Method for repairing interlayer defects of pultrusion main beam of wind power blade

Abstract

The invention relates to the technical field of wind power blade production and manufacturing, in particular to a wind power blade pultrusion girder interlayer defect repairing method which specifically comprises the following steps: S1, nondestructive testing; s2, marking defect positions; s3, polishing to remove defects; s4, confirming defect elimination; s5, slope polishing and uniaxial cloth laying are carried out; and S6, recovering the establishment of the outer skin and the vacuum system. Compared with the prior art, the method has good stability for maintaining the interlayer pouring defect of the pultrusion girder plate, a defect layer can be clearly and transparently polished, the instability caused by conventional drilling maintenance is reduced, the reliability and defect maintenance effect of a product are improved, and the quality problem caused by the interlayer defect is effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of wind turbine blade production and manufacturing, and in particular to a method for repairing interlayer defects of a pultruded main beam of a wind turbine blade. Background Art

[0002] In recent years, with the continuous upgrading of wind power industry-related industries, the power generation of wind turbine blades has been increasing, and the length of blades has also gradually increased. As the main load-bearing structure, the reliability of the quality of the blade main beam is particularly important. The wrinkle rate of the conventional thick main beam is high, and the process control is difficult. Pultruded main beams are gradually replacing glass fiber infusion main beams due to their good performance and light weight. The pultruded plate is a composite material plate formed by pre-impregnation, pultrusion and heat curing of uniaxial yarn and epoxy resin in a specific mold. The pultruded main beam is formed by stacking multiple layers of the pultruded plates. During the design, a layer of biaxial cloth should be laid between the layers, but this brings huge adjustments to the blade infusion process. The number of layers of the pultruded plate is usually between 5 and 10, and 2 to 6 plates are usually assembled side by side in the width direction. The process is complicated during infusion and the direction of the resin is changeable. In addition, the pultruded main beam has poor assembly stability, and usually there will be problems such as misalignment, intersection, and large gaps. Therefore, the infusion of the pultruded main beam in the blade is very difficult. In production, defects such as poor infiltration of the pultruded plate interlayer cloth, dry yarn, and bubbles often occur, which have a great impact on the quality of the blade.

[0003] At present, the domestic method of repairing defects such as dry yarn and bubbles in the interlayer of the pultruded main beam of wind turbine blades is to use drilling and injection of glue or drilling and vacuum injection. Although this repair method can inject some resin, due to the small gap between the plates, the compact space and the difficulty in determining the drilling depth, multiple drillings are required to accurately locate the plate, and it is difficult to inject resin into the defective layer. There are disadvantages such as low repair reliability, poor effect, and irreversible damage to the pultruded plate caused by drilling.

[0004] Publication number: CN112976617A A method for repairing a pultruded main beam of a wind turbine blade includes the following steps: determining a dry yarn defect area of ​​the pultruded main beam interlayer cloth; drilling holes in the defect area, the holes include an air extraction hole and an injection hole, and the air extraction hole and the injection hole are kept connected; laying a guide net at the hole position and encapsulating it with a vacuum; evacuating the defect area through the air extraction hole, and filling the defect area with resin through the injection hole; heating the injected defect area at a constant temperature; testing the defect area to confirm that the filling is qualified; and reinforcing the hole with a cloth layer. Although the scheme uses a non-destructive testing method to preliminarily determine the defect, it is still difficult to inject resin into the defect layer, and there are disadvantages such as low maintenance reliability, poor effect, and irreversible damage to the pultruded plate caused by drilling.

[0005] Therefore, it is urgent to propose a method for repairing interlayer defects of pultruded main beams of wind turbine blades to solve the problems of low reliability and poor repair effect of interlayer defects of pultruded main beams. Summary of the invention

[0006] In view of this, the present invention aims to propose a method for repairing interlayer defects of a pultruded main beam of a wind turbine blade, so as to solve the problem of low reliability and poor repair effect of interlayer defects of the pultruded main beam.

[0007] The technical solution of the present invention is implemented as follows: a method for repairing interlayer defects of a wind turbine blade pultruded main beam, specifically comprising the following steps:

[0008] S1: Non-destructive test: After the blade is demoulded, check the infusion quality of the biaxial cloth between the pultruded board layers;

[0009] S2: Marking defect location: When dry yarn or air bubble defects are found, the location, depth and shape information of the defects are marked on the outer surface;

[0010] S3: Grinding to remove the defect: Grinding the outer skin and the pultruded plate above the defect until the defect is exposed, and ensuring that the relevant material is completely removed in the horizontal direction;

[0011] S4: Confirm that the defect has been eliminated: Check again to confirm that the defect has been completely eliminated;

[0012] S5: Slope grinding and uniaxial cloth laying: Grind the fracture of the pultruded plate to form a chamfer with a smooth transition, and lay the uniaxial cloth in this area, and then restore all the plates for reinforcement;

[0013] S6: Restoring the outer skin and establishing the vacuum system: Finally, the outer skin is restored, the exhaust pipe, the glue injection pipe, the guide net, the bag film are re-laid, and the vacuum system is established to perform epoxy resin infusion and heat curing.

[0014] Furthermore, in step S1, non-destructive testing equipment is used to check the infusion quality of the biaxial cloth between the pultruded board layers.

[0015] Furthermore, in step S2, the position, depth and shape information of the defect are marked on the outer surface with a marking pen.

[0016] Furthermore, in step S3, an angle grinder is used to grind the outer skin and the pultruded plate layer by layer until the defects are completely exposed.

[0017] Furthermore, in step S5, the specific steps are as follows:

[0018] S51: grinding the fracture of the pultruded plate along the length direction of the blade to form a smooth transition chamfer of the pultruded plate;

[0019] S52: Laying the uniaxial fabric in the chamfered area of ​​the pultruded plate according to the principle of equivalent strength;

[0020] S53: After all the pultruded plates are equivalently restored, they are reinforced as a whole.

[0021] Furthermore, in step S51, the chamfer of the fracture of the pultruded plate is ground along the length direction of the blade at a ratio of 1:100.

[0022] Further, in step S52, the uniaxial fabric is UDS-1250, the thickness of a single layer of the uniaxial fabric is 0.83 mm, the thickness of a single layer of the pultruded plate is 5 mm, corresponding to 6 layers of the uniaxial fabric.

[0023] Further, in step S53, the two layers of the uniaxial fabric are integrally reinforced, and the radial staggering is performed at a ratio of 1:100.

[0024] Furthermore, in step S6, the outer skin is restored according to a radial staggered ratio of 1:40.

[0025] Compared with the prior art, the method for repairing interlayer defects of a wind turbine blade pultruded main beam of the present invention has the following advantages:

[0026] 1. The present invention has good stability in repairing interlayer infusion defects of pultruded main beam plates, can grind out the defective layer clearly and transparently, reduce the instability caused by conventional drilling repairs, improve product reliability and defect repair effects, and effectively avoid quality problems caused by interlayer defects.

[0027] 2. The present invention can effectively disperse the stress between the repair area and the original structure by forming a smoothly transitioned chamfer, avoid stress concentration points caused by sudden changes, help maintain the integrity of the structure, improve its fatigue resistance, and thus reduce the risk of cracks or delamination that may occur in the future.

[0028] 3. The present invention sets a scientific and reasonable inter-layer ratio to ensure that there is enough transition zone between the repair area and the original structure for quality inspection, while not removing too much healthy material, thus achieving effective utilization of resources. Accurately controlling the grinding ratio ensures that there is no obvious weak link between the repair area and the original structure, thereby improving the quality and reliability of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 It is a schematic diagram of the structure of the device of the present invention;

[0031] Figure 2 This is a schematic diagram of the device of the present invention in the AA direction;

[0032] Figure 3 It is a schematic cross-sectional view of the defect after the slope is polished in the BB direction of the device of the present invention;

[0033] Figure 4 It is a schematic cross-sectional view of the defect of the outer skin after restoration in the BB direction of the device of the present invention.

[0034] Description of reference numerals:

[0035] 1. Pultruded plate; 2. Biaxial cloth; 3. Outer skin; 4. Inner skin; 5. Core material; 6. Main mold; 7. Exhaust pipe; 8. Glue injection pipe; 9. Guide net; 10. Bag film; 11. Sealing tape; 12. Pultruded plate chamfer; 13. Uniaxial cloth; 14. Defects. DETAILED DESCRIPTION

[0036] In order to make the technical means, objectives and effects of the present invention easy to understand, the embodiments of the present invention are described in detail below with reference to specific drawings.

[0037] It should be noted that all the terms used in the present invention to indicate directionality and positionality, such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside", "top", "lower", "lateral", "longitudinal", "center", etc., are only used to explain the relative positional relationship and connection status between the components in a certain state, and are only for the convenience of describing the present invention, rather than requiring the present invention to be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0038] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0040] The pultruded main beam and the inner skin 4, core material 5, and outer skin 3 of the blade are laid on the main mold 6 according to the process requirements. The flow guide is arranged according to the flow guide process, and the auxiliary materials are laid. The auxiliary materials include the flow guide net 9, the injection hose 8, the exhaust pipe 7, the vacuum bag film 10, etc. After the infusion is completed, the mold is heated according to the curing process. After the curing is completed, the auxiliary materials are removed, and the two halves are molded and bonded. After the blade is demoulded, the main beam is non-destructively tested to check the infusion of the biaxial cloth between the pultruded board layers.

[0041] The present invention discloses a method for repairing interlayer defects of a pultruded main beam of a wind turbine blade, comprising the following specific steps:

[0042] S1: Non-destructive test: After the blade is demoulded, check the infusion quality of the biaxial cloth 2 between the layers of the pultruded plate 1;

[0043] After the blade is demoulded, non-destructive testing equipment, visual inspection, tapping test, optical coherence tomography and other technical means can be used to comprehensively check the infusion quality of the biaxial cloth 2 between the layers of the pultruded plate 1, and defects such as dry yarn and bubbles can be discovered in time14 to ensure the targetedness and effectiveness of subsequent repair work. Compared with traditional drilling detection methods, non-destructive testing will not cause additional damage to the structure and can provide more accurate defect14 information.

[0044] S2: Marking the position of the defect 14: When a defect 14 such as dry yarn or air bubble is found, the position, depth and shape of the defect 14 are marked on the outer surface;

[0045] Once the location of dry yarn or bubbles is determined through non-destructive testing, the location, depth, shape and other details of these defects 14 are accurately marked on the outer surface, and the specific location of the defects 14 is clearly identified, providing guidance for subsequent grinding and repair work, ensuring precise operations, improving repair efficiency and accuracy, avoiding unnecessary material removal, and reducing workload.

[0046] S3: Grinding to remove defect 14: Grind the outer skin 3 and the pultruded plate 1 above the defect 14 until the defect 14 is exposed, and ensure that the relevant materials are completely removed in the horizontal direction;

[0047] According to the marked position, the outer skin 3 and the pultruded plate 1 are polished until the defect 14 is completely exposed, and the relevant materials are thoroughly removed in the horizontal direction to ensure that the defect 14 area is completely exposed. Prepare the repair surface to ensure that all damaged materials are removed, prepare for the subsequent repair work, and directly treat the defect 14 part to reduce the impact on the healthy part and ensure the quality of the repair.

[0048] S4: Confirm that defect 14 has been eliminated: Use non-destructive testing equipment to check again to confirm that defect 14 has been completely eliminated;

[0049] The polished area is checked again using nondestructive testing equipment to confirm that all defects 14 have been completely eliminated, verifying whether the work before repair is completed thoroughly, preventing any potential problems from being missed, improving the reliability of the repair process and the quality of the final product, and reducing the possibility of rework.

[0050] S5: Slope grinding and uniaxial cloth 13 laying: Grind the fracture of the pultruded plate 1 to form a smooth transition chamfer, and lay the uniaxial cloth 13 in this area, and then restore all the plates and reinforce them;

[0051] It can ensure that the repaired structure has good mechanical properties and smooth transition, avoiding stress concentration. The setting adopts a slope design with a specific proportion to enhance the integrity of the structure, and at the same time uses high-strength uniaxial cloth 13 to replace the original material, thereby improving the rigidity and strength of the repaired area.

[0052] S6: Restoring the outer skin 3 and establishing the vacuum system: Finally, the outer skin 3 is restored, the exhaust pipe 7, the glue injection pipe 8, the guide net 9, the bag film 10 are re-laid, and the vacuum system is established to perform epoxy resin infusion and heating curing.

[0053] Finally, the outer skin 3 is restored, the exhaust pipe 7, the glue injection pipe 8, the guide net 9, the bag film 10 are re-laid, and a vacuum system is established to perform epoxy resin infusion and heat curing to restore the original structural form of the blade, and the vacuum infusion technology is used to ensure the close combination between the new and old materials. The restored blade not only maintains the original appearance and size, but also has a more solid internal structure, which prolongs its service life.

[0054] This setting uses non-destructive testing technology to accurately locate defects 14, reducing unnecessary damage and misjudgment, and repairs by grinding rather than drilling, avoiding irreversible damage to the pultruded plate 1, using a uniaxial cloth 13 to replace the damaged part, and through slope grinding with a specific ratio to ensure the stability and stiffness consistency of the repaired structure, thereby improving the overall repair effect and reliability.

[0055] Specifically, in step S1, non-destructive testing equipment such as ultrasonic testing or X-ray is used to check the infusion quality of the biaxial fabric 2 between the layers of the pultruded plate 1.

[0056] After the blade is demoulded, non-destructive testing technology, such as Ultrasonic Testing (UT) or Radiographic Testing (RT), is used to comprehensively check the infusion quality of the biaxial cloth 2 between the layers of the pultruded plate 1. This technology can accurately identify defects 14 such as dry yarn and bubbles between the layers of the pultruded plate 1, accurately locate the specific position, size and shape of the defects 14, facilitate marking and polishing, and will not cause damage to the material being tested, thus maintaining the structural integrity.

[0057] This setting can quickly obtain test results without disassembling or destroying samples, accurately determine the defect 14 situation, improve work efficiency, reduce the possibility of misjudgment caused by human factors, and improve the reliability of detection.

[0058] Specifically, in step S2, information such as the position, depth, and shape of the defect 14 is marked on the outer surface with a marker.

[0059] The detailed information of the defect 14 can be accurately marked on the outer surface with a marker pen, which can be conveyed to the personnel performing the repair work in an intuitive way, ensuring that they can quickly understand and take correct measures, and can better plan specific repair plans, such as determining the scope and depth of grinding.

[0060] This setting uses clear markings to reduce the time spent on finding and confirming the location of defects 14, improves the work efficiency of the entire repair process, and reduces the risk of operational errors caused by misunderstanding or neglect of certain details. When multiple workers are involved in the repair, unified and clear markings facilitate communication and cooperation between team members, ensuring that everyone can perform tasks based on the same reference standards, effectively avoiding excessive polishing or failure to completely remove defects 14, thereby ensuring the quality and performance of the repaired structure.

[0061] Specifically, in step S3, an angle grinder is used to grind the outer skin 3 and the pultruded plate 1 layer by layer until the defects 14 are completely exposed.

[0062] The angle grinder can achieve relatively fine control, allowing the operator to adjust the degree of grinding according to actual needs to avoid excessive removal of healthy material; by grinding layer by layer, the material covering the defect 14 can be accurately removed, so that the defect 14 is completely exposed to facilitate subsequent processing, ensuring that only the part containing the defect 14 is processed, and retaining the undamaged structural part to the maximum extent, providing an accurate operating surface for subsequent repair work.

[0063] This setup enables more accurate location and treatment of defects14, helping to improve the quality and reliability of repairs and reduce the risk of future failures.

[0064] Specifically, in step S5, the specific steps are as follows:

[0065] S51: grinding the fracture of the pultruded plate 1 along the length direction of the blade to form a smooth transition chamfer 12;

[0066] By forming a smoothly transitioned chamfer, the stress between the repair area and the original structure can be effectively dispersed, stress concentration points caused by sudden changes can be avoided, which helps maintain the integrity of the structure and improves its fatigue resistance, thereby reducing the risk of cracks or delamination that may occur in the future.

[0067] S52: Laying uniaxial fabric 13 in the chamfer 12 area of ​​the pultruded plate according to the principle of equivalent strength;

[0068] A specific number of layers of uniaxial fabric 13 are used to replace the original pultruded plate 1 material to ensure that the repaired area has mechanical properties that match the original structure. By selecting appropriate alternative materials and accurately controlling the number of layers, the stiffness and strength of the repaired area are consistent with the surrounding undamaged areas.

[0069] S53: After all the pultruded plates 1 are equivalently restored, they are reinforced as a whole.

[0070] The structural strength of the repaired area was further enhanced by adding additional reinforcement layers, and a staggered design with specific proportions ensured a smoother transition between the new and old materials, preventing weak links.

[0071] This setup ensures that there are no obvious weak links between the repaired section and the original structure, improving the quality and stability of the repaired area and increasing the durability and reliability of the overall structure.

[0072] Specifically, in step S51, the chamfer of the fracture of the pultruded plate 1 is ground along the length direction of the blade at a ratio of 1:100.

[0073] After confirming that defect 14 is completely eliminated, the fracture of the pultruded plate 1 is grinded at a ratio of 1:100 along the length direction of the blade to form a smooth transition chamfer, that is, the vertical height is reduced by 1 mm, then the grinding length along the length direction of the blade is 100 mm. In this way, a smooth transition between the repair area and the original structure can be ensured.

[0074] Compared with over-grinding or insufficient grinding, the 1:100 ratio provides a scientific and reasonable standard, which not only ensures sufficient transition zone, but also does not remove too much healthy material, thus realizing the efficient use of resources. The precise control of the grinding ratio ensures that there are no obvious weak links between the repair area and the original structure, thereby improving the quality and reliability of the overall structure.

[0075] Specifically, in step S52 , the uniaxial cloth 13 is UDS-1250, the single-layer thickness of the uniaxial cloth 13 is 0.83 mm, and the thickness of the single-layer pultruded plate 1 is 5 mm, corresponding to six layers of uniaxial cloth 13 .

[0076] The uniaxial cloth 13UDS-1250 is selected, and its single layer thickness is 0.83 mm. Since the thickness of the single-layer pultruded plate 1 is 5 mm, six layers of uniaxial cloth 13 need to be laid to achieve stiffness and strength similar to the original pultruded plate 1. By replacing the original material with the uniaxial cloth 13, the repaired area is not only close to the original structure in appearance, but also consistent in mechanical properties, avoiding potential risks caused by insufficient local strength. By accurately calculating the required number of layers, it is ensured that the stiffness and strength of the repaired area can match the original pultruded plate 1.

[0077] This setting can achieve a high degree of restoration of the original structural mechanical properties by selecting the appropriate type of uniaxial cloth 13 and accurately controlling the number of layers, significantly improve the overall performance of the repair area, enhance its fatigue resistance and durability, and prevent the generation of new weak points or stress concentration areas in the repair area, thereby extending the service life of the structure.

[0078] Specifically, in step S53, two layers of uniaxial fabrics 13 are integrally reinforced, with a radial staggered ratio of 1:100.

[0079] The material is laid in a radial staggered ratio of 1:100, i.e. each layer is 100 mm longer along the length of the blade than the edge of the previous layer to ensure a smooth transition. The overall strength and stiffness of the repaired part are further enhanced by adding two additional layers of uniaxial fabric 13 throughout the repair area. The radial staggered design helps to disperse stress and avoid stress concentration points caused by sudden changes between material layers, thereby reducing the risk of cracks or delamination in the future. The specific ratio makes the transition between the new and old materials smoother, prevents weak links, and improves the integrity and stability of the structure.

[0080] This setting ensures that the repaired area has sufficient strength through scientific and reasonable staggered design, which can effectively disperse stress and avoid damage caused by local overload. The staggered design follows a fixed ratio to help operators perform tasks more accurately, reduce human errors, and ensure the consistency and reliability of each repair.

[0081] Specifically, in step S6, the outer skin 33 is restored according to a staggered layer ratio of 1:40.

[0082] The outer skin 3 is polished and laid at a staggered ratio of 1:40, that is, the length of the outer skin 3 along the length of the blade is 40 mm longer than the edge of the previous layer to ensure a smooth transition. The staggered design at a ratio of 1:40 allows a smooth transition between the newly laid outer skin 3 and the original outer skin 3, avoiding stress concentration points caused by sudden changes between material layers. This helps to enhance the integrity between the repair area and the original structure, making the entire blade surface more uniform and consistent, and improving the overall strength and stability of the structure.

[0083] The setup uses a 1:40 split-layer ratio to restore the outer skin 3, significantly enhancing the long-term reliability and service life of the repaired area, reducing the need for future maintenance, helping operators perform tasks more accurately, reducing human errors, and ensuring consistency and reliability of each repair, thereby streamlining the construction process.

[0084] Example 1

[0085] In step S6, the outer skin 3 is restored according to a staggered ratio of 1:40.

[0086] like Figure 1-4 As shown, a method for repairing interlayer defects of a pultruded main beam of a wind turbine blade.

[0087] Figure 1 It is a schematic diagram of the infusion of a pultruded main beam, an inner skin 4, an outer skin 3, and a core material 5. The pultruded main beam is assembled by multiple pultruded plates 1 and interlayer biaxial cloth 2. There is a layer of biaxial cloth between every two layers of pultruded plates 1. The core material 5 is laid on both sides of the pultruded main beam. The inner skin 4 is above the pultruded main beam and the core material 5, and the outer skin 3 is below.

[0088] The pultruded main beam, inner skin 4, outer skin 3, and core material 5 are laid on the main mold 6 according to certain positioning data according to the requirements of the process documents. After the laying is completed, the vacuum system is established. The vacuum system is composed of an exhaust pipe 7, a glue injection pipe 8, a guide net 9, a bag film 10, and a sealing tape 11. The main mold 6 and the bag film 10 establish a closed environment through the sealing tape 11 to isolate the blade structure from the outside; the exhaust pipe 7 is used to connect the vacuum pump and the blade structure to completely exhaust the gas in the bag film 10 to achieve a vacuum state; the glue injection pipe 8 is used to inject epoxy resin into the blade structure.

[0089] After the blade is poured, the main mold 6 heating program is turned on to heat and solidify the blade structure. After the half piece is demoulded, the two half pieces are bonded together with adhesive to form a complete blade. After the blade is demoulded, it is transferred to the post-processing workshop to check the pouring quality of the biaxial cloth 2 between the pultruded plate 1 layers by non-destructive testing equipment. When the pouring defects 14 dry yarn, bubbles, etc. are found, the defect 14 position, depth, shape and other information are marked on the outer surface of the blade with a marker.

[0090] For ease of operation, defect 14 is usually repaired from the outer surface of the blade. The repair steps are as follows: 1. Use an angle grinder to grind the outer skin 3 and pultruded plate 11 above the defect 14 layer by layer. When the defect 14 is exposed, stop grinding downwards and remove all the outer skin 3 and pultruded plate 1 above the defect 14 in the horizontal direction. After removal, use non-destructive flaw detection equipment to check again whether the defect 14 is completely eliminated.

[0091] After confirming that the defect 14 is completely eliminated, the fracture of the pultruded plate 1 is polished along the length direction of the blade at a ratio of 1:100 to make a smooth transition of the slope, forming the pultruded plate chamfer 12, and the outer skin 3 is polished at a staggered ratio of 1:40. After the polishing is completed, according to the principle of equivalent and equal strength replacement, uniaxial cloth 13 is laid in the pultruded plate chamfer 12 area. The preferred uniaxial cloth 13 is UDS-1250, with a single layer thickness of 0.83mm, and a single layer of pultruded plate 1 with a thickness of 5mm, corresponding to 6 layers of uniaxial cloth 13. After all pultruded plates 1 are equivalently restored, 2 layers of uniaxial cloth 13 are reinforced as a whole, with a radial staggered layer of 1:100, and finally the outer skin 3 is restored at a staggered layer of 1:40.

[0092] After the maintenance layer is laid, the exhaust pipe 7, the glue injection pipe 8, the guide net 9, and the bag film 10 are laid in sequence, and a vacuum system is established by bonding them to the outer surface of the blade through the sealing tape 11, and epoxy resin is poured and heated to cure.

[0093] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for repairing interlayer defects of a wind turbine blade pultrusion main beam, characterized in that: The specific steps include: S1: Non-destructive test: After the blade is demoulded, check the infusion quality of the biaxial cloth (2) between the layers of the pultruded plate (1); S2: Marking the position of the defect (14): when the defect (14) of dry yarn or air bubble is found, the position, depth and shape information of the defect (14) are marked on the outer surface; S3: Grinding to remove the defect (14): Grinding the outer skin (3) and the pultruded plate (1) above the defect (14) until the defect (14) is exposed, and ensuring that the relevant material is completely removed in the horizontal direction; S4: Confirming that the defect (14) has been eliminated: Checking again to confirm that the defect (14) has been completely eliminated; S5: Slope grinding and uniaxial cloth (13) laying: grinding the fracture of the pultruded plate (1) to form a smooth transition chamfer, laying the uniaxial cloth (13) in the area, and reinforcing after restoring all the plates; S6: Restoring the outer skin (3) and establishing a vacuum system: Finally, the outer skin (3) is restored, the air extraction pipe (7), the glue injection pipe (8), the flow guide net (9), the bag film (10) are re-laid, and a vacuum system is established to perform epoxy resin infusion and heating curing.

2. The method for repairing interlayer defects of pultruded main beams of wind turbine blades according to claim 1 is characterized in that: In step S1, non-destructive testing equipment is used to check the infusion quality of the biaxial cloth (2) between the layers of the pultruded plate (1).

3. The method for repairing interlayer defects of pultruded main beams of wind turbine blades according to claim 1 is characterized in that: In step S2, the position, depth and shape information of the defect (14) are marked on the outer surface with a marking pen.

4. The method for repairing interlayer defects of pultruded main beams of wind turbine blades according to claim 1 is characterized in that: In step S3, an angle grinder is used to grind the outer skin (3) and the pultruded plate (1) layer by layer until the defect (14) is completely exposed.

5. The method for repairing interlayer defects of pultruded main beams of wind turbine blades according to claim 1 is characterized in that: In step S5, the specific steps are as follows: S51: grinding the fracture of the pultruded plate (1) along the length direction of the blade to form a pultruded plate chamfer (12) with a smooth transition; S52: Laying the uniaxial fabric (13) in the chamfer area (12) of the pultruded plate according to the principle of equivalent strength; S53: After all the pultruded plates (1) have been restored equivalently, they are reinforced as a whole.

6. The method for repairing interlayer defects of pultruded main beams of wind turbine blades according to claim 5 is characterized in that: In step S51, the chamfer of the fracture of the pultruded plate (1) is ground along the length direction of the blade at a ratio of 1:

100.

7. The method for repairing interlayer defects of pultruded main beams of wind turbine blades according to claim 5 is characterized in that: In step S52, the uniaxial fabric (13) is UDS-1250, the thickness of a single layer of the uniaxial fabric (13) is 0.83 mm, the thickness of a single layer of the pultruded plate (1) is 5 mm, corresponding to 6 layers of the uniaxial fabric (13).

8. The method for repairing interlayer defects of pultruded main beams of wind turbine blades according to claim 5 is characterized in that: In step S53, the two layers of the uniaxial fabric (13) are integrally reinforced, and the radial staggering is performed at a ratio of 1:

100.

9. The method for repairing interlayer defects of pultruded main beams of wind turbine blades according to claim 1 is characterized in that: In step S6, the outer skin (3) is restored according to a radial staggered ratio of 1:40.

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