Method for rapidly repairing damage of double-source cured wind power blade composite material

Abstract

The invention provides application of a modified resin composite repair material in damage repair of a wind power blade composite material. The modified resin composite repair material comprises a modified resin material and a UV isolating membrane layer compounded on the surface of the modified resin material, the modified resin material comprises resin, a photoinitiator and a microwave absorbent. The invention further provides a rapid repairing method for the wind power blade composite material combining ultraviolet light and microwave synergistic curing, repairing is carried out through the synergistic effect of a multifunctional resin system and a double-source time-sharing curing process, the limitation of traditional UV curing in a low-temperature environment and thick section repairing is solved, deep layer-surface layer synchronous rapid curing is achieved, and the service life of the wind power blade composite material is prolonged. And the uniformity and the mechanical property of the repaired interface are ensured. According to the method, the depth limitation (20 mm or above) of a single curing mode is broken through, the repairing efficiency is improved by 50% or above, the method adapts to the low-temperature construction environment of-20 DEG C, and an innovative solution is provided for on-site rapid repairing of large composite components.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine blade composite material technology, and relates to the application of modified resin composite repair materials in the repair of damage to wind turbine blade composite materials and a method for repairing damage to wind turbine blade composite materials, especially a rapid repair method for damage to wind turbine blade composite materials using dual-source curing. Background Technology

[0002] Wind turbine blades are one of the key components of wind turbines, accounting for more than 15% of the total cost. Under ideal environmental and reliable operating conditions, wind turbine blades have a design life of 20-25 years. However, in actual operating environments, blades are subjected to corrosion from various media in the air, including lightning, hail, rain, snow, dust storms, and alternating high and low temperatures, all of which constantly damage the blades. Improper operation during blade transportation, installation, and operation, or other human factors, pose significant challenges to the operational safety of wind turbines, and potential hazards can easily escalate into accidents. The main structure of the blades is made of fiberglass composite material, whose greatest advantage is its repairability. Early maintenance of blades can prevent high repair costs and reduce economic losses caused by downtime. Current repair methods involve workers applying general-purpose epoxy resin to the damaged area, followed by hand lay-up or vacuum infusion processes, and then applying a fiberglass and epoxy resin coating to repair the damaged area. This method requires heating and curing of the epoxy resin, with curing times ranging from 6 to 24 hours depending on the heating temperature; the repair efficiency is relatively low. In addition, the on-site environment of wind farms is relatively harsh, and the weather window for maintenance is very narrow. Extensive maintenance will cause wind turbines to be shut down for a long time, resulting in a significant loss of power generation.

[0003] Ultraviolet (UV) curing technology can effectively solve this problem. UV curing technology utilizes ultraviolet light to induce a photochemical reaction in photosensitive substances within a liquid resin system, generating initiating fragments that trigger polymerization and cross-linking of prepolymers and monomers within the system, rapidly transforming them into a solid state. Because UV curing technology can cure at room temperature or even low temperatures, requires no heating, has a fast curing speed, and low energy consumption, it achieves true energy conservation and emission reduction, aligning with the development direction of green environmental protection; therefore, it has been widely used in coatings, adhesives, and rapid manufacturing. UV curing technology has significant advantages in the repair of composite material structures damaged in wind turbine blades, especially suitable for rapid repair, localized reinforcement, and on-site operations. It can address the pain points of low efficiency in the aftermarket repair of wind turbine blades and the significant limitations imposed by on-site environmental conditions.

[0004] Industry reports and published patents on single-sided UV curing repair methods limit the thickness of cured composite materials. Due to the absorption of UV light by the resin matrix and reinforcing materials, even with highly reactive photoinitiators, the thickness of composite materials cured by single-sided UV irradiation is rarely more than 5 mm. For samples thicker than 10 mm, single-sided irradiation is insufficient for complete curing, requiring extended curing time and inconsistent curing uniformity. Repairing thicker composite structures necessitates layered curing, which suffers from weak interfacial properties and low efficiency.

[0005] Therefore, finding a more suitable way to solve the above-mentioned problems in the damage repair of wind turbine blade composite materials, especially for field operations, has become one of the urgent problems to be solved by many front-line researchers and R&D-oriented production enterprises in the industry. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide the application of modified resin composite repair materials in the repair of damage to wind turbine blade composite materials and a method for repairing damage to wind turbine blade composite materials, particularly a rapid repair method for damage to wind turbine blade composite materials using dual-source curing. The present invention proposes a rapid repair method for damage to wind turbine blade composite materials combining ultraviolet curing and microwave curing. This method utilizes a microwave-activated and UV-transparent resin system, combined with dual-source curing equipment, to achieve rapid resin melting and impregnation and simultaneous rapid deep-to-surface curing, solving the problems of limited thickness and difficult construction in low-temperature environments associated with traditional UV curing. Moreover, the repair process is simple, highly controllable, stable, efficient, and rapid, making it more suitable for the large-scale application of wind turbine blade repair.

[0007] This invention provides the application of modified resin composite repair materials in the repair of composite material damage in wind turbine blades;

[0008] The modified resin composite repair material includes a modified resin material and a UV isolation film layer composited on the surface of the modified resin material.

[0009] The modified resin material includes resin, photoinitiator, and microwave absorber.

[0010] Preferably, the resin includes one or more of epoxy resin, acrylic resin, vinyl resin, unsaturated polyester resin and polyurethane resin;

[0011] The photoinitiator includes one or more of the following: organic peroxide photoinitiators, azo compound photoinitiators, quinone photoinitiators, benzophenone photoinitiators, thioxanthone photoinitiators, nitroso compound photoinitiators, acryloyl halide photoinitiators, hydrazone photoinitiators, mercapto compound photoinitiators, pyran compound photoinitiators, triacryloyl imidazolium photoinitiators, diimidazole photoinitiators, chloroalkyl triazine photoinitiators, benzoin ether photoinitiators, benzoyl ketal photoinitiators, thioxanone photoinitiators, acetophenone photoinitiators, and acylphosphine oxide photoinitiators.

[0012] The microwave absorber includes one or more of the following: metal oxide nanoparticles, carbon nanotubes, graphene oxide, inorganic particles that absorb microwaves, and composite microwave absorbers.

[0013] The modified resin material also includes an active diluent and / or a dispersant.

[0014] Preferably, the resin has a mass content of 40% to 96% in the modified resin material;

[0015] The photoinitiator has a mass content of 0.5% to 5% in the modified resin material;

[0016] The microwave absorber has a mass content of 1% to 20% in the modified resin material.

[0017] Preferably, the material of the UV barrier film includes one or more of the following: metal film, organic high-barrier material film, and functional coating film containing UV-curable barrier coating.

[0018] The modified resin composite repair material has a layered structure, and the UV isolation film layer is coated on the surface of the modified resin material layer.

[0019] Preferably, the application also includes fiber-reinforced materials;

[0020] The application method involves layering modified resin composite repair material and fiber reinforced material onto the area to be repaired on the wind turbine blade, and then performing repair through microwave heating and UV curing.

[0021] The fiber-reinforced material includes transparent glass fiber and / or transparent carbon fiber fabric / felt;

[0022] In the area to be repaired, the total amount of modified resin composite repair material and fiber reinforcement material laid out contains 20wt% to 65wt% resin.

[0023] Preferably, the thickness of the modified resin material layer is 0.2~1mm;

[0024] The thickness of the fiber-reinforced material layer is 0.2~0.8 mm;

[0025] The laying method includes one or more of the following: alternating layers of modified resin material and fiber reinforcement material, or alternating layers of modified resin material and multiple layers of fiber reinforcement material.

[0026] The applications include one or more of the following: increasing the thickness of a single repair of damage to wind turbine blade composite materials, improving the uniformity of curing of the repair material structure, and improving the repair efficiency of the repair material.

[0027] The repair efficiency includes the repair efficiency of repair materials at low temperatures.

[0028] This invention also provides a method for repairing damage to composite materials in wind turbine blades, comprising the following steps:

[0029] 1) Pre-treat the areas of the wind turbine blade composite material to be repaired;

[0030] 2) Under shading conditions, the modified resin composite repair material and fiber reinforcement material are laid on the pretreated area, and the UV isolation film layer on the modified resin composite repair material is removed. Then, a vacuum bag is placed in the area and vacuum bag pressing is performed. Finally, the area is microwave heated and UV cured to obtain the repaired wind turbine blade composite material.

[0031] The modified resin composite repair material includes a modified resin material and a UV isolation film layer composited on the surface of the modified resin material.

[0032] The modified resin material includes resin, photoinitiator, and microwave absorber.

[0033] Preferably, the pretreatment steps include one or more steps, such as manually and / or using instruments to inspect the surface condition of the wind turbine blades, determining the area to be repaired and recording its shape and size data, grinding the area to be repaired, and removing surface impurities.

[0034] The surface of the pretreated area to be repaired has a groove structure;

[0035] The modified resin composite repair material includes modified resin composite repair material sheets and / or modified resin composite repair material strips;

[0036] The modified resin material also includes an active diluent and / or a dispersant;

[0037] The thickness of the modified resin material is 0.2~1mm.

[0038] Preferably, the laying method includes one or more of the following: alternating layers of modified resin material and fiber reinforcement material, or alternating layers of modified resin material and multiple layers of fiber reinforcement material.

[0039] The modified resin material of the layer includes a sheet of modified resin material or multiple strips of modified resin material placed at intervals.

[0040] The thickness of a single layer of the modified resin material is 0.2~1mm;

[0041] The thickness of a single layer of the fiber-reinforced material is 0.2~0.8 mm;

[0042] The vacuum degree of the vacuum bag is 30~40mbar;

[0043] During microwave heating, the microwave cavity of the microwave heating source is adsorbed onto the surface of the wind turbine blade.

[0044] Preferably, the microwave heating and UV curing are specifically performed by first microwave heating to melt the modified resin material and impregnate the fiber reinforcement material, and then UV curing is performed.

[0045] During UV curing, the microwave heating source is turned on or off.

[0046] The power of the microwave heating is 1~10kW;

[0047] The microwave heating time is 20-300 seconds;

[0048] The microwave heating temperature is 40~140℃;

[0049] The UV curing time is 30~1200 seconds;

[0050] The UV light source for UV curing includes one or more of mercury arc lamps, metal halide lamps, and UV LED lamps.

[0051] This invention provides the application of modified resin composite repair materials in the repair of composite material damage in wind turbine blades. The modified resin composite repair material includes a modified resin material and a UV-isolating film layer laminated on the surface of the modified resin material. The modified resin material includes resin, a photoinitiator, and a microwave absorber. Compared with existing technologies, this invention argues that although some existing technologies use UV-IR combined curing systems for wind turbine blade repair, applying resin to the composite fabric by laying up prepreg, injecting resin material into the fabric layer through vacuum-assisted resin transfer molding, or brushing resin onto the fabric layer surface until the resin material is absorbed, these methods still have limitations. For example, when using prepreg molding, air bubbles are easily generated during the prepreg layup process. These bubbles accumulate between or within the prepreg layers and are not easily expelled during vacuum bagging, ultimately affecting the repair quality. Furthermore, prepreg is expensive and can easily lead to significant material waste during the cutting process. Furthermore, when using hand lay-up or vacuum injection processes for repair, the resin viscosity is high and it is prone to crystallization in the low temperature environment of winter. This requires a long preheating time for both the resin and the fiberglass cloth before operation. Infrared heating is inefficient, which greatly affects the construction efficiency.

[0052] Based on this, the present invention specifically designs a modified resin composite repair material with a specific structure and composition for the repair of damage to composite materials in wind turbine blades. The present invention designs a microwave-activated and UV-transparent resin film layer (containing a photoinitiator and a microwave absorber), with a peelable UV isolation layer. Combined with a vacuum bag pressing + alternating layup process (modified resin sheets / strips and fiber layers are stacked layer by layer), and utilizing the microwave heating system in an integrated dual-source curing device, the resin is rapidly impregnated to reinforce the fiber layer, solving the problems of difficult and poor-quality prepreg molding, vacuum infusion, or hand lay-up operations at low temperatures.

[0053] This invention also provides a method for repairing damage to composite materials in wind turbine blades. This method combines ultraviolet (UV) light and microwave synergistic curing for rapid repair of wind turbine blade composite materials. Its core technology lies in the synergistic effect of a multifunctional resin system and a dual-source time-sharing curing process. The method uses a specialized resin film containing photoinitiators and microwave absorbers, combined with a peelable UV isolation layer design, to achieve alternating layers of resin and fiber reinforcement under vacuum bag pressure. During the repair process, the penetrating heating characteristics of microwaves are first used to melt the resin and fully impregnate the fiber layer, overcoming the limitations of traditional UV curing in low-temperature environments and thick-section repairs. Subsequently, a UV light source initiates a rapid photopolymerization reaction of the surface resin, achieving simultaneous rapid curing of the deep and surface layers. The system integrates a flexible microwave cavity and a modular UV light source, using real-time temperature feedback to regulate energy input and ensure the uniformity and mechanical properties of the repair interface. This technology breaks through the depth limitations of single curing methods (reaching over 20mm), increasing repair efficiency by more than 50%, while adapting to low-temperature construction environments of -20℃, providing an innovative solution for the rapid on-site repair of large composite material components.

[0054] The rapid repair method provided by this invention utilizes a microwave-activated and UV-transparent resin system, combined with a dual-source curing device, to achieve rapid resin melting and impregnation, as well as simultaneous rapid deep-to-surface curing. This solves the problems of limited thickness and difficult construction in low-temperature environments associated with traditional UV curing. Compared to UV-IR combinations (which rely on heat conduction), this invention directly achieves deep resin melting through microwave volumetric heating, overcoming the limitations of low efficiency and large temperature gradients in infrared heating. Furthermore, in terms of equipment and process integration, a suction cup-type flexible microwave cavity is designed to directly conform to the curved surface of the blade, forming a sealed space, which is unsuitable for complex curved surfaces compared to fixed radiation sources. The integrated vacuum bag pressing + alternating layup process (modified resin sheets / strips and fiber layers are stacked layer by layer) ensures uniform impregnation, a structured layup design not addressed in existing repair processes. A closed-loop temperature monitoring system can also be added to dynamically adjust microwave power and prevent overheating.

[0055] The rapid repair method for wind turbine blade composite material damage provided by the present invention has the following beneficial effects: (1) By using a microwave-activated and UV-transparent resin system, combined with a dual-source curing device, the rapid melting and impregnation of resin and the simultaneous curing of deep and surface layers are achieved, overcoming the thickness limitation of traditional UV curing technology. The synergistic effect can increase the curing thickness of composite materials to more than 20 mm (traditional UV curing is generally less than 5 mm), solving the weak interface problem caused by the need for layer curing and then layer stacking in conventional thick structure photocuring repair, and meeting the repair needs under different thicknesses. (2) The dual-source curing device is used to rapidly heat and cure the repair area. First, the modified resin sheet / modified resin strip layer is rapidly melted and impregnated with the fiber reinforcement layer by the microwave source, and then the thin and deep layers of the repair structure are simultaneously and rapidly cured by the ultraviolet light source, which significantly improves the uniformity and efficiency of the curing of the repair composite material structure. (3) By applying a microwave source to the surface of the fiber-reinforced material and the modified resin sheet / strip layer, the modified resin sheet / strip layer is rapidly melted and impregnated with the fiber-reinforced layer, solving the problem of resin crystallization or high viscosity in low-temperature (above -20℃) environments. This avoids the problem of low efficiency in traditional hand lay-up repair methods, greatly improving the work efficiency of wind turbine blade repair in winter, while reducing interlayer bubble residue and improving repair quality. (4) By adopting a pattern of alternating layers of modified resin sheet / strip with a fiber-reinforced layer or alternating layers of modified resin sheet / strip with multiple layers of fiber-reinforced layer, economical resin usage and good repair effect are achieved, reducing repair costs. Attached Figure Description

[0056] Figure 1 A simplified structural diagram of the modified resin composite repair material provided by this invention;

[0057] Figure 2 A schematic diagram of the blade structure repair area provided by the present invention, showing alternating layers of fiber and modified resin repair material sheets;

[0058] Figure 3 A schematic diagram of the blade structure repair area provided by the present invention, showing alternating layers of fiber and modified resin repair material strips;

[0059] Figure 4 This invention provides a schematic diagram of a blade structure repair area, comprising alternating layers of fiber and modified resin repair material sheets and strips. Detailed Implementation

[0060] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention and not for limiting the claims of the present invention.

[0061] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0062] There are no particular restrictions on the purity of any of the raw materials used in this invention. However, this invention preferably uses industrial-grade pure materials or materials with conventional purity used in the field of wind turbine blade repair and preparation.

[0063] This invention provides the application of modified resin composite repair materials in the repair of composite material damage in wind turbine blades;

[0064] The modified resin composite repair material includes a modified resin material and a UV isolation film layer composited on the surface of the modified resin material.

[0065] The modified resin material includes resin, photoinitiator, and microwave absorber.

[0066] In this invention, the resin preferably includes one or more of epoxy resin, acrylic resin, vinyl resin, unsaturated polyester resin, and polyurethane resin, and can be epoxy resin, acrylic resin, vinyl resin, unsaturated polyester resin, or polyurethane resin. Specifically, the multiple resins include two or more resins combined or modified with each other.

[0067] In this invention, the photoinitiator preferably includes organic peroxide photoinitiators, azo compound photoinitiators, quinone photoinitiators, benzophenone photoinitiators, thioxanthone photoinitiators, nitroso compound photoinitiators, acryloyl halide photoinitiators, hydrazone photoinitiators, mercapto compound photoinitiators, pyran compound photoinitiators, triacryloyl imidazole photoinitiators, diimidazole photoinitiators, chloroalkyl triazine photoinitiators, benzoin ether photoinitiators, benzoylazone ketal photoinitiators, thioxanone photoinitiators, acetophenone photoinitiators, and acylphosphine oxide photoinitiators. One or more of the following photoinitiators may be organic peroxide photoinitiators, azo compound photoinitiators, quinone photoinitiators, benzophenone photoinitiators, thioxanthone photoinitiators, nitroso compound photoinitiators, acryloyl halide photoinitiators, hydrazone photoinitiators, mercapto compound photoinitiators, pyran compound photoinitiators, triacryloyl imidazole photoinitiators, diimidazole photoinitiators, chloroalkyl triazine photoinitiators, benzoin ether photoinitiators, benzoylazone ketal photoinitiators, thioxanone photoinitiators, acetophenone photoinitiators, or acylphosphine oxide photoinitiators.

[0068] In this invention, the microwave absorber preferably comprises one or more of the following: metal oxide nanoparticles, carbon nanotubes, graphene oxide, inorganic particles that absorb microwaves, and composite microwave absorbers. It can be metal oxide nanoparticles, carbon nanotubes, graphene oxide, inorganic particles that absorb microwaves, or composite microwave absorbers. Among them, metal oxide nanoparticles include barium titanate, ferrite, zirconium titanate, ZnO, etc.

[0069] In this invention, the modified resin material preferably includes a photosensitizing agent, an active diluent, and / or a dispersant, which can be a photosensitizing agent, an active diluent, or a dispersant.

[0070] In this invention, the mass content of the resin in the modified resin material is preferably 40% to 96%, specifically 50%, 60%, 70%, 80% or 90%.

[0071] In this invention, the photoinitiator in the modified resin material is preferably 0.5% to 5% by mass, specifically 1%, 2%, 3% or 4%.

[0072] In this invention, the microwave absorber is preferably 1% to 20% by mass in the modified resin material, specifically 3%, 5%, 7%, 13%, 15% or 18%.

[0073] In this invention, the material of the UV barrier film preferably includes one or more of the following: a metal film, an organic high-barrier material film, and a functional coating film containing a UV-curable barrier coating. It can be a metal film, an organic high-barrier material film, or a functional coating film containing a UV-curable barrier coating.

[0074] In this invention, the modified resin composite repair material preferably has a layered structure, and the UV isolation film layer preferably covers the surface of the modified resin material layer.

[0075] In this invention, the application preferably includes fiber-reinforced materials. Specifically, the application of modified resin composite repair materials and fiber-reinforced materials in the repair of composite material damage in wind turbine blades.

[0076] In this invention, the preferred method of application includes layering modified resin composite repair material and fiber reinforced material on the area to be repaired of the wind turbine blade, and then performing repair by microwave heating and UV curing.

[0077] In this invention, the fiber-reinforcing material preferably includes translucent glass fiber and / or translucent carbon fiber fabric / felt, which can be translucent glass fiber or translucent carbon fiber fabric / felt.

[0078] In this invention, in the area to be repaired, the resin content in the total amount of modified resin composite repair material and fiber reinforcement material laid is preferably 20wt%~65wt%, can be 30wt%~55wt%, or can be 40wt%~45wt%.

[0079] In this invention, the thickness of the modified resin material is preferably 0.2~1mm, but can be 0.3~0.9mm or 0.5~0.7mm.

[0080] In this invention, the layer thickness of the fiber-reinforced material is preferably 0.2~0.8 mm, but can be 0.3~0.7 mm or 0.4~0.6 mm.

[0081] In this invention, the modified resin composite repair material preferably comprises modified resin composite repair material sheets and / or modified resin composite repair material strips. That is, the modified resin material preferably comprises modified resin material sheets and / or modified resin material strips.

[0082] In this invention, the laying method preferably includes one or more of the following: alternating layers of modified resin material and fiber reinforcement material, or alternating layers of modified resin material and multiple layers of fiber reinforcement material. It can also be a combination of alternating single layers of modified resin material and single layers of fiber reinforcement material, or alternating single layers of modified resin material and multiple layers of fiber reinforcement material. Specifically, during the laying process, under light-shielding conditions, the UV-blocking film layer on the surface of the modified resin composite repair material is removed to obtain the modified resin material. If described in terms of the structure before removing the UV-blocking film layer, it is one or more of alternating layers of modified resin composite repair material and fiber reinforcement material, or alternating layers of modified resin composite repair material and multiple layers of fiber reinforcement material.

[0083] In this invention, the preferred application includes one or more of the following: increasing the thickness of a single repair of damage to wind turbine blade composite materials, improving the uniformity of curing of the repair material structure, and improving the repair efficiency of the repair material.

[0084] In this invention, the repair efficiency preferably includes the repair efficiency of the repair material at low temperatures.

[0085] This invention provides a method for repairing damage to composite materials in wind turbine blades, comprising the following steps:

[0086] 1) Pre-treat the areas of the wind turbine blade composite material to be repaired;

[0087] 2) Under shading conditions, the modified resin composite repair material and fiber reinforcement material are laid on the pretreated area, and the UV isolation film layer on the modified resin composite repair material is removed. Then, a vacuum bag is placed in the area and vacuum bag pressing is performed. Finally, the area is microwave heated and UV cured to obtain the repaired wind turbine blade composite material.

[0088] The modified resin composite repair material includes a modified resin material and a UV isolation film layer composited on the surface of the modified resin material.

[0089] The modified resin material includes resin, photoinitiator, and microwave absorber.

[0090] The present invention first pre-treats the area of ​​the composite material of the wind turbine blade to be repaired.

[0091] In this invention, the thickness of the area to be repaired is preferably less than or equal to 50 mm, and can be 0.2~40 mm, 1~35 mm, 5~30 mm, or 10~25 mm.

[0092] In this invention, the pretreatment step preferably includes one or more steps, namely, manually and / or using instruments to inspect the surface condition of the wind turbine blade, determine the area to be repaired and record its shape and size data, polish the area to be repaired, and remove surface impurities. These steps can be multiple steps, including manually and / or using instruments to inspect the surface condition of the wind turbine blade, determine the area to be repaired and record its shape and size data, polish the area to be repaired, and remove surface impurities.

[0093] In this invention, the surface of the pretreated area to be repaired preferably has a groove structure.

[0094] In this invention, under shading conditions, a modified resin composite repair material and a fiber reinforcement material are laid on the pretreated area, and the UV isolation film layer on the modified resin composite repair material is removed. Then, a vacuum bag is placed in the area and vacuum bag pressing is performed. Finally, the area is microwave heated and UV cured to obtain the repaired wind turbine blade composite material.

[0095] The modified resin composite repair material includes a modified resin material and a UV isolation film layer composited on the surface of the modified resin material.

[0096] The modified resin material includes resin, photoinitiator, and microwave absorber.

[0097] In this invention, the modified resin composite repair material preferably includes modified resin composite repair material sheets and / or modified resin composite repair material strips, which can be modified resin composite repair material sheets or modified resin composite repair material strips.

[0098] In this invention, the modified resin composite repair material preferably has a layered structure, and the UV isolation film layer preferably covers the surface of the modified resin material layer.

[0099] In this invention, the thickness of the modified resin material is preferably 0.2~1mm, can be 0.3~0.9mm, or can be 0.5~0.7mm. The thickness of the UV isolation film layer is relatively thin and can be ignored. The thickness of the modified resin composite repair material is preferably as described above.

[0100] In this invention, the modified resin material preferably also includes an active diluent and / or a dispersant, which can be an active diluent or a dispersant.

[0101] In this invention, the laying method preferably includes one or more of the following: alternating laying of one layer of modified resin material and one layer of fiber reinforcement material, alternating laying of one layer of modified resin material and multiple layers of fiber reinforcement material.

[0102] In this invention, the modified resin composite repair material preferably comprises modified resin composite repair material sheets and / or modified resin composite repair material strips. That is, the modified resin material preferably comprises modified resin material sheets and / or modified resin material strips.

[0103] In this invention, the modified resin material of the layer preferably includes a sheet of modified resin material or a plurality of modified resin material strips placed at intervals.

[0104] In this invention, the thickness of a single layer of the modified resin material is preferably 0.2~1mm, but can be 0.3~0.9mm or 0.5~0.7mm.

[0105] In this invention, the thickness of the single layer of fiber-reinforced material is preferably 0.2~0.8mm, but can be 0.3~0.7mm or 0.4~0.6mm.

[0106] In this invention, the vacuum degree of the vacuum bag is preferably 30~40mbar, can be 32~38mbar, or can be 34~36mbar.

[0107] In this invention, when performing microwave heating, the microwave cavity of the microwave heating source is preferably adsorbed onto the surface of the wind turbine blade.

[0108] In this invention, the microwave heating and UV curing are preferably performed by first microwave heating to melt the modified resin material and impregnate the fiber reinforcement material, and then UV curing is performed.

[0109] In this invention, when performing UV curing, the microwave heating source is preferably turned on or off.

[0110] In this invention, the power of the microwave heating is preferably 1~10kW, can be 3~8kW, or can be 5~6kW.

[0111] In this invention, the microwave heating time is preferably 20-300 seconds, can be 70-250 seconds, or can be 120-200 seconds.

[0112] In this invention, the microwave heating temperature is preferably 40~140℃, can be 60~120℃, or can be 80~100℃.

[0113] In this invention, the UV curing time is preferably 30-1200 seconds, but can be 200-1000 seconds or 400-800 seconds.

[0114] In this invention, the UV light source for UV curing preferably includes one or more of a mercury arc lamp, a metal halide lamp, and a UV LED lamp, and can be a mercury arc lamp, a metal halide lamp, or a UV LED lamp.

[0115] This invention aims to complete and refine the overall technical solution, better ensure the structure and composition of the modified resin composite repair material, and further improve the repair thickness, curing uniformity, and modification efficiency of wind turbine blade composite material damage repair. The application of the aforementioned modified resin composite repair material in wind turbine blade composite material damage repair, as well as a dual-source curing method for rapid repair of wind turbine blade composite material damage, specifically includes the following:

[0116] The present invention proposes a rapid repair method for wind turbine blade composite material damage combining ultraviolet curing and microwave curing, specifically including:

[0117] (1) First, the area to be repaired and reinforced is polished to form a rough interface.

[0118] (2) Lay the fiber-reinforced material and modified composite resin sheets / strips under light-shielding conditions, vacuum pack and vacuum bag press. The modified composite resin sheets / strips contain a modified resin film layer and a UV isolation layer. The modified resin film layer contains a photoinitiator and a microwave absorber. The UV isolation layer serves to block ultraviolet light. The UV isolation layer on the surface of the modified resin film layer (modified resin sheet / strip) is removed during the layup process.

[0119] Specifically, the thickness can be achieved by alternating layers of modified resin sheets / strips with fiber reinforcement layers, or by alternating layers of modified resin sheets / strips with multiple layers of fiber reinforcement layers. The thickness of the modified resin sheets / strips can be selected based on the amount of fiber reinforcement layer used in the repair and reinforcement area and the final required resin content. The fiber reinforcement layer can be glass fiber, carbon fiber, or a mixture of glass fiber and carbon fiber, preferably a transparent or translucent fiber material.

[0120] (3) A dual-source curing device is used to rapidly heat and cure the repaired area. The device consists of a microwave heating system, a UV light source system, and a temperature monitoring and feedback system. The microwave heating system includes a microwave generator and a microwave cavity. The microwave cavity can be attached to the blade surface by a suction cup to form a relatively sealed space with the area to be repaired. The microwave generator produces microwave energy of a specific frequency, which is radiated directionally to the damaged area of ​​the blade.

[0121] Specifically, the microwave generator can be a multi-antenna array or a flexible radiator, adaptable to the curved shape of the blade. The microwave cavity can be a flexible microwave cavity with suction cup adsorption. A temperature monitoring and feedback system monitors the material surface temperature in real time to prevent overheating. The UV light source system can be single or arrayed. The microwave source and UV light source can be controlled to turn on and off independently.

[0122] During heat curing, the microwave cavity of the dual-source curing equipment is first adsorbed onto the surface of the blade in the area to be repaired. The microwave heating system is then activated, causing the modified resin sheet / strip layer to melt rapidly and impregnate the fiber reinforcement layer. After the modified resin sheet / strip layer has completely impregnated the fiber reinforcement material, the ultraviolet curing system is turned on to achieve simultaneous and rapid curing of the thin and deep layers of the repair structure.

[0123] This invention utilizes a microwave-activated and UV-transparent resin system, combined with a dual-source curing device, to achieve rapid resin melting and impregnation and simultaneous rapid deep-to-surface curing, solving problems such as limited thickness and difficulties in low-temperature construction associated with traditional UV curing.

[0124] Furthermore, the specific steps of the above-mentioned rapid repair method for damage to wind turbine blade composite materials combining ultraviolet curing and microwave curing can be as follows:

[0125] Step 1: Perform surface treatment on the area to be repaired:

[0126] Specifically, the surface condition of the wind turbine blades is inspected manually or by scanning the surface of the wind turbine blades with a laser scanner to identify the repair area and record the shape and size data of the repair area.

[0127] Specifically, the repair area is ground using an angle grinder or a CNC grinder to create a micro-groove structure on the surface.

[0128] Specifically, compressed air with a pressure of 0.4~0.6MPa is used to blow the repair area or negative pressure dust collection is used to remove surface impurities.

[0129] Step 2: Laying fiber-reinforced material and modified composite resin sheets / strips:

[0130] Alternately lay modified composite resin sheets / strips and fiber reinforcement layers on the surface of the area to be repaired, wrap it in a vacuum bag, and apply vacuum pressure to the bag at a vacuum level of 30~40mbar.

[0131] The modified composite resin sheet / strip consists of two layers: a modified resin layer and a UV isolation film layer. The UV isolation film layer protects the resin layer from UV radiation. After the layers are laid up and fixed, the UV isolation film can be easily peeled off from the surface of the resin layer.

[0132] Specifically, the thickness of the modified resin layer in the modified composite resin sheet / modified composite resin strip is 0.2~1mm.

[0133] Specifically, the resin system can be epoxy resin, acrylic resin, vinyl resin, unsaturated polyester resin, polyurethane resin, etc.

[0134] Specifically, the modified resin contains a photoinitiator, which includes organic peroxides, azo compounds, quinones, benzophenones, nitroso compounds, acryloyl halides, hydrazones, mercapto compounds, pyran compounds, triacryloyl imidazoles, diimidazoles, chloroalkyl triazines, benzoin ethers, benzoylacetyl ketals, thioxanones, acetophenones, acylphosphine oxides, or combinations thereof. Preferably, a cationic photoinitiator that does not produce gaseous components upon decomposition is preferred.

[0135] Specifically, the modified resin also contains a microwave absorber, which can be metal oxide nanoparticles such as barium titanate, ferrite, zirconium titanate, ZnO, carbon nanotubes, graphene oxide, inorganic particles or composite absorbers that absorb microwaves, preferably white or light-colored absorbers.

[0136] Specifically, the material of the UV barrier layer coating needs to meet the requirements of high UV blocking rate, easy peeling, temperature resistance and flexibility. Commonly used materials include: metal films such as aluminum foil composite film and vacuum metallized film; organic high barrier materials such as EVOH co-extruded film, PVDF coated film and carbon black PE film; and functional coating films containing UV-curable barrier coatings.

[0137] Specifically, the typical preparation steps and parameters of modified composite resin sheets / modified composite resin strips include: (1) Premixing: The resin and active diluent are stirred and mixed (300 rpm / 30 min), and then the photoinitiator is added and stirred and dissolved in the dark; (2) Grinding and dispersing: Microwave absorber / dispersant is added, and the mixture is circulated using a three-roll mill (roller gap 50 μm, 3-5 times) to confirm that the fineness is ≤15 μm (detected by a scraper fineness gauge); (3) Degassing: Vacuum degassing machine is used (-0.1 MPa, 20 min) until no visible bubbles are found; (4) Coating and film formation: The film is coated using a comma doctor blade coater (gap 0.2-1 mm); (5) Drying: Segmented oven drying. For example, 60℃ (5 min) → 80℃ (10 min) → 100℃ (5 min); (6) Coating with UV blocking film layer: Composite UV blocking film (transmittance <5%@365nm), tension controlled at 10-15 N / cm.

[0138] See Figure 1 , Figure 1 This is a simplified structural diagram of the modified resin composite repair material provided by the present invention. Wherein, 10 is a modified resin film layer; 11 is a UV isolation film layer.

[0139] Specifically, the fiber reinforcement layer can be glass fiber, carbon fiber fabric / felt, or a mixture of glass fiber and carbon fiber fabric / felt, preferably a transparent or translucent fiber reinforcement material. The thickness of a single layer of fiber reinforcement material is 0.2~0.8 mm.

[0140] Specifically, in terms of thickness, a modified resin sheet / strip can be alternately laid with a layer of fiber reinforcement, or a modified resin sheet / strip can be alternately laid with multiple layers of fiber reinforcement. The thickness of the modified resin sheet / strip can be selected according to the amount of fiber reinforcement used in the repair and reinforcement area and the final required resin content.

[0141] Specifically, the resin film thickness is 0.2~1mm, and the resin content of the final repaired composite material area is 20wt%~65wt%. The thickness of the repaired area can reach more than 20mm.

[0142] See Figure 2 , Figure 2 This is a schematic diagram of the blade structure repair section provided by the present invention, showing alternating layers of fiber and modified resin repair material sheets. Wherein, 1 is the blade; 2 is the modified resin sheet; 3 is the modified resin strip; and 4 is the reinforcing fiber layer.

[0143] See Figure 3 , Figure 3This is a schematic diagram of the blade structure repair section provided by the present invention, showing alternating layers of fiber and modified resin repair material strips. Wherein, 1 is the blade; 2 is the modified resin sheet; 3 is the modified resin strip; and 4 is the reinforcing fiber layer.

[0144] See Figure 4 , Figure 4 This invention provides a schematic diagram of a blade structure repair area, comprising alternating layers of fiber and modified resin repair material sheets and strips. Wherein, 1 is the blade; 2 is the modified resin sheet; 3 is the modified resin strip; and 4 is the reinforcing fiber layer.

[0145] Step 3: Perform dual-source curing treatment:

[0146] The dual-source curing equipment includes a microwave heating system, a UV light source system, and a temperature monitoring and feedback system. The microwave heating system includes a microwave generator and a microwave cavity. The microwave generator produces microwave energy at a specific frequency, such as 2.45 GHz or 915 MHz, with adjustable power, typically 1~10kW. The microwave cavity can be adsorbed onto the surface of the blade via suction cups to form a relatively sealed space with the area to be repaired.

[0147] The microwave generator directs microwave energy to the damaged area of ​​the blade. Specifically, the microwave generator can be a multi-antenna array or a flexible radiator, adaptable to the curved shape of the blade. A temperature monitoring and feedback system monitors the material surface temperature in real time to prevent overheating. The UV light source system can be a single unit or an array. The microwave source and UV light source can be controlled to turn on and off independently.

[0148] During heat curing, the microwave cavity of the dual-source curing device is attached to the blade surface of the area to be repaired. The microwave source is activated, and the modified resin sheet / strip and fiber reinforcement material are heated to 40-140°C within 20-300 seconds. The modified resin sheet / strip layer melts rapidly and impregnates the fiber reinforcement material. After the resin has completely melted and impregnated the fiber reinforcement material, the UV light source is activated to perform photocuring on the repaired structure for 30-1200 seconds, achieving simultaneous and rapid curing of the deep and surface layers.

[0149] Specifically, the microwave source can be kept operational after the UV light source is activated, and can be turned off when the resin system contains a photothermal promoting photoinitiator. The power and on-time of the microwave and UV light sources can be controlled according to the repair structure and resin system.

[0150] Based on the material system, photoinitiator type and concentration, and composite material repair structure, adjust the core UV curing process parameters.

[0151] Specifically, the UV light source can be a mercury arc lamp, a metal halide lamp, or a UV LED lamp. The spectral distribution of the light source must effectively match the absorption peak of the photoinitiator (PI) in the formulation (e.g., using a 365nm, 385nm, 395nm, or 405nm LED light source corresponding to a specific PI). Irradiance (mW / cm²) directly affects the surface curing speed and efficiency, while the cumulative energy density (mJ / cm² = irradiance × exposure time) determines the curing depth and completeness. A minimum critical energy needs to be set based on the PI reaction threshold and the thickness of the composite material structure. Irradiation distance significantly affects the irradiance distribution (approximately following the inverse square law) and the uniformity of the light spot.

[0152] This invention provides the application of modified resin composite repair materials in the repair of damage to wind turbine blade composite materials, as well as a rapid repair method for wind turbine blade composite material damage using dual-source curing. The invention features a specially designed modified resin composite repair material with a specific structure and composition for repairing damage to wind turbine blade composite materials. This invention designs a microwave-activated and UV-transparent resin film layer (containing a photoinitiator and a microwave absorber), with a peelable UV isolation layer. Combined with a vacuum bag pressing + alternating layup process (modified resin sheets / strips and fiber layers are stacked layer by layer), and utilizing the microwave heating system in an integrated dual-source curing device, it achieves rapid resin impregnation to reinforce the fiber layer, solving the problems of difficult and poor-quality prepreg molding, vacuum infusion, or hand lay-up operations at low temperatures.

[0153] This invention also provides a method for repairing damage to composite materials in wind turbine blades. The core technology lies in the synergistic effect of a multifunctional resin system and a dual-source time-sharing curing process. This method employs a specialized resin film containing photoinitiators and microwave absorbers, combined with a peelable UV isolation layer design, to achieve alternating layers of resin and fiber reinforcement under vacuum bag pressure. During the repair process, the penetrating heating characteristics of microwaves are first used to melt the resin and fully impregnate the fiber layer, overcoming the limitations of traditional UV curing in low-temperature environments and thick-section repairs. Subsequently, a UV light source initiates a rapid photopolymerization reaction of the surface resin, achieving simultaneous and rapid curing of the deep and surface layers. The system integrates a flexible microwave cavity and a modular UV light source, using real-time temperature feedback to regulate energy input and ensure the uniformity and mechanical properties of the repair interface. This technology overcomes the depth limitations of single curing methods (reaching over 20mm), increasing repair efficiency by more than 50%, while adapting to low-temperature construction environments of -20℃, providing an innovative solution for the rapid on-site repair of large composite material components.

[0154] The rapid repair method provided by this invention utilizes a microwave-activated and UV-transparent resin system, combined with a dual-source curing device, to achieve rapid resin melting and impregnation, as well as simultaneous rapid deep-to-surface curing. This solves the problems of limited thickness and difficult construction in low-temperature environments associated with traditional UV curing. Compared to UV-IR combinations (which rely on heat conduction), this invention directly achieves deep resin melting through microwave volumetric heating, overcoming the limitations of low efficiency and large temperature gradients in infrared heating. Furthermore, in terms of equipment and process integration, a suction cup-type flexible microwave cavity is designed to directly conform to the curved surface of the blade, forming a sealed space, which is unsuitable for complex curved surfaces compared to fixed radiation sources. The integrated vacuum bag pressing + alternating layup process (modified resin sheets / strips and fiber layers are stacked layer by layer) ensures uniform impregnation, a structured layup design not addressed in existing repair processes. A closed-loop temperature monitoring system can also be added to dynamically adjust microwave power and prevent overheating.

[0155] The rapid repair method for wind turbine blade composite material damage provided by the present invention has the following beneficial effects: (1) By using a microwave-activated and UV-transparent resin system, combined with a dual-source curing device, the rapid melting and impregnation of resin and the simultaneous curing of deep and surface layers are achieved, overcoming the thickness limitation of traditional UV curing technology. The synergistic effect can increase the curing thickness of composite materials to more than 20 mm (traditional UV curing is generally less than 5 mm), solving the weak interface problem caused by the need for layer curing and then layer stacking in conventional thick structure photocuring repair, and meeting the repair needs under different thicknesses. (2) The dual-source curing device is used to rapidly heat and cure the repair area. First, the modified resin sheet / modified resin strip layer is rapidly melted and impregnated with the fiber reinforcement layer by the microwave source, and then the thin and deep layers of the repair structure are simultaneously and rapidly cured by the ultraviolet light source, which significantly improves the uniformity and efficiency of the curing of the repair composite material structure. (3) By applying a microwave source to the surface of the fiber-reinforced material and the modified resin sheet / strip layer, the modified resin sheet / strip layer is rapidly melted and impregnated with the fiber-reinforced layer, solving the problem of resin crystallization or high viscosity in low-temperature (above -20℃) environments. This avoids the problem of low efficiency in traditional hand lay-up repair methods, greatly improving the work efficiency of wind turbine blade repair in winter, while reducing interlayer bubble residue and improving repair quality. (4) By adopting a pattern of alternating layers of modified resin sheet / strip with a fiber-reinforced layer or alternating layers of modified resin sheet / strip with multiple layers of fiber-reinforced layer, economical resin usage and good repair effect are achieved, reducing repair costs.

[0156] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, describes the application of the modified resin composite repair material provided by the present invention in the repair of damage to composite materials of wind turbine blades and a method for repairing damage to composite materials of wind turbine blades. However, it should be understood that these embodiments are implemented under the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operating procedures. They are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention. The scope of protection of the present invention is not limited to the following embodiments.

[0157] Example 1

[0158] Repair of conventional shallow cracks in wind turbine blades at ambient temperature

[0159] This embodiment addresses the repair of common shallow cracks (approximately 3 mm deep) on wind turbine blades at room temperature (25°C).

[0160] The repair steps are as follows:

[0161] Step 1: Pre-process the area of ​​the wind turbine blade to be repaired.

[0162] The cracked area is visually inspected, and the cracked surface is ground using a CNC grinding machine to create a rough interface. Impurities are removed using negative pressure vacuuming to ensure surface cleanliness.

[0163] Step 2: Lay the modified resin composite repair material and fiber reinforcement material.

[0164] Prepare modified resin composite repair material and fiber reinforcement material. The modified resin composite repair material uses acrylic-modified epoxy resin sheets with a thickness of 0.4 mm. The resin material contains 4-phenylbenzophenone photoinitiator and barium titanate nanoparticle microwave absorber, with the photoinitiator and microwave absorber having a mass content of 1% and 5%, respectively. A UV-blocking film layer is laminated to the surface of the resin sheet, which is made of aluminum foil composite film with a UV transmittance of <5%. The fiber reinforcement material is made of translucent glass fiber fabric with a single layer thickness of 0.5 mm.

[0165] Nine layers were applied, alternating between one layer of resin sheet and two layers of fiber reinforcement. The specific sequence was as follows: first, two layers of fiber fabric were laid on the blade surface; then, the UV-blocking film layer on the resin sheet was removed; one layer of resin sheet was laid; then two layers of fiber fabric were laid, and this process was repeated. The removal of the UV-blocking film and the application of the resin sheet were both carried out under conditions of shade from sunlight.

[0166] After application, wrap the repair area with a vacuum bag and evacuate to 35 mbar, maintaining this position for 10 minutes to remove air bubbles. The final resin content of the repaired area is 40 wt% (calculated based on the total mass of the material).

[0167] Step 3: Curing is performed using an integrated dual-source curing device (including a microwave heating system, a UV light source system, and a temperature monitoring system).

[0168] The flexible microwave cavity (suction cup type) of the microwave heating equipment is attached to the curved surface of the blade to form a sealed space. The microwave generator power is set to 2kW and the frequency to 2.45GHz. Microwave heating is started, and the material temperature rises to 60℃ in 1 minute. The microwave absorber causes the resin to melt rapidly, impregnating the fiber layer.

[0169] After microwave heating, turn off the microwave source and simultaneously turn on the UV LED light source (wavelength 395nm, irradiance 4000mJ / cm²). 2 The UV curing time is 3 minutes, and the photoinitiator triggers resin polymerization, achieving simultaneous curing of the surface and deep layers. The entire curing process takes a total of 4 minutes.

[0170] In this embodiment, the total curing time is 4 minutes, which is about 90% more efficient than traditional epoxy repair (requiring 6-24 hours). The repaired area is about 4 mm thick, and the Shore hardness of the repaired composite material surface is 84, with a Tg of 79.3°C. There are no bubbles at the interface after repair. The repaired composite material test specimen prepared using the same repair process has an interfacial tensile shear strength of 29.3 MPa. The tensile, compressive, and shear properties of the repaired composite material are comparable to the mechanical properties of conventional hand lay-up epoxy resin composite materials.

[0171] Example 2

[0172] Repair of deep-seated defects in wind turbine blades under ambient temperature conditions

[0173] This embodiment addresses the repair of deep-seated defects in the thick cross-section of wind turbine blades with a thickness of up to 20mm, performed at room temperature (25℃). The repair steps are as follows:

[0174] Step 1: Pre-process the area of ​​the wind turbine blade to be repaired.

[0175] Defective areas are inspected manually, and the surface is then ground using a CNC grinding machine to create a roughened interface. Compressed air is used to remove impurities, ensuring a clean surface.

[0176] Step 2: Lay the modified resin composite repair material and fiber reinforcement material.

[0177] Prepare modified resin composite repair materials and fiber reinforcement materials. The modified resin composite repair material uses aliphatic polyurethane acrylate resin strips and sheets, with a thickness of 0.3 mm. The resin material contains a photoinitiator system composed of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-isopropylthioxanthone, and ethyl 4-dimethylaminobenzoate, and a ferrite nanoparticle microwave absorber, with mass contents of 3%, 0.5%, 0.5%, and 15%, respectively. The UV isolation film is an aluminum foil composite film. The fiber reinforcement material is a translucent glass fiber fabric with a single-layer thickness of 0.8 mm.

[0178] A hybrid layup method was used, alternating between layers of resin sheets or strips and layers of fiber fabric, for a total of 50 layers. The specific sequence was as follows: first, a layer of fiber fabric was laid on the blade surface; then, the UV-protective film layer on the resin strip was removed; resin strips were then laid, spaced apart to fill the deepest, irregular pores of the defect; then fiber fabric was laid, and this process was repeated 5 times. Then, another layer of fiber fabric was laid on top, the UV-protective film layer on the resin sheet was removed, the resin sheet was laid, and then fiber fabric was laid, and this process was repeated 20 times. This layup method ensured uniform resin impregnation, reduced air bubbles, and provided good adhesion to the thickest parts of irregular defects. The removal of the UV-protective film and the laying of the resin sheet were both performed under conditions of shade from sunlight. The final resin content in the repaired area was 45 wt% (based on the total mass of the material).

[0179] Step 3: Curing is performed using an integrated dual-source curing device (including a microwave heating system, a UV light source system, and a temperature monitoring system).

[0180] The flexible microwave cavity (suction cup type) of the microwave heating equipment is attached to the curved surface of the blade to form a sealed space. The microwave generator power is set to 5kW and the frequency to 2.45GHz. Microwave heating is started, and the material temperature rises to 85℃ in 4 minutes. The microwave absorber causes the resin to melt rapidly and impregnate the fiber layer. After microwave heating, the microwave source is kept on (for auxiliary heat preservation to promote deep curing), and the mercury arc lamp source (irradiance 2500mJ / cm²) is turned on simultaneously for 20 minutes of curing. The photoinitiator triggers resin polymerization, achieving simultaneous surface and deep curing. The entire curing process takes 24 minutes.

[0181] In this embodiment, the thickest part of the final repair area reaches approximately 26 mm, far exceeding the 5 mm depth of traditional UV curing. After curing, the entire thickness range is completely cured without any sticky layer.

[0182] Repair composite test specimens prepared using the same repair process were tested for curing degree at different repair thicknesses using DSC. The Tg of the surface layer (0-5mm) was 88℃, the Tg of the middle layer (10-16mm) was 82℃, and the Tg of the bottom layer (20-26mm) was 83℃, exhibiting excellent uniformity. The Shore hardness of the repaired area was 82-88, comparable to that of the original blade substrate. The interfacial tensile shear strength of the repair composite was 28.6MPa. The tensile, compressive, and shear mechanical properties of the repair composite test specimens were comparable to those of conventional hand lay-up epoxy resin composites. In this embodiment, the total curing time was only 24 minutes, representing an efficiency improvement of over 90% compared to the traditional epoxy resin repair process (which requires heating to 70°C and holding for more than 6 hours).

[0183] Example 3

[0184] Repairing common defects in wind turbine blades at -20℃

[0185] This embodiment addresses the repair of defects in a 5mm thick wind turbine blade at -20℃. The repair steps are as follows:

[0186] Step 1: Pre-process the area of ​​the wind turbine blade to be repaired.

[0187] The defective areas are inspected manually by visual inspection. The defective surfaces are then ground with a CNC grinding machine to create a rough interface. Impurities are removed using negative pressure dust extraction to ensure surface cleanliness.

[0188] Step 2: Preheat the modified resin composite repair material and fiber reinforcement material and lay them out.

[0189] Prepare modified resin composite repair materials and fiber reinforcement materials. The modified resin composite repair material uses epoxy acrylate resin sheets with a thickness of 0.8 mm. The resin material contains phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide photoinitiator and graphene oxide, with the photoinitiator and microwave absorber having a mass content of 1.5% and 10%, respectively. The UV isolation film is a PVDF coated film. The fiber reinforcement material is made of translucent carbon fiber fabric with a single layer thickness of 0.5 mm.

[0190] The modified resin composite repair material and fiber reinforcement material are preheated using the microwave heating system in the integrated dual-source curing equipment. The cut modified resin composite repair material and fiber reinforcement material are placed on the area of ​​the blade to be repaired. The flexible microwave cavity (suction cup type) of the microwave heating equipment is then fitted to the curved surface of the blade to form a sealed space. The microwave generator power is set to 2kW and the frequency to 2.45GHz. Microwave heating is started for 1 minute to preheat the material to a temperature of 20~30℃. The integrated dual-source curing equipment is then removed, and the repair area is then laid up.

[0191] A total of 12 layers were laid, alternating between one layer of resin sheet and two layers of fiber reinforcement material. The specific sequence was as follows: first, two layers of fiber fabric were laid on the blade surface, then the UV shielding film layer on the resin sheet was removed, the resin sheet was laid, and then the fiber fabric was laid, and so on. The processes of removing the UV shielding film and laying the resin sheet were all carried out under conditions of shade from sunlight.

[0192] After application, wrap the repair area with a vacuum bag, evacuate to 35 mbar, and maintain for 10 minutes to remove air bubbles. The final resin content of the repaired area is approximately 51 wt% (based on the total mass of the material).

[0193] Step 3: Curing is performed using an integrated dual-source curing device (including a microwave heating system, a UV light source system, and a temperature monitoring system).

[0194] The flexible microwave cavity (suction cup type) of the microwave heating equipment is attached to the curved surface of the blade to form a sealed space. The microwave generator power is set to 2kW and the frequency to 2.45GHz. Microwave heating is started, and the time is 2 minutes, raising the material temperature to 40℃. The microwave absorber causes the resin to melt rapidly, impregnating the fiber layer. Real-time temperature monitoring prevents overheating. After microwave heating, the microwave source is kept on (to promote deep curing), and the UV LED light source (wavelength 395nm, irradiance 3000mJ / cm²) is activated simultaneously. The UV curing time is 5 minutes, and the photoinitiator triggers resin polymerization, achieving simultaneous surface and deep curing. The entire curing process takes a total of 7 minutes.

[0195] Under the same low-temperature environment, traditional hand lay-up epoxy resin repair methods require prolonged preheating of the material and substrate for 1-2 hours, with a curing time of 6-24 hours. This invention can preheat the repair material within minutes, and the overall curing time is less than 25 minutes, far shorter than the 6-24 hours of traditional methods. In this embodiment, the thickest part of the final repaired area reaches approximately 6.9 mm, the repaired surface is dry, and the Shore hardness reaches 85, with a Tg of 83°C.

[0196] The repaired composite test specimen prepared using the same repair process had an interfacial tensile shear strength of 25.9 MPa. The tensile, compressive, and shear properties of the repaired composite material were comparable to those of conventional hand lay-up epoxy resin composite materials.

[0197] The above provides a detailed description of the application of the modified resin composite repair material provided by this invention in the repair of damage to wind turbine blade composite materials, as well as a rapid repair method for damage to wind turbine blade composite materials using dual-source curing. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of this invention, including the best mode, and also to enable any person skilled in the art to practice this invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, several improvements and modifications can be made to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the textual description of the claims, or if they include equivalent structural elements that are not substantially different from the textual description of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. Application of modified resin composite repair material in repairing damage of wind turbine blade composite material; The modified resin composite repair material comprises a modified resin material and a UV isolation film layer on the surface of the modified resin material; The modified resin material comprises resin, photoinitiator and microwave absorber.

2. Use according to claim 1, characterized in that, The resin comprises one or more of epoxy resin, acrylic resin, vinyl resin, unsaturated polyester resin and polyurethane resin; The photoinitiator comprises one or more of organic peroxide photoinitiator, azo compound photoinitiator, quinone photoinitiator, benzophenone photoinitiator, thioxanthone photoinitiator, nitroso compound photoinitiator, acryloyl halide photoinitiator, hydrazone photoinitiator, mercapto compound photoinitiator, pyran compound photoinitiator, triacryloyl imidazole photoinitiator, bisimidazole photoinitiator, chloroalkyl triazine photoinitiator, benzoin ether photoinitiator, benzil ketone photoinitiator, thioxanthone photoinitiator, acetophenone photoinitiator and acyl phosphine oxide photoinitiator; The microwave absorber comprises one or more of metal oxide nanoparticles, carbon nanotubes, graphene oxide, microwave-absorbing inorganic particles and composite microwave absorber; The modified resin material further comprises active diluent and / or dispersant.

3. Use according to claim 1, characterized in that, The mass content of the resin in the modified resin material is 40% to 96%; The mass content of the photoinitiator in the modified resin material is 0.5% to 5%; The mass content of the microwave absorber in the modified resin material is 1% to 20%.

4. Use according to claim 1, characterized in that, The material of the UV isolation film comprises one or more of metal film, organic high-barrier material film and functional coating film containing UV-cured barrier coating; The modified resin composite repair material has a layer structure, and the UV isolation film layer is coated on the surface of the modified resin material layer.

5. The use according to claim 1, characterized in that, The application further comprises fiber reinforced material; The application comprises laminating the modified resin composite repair material and the fiber reinforced material on the to-be-repaired area of the wind turbine blade, and performing repair through microwave heating and UV light curing; The fiber reinforced material comprises light-transmitting glass fiber and / or light-transmitting carbon fiber fabric / felt; In the to-be-repaired area, the content of the resin in the total amount of the modified resin composite repair material and the fiber reinforced material laid is 20wt% to 65wt%.

6. Use according to claim 5, characterized in that, The layer thickness of the modified resin material is 0.2 to 1mm; The layer thickness of the fiber reinforced material is 0.2 to 0.8mm; The laying mode comprises one or more of alternately laying one layer of modified resin material and one layer of fiber reinforced material, and alternately laying one layer of modified resin material and multiple layers of fiber reinforced material; The application comprises one or more of improving the single-repair thickness of the wind turbine blade composite material damage, improving the uniformity of the structure curing of the repair material and improving the repair efficiency of the repair material; The repair efficiency comprises the repair efficiency of the repair material at low temperature.

7. A method of repairing a composite material damage in a wind turbine blade, characterized in that, The method comprises the following steps: 1) Preprocessing the to-be-repaired area of the wind turbine blade composite material; 2) laying modified resin composite repair material and fiber reinforced material on the pretreated area under light shielding condition, removing the UV isolation film layer on the modified resin composite repair material, then vacuum bagging the area, vacuum bag pressing, finally, microwave heating and UV light curing the area to obtain a repaired wind turbine blade composite material; The modified resin composite repair material comprises modified resin material and a UV isolation film layer on the surface of the modified resin material. The modified resin material comprises resin, photoinitiator and microwave absorber.

8. The preparation method according to claim 7, characterized in that, The pretreatment step comprises one or more of the following steps: manually and / or instrumentally checking the surface state of the wind turbine blade, determining the repair area and recording the shape and size data, polishing the repair area, and removing surface impurities. The surface of the pretreated repair area has a groove structure. The modified resin composite repair material comprises modified resin composite repair material sheets and / or modified resin composite repair material strips. The modified resin material further comprises active diluent and / or dispersant. The thickness of the modified resin material is 0.2-1 mm.

9. The preparation method according to claim 7, characterized in that, The laying method comprises one or more of the following methods: alternatingly laying one layer of modified resin material and one layer of fiber reinforced material, and alternatingly laying one layer of modified resin material and multiple layers of fiber reinforced material. The one layer of modified resin material comprises one modified resin material sheet or multiple modified resin material strips arranged at intervals. The thickness of a single layer of the modified resin material is 0.2-1 mm. The thickness of a single layer of the fiber reinforced material is 0.2-0.8 mm. The vacuum degree of the vacuum bag pressing is 30-40 mbar. When microwave heating, the microwave cavity of the microwave heating source is adsorbed on the surface of the wind turbine blade.

10. The preparation method according to claim 7, characterized in that, The microwave heating and UV light curing are performed in the following order: microwave heating, melting the modified resin material and impregnating the fiber reinforced material, and then UV light curing. When performing UV light curing, the microwave heating source is turned on or off. The power of the microwave heating is 1-10 kW. The time of the microwave heating is 20-300 seconds. The temperature of the microwave heating is 40-140℃. The time of the UV light curing is 30-1200 seconds. The UV light source for the UV light curing comprises one or more of the following: mercury arc lamp, metal halide lamp and UV LED lamp.

Images