotubes grafted with polyetheretherketone in NM under ultrasonic conditions, then pouring the base sizing agent prepared in step (1), and dispersing again by ultrasonication to obtain the final sizing agent; Step (4): modifying the carbon fiber using the final sizing agent prepared in step (3) to obtain modified carbon fiber; Step (5): The shell is first spirally wound and then circumferentially wound to form a stepped structure with a gradually decreasing height from the barrel to the head section, and solidified once; a two-stage fan-shaped two-layer patch is used to reinforce the stepped height difference, and the entire shell is spirally wound, and a solid rocket engine shell is obtained after secondary solidification.

2. The method according to claim 1, characterized in that Step (1) is specifically as follows: polyetheretherketone-1,3-dithiocyclopentane PEEKDith with different molecular weights and carbonyl contents is synthesized by protecting the carbonyl group to prevent it from undergoing unnecessary reactions, PEEKDith-2.5-100 is subjected to a substitution reaction to synthesize polyetheretherketone-1,3-dioxolane, which is dissolved in N-methylpyrrolidone and reacted at room temperature for 2±0.2h under magnetic stirring to prepare a base sizing agent.

3. The method according to claim 2, characterized in that Step (2) specifically includes the following steps: Step (21): PEEKDith-2.0-20 is dissolved in tetrahydrofuran (THF) under magnetic stirring, and then NaBH4 and anhydrous methanol are added in sequence, and the mixture is reacted at room temperature for 10±1h to obtain a mixture, and the mixture is poured into ethanol to produce a white precipitate; the precipitate is boiled and washed in ethanol for multiple times, and then dried at 100±5°C to obtain a white PEEKDith-2.0-20-OH powder, and PEEKDith-2.0-144-OH powder is obtained in the same way; Step (22): performing an oxidation reaction on the CNT to obtain carboxylated carbon nanotubes CNT-COOH; The carboxylated carbon nanotubes CNT-COOH are added to anhydrous N-methylpyrrolidone NMP to obtain a CNT-COOH suspension, and after ultrasonic dispersion, DCC and DMAC are added, and then ultrasonic treatment is performed at 40±2°C for 2±0.2h to obtain a CNT-COOH suspension after ultrasonic treatment; Step (23): dissolving the PEEKDith-2.0-20-OH powder or PEEKDith-2.0-144-OH powder prepared in step (21) in THF, then adding DCC and pouring it into the ultrasonic CNT-COOH suspension under ultrasonic stirring, and reacting it under an ultrasonic environment of 50-60°C for 70±5h, heating to reflux for 24±2h, and filtering to obtain a crude product of CNT grafted with PEEK-1,3-dithiolane; washing the crude product of CNT grafted with PEEK-1,3-dithiolane with NMP, THF and DMF under reflux conditions to remove excess polymer, and drying to obtain CNT grafted with PEEK-1,3-dithiolane; Step (24): under 400W ultrasonic conditions, adding the PEEK-1,3-dithiocyclopentane grafted CNT to chloroform, ultrasonically dispersing for 2±0.2 hours, sequentially adding dimethyl sulfoxide DMSO and 2-iodo-2-methylpropane, and then ultrasonically treating at 60±2°C for 24±2 hours; after ultrasonic treatment, heating to 65±1°C and maintaining for 48±1 hours to obtain a crystalline PEEK grafted CNT crude product, washing the crystalline PEEK grafted CNT crude product with methanol for multiple times and drying at 80±2°C to obtain a crystalline PEEK grafted CNT, i.e., CNT-gPEEK-20 or CNT-gPEEK-144; Step (25): Disperse the original carbon nanotubes Raw-CNT, CNT-COOH and CNT-gPEEK-20 or CNT-gPEEK-144 in NMP under ultrasonic conditions for 2 hours, then slowly pour the base sizing agent into the above suspension, followed by ultrasonic dispersion for another 2 hours to obtain the final sizing agent.

4. The method according to claim 3, characterized in that: Step (4) is specifically as follows: the unsized carbon fiber passes through a sizing tank containing a final sizing agent at a speed of 0.1±0.02 m / min, and then is vacuum dried at 160±5°C; the sized carbon fiber passes through a 1 mol / L hydrogen chloride solution and deionized water in turn, and finally is vacuum dried at 80±2°C to obtain modified carbon fiber.

5. The method according to claim 4, characterized in that Step (5) is specifically as follows: Step (51): using a wet winding process, unfolding the modified carbon fiber bundle obtained in step (4), mixing it with a liquid polyetheretherketone matrix resin by dipping it through a resin tank, and directly winding it on a core mold installed on a winding machine tool; applying a constant tension of 2.5N to the fiber bundle during the winding process, and setting the heating temperature to 120-180°C; Step (52): Calculate the winding angle of the spiral winding, calculate the thickness of the spiral winding layer of the barrel section, the thickness of the circumferential winding layer, and determine the layer laying sequence; perform winding of the innermost complete spiral layer and winding of the circumferential layer of the middle barrel section to obtain a semi-finished shell; Step (53): placing the semi-finished shell into a curing chamber for vacuuming and first curing treatment; Step (54): After the first curing is completed, the area of ​​the head section to be patched is polished and shot peened, and two layers of patch reinforcement are performed on the head section. Each layer of patch reinforcement is two-stage, and each stage is composed of a plurality of fan-shaped patches. After the patch reinforcement, the shell is spirally wound with carbon fiber epoxy resin material as a whole; Step (55): After the final spiral winding is completed, a second curing treatment is performed.

6. The method according to claim 5, characterized in that In step (52), the thickness of the spiral winding layer of the barrel section is 1.5±0.1 mm, and the thickness of the hoop winding layer is 2.2±0.1 mm; the spiral winding layer is determined to be 2 layers and the hoop winding layer is determined to be 2 layers, and the ply laying sequence is determined to be {[(15.1°), (-15.1°)], (90°)2}.

7. The method according to claim 6, characterized in that The curing of step (53) is specifically as follows: heating from room temperature to 250±10°C at a heating rate of 40-50°C / h, keeping warm for 2-4 hours, and naturally cooling to room temperature after the curing is completed; and during the curing process, the shell is kept rotating uniformly at a speed of 2±0.1r / min.

8. The method according to claim 7, characterized in that In step (54), the surface is polished using sandpaper with a fine grain size of 320 mesh, and the speed of the polisher is 800-1200 rpm; When sandblasting, choose plastic particle sandblasting media, set the sandblasting distance to 15-20 cm, and the sandblasting pressure to 0.2-0.4MPa; The overall spiral winding angle is 40±2°, the winding layer is 2 layers, and the winding thickness is 1.5±0.1mm.

9. The method according to claim 8, characterized in that The curing step (55) is as follows: the entire shell is placed in a curing chamber, and the temperature is increased from room temperature to 90°C-120°C at a heating rate of 25°C-30°C / h, and kept warm for 2-4 hours. After the curing is completed, the shell is naturally cooled to room temperature and then demolded.

10. A method for manufacturing a carbon fiber modified and patch-wound reinforced solid rocket engine casing, characterized in that: The method is prepared by any one of claims 1 to 9.

Images