A wedge for a wind power blade and a method of processing the same

Abstract

The application discloses a wedge-shaped block for wind power generation blades and a processing method thereof, belongs to the technical field of wind power generation blade matching components and composite material processing, and aims to solve the problems of low matching degree of fiber orientation and stress distribution, and internal stress and warping defects of processing products. The wedge-shaped block is made of continuous fiber reinforced thermoplastic composite material, the thickness continuously changes in the length direction, the internal fiber orientation is automatically deflected along the shape, and there is no thermosetting adhesive layer between the layers. The processing method comprises the steps of fiber path topology optimization, dynamic variable-angle laser in-situ fiber laying and differential temperature pulse mold pressing and shaping, and can realize mold-free iterative manufacturing. The wedge-shaped block is used for gap filling and structure connection between a main beam and a shear web of a wind power generation blade.

Description

Technical Field

[0001] This invention relates to the field of wind turbine blade components and composite material processing technology, specifically to the gap filling and structural connection of wedge-shaped components between the main beam and shear web of wind turbine blades, and the precision forming and processing technology of such variable thickness continuous fiber reinforced composite components. Background Technology

[0002] Currently, the gap between the main beam and the shear web of wind turbine blades is usually filled with thermosetting resin-based composite wedge blocks. During processing, pre-laid fibers are often used and then molded, resulting in fixed fiber orientation. This cannot match the stress distribution requirements of the wedge area. The interlayer relies on thermosetting adhesive layers for bonding, which results in insufficient toughness. During processing, fibers need to be cut according to the wedge shape, leading to low material utilization. The same consolidation process parameters for different thickness areas can easily generate internal stress and warping defects, resulting in poor product consistency and difficulty in meeting the assembly requirements of large thickness gradient areas. Summary of the Invention

[0003] The purpose of this invention is to provide a wedge block for wind turbine blades and its processing method, which solves the problems of existing wedge blocks for wind turbine blades, such as the inability to match fiber orientation with stress distribution and insufficient interlayer toughness. At the same time, it also solves the problems of low material utilization, poor matching of consolidation processes in different thickness areas, easy generation of internal stress and warping defects, and insufficient precision and service reliability of finished products.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A wedge-shaped block for wind turbine blades is made of continuous fiber-reinforced thermoplastic composite material. The thickness varies continuously in a wedge shape along the length direction, the internal fiber orientation continuously deflects adaptively with the wedge geometry, the stiffness and strength are distributed in a gradient, and there is no thermosetting adhesive layer between the layers.

[0005] Furthermore, a method for processing wedge blocks for wind turbine blades includes the following main steps: First, based on the service stress field of the wedge block, a spatially continuously varying fiber vector field is generated through an algorithm, so that the fibers are distributed along the principal stress trace; Subsequently, a six-axis robot equipped with a laser-heated fiber placement head was used to adjust the placement angle, number of layers and feed speed in real time on a moving base, forming a variable thickness wedge blank in one piece, with no fiber cutting and no wrinkles. Subsequently, the wedge-shaped blank is molded and shaped using a mold with independent temperature control for surface partitions and internal pulse pressurization, so that areas of different thicknesses can be solidified under the corresponding process window; During processing, fiber content and orientation are detected online, and closed-loop control is implemented to achieve moldless iterative manufacturing.

[0006] Compared with the prior art, the wedge block for wind turbine blades and its processing method disclosed in this invention have the following advantages: 1. The wedge-shaped fiber is distributed along the principal stress line, which is suitable for the stress requirements of the gradual region. There is no thermosetting adhesive layer between the layers, and the interlayer toughness is high. It can effectively transfer shear force and bending moment and eliminate assembly stress. 2. The processing adopts in-situ fiber laying and integrated forming, without fiber cutting, and the material utilization rate can reach more than 97.5%; 3. Differential temperature pulse molding can match the consolidation process requirements of different thickness areas, eliminate internal stress and warping defects, and produce high precision finished products; 4. The processing can be monitored and controlled online, with high flexibility, and iterative manufacturing can be completed without additional mold opening. Attached Figure Description

[0007] Figure 1 This is a schematic diagram illustrating the application state of the wedge block in this invention; Figure 2 This is a schematic diagram of the overall structure of the wedge block in the invention; Figure 3 This is a schematic diagram of the fiber orientation inside the wedge block in the invention; Figure 4 This is a flowchart illustrating the wedge block processing method in the invention. Figure 5 This is a schematic diagram of the laser in-situ filament placement process in the invention. Figure 6 This is a schematic diagram of the structure of a differential temperature pulse molding die for the invention. Figure 7 This is a schematic diagram of the processing control logic in the invention.

[0008] Explanation of reference numerals in the attached figures: 10. Main beam of wind turbine blade; 20. Shear web; 30. Wedge block; 31. Wedge-shaped thin end; 32. Wedge-shaped thick end; 33. Reinforcing fiber bundle; 34. Thermoplastic resin matrix; 41. Fiber path optimization step; 42. In-situ fiber placement forming step; 43. Differential temperature molding and shaping step; 51. Six-axis robot; 52. Laser-heated filament placement head; 53. Mobile base; 61. Zoned temperature-controlled upper mold; 62. Pulse-pressurized lower mold; 63. Wedge-shaped blank; 71. Digital twin model module; 72. Online detection module; 73. Parameter closed-loop control module. Detailed Implementation

[0009] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. In the description of the present invention, it should be noted that if the directions or positional relationships indicated by terms such as "upper", "middle", "lower", "inner", and "outer" are based on the directions or positional relationships shown in the accompanying drawings, they are only for the purpose of facilitating the description of the technical solutions of the present invention and simplifying the description, and do not indicate or imply that the structure or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0010] Please refer to the following: Figures 1-3 Example 1: A wedge-shaped block for wind turbine blades, corresponding to the attached... Figure 1 Appendix Figure 2 Appendix Figure 3 The structure. For example... Figure 1 As shown, the wedge block 30 is disposed in the gap between the main beam 10 of the wind turbine blade and the shear web 20 to fill the gap and achieve a structural connection between the two. In this embodiment, the wedge block 30 is made of a continuous glass fiber reinforced thermoplastic resin matrix 34 (polypropylene) composite material, with a thickness that gradually increases from 1 mm to 20 mm along the length direction in a wedge shape. Figure 2 The overall structure. The internal fiber orientation of the wedge block 30 adaptively and continuously deflects according to the wedge geometry, corresponding to the attached... Figure 3 The fiber orientation diagram shows that each fiber is distributed along the principal stress trace corresponding to the service stress field of the wedge block 30. The stiffness and strength are distributed in a gradient with thickness along the length direction. The interlayer is a bonding interface formed by the fusion and solidification of the polypropylene matrix, without an additional thermosetting adhesive layer. In this embodiment, when the wedge block 30 is assembled, its two side surfaces are adapted to the bonding surfaces of the wind turbine blade main beam 10 and the shear web 20, respectively. It can fill the gap without additional shaping, accurately transmit shear force and bending moment, and eliminate assembly stress.

[0011] As an optional implementation of this embodiment, depending on the load level of the wind turbine blade, the continuous reinforcing fiber bundle 33 can be replaced with any one of continuous carbon fiber or continuous basalt fiber, the thermoplastic matrix can be replaced with any one of polyamide or polyetheretherketone, and the thickness gradient range can be adjusted to different specifications such as 2mm to 28mm or 3mm to 35mm according to the actual gap size. Example

[0012] This technical solution also discloses an embodiment of a processing method for the aforementioned wedge block 30 for wind turbine blades, with corresponding appendices. Figure 4 To be continued Figure 7 The process and equipment structure, and the processing flow are as follows: Figure 4 As shown.

[0013] In the first step, a fiber vector field is generated, which is implemented in a manner driven by fiber path topology optimization and digital twin: first, the simulation data of the service alternating stress field of the target wind power blade and the dimensional tolerance requirements for the installation position of the wedge block 30 are collected, the above data are input into an evolutionary structural optimization algorithm to generate a spatially continuously varying fiber vector field, so that the fibers are distributed along the principal stress trajectories, while a digital twin model corresponding to the wedge block 30 is constructed, and all the stress data, fiber vector data and preset processing parameters are incorporated into the twin model to complete virtual rehearsal and verify the feasibility of fiber placement. As an optional implementation of this step, the topology optimization algorithm can be replaced with a level set algorithm, which is suitable for application scenarios with higher requirements on fiber orientation accuracy.

[0014] In the second step, a wedge blank 63 is formed by laser in-situ fiber placement, corresponding to the accompanying Figure 5 operation schematic: the fiber placement control data exported from the digital twin model is imported into the six-axis robot control system, the six-axis robot 51 is equipped with a laser heating fiber placement head 52 and works in cooperation with the movable base station 53. When polypropylene matrix is adopted in this embodiment, the laser heating temperature is set to 175-185°C, and the feed speed is set to 10-30 m / min. During the operation, the placement angle is adjusted in real time according to the fiber vector data, and the number of placement layers (2 layers at the wedge thin end 31 and 40 layers at the wedge thick end 32) and the feed speed are adjusted in real time according to the wedge thickness requirement. While performing in-situ melting placement, the placement layers are compacted by the pressing roller matched with the fiber placement head, and the finally obtained variable-thickness wedge blank 63 has fibers that are not cut off or wrinkled throughout the whole process. As an optional implementation of this step, the laser heating power can be adaptively adjusted in real time according to the ambient temperature to ensure consistent melting effect of the thermoplastic matrix.

[0015] In the third step, differential temperature pulse molding and shaping is performed, corresponding to the accompanying Figure 6 mold structure: the formed wedge blank 63 is placed into a compression mold, the surface of the zone-controlled temperature upper mold 61 is divided into three independent temperature control zones according to the thickness of the corresponding wedge block 30, the temperature of the zone corresponding to the wedge thin end 31 is set to 155°C, the intermediate transition zone is set to 150°C, and the zone corresponding to the wedge thick end 32 is set to 145°C. The temperature of the three zones all corresponds to the optimal consolidation process window of their respective thickness zones. At the same time, the pressurizing device inside the pulse pressurizing lower mold 62 applies pulse pressure with a frequency of 0.5-2 Hz and a peak value of 3-5 MPa, and the pressure is maintained for 10-30 min to complete the consolidation of each thickness zone, eliminating internal stress and warpage caused by thermal history differences. As an optional implementation of this step, for the wedge block 30 with a larger thickness gradient range, the number of temperature control zones can be adjusted to 5 to further ensure the matching of the consolidation process in each zone. For the wedge block 30 customized in small batches, the molding step can also be omitted, and the finished product can be directly obtained through in-situ compaction during the fiber placement process, so as to improve the manufacturing efficiency.

[0016] The entire processing process of this embodiment corresponds to the accompanying Figure 7The control logic employs online detection closed-loop control: an online visual inspection system is installed at the yarn laying station to collect fiber content and fiber orientation data for each layer of yarn laying in real time. The collected actual parameters are transmitted to the control system and compared with preset parameters in the digital twin model. When the deviation exceeds ±2%, the control system adjusts the yarn laying angle, feed speed, or number of layers for the next layer in real time, forming a closed-loop control. As an optional implementation method for this step, online detection can be replaced with an infrared spectroscopy detection system, suitable for scenarios with higher requirements for fiber content detection accuracy.

[0017] The entire processing flow of this embodiment realizes moldless iterative manufacturing from digital model to final part. Only the control parameters need to be adjusted to adapt to the processing of wedge blocks 30 of different specifications. There is no need to open additional shaping molds. No excess scrap is generated during the wire laying process. The material utilization rate reaches 98.2%, which meets the requirement of greater than 97.5%.

[0018] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. For those skilled in the art, various changes, modifications or additions made without departing from the concept of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A wedge-shaped block for wind turbine blades, used to fill the gap between the main beam (10) and the shear web (20) of the wind turbine blade and to achieve a structural connection between the two, characterized in that: The wedge block (30) is made of continuous fiber reinforced thermoplastic composite material. The thickness varies continuously in a wedge shape along the length direction. The internal fiber orientation continuously deflects with the wedge geometry. The stiffness and strength are distributed in a gradient. There is no thermosetting adhesive layer between the layers.

2. The wedge block for wind turbine blades according to claim 1, characterized in that: Each fiber inside the wedge (30) is distributed along the principal stress trace corresponding to its service stress field.

3. A method for processing a wedge block for wind turbine blades, used to manufacture the wedge block for wind turbine blades as described in any one of claims 1-2, characterized in that, include: S1: First, based on the service stress field of the wedge block (30), a spatially continuously changing fiber vector field is generated through an algorithm, so that the fibers are distributed along the principal stress trace; S2: Subsequently, a six-axis robot (51) equipped with a laser-heated fiber laying head (52) was used to adjust the laying angle, number of layers and feed speed in real time on a moving base (53) to form a variable thickness wedge blank (63) in one piece. During the forming process, the fibers were not cut or wrinkled. S3: Then, the wedge blank (63) is molded and shaped using a mold with independent temperature control of surface partitions and internal pulse pressure, so that different thickness areas of the wedge blank (63) are solidified under their respective process windows.

4. A method for processing a wedge block for wind turbine blades according to claim 3, characterized in that: The generation of the fiber vector field is achieved through fiber path topology optimization and digital twin-driven methods.

5. A method for processing a wedge block for wind turbine blades according to claim 3, characterized in that: Throughout the entire processing, fiber content and orientation are monitored online and controlled in a closed loop.

6. A method for processing a wedge block for wind turbine blades according to claim 3, characterized in that: The entire processing flow enables moldless iterative manufacturing from digital model to final part, with a material utilization rate of over 97.5%.

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