3D printing unmanned aerial vehicle light-weight fuselage based on basalt fiber composite material

Abstract

The invention belongs to the technical field of unmanned aerial vehicle structural design and 3D printing, and particularly relates to a 3D printing unmanned aerial vehicle lightweight fuselage based on basalt fiber composites.The 3D printing unmanned aerial vehicle lightweight fuselage comprises a fuselage body, the fuselage body comprises a fuselage main body part, and a fuselage anti-collision part is arranged on the front side of the fuselage main body part; a wing connecting part is arranged on the side surface of the fuselage main body part, an undercarriage mounting part is arranged at the bottom of the fuselage main body part, and the fuselage main body is integrally formed by adopting a basalt fiber reinforced thermoplastic composite material through 3D printing. Through differentiated structures (honeycomb-grating, dot matrix and the like) of all parts of the fuselage and fiber content design and in combination with precise matching of stress requirements, the structure performance is distributed according to needs, light weight and reliability are considered, and the problem of redundancy or insufficient strength of a single structure is avoided.

Description

Technical Field

[0001] This invention relates to the field of drone structural design and 3D printing technology, specifically to a lightweight drone fuselage based on basalt fiber composite materials. Background Technology

[0002] With the rapid development of drone technology, its applications in various fields such as aerial surveying and mapping, power line inspection, agricultural plant protection, and emergency rescue are becoming increasingly widespread. The endurance, payload, and maneuverability of drones are core performance indicators, and these indicators are all closely related to the airframe weight—a lightweight airframe can significantly reduce energy consumption, increase flight time, and carry more mission equipment, enhancing operational capabilities. Therefore, lightweight airframe design has become one of the key directions in drone technology research and development.

[0003] Currently, commonly used materials for drone fuselages include aluminum alloys and carbon fiber composites. While aluminum alloys offer good machinability and cost advantages, their high density makes them unsuitable for the extreme lightweight requirements of high-end drones. Carbon fiber composites, on the other hand, have low density and are ideal for lightweighting, but their production and processing costs are high, raw materials are imported, and carbon fiber production and recycling processes can easily cause environmental pollution, limiting their large-scale application in the low-to-mid-range drone market.

[0004] 3D printing technology (additive manufacturing technology), with its advantages of not requiring molds, flexible molding, and the ability to fabricate complex structures in one piece, is increasingly being applied to the manufacture of drone fuselages. This effectively reduces the number of parts, minimizes assembly errors, and further improves the efficiency of the fuselage structure. However, combining 3D printing technology with lightweight composite materials still presents several compatibility issues: existing composite materials used for 3D printing mostly use glass fiber and carbon fiber as reinforcement phases. Glass fiber composites have insufficient specific strength, while carbon fiber composites suffer from the aforementioned cost and environmental problems. Furthermore, composite fuselages produced by conventional 3D printing processes exhibit low interfacial bonding strength between fibers and the matrix, leading to easy delamination between layers. This results in poor impact resistance and fatigue performance, making it difficult to withstand the complex forces such as aerodynamic and vibration loads during drone flight. In addition, existing printing solutions often employ single fiber content or single structural designs, failing to achieve differentiated reinforcement based on the stress requirements of different parts of the fuselage, leading to material waste or insufficient local structural strength.

[0005] Basalt fiber, a novel inorganic and environmentally friendly composite material, is made from natural basalt through high-temperature melting and drawing. It boasts significant advantages such as low density (approximately 2.6 g / cm³), specific strength approaching that of carbon fiber, cost only 1 / 3 to 1 / 2 that of carbon fiber, high-temperature resistance, corrosion resistance, and environmental biodegradability. However, the application of basalt fiber composite materials in 3D printing drone fuselages is currently unexplored. The core bottleneck lies in the low surface activity of basalt fiber, resulting in poor interfacial compatibility with commonly used thermoplastic matrices in 3D printing (such as polylactic acid and nylon). Direct use in printing easily leads to fiber agglomeration and interfacial delamination. Furthermore, the lack of suitable 3D printing processes and corresponding fuselage structure designs for basalt fiber composite materials prevents the full realization of its synergistic advantages of lightweight and high strength.

[0006] Based on the above background technical analysis, the following core issues currently exist in the application fields of drone fuselages and 3D printed composite materials: 1. Poor material compatibility: Existing lightweight drone fuselage materials struggle to balance lightweight, high strength, low cost, and environmental friendliness. Aluminum alloys have high density, carbon fiber composites are costly and have poor environmental performance, and glass fiber composites have insufficient specific strength. Although basalt fiber composites possess comprehensive advantages, their compatibility with 3D printing processes is insufficient, and the interfacial bonding strength between the fiber and the matrix is ​​low.

[0007] 2. Unreasonable structural design: Conventional 3D printed drone fuselages use a single structure or a single material formula, which cannot achieve differentiated reinforcement based on the stress differences of different parts of the fuselage (such as the nose, wings, main body, and landing gear connection parts). This results in structural redundancy or insufficient local strength, making it difficult to balance lightweight effect with structural reliability.

[0008] 3. Immature printing technology: When existing 3D printing technologies (such as fused deposition modeling (FDM) and stereolithography (SLA) are used to print composite materials, problems such as disordered fiber orientation, weak interlayer bonding, and low printing accuracy are likely to occur. This results in poor impact resistance and fatigue performance of the fuselage, which cannot meet the complex load requirements of UAVs during flight.

[0009] 4. Imbalance between manufacturing efficiency and cost: 3D printing of carbon fiber composite materials is expensive and requires multiple post-processing steps after molding; conventional glass fiber composite material printing parts require additional reinforcement, resulting in long manufacturing cycles, increased costs, and difficulty in achieving large-scale production. Summary of the Invention

[0010] To address the aforementioned technical problems of poor material compatibility, unreasonable structural design, immature printing technology, and imbalance between manufacturing efficiency and cost, this invention provides the following technical solution: A lightweight fuselage for a 3D-printed drone based on basalt fiber composite material includes a fuselage body, which includes a main fuselage section. The front of the main fuselage section is provided with a nose impact protection section, the side of the main fuselage section is provided with a wing connection section, and the bottom of the main fuselage section is provided with a landing gear mounting section. The fuselage body is integrally formed by 3D printing using basalt fiber reinforced thermoplastic composite material. The main body of the fuselage adopts a hollow lattice structure and has a fiber content of 25-30%; the nose impact protection part adopts a honeycomb-grid composite structure and has a fiber content of 35-40%; the wing connection part and the landing gear mounting part both adopt a dense layer-lattice composite structure and have a fiber content of 35-40%.

[0011] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, the hollow lattice structure includes several regular tetrahedrons, which are spliced ​​together along the three-dimensional direction to form an overall hollow mesh structure. The regular tetrahedrons are composed of several hollow rods connected end to end.

[0012] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, the honeycomb-grid composite structure includes a regular hexagonal honeycomb layer composed of several regular hexagonal honeycomb units, wherein grids are intersected in the regular hexagonal honeycomb units.

[0013] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, the dense layer-lattice composite structure includes an outer layer and an inner layer, wherein the outer layer is a dense material layer and the inner layer is a lattice structure (same as the hollow lattice structure).

[0014] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, the basalt fiber reinforced thermoplastic composite material is composed of matrix resin, modified basalt fiber, compatibilizer and additives in a mass ratio of (50-70):(25-40):(3-8):(1-2).

[0015] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, the matrix resin is a blend of polylactic acid (PLA) and nylon 6 (PA6) in a mass ratio of 3:1.

[0016] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, the modified basalt fiber is surface-modified using a silane coupling agent (KH-550), and the fiber length is 0.5-2 mm and the diameter is 10-20 μm.

[0017] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, the compatibilizer is maleic anhydride-grafted polypropylene (MAH-g-PP) to enhance the compatibility between polylactic acid and nylon 6.

[0018] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, the additive is a blend of antioxidant (1010) and lubricant (zinc stearate) in a mass ratio of 1:1.

[0019] As a preferred embodiment of the lightweight fuselage of a 3D-printed drone based on basalt fiber composite material described in this invention, it further includes a preparation method, the specific steps of which are as follows: S1, Preparation of composite filaments: The matrix resin, modified basalt fiber, compatibilizer and additives are mixed in a mass ratio and fed into a twin-screw extruder for melt blending. The extrusion temperature is set to 180-230℃ (gradually increasing from the feed inlet to the die head), and the screw speed is 100-150 r / min. After extrusion, cooling, traction and pelletizing, composite granules are obtained. The composite granules are then fed into a single-screw pelletizer to prepare 3D printing filaments with a diameter of 1.75 mm or 3.0 mm. S2, Plasma Activation Pretreatment of Wires: The prepared composite material wires are fed into a low-temperature plasma treatment device. A mixture of argon and oxygen (volume ratio 3:1) is used as the discharge gas. The treatment power is set to 80-120W, the treatment speed is synchronized with the wire conveying speed (0.5-1m / min), and the treatment time is 30-60s. By bombarding the surface of the wires with plasma, active groups such as hydroxyl and carboxyl groups are introduced, which further improves the compatibility between the wires and the printing nozzles and the bonding force of the fiber-matrix interface. At the same time, residual impurities on the surface of the wires are removed to avoid the problem of nozzle clogging during printing. S3, Fuselage Model Optimization and Slicing: A 3D model of the UAV fuselage is created using 3D modeling software (such as SolidWorks). Based on the stress requirements of each part (determined through finite element simulation analysis), differentiated printing parameters are set in slicing software (such as Cura). These parameters include printing speed, printing temperature, infill density, and fiber orientation. For the printing speed, the nose impact protection section, wing connection section, and landing gear mounting section are set at 30-40 mm / s, while the main fuselage section is set at 50-60 mm / s. For the printing temperature, the nozzle temperature... The temperature ranges from 210 to 240°C, and the heated bed temperature is 60 to 80°C. In the filling density, the filling density of the nose impact protection section, wing connection section, and landing gear mounting section is 100%, and the filling density of the lattice structure is 30-40%. The filling density of the main fuselage section is 25-30%. In the fiber orientation, the nozzle movement trajectory is controlled by slicing software to orient the basalt fibers along the main stress direction of the fuselage body (e.g., the fibers in the wing connection section are oriented along the tensile direction, and the fibers in the main fuselage section are oriented along a circumferential and axial cross-direction), thereby improving the structural load-bearing efficiency. S4 3D Printing: The pre-treated composite material filament is loaded into the FDM 3D printer and printed according to optimized slicing parameters. During the printing process, the material pressure at the nozzle exit is monitored in real time by the pressure sensor on the printer, and the screw advance pressure is dynamically adjusted according to the structural characteristics of different parts (dense layer / lattice layer). The pressure is increased when printing the dense layer to ensure full material filling; the pressure is reduced when printing the lattice layer to avoid excessive compression that could cause fiber breakage. At the same time, inert gas (nitrogen) protection is used to prevent oxidation of the matrix resin. After printing, the printed body is placed in a constant temperature oven for post-processing at a temperature of 80-100℃ for 2-4 hours to eliminate printing internal stress and improve structural stability.

[0020] Compared with existing technologies: 1. By selecting modified basalt fiber and PLA / PA6 blend matrix, and adding compatibilizer to optimize interface bonding, it can achieve precise matching between materials and 3D printing process, and take into account lightweight, high strength, low cost and environmental protection, thus solving the core pain point of insufficient compatibility of traditional materials. 2. By designing differentiated structures (honeycomb-grid, dot matrix, etc.) and fiber content for different parts of the fuselage, and combining them with the stress requirements for precise matching, it can achieve on-demand allocation of structural performance, take into account both lightweight and reliability, and avoid the problems of redundancy or insufficient strength of a single structure. 3. By optimizing printing parameters, controlling fiber orientation, adopting inert gas protection and post-processing, it can achieve stable molding of composite materials, improve interlayer bonding and printing accuracy, and solve the problems of poor performance and insufficient adaptability of traditional processes; 4. By eliminating the mold and assembly steps through integrated 3D printing, using low-cost basalt fiber and simplifying post-processing, it can improve manufacturing efficiency and control costs. At the same time, it is compatible with multiple types of drones and has the advantage of large-scale production. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a top view of the structure of the present invention; Figure 3 This is a bottom view of the structure of the present invention; Figure 4 This is a cross-sectional schematic diagram of the main body of the fuselage of the present invention; Figure 5 This is a cross-sectional schematic diagram of the anti-collision part of the machine head of the present invention; Figure 6 This is a cross-sectional schematic diagram of the wing connection part of the present invention.

[0022] In the figure: main fuselage 10, nose impact protection 20, wing connection 30, landing gear mounting 40. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Example 1:

[0024] This invention provides a lightweight fuselage for a 3D-printed drone based on basalt fiber composite materials. Please refer to [link / reference]. Figures 1-6 The fuselage includes a fuselage body, which includes a fuselage main body 10. The fuselage main body 10 has a nose impact protection part 20 on its front side, a wing connection part 30 on its side side, and a landing gear mounting part 40 on its bottom. The fuselage body is made of basalt fiber reinforced thermoplastic composite material and is integrally formed by 3D printing. The main fuselage 10 adopts a hollow dot matrix structure and has a fiber content of 25%; the nose impact protection part 20 adopts a honeycomb-grid composite structure and has a fiber content of 35%; the wing connection part 30 and the landing gear mounting part 40 both adopt a dense layer-dot matrix composite structure and have a fiber content of 35%.

[0025] The hollow lattice structure includes several regular tetrahedrons, which are spliced ​​together along three-dimensional directions to form an overall hollow mesh structure. Each regular tetrahedron is composed of several hollow rods connected end to end.

[0026] The honeycomb-grid composite structure includes a regular hexagonal honeycomb layer composed of several regular hexagonal honeycomb units, in which grids are intersected.

[0027] The dense layer-lattice composite structure includes an outer layer and an inner layer. The outer layer is a dense material layer, and the inner layer is a lattice structure (same as the hollow lattice structure).

[0028] The basalt fiber reinforced thermoplastic composite material is composed of matrix resin, modified basalt fiber, compatibilizer and additives in a mass ratio of 50:25:3:1.

[0029] The matrix resin is a blend of polylactic acid (PLA) and nylon 6 (PA6) in a mass ratio of 3:1.

[0030] The modified basalt fiber is surface modified with silane coupling agent (KH-550), and the fiber length is 0.5 mm and the diameter is 10 μm.

[0031] The compatibilizer is maleic anhydride-grafted polypropylene (MAH-g-PP), which enhances the compatibility between polylactic acid and nylon 6.

[0032] The additive is a blend of antioxidant (1010) and lubricant (zinc stearate) in a mass ratio of 1:1.

[0033] It also includes a preparation method, the specific steps of which are as follows: S1, Preparation of composite filaments: The matrix resin, modified basalt fiber, compatibilizer and additives are mixed in a mass ratio and fed into a twin-screw extruder for melt blending. The extrusion temperature is set to 180℃ (gradually increasing from the feed inlet to the die head), and the screw speed is 100r / min. After extrusion, cooling, traction and pelletizing, composite granules are obtained. The composite granules are then fed into a single-screw pelletizer to prepare 3D printing filaments with a diameter of 1.75mm or 3.0mm. S2, Plasma Activation Pretreatment of Wire: The prepared composite material wire is fed into a low-temperature plasma treatment device. A mixture of argon and oxygen (volume ratio 3:1) is used as the discharge gas. The treatment power is set to 80W, the treatment speed is synchronized with the wire conveying speed (0.5m / min), and the treatment time is 30s. By bombarding the wire surface with plasma, active groups such as hydroxyl and carboxyl groups are introduced, which further improves the compatibility between the wire and the printing nozzle and the bonding force of the fiber-matrix interface. At the same time, it removes residual impurities on the wire surface and avoids the problem of nozzle clogging during printing. S3, Fuselage Model Optimization and Slicing: A 3D model of the UAV fuselage is created using 3D modeling software (such as SolidWorks). Based on the stress requirements of each part (determined through finite element simulation analysis), differentiated printing parameters are set in slicing software (such as Cura); these include printing speed, printing temperature, infill density, and fiber orientation; among the printing speeds, the nose impact protection part 20, wing connection part 30, and landing gear mounting part 40 are 30 mm / s, and the fuselage main body part 10 is 50 mm / s; among the printing temperatures, the spray... The nozzle temperature is 210℃, and the heated bed temperature is 60℃. In the filling density, the filling density of the nose impact protection section 20, wing connection section 30, and landing gear mounting section 40 is 100%, and the filling density of the lattice structure is 30%. The filling density of the fuselage main body section 10 is 25%. In the fiber orientation, the nozzle movement trajectory is controlled by slicing software to orient the basalt fibers along the main stress direction of the fuselage body (e.g., the wing connection section fibers are oriented along the tensile direction, and the fuselage main body fibers are oriented along a circumferential and axial cross-orientation), thereby improving the structural load-bearing efficiency. S4, 3D Printing: The pre-treated composite material filament is loaded into the FDM 3D printer and printed according to optimized slicing parameters. During the printing process, the material pressure at the nozzle exit is monitored in real time by the pressure sensor on the printer, and the screw advance pressure is dynamically adjusted according to the structural characteristics of different parts (dense layer / lattice layer). The pressure is increased when printing the dense layer to ensure full material filling; the pressure is reduced when printing the lattice layer to avoid excessive compression that could cause fiber breakage. At the same time, inert gas (nitrogen) protection is used to prevent oxidation of the matrix resin. After printing, the printed body is placed in a constant temperature oven for post-processing at 80°C for 2 hours to eliminate internal printing stress and improve structural stability. Example 2:

[0034] This invention provides a lightweight fuselage for a 3D-printed drone based on basalt fiber composite materials. Please refer to [link / reference]. Figures 1-6 The fuselage includes a fuselage body, which includes a fuselage main body 10. The fuselage main body 10 has a nose impact protection part 20 on its front side, a wing connection part 30 on its side side, and a landing gear mounting part 40 on its bottom. The fuselage body is made of basalt fiber reinforced thermoplastic composite material and is integrally formed by 3D printing. The main fuselage 10 adopts a hollow dot matrix structure and has a fiber content of 27.5%; the nose impact protection part 20 adopts a honeycomb-grid composite structure and has a fiber content of 37.5%; the wing connection part 30 and the landing gear mounting part 40 both adopt a dense layer-dot matrix composite structure and have a fiber content of 37.5%.

[0035] The hollow lattice structure includes several regular tetrahedrons, which are spliced ​​together along three-dimensional directions to form an overall hollow mesh structure. Each regular tetrahedron is composed of several hollow rods connected end to end.

[0036] The honeycomb-grid composite structure includes a regular hexagonal honeycomb layer composed of several regular hexagonal honeycomb units, in which grids are intersected.

[0037] The dense layer-lattice composite structure includes an outer layer and an inner layer. The outer layer is a dense material layer, and the inner layer is a lattice structure (same as the hollow lattice structure).

[0038] The basalt fiber reinforced thermoplastic composite material is composed of matrix resin, modified basalt fiber, compatibilizer and additives in a mass ratio of 60:32.5:5.5:1.5.

[0039] The matrix resin is a blend of polylactic acid (PLA) and nylon 6 (PA6) in a mass ratio of 3:1.

[0040] The modified basalt fiber is surface modified with silane coupling agent (KH-550), and the fiber length is 12.5 mm and the diameter is 15 μm.

[0041] The compatibilizer is maleic anhydride-grafted polypropylene (MAH-g-PP), which enhances the compatibility between polylactic acid and nylon 6.

[0042] The additive is a blend of antioxidant (1010) and lubricant (zinc stearate) in a mass ratio of 1:1.

[0043] It also includes a preparation method, the specific steps of which are as follows: S1, Preparation of composite filaments: The matrix resin, modified basalt fiber, compatibilizer and additives are mixed in a mass ratio and fed into a twin-screw extruder for melt blending. The extrusion temperature is set to 205℃ (gradually increasing from the feed inlet to the die head), and the screw speed is 125r / min. After extrusion, cooling, traction and pelletizing, composite granules are obtained. The composite granules are then fed into a single-screw pelletizer to prepare 3D printing filaments with a diameter of 1.75mm or 3.0mm. S2, Plasma Activation Pretreatment of Wire: The prepared composite material wire is fed into a low-temperature plasma treatment device. A mixture of argon and oxygen (volume ratio 3:1) is used as the discharge gas. The treatment power is set to 100W, the treatment speed is synchronized with the wire conveying speed (7.5m / min), and the treatment time is 45s. By bombarding the surface of the wire with plasma, active groups such as hydroxyl and carboxyl groups are introduced, which further improves the compatibility between the wire and the printing nozzle and the bonding force of the fiber-matrix interface. At the same time, it removes residual impurities on the surface of the wire to avoid the problem of nozzle clogging during printing. S3, Fuselage Model Optimization and Slicing: A 3D model of the UAV fuselage is created using 3D modeling software (such as SolidWorks). Based on the stress requirements of each part (determined through finite element simulation analysis), differentiated printing parameters are set in slicing software (such as Cura); these include printing speed, printing temperature, infill density, and fiber orientation; in the printing speed, the nose impact protection part 20, wing connection part 30, and landing gear mounting part 40 are 35 mm / s, and the fuselage main body part 10 is 55 mm / s; in the printing temperature, the nozzle... The temperature is 225℃, and the heated bed temperature is 70℃. In the filling density, the filling density of the nose impact protection part 20, the wing connection part 30, and the landing gear mounting part 40 is 100%, and the filling density of the lattice structure is 35%. The filling density of the fuselage main body part 10 is 27.5%. In the fiber orientation, the nozzle movement trajectory is controlled by slicing software to orient the basalt fibers along the main force direction of the fuselage body (e.g., the wing connection part fibers are oriented along the tensile direction, and the fuselage main body fibers are oriented along a circumferential and axial cross-direction), thereby improving the structural load-bearing efficiency. S4, 3D Printing: The pre-treated composite material filament is loaded into the FDM 3D printer and printed according to optimized slicing parameters. During the printing process, the material pressure at the nozzle exit is monitored in real time by the pressure sensor on the printer, and the screw advance pressure is dynamically adjusted according to the structural characteristics of different parts (dense layer / lattice layer). The pressure is increased when printing the dense layer to ensure full material filling; the pressure is reduced when printing the lattice layer to avoid excessive compression that could cause fiber breakage. At the same time, inert gas (nitrogen) protection is used to prevent oxidation of the matrix resin. After printing, the printed body is placed in a constant temperature oven for post-processing at 90°C for 3 hours to eliminate internal printing stress and improve structural stability. Example 3:

[0044] This invention provides a lightweight fuselage for a 3D-printed drone based on basalt fiber composite materials. Please refer to [link / reference]. Figures 1-6 The fuselage includes a fuselage body, which includes a fuselage main body 10. The fuselage main body 10 has a nose impact protection part 20 on its front side, a wing connection part 30 on its side side, and a landing gear mounting part 40 on its bottom. The fuselage body is made of basalt fiber reinforced thermoplastic composite material and is integrally formed by 3D printing. The fuselage body 10 adopts a hollow dot matrix structure and has a fiber content of 30%; the nose impact protection part 20 adopts a honeycomb-grid composite structure and has a fiber content of 40%; the wing connection part 30 and the landing gear mounting part 40 both adopt a dense layer-dot matrix composite structure and have a fiber content of 40%.

[0045] The hollow lattice structure includes several regular tetrahedrons, which are spliced ​​together along three-dimensional directions to form an overall hollow mesh structure. Each regular tetrahedron is composed of several hollow rods connected end to end.

[0046] The honeycomb-grid composite structure includes a regular hexagonal honeycomb layer composed of several regular hexagonal honeycomb units, in which grids are intersected.

[0047] The dense layer-lattice composite structure includes an outer layer and an inner layer. The outer layer is a dense material layer, and the inner layer is a lattice structure (same as the hollow lattice structure).

[0048] The basalt fiber reinforced thermoplastic composite material is composed of matrix resin, modified basalt fiber, compatibilizer and additives in a mass ratio of 70:40:8:2.

[0049] The matrix resin is a blend of polylactic acid (PLA) and nylon 6 (PA6) in a mass ratio of 3:1.

[0050] The modified basalt fiber is surface modified using a silane coupling agent (KH-550), and the fiber length is 2 mm and the diameter is 20 μm.

[0051] The compatibilizer is maleic anhydride-grafted polypropylene (MAH-g-PP), which enhances the compatibility between polylactic acid and nylon 6.

[0052] The additive is a blend of antioxidant (1010) and lubricant (zinc stearate) in a mass ratio of 1:1.

[0053] It also includes a preparation method, the specific steps of which are as follows: S1, Preparation of composite filaments: The matrix resin, modified basalt fiber, compatibilizer and additives are mixed in a mass ratio and fed into a twin-screw extruder for melt blending. The extrusion temperature is set to 230℃ (gradually increasing from the feed inlet to the die head), and the screw speed is 150 r / min. After extrusion, cooling, traction and pelletizing, composite granules are obtained. The composite granules are then fed into a single-screw pelletizer to prepare 3D printing filaments with a diameter of 1.75 mm or 3.0 mm. S2, Plasma Activation Pretreatment of Wire: The prepared composite material wire is fed into a low-temperature plasma treatment device. A mixture of argon and oxygen (volume ratio 3:1) is used as the discharge gas. The treatment power is set to 120W, the treatment speed is synchronized with the wire conveying speed (0.5-1m / min), and the treatment time is 60s. By bombarding the surface of the wire with plasma, active groups such as hydroxyl and carboxyl groups are introduced, which further improves the compatibility between the wire and the printing nozzle and the bonding force of the fiber-matrix interface. At the same time, it removes residual impurities on the surface of the wire to avoid the problem of nozzle clogging during printing. S3, Fuselage Model Optimization and Slicing: A 3D model of the UAV fuselage is created using 3D modeling software (such as SolidWorks). Based on the stress requirements of each part (determined through finite element simulation analysis), differentiated printing parameters are set in slicing software (such as Cura); these include printing speed, printing temperature, infill density, and fiber orientation; among the printing speeds, the nose impact protection part 20, wing connection part 30, and landing gear mounting part 40 are 40 mm / s, and the fuselage main body part 10 is 60 mm / s; among the printing temperatures, the spray... The nozzle temperature is 240℃, and the heated bed temperature is 80℃. In the filling density, the filling density of the nose impact protection section 20, wing connection section 30, and landing gear mounting section 40 is 100%, and the filling density of the lattice structure is 40%. The filling density of the fuselage main body section 10 is 30%. In the fiber orientation, the nozzle movement trajectory is controlled by slicing software to orient the basalt fibers along the main force direction of the fuselage body (e.g., the fibers in the wing connection section are oriented along the tensile direction, and the fibers in the fuselage main body section are oriented along a circumferential and axial cross-orientation), thereby improving the structural load-bearing efficiency. S4, 3D Printing: The pre-treated composite material filament is loaded into the FDM 3D printer and printed according to optimized slicing parameters. During the printing process, the material pressure at the nozzle exit is monitored in real time by the pressure sensor on the printer, and the screw advance pressure is dynamically adjusted according to the structural characteristics of different parts (dense layer / lattice layer). The pressure is increased when printing the dense layer to ensure full material filling; the pressure is reduced when printing the lattice layer to avoid excessive compression that could cause fiber breakage. At the same time, inert gas (nitrogen) protection is used to prevent oxidation of the matrix resin. After printing, the printed body is placed in a constant temperature oven for post-processing at 100°C for 4 hours to eliminate internal printing stress and improve structural stability.

[0054] Example 1 Example 2 Example 3 Tensile strength 92MPa 94MPa 89MPa Bending strength 127MPa 138MPa 135MPa Impact strength 20kJ / m² 24kJ / m² 19kJ / m² As can be seen from the table above, the lightweight fuselage of the UAVs prepared in Examples 1-3 all have good performance in terms of tensile strength, bending strength and impact strength. After use, Example 2 has the best effect.

[0055] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A lightweight fuselage for a 3D-printed unmanned aerial vehicle based on basalt fiber composite material, comprising a fuselage body, the fuselage body including a main fuselage section (10), a nose impact protection section (20) provided on the front side of the main fuselage section (10), a wing connection section (30) provided on the side of the main fuselage section (10), and a landing gear mounting section (40) provided at the bottom of the main fuselage section (10), characterized in that, The fuselage body is integrally formed by 3D printing using basalt fiber reinforced thermoplastic composite material. The main body of the fuselage (10) adopts a hollow dot matrix structure and has a fiber content of 25-30%; the nose impact protection part (20) adopts a honeycomb-grid composite structure and has a fiber content of 35-40%; the wing connection part (30) and the landing gear mounting part (40) both adopt a dense layer-dot matrix composite structure and have a fiber content of 35-40%.

2. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 1, characterized in that, The hollow lattice structure includes several regular tetrahedrons, which are spliced ​​together along three-dimensional directions to form an overall hollow mesh structure. Each regular tetrahedron is composed of several hollow rods connected end to end.

3. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 1, characterized in that, The honeycomb-grid composite structure includes a regular hexagonal honeycomb layer composed of several regular hexagonal honeycomb units, in which grids are intersected.

4. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 1, characterized in that, The dense layer-lattice composite structure includes an outer layer and an inner layer, wherein the outer layer is a dense material layer and the inner layer is a lattice structure.

5. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 1, characterized in that, The basalt fiber reinforced thermoplastic composite material is composed of matrix resin, modified basalt fiber, compatibilizer and additives in a mass ratio of (50-70):(25-40):(3-8):(1-2).

6. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 5, characterized in that, The matrix resin is a blend of polylactic acid and nylon 6 in a mass ratio of 3:

1.

7. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 5, characterized in that, The modified basalt fiber is surface modified using a silane coupling agent, and the fiber length is 0.5-2 mm and the diameter is 10-20 μm.

8. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 5, characterized in that, The compatibilizer is maleic anhydride-grafted polypropylene, which enhances the compatibility between polylactic acid and nylon 6.

9. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 5, characterized in that, The additive is a blend of antioxidant and lubricant in a mass ratio of 1:

1.

10. The lightweight fuselage of a 3D-printed drone based on basalt fiber composite material according to claim 5, characterized in that, It also includes a preparation method, the specific steps of which are as follows: S1, Preparation of composite filaments: The matrix resin, modified basalt fiber, compatibilizer and additives are mixed in a mass ratio and fed into a twin-screw extruder for melt blending. The extrusion temperature is set to 180-230℃ and the screw speed is 100-150r / min. After extrusion, cooling, traction and pelletizing, composite granules are obtained. The composite granules are then fed into a single-screw pelletizer to prepare 3D printing filaments with a diameter of 1.75mm or 3.0mm. S2, Plasma activation pretreatment of wire: The prepared composite wire is sent into a low-temperature plasma treatment device, using a mixture of argon and oxygen as the discharge gas, with the treatment power set to 80-120W, the treatment speed synchronized with the wire conveying speed, and the treatment time 30-60s; active groups are introduced by bombarding the surface of the wire with plasma. S3, Fuselage Model Optimization and Slicing: A 3D model of the UAV fuselage is created using 3D modeling software, and differentiated printing parameters are set in the slicing software according to the stress requirements of each part; The printing speed includes printing speed, printing temperature, filling density, and fiber orientation. In the printing speed, the printing speed of the nose impact protection part (20), wing connection part (30), and landing gear mounting part (40) is 30-40 mm / s, and the printing speed of the fuselage body part (10) is 50-60 mm / s. In the printing temperature, the nozzle temperature is 210-240℃, and the heated bed temperature is 60-80℃. In the filling density, the filling density of the nose impact protection part (20), wing connection part (30), and landing gear mounting part (40) is 100%, and the filling density of the dot matrix structure is 30-40%. The filling density of the fuselage body part (10) is 25-30%. In the fiber orientation, the nozzle movement trajectory is controlled by the slicing software to orient the basalt fibers along the main force direction of the fuselage body. S4, 3D Printing: The pre-treated composite material filament is loaded into the FDM 3D printer and printed according to the optimized slicing parameters. During the printing process, the material pressure at the nozzle exit is monitored in real time by the pressure sensor on the printer, and the screw feed pressure is dynamically adjusted according to the structural characteristics of different parts. At the same time, inert gas protection is used to avoid oxidation of the matrix resin. After printing, the printed body is placed in a constant temperature oven for post-processing at a temperature of 80-100℃ for 2-4 hours to eliminate printing internal stress and improve structural stability.

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