Composite material glass fiber and shell structure and manufacturing process thereof
Through the composite shell structure of the multi-layer glass fiber reinforced layer and the hexagonal honeycomb core layer, the problems of large weight, easy corrosion and difficulty in controlling vibration noise in traditional metal shells are solved, and lightweight, durability and production efficiency are improved.
Patent Information
- Application Number
- CN202510527188.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2025-07-11
AI Technical Summary
Traditional metal shells are too heavy, easy to corrode, and difficult to control vibration and noise. The composite shells have problems such as anisotropy, low interlayer peel strength, and long production cycle.
The glass fiber reinforced layer with a multi-layer reinforced structure is combined with the hexagonal honeycomb core material layer, and the surface protective layer is sprayed with fluorocarbon resin and vinyl ester resin, combined with laser projection positioning and automated molding technology to optimize the laying design and production process.
The shell weight reduction is achieved by 20%~30%, the corrosion resistance time is extended by 54%, the fatigue life is increased by 5 times, the production cycle is shortened, which significantly improves mechanical properties and durability and reduces production costs.
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Figure CN120287665A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of shell structure design, and more specifically, to a composite glass fiber, a shell structure and a manufacturing process thereof. Background Art
[0002] With the continuous progress of technology, the performance requirements for shell structural components in various industries have become increasingly stringent, and the limitations of traditional metal shells have become increasingly prominent: First, the high-density characteristic results in excessive weight (a typical water jet thruster shell reaches 50 kg), significantly increasing energy consumption and restricting mobility; Second, when exposed to harsh environments such as seawater and high temperatures for a long time, metal materials are prone to electrochemical corrosion and fatigue failure; Third, in complex working conditions, there are problems in vibration and noise control. Due to too many connecting parts in the traditional split design, stress concentration is likely to occur.
[0003] To address the above challenges, composite shells have been gradually applied to scenarios such as water jet thrusters. Their integrated design can reduce the number of parts and reduce vibration transmission through a encapsulated structure. However, in the prior art, there are the following prominent problems: In terms of mechanical properties, the traditional unidirectional ply structure leads to significant anisotropy, insufficient in-plane shear stiffness, low interlaminar peel strength, and it is difficult to withstand multi-directional composite loads. The single-layer reinforcement is prone to local buckling under compression, and the interfacial bonding strength between the core material and the reinforcement layer is insufficient. The mechanical properties decay severely under high-temperature working conditions; At the production process level, it is necessary to rely on manual hand lay-up, resulting in large angular deviations and long production cycles. Therefore, we propose a composite glass fiber, a shell structure and a manufacturing process thereof. Summary of the Invention
[0004] In view of the deficiencies in the prior art, the present invention provides a new technical solution for a composite glass fiber, a shell structure and a manufacturing process thereof.
[0005] The object of the present invention is achieved as follows: A composite glass fiber structure includes a glass fiber reinforcement layer, a core material layer and a surface protection layer. The glass fiber reinforcement layer has a multi-layer reinforcement structure. The glass fiber reinforcement layer and the core material layer are bonded by an epoxy film to form a ply stack. The surface protection layer includes an outer protection layer and an inner protection layer. The outer protection layer is made by spraying a fluorocarbon resin-modified epoxy resin, and the inner protection layer is made by spraying a vinyl ester resin.
[0006] Optionally, the glass fiber reinforcement layer uses E-type glass fiber. The multi-layer reinforcement structure is formed by two-way braiding. The laying angle of the glass fiber is designed based on the stress distribution received by the shell; Among them, some of the glass fibers are cross-laid at 0° and 90° to withstand tensile stress; Some of the glass fibers are additionally laid obliquely at 45° to withstand shear stress.
[0007] Optionally, the core material layer is sandwiched between the fiberglass reinforced layers, and the core material layer is arranged in a hexagonal honeycomb shape.
[0008] A housing structure, which is made of the above-mentioned composite material fiberglass, includes an upper housing and a lower housing. A boss is provided on the upper housing, and a housing corner box is provided on the upper housing. The number of the housing corner boxes is multiple, and the multiple housing corner boxes are symmetrically distributed. A housing flange is provided on the housing corner box. The upper housing and the lower housing are correspondingly arranged and buckled together.
[0009] A manufacturing process for a housing structure, which is used to prepare the above-mentioned housing structure, and the specific steps are as follows: Mold pretreatment: Prepare the housing and housing corner box molds respectively and perform pretreatment; Prepreg cutting: Use E-type fiberglass and resin to make prepreg, generate a layup cutting diagram with analysis software, and perform cutting and marking; Housing layup: Layer by layer lay up the prepreg on the mold and sandwich the core material layer to form a layup body; Make a vacuum bag: Set a vacuum bag film on the surface of the layup body; Into the autoclave for curing: Heat up and pressurize based on the resin curing system to make the resin flow and fully crosslink; After curing, cool down and demold; Post-treatment: Cut the demolded housing, remove the excess edge material and perform trimming, and spray a surface protection layer; Inspection: Perform quality inspection on the housing and accept it into the warehouse.
[0010] Optionally, both the housing and housing corner box molds are formed by male mold molds, and cutting lines and bolt hole lines are preset; The pretreatment is specifically: Wipe the film surface of the mold with acetone to remove surface contaminants. After the acetone has evaporated and dried, apply a release agent on the mold surface. 2 to 3 layers of the release agent are applied, and the wiping time interval between each layer of the release agent is more than 15 minutes.
[0011] Optionally, the layup cutting diagram includes layup basic information, geometric shape and size, and process requirements; The layup basic information includes the sheet number, prepreg grade, layup number of layers, and fiberglass laying direction marking; The geometric shape and size include the sheet contour boundary and reference line marking; The process requirements include the sheet layup sequence, sheet overlap control, and special area marking.
[0012] Optionally, the laminated prepreg is specifically: the first layer of prepreg is spliced by lapping, and the subsequent layers are butted and staggered. After every four layers of prepreg sheets are laid, vacuum compaction is carried out and recorded as a single-point reinforced layer unit. A core material layer is arranged between every two reinforced layer units, and the core material layer and the reinforced layer unit are bonded by an epoxy film and then vacuum compacted again.
[0013] Optionally, the spraying of the surface protective layer is specifically: spraying fluorocarbon-modified epoxy resin on the outer surface of the housing, and coating vinyl ester resin on the inner surface of the housing. The coating needs to be cured at room temperature or cured by acceleration.
[0014] Optionally, the quality inspection includes: fiber lay-up angle, porosity and interlayer bonding; The fiber lay-up angle is compared by laser projection, and the required angle deviation ; The porosity is measured by ultrasonic C-scan, and the required porosity ; The interlayer bonding is tested by a pull-out test, and the required interlayer bonding strength 。
[0015] Compared with the prior art, the beneficial effects of the novel invention of the present invention are as follows: through the combination of multi-angle fiber lay-up design and hexagonal honeycomb core material layer, the weight of the housing is reduced by 20% to 30% while ensuring mechanical properties, the overall quality is reduced compared with the traditional metal housing, lightweight is achieved, and the overall strength is increased. The use of fluorocarbon-modified epoxy resin outer coating and vinyl ester inner coating spraying protective layer extends the salt spray corrosion resistance time by 54% to 2000 hours, and the mechanical property retention rate after 10 years of natural aging exceeds 90%, which is significantly better than 82% of the traditional process.
[0016] In terms of the production process, laser projection positioning and automated forming technology are introduced, which reduces the single-piece production cycle, improves the qualification rate, and reduces the number of defective products. The effects of lightweight, high durability and high-efficiency production are achieved, making it widely used in new energy vehicles, marine equipment and wind power fields, helping to achieve energy conservation and emission reduction and high-end equipment upgrading, reducing the comprehensive cost, and having significant economic benefits and market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.
[0018] Figure 1 It is a schematic diagram of the overall structure of a housing structure provided by the present invention.
[0019] Figure 2 It is a schematic diagram of the process flow of a manufacturing process for a housing structure provided by the present invention.
[0020] Figure 3 It is a schematic diagram of housing restraint and load of a manufacturing process for a housing structure provided by the present invention.
[0021] Figure 4 It is a housing displacement nephogram of a manufacturing process for a housing structure provided by the present invention.
[0022] Figure 5 It is a housing stress nephogram of a manufacturing process for a housing structure provided by the present invention.
[0023] Figure 6 It is the maximum tensile strain of the housing in the 0° direction of a manufacturing process for a housing structure provided by the present invention.
[0024] Figure 7 It is the maximum compressive strain of the housing in the 0° direction of a manufacturing process for a housing structure provided by the present invention.
[0025] Figure 8 It is the maximum tensile strain of the housing in the 90° direction of a manufacturing process for a housing structure provided by the present invention.
[0026] In the figure: 1. Upper housing; 2. Lower housing; 3. Boss; 4. Housing corner box; 5. Housing flange. Detailed implementation manners
[0027] Next, the technical solutions in the new embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the new embodiments of the present invention. Obviously, the described embodiments are only a part of the new embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the new embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the new embodiments of the present invention.
[0028] As Figures 1 to 8 shown, a composite material glass fiber structure includes a glass fiber reinforcement layer, a core material layer, and a surface protection layer. The glass fiber reinforcement layer has a multi-layer reinforcement structure. The glass fiber reinforcement layer and the core material layer are bonded through an epoxy film to form a laminate. The surface protection layer includes an outer protection layer and an inner protection layer. The outer protection layer is made by spraying fluorocarbon resin-modified epoxy resin, and the inner protection layer is made by spraying vinyl ester resin.
[0029] It should be noted that first, finite element calculations such as HyperMesh need to be used to optimize the structure and laying method of the glass fiber reinforced layer through reasonable design, so that the shell can be optimized according to the actual stress conditions, maximize the mechanical properties of the glass fiber, and thus improve the bearing capacity and fatigue resistance of the shell.
[0030] Secondly, the introduction of the core material layer not only reduces the weight of the shell, but also enhances its structural stability and energy absorption capacity, enabling the shell to perform better under complex working conditions such as impact and vibration.
[0031] Finally, the setting of the surface protection layer can effectively improve the durability and adaptability of the shell, enabling it to operate reliably in harsh external environments and special working media, and broadening the application range of the shell.
[0032] Specifically, the glass fiber reinforced layer uses E-type glass fiber, the multi-layer reinforcement structure is formed by two-way weaving, and the laying angle of the glass fiber is designed based on the stress distribution on the shell; Among them, some of the glass fibers are cross-laid at 0° and 90° to withstand tensile stress; Some of the glass fibers are additionally provided with a 45° oblique laying layer to withstand shear stress.
[0033] Furthermore, based on the use of HyperMesh finite element calculations, as Figures 3 to 8 shown, the mechanical properties and durability of the shell can be improved through the optimization of the laying angle. In the area where large tensile stress is applied, the 0° or 90° cross-laying can fully exert the high tensile strength of the fiber axis and resist unidirectional loads; while in the area of high shear stress, adding a 45° oblique laying layer can improve the in-plane shear stiffness and prevent interlayer delamination and shear deformation; Furthermore, the multi-angle laying realizes the efficient transfer of loads and avoids local stress concentration caused by single-direction laying. At the same time, the two-way weaving structure gives the material an isotropic tendency, takes into account the mechanical requirements in different directions, and reduces the weaknesses of anisotropy. In addition, the synergistic effect of the corrosion resistance of E-type glass fiber and the resin matrix can further enhance the stability of the structure in complex environments.
[0034] Specifically, the core material layer is sandwiched between the glass fiber reinforced layers, and the core material layer is arranged in a hexagonal honeycomb shape.
[0035] Furthermore, a hexagonal honeycomb core material layer is sandwiched between the glass fiber reinforced layers to improve the comprehensive performance of the composite structure; The hexagonal honeycomb structure has extremely high specific stiffness and specific strength, providing excellent compression and shear resistance with extremely light weight, while dispersing the in-plane load. The honeycomb core material and the upper and lower glass fiber reinforcement layers form a sandwich structure, which improves the overall bending stiffness and anti-buckling ability and avoids local instability of the single-layer structure when subjected to force. The closed-cell structure of the hexagonal honeycomb can also block the crack propagation path and improve impact resistance; In addition, the low density of the honeycomb core layer helps to achieve lightweight design, while its porous structure can further provide sound insulation, thermal insulation or damping functions; The weight and mechanical properties of the shell of the present invention and the traditional shell are compared, as shown in Table 1: Table 1 Furthermore, under the premise of ensuring the same strength and rigidity, the shell structure prepared by E-glass fiber / epoxy resin prepreg can reduce the overall weight by 20%~30%. Taking the automobile engine shell as an example, the weight of the traditional metal shell is about 50kg. After adopting the E-glass fiber / epoxy resin prepreg shell of this patented technical solution, the weight can be reduced to 35kg~40kg, thereby improving the fuel economy and handling performance of the car.
[0036] The environmental resistance performance of the housing of the present invention is compared with that of the traditional housing, as shown in Table 2: Table 2 Furthermore, the corrosion resistance is improved: after special surface treatment and the selection of corrosion-resistant resin matrix, the corrosion resistance time of the shell can be extended to more than 2000 hours in the salt spray test simulating the marine environment, which is about 50% higher than the traditional glass fiber shell. It can be widely used in harsh corrosive environments such as marine engineering and chemical equipment.
[0037] Enhanced weather resistance: In the outdoor long-term exposure test, after 10 years of natural aging, the appearance and performance of the shell can still be maintained in good condition, with the color change less than 5% and the mechanical property decrease less than 10%, which can meet the requirements of long-term outdoor use such as building curtain walls and outdoor communication equipment casings.
[0038] A shell structure, which is made based on the above-mentioned composite material glass fiber, includes an upper shell body 1 and a lower shell body 2, a boss 3 is arranged on the upper shell body 1, a shell corner box 4 is arranged on the upper shell body 1, the number of the shell corner boxes 4 is multiple, and the multiple shell corner boxes 4 are symmetrically distributed, and a shell flange 5 is arranged on the shell corner box 4, the upper shell body 1 and the lower shell body 2 are arranged correspondingly, and the upper shell body 1 and the lower shell body 2 are buckled together.
[0039] It should be noted that the shell is fabricated by the process of pre-impregnated material laying and autoclave molding. The shell consists of two parts, namely the upper shell 1 and the lower shell 2, and several shell corner boxes 4. The shell corner boxes 4 are fixed at the connection between the upper shell 1 and the lower shell 2 by means of post-bonding. The upper shell 1 and the lower shell 2 are fixed by bolts to form a complete shell. Among them, the shell corner boxes 4 need to be post-processed by machining according to the digital model after curing to ensure that the bonding surface fits and bonds with the surfaces of the upper shell 1 and the lower shell 2, thereby optimizing the load transfer path. The post-bonding process is adopted to avoid the residual stress that may be generated by co-curing, and at the same time allows for separate quality control of the connection parts.
[0040] A manufacturing process for a shell structure, which is used to prepare the shell structure described in claim 3. The specific steps are as follows: Mold pretreatment: Prepare the shell and shell corner box molds respectively and conduct pretreatment. Pre-impregnated material cutting: Use E-type glass fiber and resin for pre-impregnated material, generate a laying cutting diagram with analysis software, and perform cutting and marking. Shell laying: Lay the pre-impregnated material in layers on the mold and sandwich a core material layer to form a laid body. Make a vacuum bag: Set a vacuum bag film on the surface of the laid body. Enter the autoclave for curing: Heat and pressurize based on the resin curing system to make the resin flow and fully crosslink; after curing, cool down and demold. Post-treatment: Cut the demolded shell, remove the excess edge material and perform trimming, and spray a surface protection layer. Inspection: Conduct quality inspection on the shell and check and accept it into the warehouse.
[0041] Specifically, both the shell and shell corner box molds are formed by male mold molding, and cutting lines and bolt hole lines are preset. The specific pretreatment is as follows: Wipe the film surface of the mold with acetone to remove surface contaminants. After the acetone has evaporated and dried, apply a release agent on the mold surface. The release agent is applied in 2 - 3 layers, and the application time interval for each layer of the release agent is more than 15 minutes.
[0042] Furthermore, the shell and corner box male molds are made of Q45 steel, which has high strength, wear resistance, and dimensional stability, and can ensure that the mold does not deform during the laying of the pre-impregnated material and the autoclave curing process. The cutting lines and bolt hole lines set on the mold surface can accurately locate the subsequent processing positions, improve the assembly accuracy, reduce the manual scribing error, simplify the process flow at the same time, improve the production efficiency, and ensure the dimensional consistency of the shell and the corner box.
[0043] It should be noted that for new molds, more than 8 layers of release agent need to be applied to form a complete demolding layer.
[0044] Furthermore, the prepreg is prepared by hot melting E-glass fiber and epoxy resin. The comparison between the prepreg of this application and other prepregs is shown in Table 3: Table 3 Comparing the prepreg prepared from E-glass fiber and epoxy resin with other prepregs and combining the comparison data, it can be concluded that the core advantages of the E-glass fiber / epoxy resin prepreg are reflected in high cost performance and functional balance: The dielectric constant of the E-glass fiber / epoxy resin prepreg is better than that of carbon fiber and close to that of aramid. It has both low cost and performance advantages in electrical insulation scenarios (such as radomes and circuit boards); The corrosion resistance is better than that of carbon fiber (sensitive to electrochemical corrosion) and aramid (easy to age by ultraviolet rays), and it is suitable for corrosive environments such as chemical industry and ships; Although the tensile strength is lower than that of carbon fiber and aramid, it is sufficient to meet the medium-strength requirements such as automotive lightweight and wind turbine blades, and it realizes metal substitution through low cost.
[0045] Generally speaking, E-glass fiber / epoxy takes economy as the core and provides the optimal cost-effective solution in the scenarios of electrical insulation, corrosion resistance and medium mechanics.
[0046] Specifically, the laying and cutting diagram includes laying basic information, geometric shape and size, and process requirements; The laying basic information includes the sheet number, prepreg grade, laying layer number and glass fiber laying direction marking; The geometric shape and size include the sheet contour boundary and reference line marking; The process requirements include the sheet laying sequence, sheet overlap control and special area marking.
[0047] Furthermore, the laying basic information is used to clarify the attributes of each layer of prepreg, ensuring the correct material and laying sequence; Sheet number: Set a unique number for each layer of prepreg to prevent the sequence from being disordered during laying and facilitate quality traceability.
[0048] The prepreg grade is used to indicate the model of the prepreg; Exemplarily, for E-glass fiber / epoxy resin, the thickness of a single-layer prepreg is 0.2 mm, denoted as: E-GF / EP-200.
[0049] The laying layer number is used to mark the total number of layers and the position of the current layer, avoiding missing laying or over-laying and ensuring the designed thickness.
[0050] The glass fiber laying direction uses angles to mark the fiber direction, including: "0°", "45°", "90°", with the die reference line as the reference; Furthermore, 0° fibers can provide axial strength, such as bearing tensile forces; ±45° fibers can improve shear and torsional resistance; 90° fibers can enhance lateral stiffness.
[0051] Exemplarily, the basic information of the ply is shown in Table 4 as follows: Table 4 Furthermore, in the manufacturing of composite material glass fiber plies, precise control of geometry and dimensions directly determines the quality and performance of the final product. Among them, the contour boundary of the blank refers to the actual outer contour shape of the glass fiber / epoxy prepreg during laying, which is generated by CAD software (such as Fibersim) and converted into a laser cutting path; Furthermore, the outer shape curve of the glass fiber / epoxy prepreg: includes straight lines, arcs, free curves, etc., and the key dimensions marked include length, radius, and angle; Cutting allowance: 2 - 5 mm larger than the theoretical size for subsequent trimming; Special features: special marks such as openings and notches; Exemplarily, the blank number: PLY - 03 Contour dimensions: 1200 mm × 800 mm (main rectangle) + R50 mm rounded corners (at four corners) Cutting allowance: +3 mm (manual trimming after laser cutting) Special features: 2 × Φ10 mm positioning holes (center distance 600 mm); Specifically, the laminated prepreg is specifically as follows: The first - layer prepreg is laid by lap splicing, and subsequent layers are laid by butt joint with staggered joints. After laying every four layers of prepreg blanks, vacuum compaction is carried out and recorded as a point - strengthened layer unit. A core layer is arranged between every two strengthened layer units, and the core layer and the strengthened layer unit are bonded by an epoxy film and then subjected to secondary vacuum compaction.
[0052] Furthermore, in the first - layer laying stage, a lap splicing method with a width of 20 mm is adopted, and epoxy resin glue is evenly coated in the lap area. The lap direction is strictly parallel to the main stress direction to ensure the stability of the initial laying and the stress transfer efficiency. Starting from the second layer, precise butt joint is carried out, requiring the edge alignment error not to exceed 0.5 mm, and at the same time, the standard of seam stagger ≥ 300 mm is strictly implemented, and the stagger accuracy is ensured through a laser positioning system; After every 4 layers of prepreg are laid, vacuum compaction treatment is carried out with a vacuum degree of -0.09 MPa for 10 - 20 minutes. During the process, the pressure is monitored in real time to ensure the thorough elimination of interlayer bubbles. After each reinforcement layer unit is completed, thickness detection is carried out, and the allowable deviation is controlled within the range of ±0.1 mm. At the same time, unit marking and quality traceability records are made.
[0053] The core layer uses honeycomb core material. The regular arrangement of the honeycomb structure provides excellent compressive performance and energy absorption capacity for the shell. At the same time, it has a low density in the direction perpendicular to the plate surface, reducing the structural weight. And a 0.2 mm thick modified epoxy adhesive film is used as the bonding medium between the core layer and the reinforcement layer unit. The activation temperature of the adhesive film is strictly controlled at 80 ± 5 °C. The secondary vacuum compaction process is extended to 30 minutes, and ultrasonic non-destructive testing is carried out immediately after compaction to ensure that the interface bonding quality meets the standards. Furthermore, through segmented compaction, the interlayer porosity is reduced from 2 - 3% to less than 1%; the staggered joint design can increase the fatigue life by more than 20%; the core material interface treatment process makes the peel strength reach more than 50 N / mm; the overall structure achieves a weight reduction effect of more than 25% while ensuring strength.
[0054] Specifically, the sprayed surface protective layer is as follows: Fluorocarbon-modified epoxy resin is sprayed on the outer surface of the shell, and vinyl ester resin is coated on the inner surface of the shell. The coating needs to be cured at room temperature or accelerated curing.
[0055] Furthermore, for the outer surface of the shell, fluorocarbon-modified epoxy resin is selected as the protective material. The fluorocarbon-modified epoxy resin is composed of a special resin with a solid content of 70% and a fluorocarbon modifier of 30%. It is constructed by high-pressure airless spraying process. The spray gun pressure is controlled at 15 - 20 MPa, the nozzle diameter is 0.5 mm, the spraying distance is maintained at 30 - 40 cm, and it is completed by cross-spraying in 3 passes, with an interval of 15 minutes between each pass. The final dry film thickness is strictly controlled within the range of 100 - 120 μm, and 100% detection is carried out using an electromagnetic thickness gauge. The inner surface of the shell uses vinyl ester resin with chemical corrosion resistance, which contains 45% bisphenol A vinyl ester resin, 30% styrene monomer, and 25% special filler. It is constructed by roller coating process. The roller is selected with a 5 mm short plush material, and the construction viscosity is controlled at 25 - 30 seconds of the No. 4 cup. The final dry film thickness is guaranteed to be between 80 - 100 μm, and the key areas are rechecked using an ultrasonic thickness gauge.
[0056] Furthermore, the standard curing conditions include: curing at room temperature (23 ± 2 °C) for 24 hours, and the relative humidity is controlled at 50% - 70%. Accelerated curing: Treat with an 80 °C hot air circulation oven for 2 hours, and the heating rate is controlled at 2 °C / min to ensure full cross-linking of the coating.
[0057] Furthermore, the fluorocarbon-modified epoxy resin outer coating has excellent weather resistance and impact resistance; the vinyl ester inner coating exhibits excellent chemical resistance (no change after being immersed in 10% sulfuric acid solution for 30 days); This enables the overall protection system to extend the service life of the housing, making it suitable for composite products in harsh environments such as marine equipment and chemical containers, achieving optimal cost control while ensuring the protection effect.
[0058] Specifically, the quality inspection includes: fiber laying angle, porosity, and interlayer bonding; The fiber laying angle is compared by laser projection, and the angle deviation is required to be ; The porosity is detected by ultrasonic C-scan, and the porosity is required to be ; The interlayer bonding is tested by a pull-out test, and the interlayer bonding strength is required to be 。
[0059] Furthermore, through a three-dimensional quality inspection system, the structural integrity of composite products is ensured. In terms of fiber laying angle detection, a method combining a high-precision laser projection system and digital image processing technology is adopted to compare the actual laying with the CAD design model in real time. The laying deviation in the 0° direction is required to be ≤0.5°, the deviation in the ±45° direction is ≤1.0°, and the deviation in the 90° direction is ≤0.8°. This can avoid local stress overrun (the peak stress is reduced by 25%) and significantly improve the fatigue resistance life of the housing (the life under cyclic load ≥1×10 7 times); For porosity detection, a high-frequency ultrasonic C-scan system is selected and combined with water immersion coupling technology for hierarchical control. The porosity in area A (main load-bearing area) is required to be ≤1%, in area B ≤2%, and in area C ≤3%. The system automatically identifies and marks the areas exceeding the standard, generating a three-dimensional porosity distribution model to provide data support for process improvement; the low porosity (≤1% in area A) significantly reduces the microcrack initiation sources, and the mechanical property retention rate in the humid and hot environment is ≥95% (only 80% for the traditional process), and the salt spray corrosion rate is reduced by 40%; The reduction of porosity increases the effective load-bearing area of the material by 12%, and the specific strength of the housing is increased to 30 MPa·m³ / kg (20% higher than the traditional process), while reducing the weight by 15%-20%; The three-dimensional porosity distribution model guides process optimization (such as adjusting the injection pressure), reducing the standard deviation of porosity between batches from 0.8% to 0.2%.
[0060] The interlayer bonding performance is detected using a hydraulic servo pull-out testing machine, equipped with a special fixture. The loading rate is controlled at 1 mm / min. It is required that the interlayer bonding strength is ≥40 MPa at room temperature and ≥30 MPa under high-temperature conditions. For each batch of products, 3 specimens are randomly selected and tested in the directions of 0°, 45°, and 90° respectively to ensure isotropy.
[0061] The high bonding strength (40 MPa at room temperature) increases the interlayer shear strength by 33%, and there is no delamination propagation under multi-directional impact loads (for traditional shells, delamination ≥5 mm occurs at 30 MPa); the bonding strength at high temperature (120 °C) is ≥30 MPa, ensuring that the interlayer performance attenuation of the shell is ≤10% during long-term service in high-temperature scenarios such as the engine compartment (the attenuation of traditional materials is ≥30%); the strength difference in three directions (0° / 45° / 90°) is ≤8%, avoiding local weak areas caused by layup angle deviation, and increasing the deformation uniformity of the shell under complex loads by 25%.
[0062] Laser projection technology can improve the layup angle control accuracy by 50%, effectively avoiding the decline in mechanical properties caused by fiber orientation deviation; ultrasonic C-scan can achieve 100% full inspection, with the detection efficiency being 10 times higher than that of traditional metallographic methods, and it can detect micro-defects of 0.1 mm level; the pull-out test adopts a multi-directional sampling strategy to comprehensively evaluate the interlayer performance, prevent delamination risks, and increase the product qualification rate to over 99.5%, reducing the quality risks during use.
[0063] The comparison of the production efficiency and cost between the shell of the present invention and traditional shells is shown in Table 5 as follows: Table 5 Improved production efficiency: By adopting an automated molding process, the resin transfer molding (RTM) process combined with preform technology, the production cycle of a single shell is shortened from 8 hours of the traditional process to within 4 hours, and the production efficiency is increased by more than double, which is beneficial to large-scale production and cost reduction. The comparison of the quality qualification rate between the shell of the present invention and traditional shells is shown in Table 6 as follows: Table 6 Reduced scrap rate: Through precise mold design and process control, the scrap rate is reduced from about 10% of the traditional process to below 3%, reducing the waste of raw materials and production costs, and improving the quality stability and market competitiveness of the product.
[0064] In summary, the composite glass fiber shell structure provided by this application has the following advantages: as Figures 3 - 8As shown in the figure, first, use finite element calculations such as HyperMesh to design the structure and laying method of the glass fiber reinforcement layer, so that the shell can be optimized according to the actual stress conditions, maximizing the mechanical properties of the glass fiber, thereby improving the bearing capacity and fatigue resistance of the shell; second, the introduction of the core material layer not only reduces the weight of the shell, but also enhances its structural stability and energy absorption capacity, enabling the shell to perform better in the face of complex working conditions such as impact and vibration; furthermore, the setting of the surface protection layer can effectively improve the durability and adaptability of the shell, enabling it to operate reliably in harsh external environments and special working media, expanding the application range of the shell; After actual testing, compared with traditional metal shells, the composite glass fiber shell of the present invention has a weight reduction of more than 30%, a fatigue life increase of 5 times, and also a significant improvement in corrosion resistance under the same strength requirements, and can meet the application scenarios with extremely high performance requirements for shells such as the intake duct shell of an aeroengine, lightweight body structural parts of an automobile, and the superstructure of a ship.
[0065] The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
Claims
1. A composite material glass fiber structure, characterized in that: It includes a glass fiber reinforced layer, a core material layer and a surface protection layer. The glass fiber reinforced layer has a multi-layer reinforced structure. The glass fiber reinforced layer and the core material layer are bonded by an epoxy film to form a laminate. The surface protection layer includes an outer protection layer and an inner protection layer. The outer protection layer is made by spraying fluorocarbon resin modified epoxy resin, and the inner protection layer is made by spraying vinyl ester resin.
2. A composite material glass fiber structure according to claim 1, characterized in that: The glass fiber reinforced layer uses E-type glass fiber. The multi-layer reinforced structure is formed by two-way weaving. The laying angle of the glass fiber is designed based on the stress distribution on the shell. Among them, part of the glass fiber is cross-laid at 0° and 90° to withstand tensile stress. Part of the glass fiber is additionally provided with a 45° oblique laying to withstand shear stress.
3. A composite material glass fiber structure according to claim 1, characterized in that: The core material layer is sandwiched between the glass fiber reinforced layers, and the core material layer is arranged in a hexagonal honeycomb shape.
4. A housing structure, characterized in that: The shell structure is made of the composite material glass fiber described in claims 1-3, and includes an upper shell (1) and a lower shell (2). A boss (3) is provided on the upper shell (1). A shell corner box (4) is provided on the upper shell (1). The number of the shell corner boxes (4) is multiple, and the multiple shell corner boxes (4) are symmetrically distributed. A shell flange (5) is provided on the shell corner box (4). The upper shell (1) and the lower shell (2) are correspondingly arranged, and the upper shell (1) and the lower shell (2) are buckled.
5. A manufacturing process for a housing structure, characterized in that: The manufacturing process is used to prepare the shell structure described in claim 3, and the specific steps are as follows: Mold pretreatment: Prepare the shell and shell corner box molds respectively, and perform pretreatment. Prepreg cutting: Use E-type glass fiber and resin to make prepreg, generate a laying cutting diagram by using analysis software, and perform cutting and marking. Shell laying: Lay the prepreg on the mold layer by layer, and sandwich the core material layer to form a laminate. Make a vacuum bag: Set a vacuum bag film on the surface of the laminate. Into the autoclave for curing: Heat up and pressurize based on the resin curing system to make the resin flow and fully crosslink; After curing, cool down and demold. Post-treatment: Cut the demolded shell, remove the excess edge material and perform trimming, and spray the surface protection layer. Inspection: Perform quality inspection on the shell and check and accept it into the warehouse.
6. The manufacturing process of a housing structure according to claim 5, characterized in that: Both the shell and shell corner box molds are formed by male mold molds, and cutting lines and bolt hole lines are preset. The pretreatment is specifically: Wipe the film surface of the mold with acetone to remove surface contaminants. After the acetone volatilizes and dries, apply a release agent on the mold surface. The release agent is applied in 2-3 layers, and the application time interval between each layer of release agent is more than 15 minutes.
7. A manufacturing process for a housing structure according to claim 5, characterized in that: The laying cutting diagram includes laying basic information, geometric shape and size, and process requirements. The laying basic information includes sheet number, prepreg grade, laying number of layers and glass fiber laying direction marking. The geometric shape and size include sheet contour boundary, reference line marking. The process requirements include sheet laying sequence, sheet overlap control and special area marking.
8. A manufacturing process of a housing structure according to claim 5, characterized in that: The stratified pre-preg laying is specifically as follows: for the first layer of pre-preg laying, lap splicing is adopted, and butt joint with staggered joints is adopted for subsequent laying. After every four layers of pre-preg sheets are laid, vacuum compaction is carried out and recorded as a point strengthening layer unit. A core material layer is arranged between every two strengthening layer units. The core material layer and the strengthening layer unit are bonded by an epoxy adhesive film and subjected to secondary vacuum compaction.
9. A manufacturing process for a housing structure according to claim 5, characterized in that: The spraying of the surface protective layer is specifically as follows: fluorocarbon-modified epoxy resin is sprayed on the outer surface of the shell, and vinyl ester resin is coated on the inner surface of the shell. The coating needs to be cured at room temperature or cured acceleratively.
10. A manufacturing process for a housing structure according to claim 5, characterized in that: The quality inspection includes: fiber laying angle, porosity and interlayer bonding; The fiber laying angle is compared by laser projection, and the angle deviation is required to be ; The porosity is measured by ultrasonic C-scan, and the porosity is required to be ; The interlayer bonding is tested by a pull-out test, and the interlayer bonding strength is required .