Wind turbine blade strength prediction device and prediction method

Abstract

The present invention discloses a wind turbine blade strength prediction device and a prediction method thereof, which belong to the field of blade fatigue testing technology. The device comprises a specimen support mechanism for being connected and fixed to the blade root of a blade specimen and a movable blade tooling fixed to the outside of the blade specimen; the movable blade tooling comprises a support frame, a spacing adjustment component, a lateral support component and an adaptive support component. Through the above-mentioned method, the movable blade tooling can adapt to blade specimens of different widths and thicknesses. After the movable blade tooling is installed on the blade specimen, it can be moved along the length direction of the movable blade tooling to detect the strength of each point of the blade specimen, so as to realize multi-point force detection of the blade specimen. Through comprehensive analysis of the data of each point, potential defects in each area, such as delamination, microcracks, etc., are actively stimulated to avoid the blind spots of single loading point testing, thereby achieving a more realistic and practical simulation effect and ensuring the accuracy of the prediction results.

Description

Technical Field

[0001] The present invention relates to the technical field of blade fatigue testing, and in particular to a wind turbine blade strength prediction device and a prediction method thereof. Background Art

[0002] By performing fatigue tests on a sampling of wind turbine blades, the fatigue performance of wind turbine blades can be comprehensively evaluated to ensure their long-term reliability under complex wind conditions.

[0003] Chinese patent application CN111811965A discloses a wind turbine blade fatigue testing device and method, comprising: a blade root bracket for fixing the blade root; a fixed frame, which is arranged near the blade tip and has an opening on one side facing the blade; a blade tip clamp for clamping the blade tip and transmitting driving force; a longitudinal drive mechanism having a longitudinal connecting rod, which is arranged at the bottom of the blade tip clamp, and the longitudinal drive mechanism is used to drive the blade tip clamp to reciprocate in the vertical direction; a transverse drive mechanism having a transverse connecting rod, which is arranged on the side of the blade tip clamp, and the transverse drive mechanism is used to drive the blade tip clamp to reciprocate in the horizontal direction; through the drive of the blade tip clamp, the transverse drive mechanism and the longitudinal drive mechanism, the blade makes an elliptical motion on the surface where the cross section is located, which simulates the up and down swing of the blade and the wind blowing direction and twisting deformation of the blade during actual operation. However, the device still has the following problems:

[0004] 1. The strength of blades varies in different areas. During fatigue testing, dynamic force and load control need to be applied to multiple points on the blade. This requires operators to constantly climb to disassemble and assemble the tooling to change the position of the tooling on the blade. At the same time, the size of the blade tooling is usually fixed. When clamping and fixing blades of different models or blades of the same model at different positions, the profiling mold needs to be remade. This not only increases the test cost, causes waste of control of unused tooling, but also increases the time of fatigue testing.

[0005] 2. During fatigue testing, the blades need to be dynamically forced in both the swing and flapping directions, requiring separate control by two sets of drive structures. This not only increases the test cost but also makes it inconvenient to control the composite motion trajectory of the blades in both directions during actual operation.

[0006] Based on this, the present invention designs a wind turbine blade strength prediction device and a prediction method thereof to solve the above problems. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the prior art, the present invention provides a wind turbine blade strength prediction device and a prediction method thereof.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A wind turbine blade strength prediction device comprises a specimen support mechanism for connecting and fixing to the blade root of a blade specimen and a movable blade tooling fixed to the outside of the blade specimen;

[0010] The movable blade tooling includes a support frame, a spacing adjustment component, a lateral support component and an adaptive support component. The two support frames are symmetrically arranged on the upper and lower sides of the blade specimen. A moving component is provided in the middle of the support frame, and the moving component is used to drive the support frame to move along the length direction of the blade specimen; adaptive support components are symmetrically provided on both sides of the support frame, and the adaptive support components are used to fit with the upper and lower outer walls of the blade specimen so that the support frame remains horizontal on the blade specimen; a spacing adjustment component is provided between the two ends of the two support frames, and the spacing adjustment component is used to adjust the spacing between the upper and lower support frames. A lateral support component is also provided at the movable end of each support frame, and the lateral support component is used to limit the left and right outer walls of the blade specimen;

[0011] A composite swing amplitude control mechanism is provided on the lower side of the movable blade tooling. The output end of the composite swing amplitude control mechanism is connected to the support frame. The composite swing amplitude control mechanism realizes dynamic force application on the blade specimen in the swinging direction and the swinging direction through a single power source. The composite swing amplitude control mechanism is fastened to the ground or the support platform.

[0012] Furthermore, the support frame is composed of two parallel cross bars and a connecting plate fixedly installed between the middle parts of the cross bars; the moving assembly includes a moving motor and a fixed moving wheel, and two fixed moving wheels that are rollingly connected to the outer wall of the blade specimen are rotatably installed on the connecting plate close to one end of the blade specimen. The fixed moving wheels are distributed along the length direction of the blade specimen, and a moving motor is fixedly installed on the other end of the connecting plate. The output end of the moving motor is connected to any fixed moving wheel through a transmission assembly.

[0013] Furthermore, the adaptive support assembly includes a second support plate, a scissors bracket, a servo push rod and a floating support assembly. The second support plates are provided in plurality and are evenly distributed along the length direction of the blade specimen. The second support plates are slidingly connected to the cross bar, and each second support plate is provided with a floating support assembly that conforms to the side wall of the blade specimen; the servo push rod is fixedly connected to the end of the cross bar, and the output end of the servo push rod is fixedly connected to the second support plate; a scissors bracket is provided on the second support plate, so that the second support plate can be expanded or contracted along the length direction of the cross bar with the connecting plate as the starting point.

[0014] Furthermore, the floating support assembly is composed of multiple groups of movable floating support structures and fixed floating support structures staggered on the second support plate. The movable floating support structure is used to fit with the outer wall of the blade specimen when the support frame moves on the blade specimen so that the support frame remains balanced. The fixed floating support structure is used to fit with the outer wall of the blade specimen when the support frame needs to be fixed on the outside of the blade specimen so that the support frame and the blade specimen remain tight.

[0015] Furthermore, the fixed floating support structure includes a first push cylinder, an arc-shaped support plate and a pressure sensor. The first push cylinder is fixedly connected to the second support plate. The output end of the first push cylinder is hinged to the arc-shaped support plate, and the arc-shaped support plate is restricted by the rotation of the hinge seat so that the rotation range of the arc-shaped support plate is forty-five degrees to one hundred and thirty-five degrees; an anti-slip rubber layer is provided on the arc-shaped support plate to increase friction; pressure sensors are provided at both ends of the arc-shaped support plate.

[0016] Furthermore, the mobile floating support structure includes a second push cylinder, a support roller and a pressure sensor. The second push cylinder is fixedly connected to the second support plate. The output end of the second push cylinder is equipped with a pressure sensor, and the lower end of the pressure sensor is equipped with a support roller.

[0017] Furthermore, the spacing adjustment assembly includes a first support plate, an adjusting motor and a rotating rod, the first support plate is slidingly connected to the cross bar, and the first support plate is fixedly connected to the outermost second support plate; the two rotating rods are rotatably connected to the first support plate on the upper support frame through bearings and are symmetrically distributed front and back, and the two rotating rods are connected by a transmission assembly to achieve synchronous rotation, the lower end of the rotating rod is provided with a thread, and a screw sleeve matching the thread is fixedly installed on the first support plate of the lower support frame; the adjusting motor is fixedly connected to the first support plate, and the output end of the adjusting motor is fixedly connected to any rotating rod.

[0018] Furthermore, the lateral support assembly includes a connecting sleeve and a baffle. The connecting sleeve is rotatably mounted on the first support plate through a bearing, and the baffle is fixedly mounted between the connecting sleeves. The baffle is used to abut against the side of the blade specimen.

[0019] Furthermore, the composite swing amplitude control mechanism includes a bracket, a longitudinal swing component, a lateral swing component, a linkage rod and a third push cylinder. The longitudinal swing component is arranged on the lower side of the blade specimen, the bracket is arranged on the left or right side of the blade specimen, and the top of the bracket is equipped with a lateral swing component. The two ends of the linkage rod are respectively hinged to the moving ends of the longitudinal swing component and the lateral swing component; the third push cylinder is fixedly installed at the upper end of the bracket, and the output end of the third push cylinder is fixedly connected to the moving end of the lateral swing component; the moving ends of the longitudinal swing component and the lateral swing component are respectively connected to the bottom and side of the support frame, and are respectively used to control the swing of the blade specimen in the swing direction and the swinging direction.

[0020] In order to better achieve the purpose of the present invention, the present invention also provides a prediction method of a wind turbine blade strength prediction device, comprising the following steps:

[0021] Step 1: Install strain gauges, displacement gauges, and accelerometers on the surface and inside of the blade specimen at set intervals along the length of the blade specimen;

[0022] Step 2: Install the movable blade fixture in the middle of the blade specimen, and adjust the distance between the upper and lower support frames using the spacing adjustment assembly so that the movable assemblies on the two support frames always fit in with the upper and lower side walls of the blade specimen, adapting to the different thicknesses of the blade specimen;

[0023] Step 3: Use the servo push rod to push the first support plate and the second support plate to move synchronously along the length direction of the blade specimen, so that the baffles on both sides always abut against the two sides of the blade specimen to adapt to the parts of different widths of the blade specimen;

[0024] Step 4: The second push cylinder drives the support roller to move vertically until the pressure sensor reading at the end of the second push cylinder reaches the set value. The output end of the second push cylinder stops moving, so that each support roller is in contact with the outer wall of the blade specimen and the force is balanced. The fixed moving wheel is controlled to rotate by the moving motor to drive the support frame to move along the length direction of the blade specimen to the force application point.

[0025] Step 5: After the support frame moves to the force application point of the blade specimen, the arc-shaped support plate is driven to move vertically by the first push cylinder. After the arc-shaped support plate contacts the outer wall of the blade specimen, it automatically rotates and adjusts its angle to maximize the contact area between the arc-shaped support plate and the outer wall of the blade specimen. When the readings of the pressure sensors at both ends of the arc-shaped support plate reach the set value, the output end of the first push cylinder stops moving, so that the forces on each arc-shaped support plate are balanced, thereby fastening the support frame to the blade specimen.

[0026] Step 6: The third push cylinder drives the transverse slide to move back and forth in the horizontal direction. The transverse slide drives the longitudinal slide to move back and forth in the vertical direction synchronously through the linkage rod. The approach and distance between the transverse slide and the blade specimen are opposite, and the combination of the two realizes the elliptical motion of the blade specimen. After the test is completed, the first push cylinder drives the arc support plate to reset.

[0027] Step 7: Check whether the readings of the strain gauge, displacement meter and accelerometer are consistent with the set values;

[0028] Step 8: Repeat steps 4 to 7 until fatigue testing is performed on multiple points in the middle and tip of the blade specimen, and make a comprehensive judgment on the strength of the blade specimen based on the readings of the sensors.

[0029] Compared with the prior art, the present invention has the following beneficial effects: 1. The movable blade tooling can adapt to blade specimens of different widths and thicknesses. After the movable blade tooling is installed on the blade specimen, it can be moved along the length direction of the movable blade tooling to detect the strength of each point of the blade specimen, so as to realize multi-point force detection of the blade specimen. Through comprehensive analysis of the data of each point, the potential defects of each area, such as delamination, microcracks, etc., are actively stimulated to avoid the blind spots of single loading point testing, thereby achieving a more realistic and practical simulation effect and ensuring the accuracy of the prediction results.

[0030] 2. Under the action of the linkage rod, when the transverse slide approaches the blade specimen, the longitudinal slide synchronously moves away from the blade specimen, and when the transverse slide moves away from the blade specimen, the longitudinal slide synchronously approaches the blade specimen. Therefore, under the drive of a power source of the third push cylinder, the blade specimen can be controlled to swing in the swing direction and the swinging direction. The two are combined to realize the elliptical motion of the blade specimen, achieve a more practical simulation effect, and ensure the accuracy of the prediction results. In addition, the power required by the third push cylinder increases only when the transverse slide or the longitudinal slide moves away from the blade specimen, while the approach and distance between the transverse slide and the blade specimen and the longitudinal slide and the blade specimen are opposite, which will not cause a large load on the third push cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0032] Figure 1 A three-dimensional wind turbine blade strength prediction device according to the present invention Figure 1 ;

[0033] Figure 2 This is a front view of a wind turbine blade strength prediction device according to the present invention;

[0034] Figure 3 A three-dimensional wind turbine blade strength prediction device according to the present invention Figure 2 ;

[0035] Figure 4 A three-dimensional wind turbine blade strength prediction device according to the present invention Figure 3 ;

[0036] Figure 5 A three-dimensional wind turbine blade strength prediction device according to the present invention Figure 4 ;

[0037] Figure 6The movable blade tooling of the present invention is a three-dimensional Figure 1 ;

[0038] Figure 7 The movable blade tooling of the present invention is a three-dimensional Figure 2 ;

[0039] Figure 8 for Figure 6 Enlarged view of point A in the middle;

[0040] Figure 9 for Figure 7 Enlarged view of point B in the middle;

[0041] Figure 10 It is a three-dimensional diagram of the floating support assembly of the present invention.

[0042] The numbers in the figure represent:

[0043] 1. Blade specimen; 2. Specimen support mechanism; 3. Mobile blade fixture; 31. Support frame; 311. Crossbar; 312. Connecting plate; 32. Spacing adjustment assembly; 321. First support plate; 322. Adjusting motor; 323. Rotating rod; 324. Thread; 325. Screw sleeve; 33. Lateral support assembly; 331. Connecting sleeve; 332. Baffle; 34. Adaptive support assembly; 341. Second support plate; 342. Scissor bracket; 3421. Connecting rod; 3422 , pin shaft; 343, servo push rod; 344, first push cylinder; 345, arc support plate; 346, pressure sensor; 347, second push cylinder; 348, support roller; 35, moving component; 351, moving motor; 352, fixed moving wheel; 4, compound swing amplitude control mechanism; 41, bracket; 42, transverse slide; 43, transverse slide; 44, transverse connecting rod; 45, longitudinal slide; 46, longitudinal slide; 47, longitudinal connecting rod; 48, linkage rod; 49, third push cylinder. DETAILED DESCRIPTION

[0044] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] The terms “left,” “right,” “front,” “back,” “up,” and “down” mentioned in the following description are oriented in the viewing direction of the front view.

[0046] Example 1: In some embodiments, please refer to the accompanying drawings of the specification. Figure 1、 Figure 2 、 Figure 5 and Figure 6 A wind turbine blade strength prediction device includes a specimen support mechanism 2 connected and fixed to the blade root of a blade specimen 1 and a movable blade tooling 3 fixed to the outside of the blade specimen 1;

[0047] The specimen support mechanism 2 can be a wall structure formed by welding profiles or pouring concrete, and is fixed by connecting the flange with the blade root bolts of the blade specimen 1;

[0048] The movable blade tooling 3 includes a support frame 31, a spacing adjustment component 32, a lateral support component 33 and an adaptive support component 34. The two support frames 31 are symmetrically arranged on the upper and lower sides of the blade specimen 1. A moving component 35 is provided in the middle of the support frame 31. The moving component 35 is used to drive the support frame 31 to move along the length direction of the blade specimen 1; adaptive support components 34 are symmetrically provided on both sides of the support frame 31. The adaptive support components 34 are used to fit with the upper and lower outer walls of the blade specimen 1 so that the support frame 31 remains horizontal on the blade specimen 1; a spacing adjustment component 32 is provided between the two ends of the two support frames 31. The spacing adjustment component 32 is used to adjust the spacing between the upper and lower support frames 31. A lateral support component 33 is also provided at the movable end of each support frame 31. The lateral support component 33 is used to limit the left and right outer walls of the blade specimen 1;

[0049] A composite swing amplitude control mechanism 4 is provided on the lower side of the movable blade fixture 3. The output end of the composite swing amplitude control mechanism 4 is connected to the support frame 31. The composite swing amplitude control mechanism 4 uses a single power source to dynamically apply force to the blade specimen 1 in the swinging direction and the shimmying direction. The composite swing amplitude control mechanism 4 is fastened to the ground or the support platform.

[0050] In the present invention, the movable blade fixture 3 is installed in the middle of the blade of the blade specimen 1, and the spacing between the upper and lower support frames 31 is adjusted by the spacing adjustment component 32, so that the movable components 35 on the two support frames 31 are respectively fitted with the upper and lower side walls of the blade specimen 1, and the adaptive support component 34 is controlled to be fitted with the upper and lower outer walls of the blade specimen 1 to keep the support frame 31 horizontal, and with the cooperation of the lateral support component 33, the entire movable blade fixture 3 is tightly connected to the outer wall of the blade specimen 1, and then the support frame 31 is driven to move by the movable component 35, and the position of the movable blade fixture 3 is adjusted to the set point of the blade specimen 1, and the blade specimen 1 is clamped by the adaptive support component 34. The support frame 31 is fastened to the blade specimen 1, and then the output end of the composite swing amplitude control mechanism 4 is connected to the blade specimen 1. The composite swing amplitude control mechanism 4 is used to realize dynamic force application to the blade specimen 1. When the number of cycles of dynamic force application reaches the set value, the strength of each point of the blade specimen 1 is tested, and then the position of the support frame 31 on the blade specimen 1 is adjusted to perform dynamic force application operation. This is repeated several times to realize multi-point force detection of the blade specimen 1. Through comprehensive analysis of the data of each point, potential defects in each area, such as delamination, microcracks, etc., are actively stimulated to avoid the blind spots of single loading point testing, thereby achieving a more realistic and practical simulation effect and ensuring the accuracy of the prediction results.

[0051] See also Figures 5-10 The support frame 31 is composed of two parallel cross bars 311 and a connecting plate 312 fixedly installed between the middle parts of the cross bars 311. A linear guide rail is fixedly installed on the cross bar 311. The moving assembly 35 includes a moving motor 351 and a fixed moving wheel 352. One end of the connecting plate 312 close to the blade specimen 1 is rotatably installed with two fixed moving wheels 352 that are rollingly connected to the outer wall of the blade specimen 1. The fixed moving wheels 352 are distributed along the length direction of the blade specimen 1. The other end of the connecting plate 312 is fixedly installed with a moving motor 351. The output end of the moving motor 351 is connected to any fixed moving wheel 352 through a transmission assembly. The transmission assembly can adopt a belt and pulley transmission structure.

[0052] The adaptive support assembly 34 includes a second support plate 341, a scissor bracket 342, a servo push rod 343 and a floating support assembly. The second support plates 341 are provided with multiple and evenly spaced along the length direction of the blade specimen 1. The second support plates 341 are limitedly slidably connected to the linear guide rail on the cross bar 311 through a slider. Each second support plate 341 is provided with a floating support assembly that conforms to the side wall of the blade specimen 1; the servo push rod 343 is fixedly connected to the end of the cross bar 311, and the output end of the servo push rod 343 is fixedly connected to the second support plate 341;

[0053] The scissor bracket 342 is formed by a plurality of scissor parts hinged end to end. The scissor parts include two connecting rods 3421 and a pin 3422. The pin 3422 is hinged at the middle of the two connecting rods 3421. The plurality of pins 3422 are respectively fixedly connected to the second support plate 341, and the pin 3422 closest to the connecting plate 312 is fixedly connected to the connecting plate 312, so that the second support plate 341 can be expanded or contracted along the length direction of the crossbar 311 with the connecting plate 312 as the starting point. The servo push rod 343 is fixedly connected to the end of the blade specimen 1, and the output end of the servo push rod 343 is fixedly connected to the outermost second support plate 341.

[0054] The floating support assembly is composed of a plurality of groups of movable floating support structures and fixed floating support structures staggered on the second support plate 341. The movable floating support structure is used to fit with the outer wall of the blade specimen 1 when the support frame 31 moves on the blade specimen 1 so as to keep the support frame 31 balanced. The fixed floating support structure is used to fit with the outer wall of the blade specimen 1 when the support frame 31 needs to be fixed on the outside of the blade specimen 1 so as to keep the support frame 31 and the blade specimen 1 fastened.

[0055] The fixed floating support structure includes a first push cylinder 344, a curved support plate 345, and a pressure sensor 346. The first push cylinder 344 is fixedly connected to the second support plate 341. The output end of the first push cylinder 344 is hinged to the curved support plate 345. The curved support plate 345 is restricted in rotation by the hinge seat so that the rotation range of the curved support plate 345 is 45 degrees to 135 degrees. The curved support plate 345 is provided with an anti-slip rubber layer for increasing friction. Pressure sensors 346 are provided at both ends of the curved support plate 345.

[0056] The mobile floating support structure includes a second push cylinder 347, a support roller 348 and a pressure sensor 346. The second push cylinder 347 is fixedly connected to the second support plate 341. The output end of the second push cylinder 347 is equipped with a pressure sensor 346. The lower end of the pressure sensor 346 is equipped with a support roller 348. The support roller 348 is a steel ball roller.

[0057] The first support plate 321 is connected to the linear guide rail on the cross bar 311 by a slider, and the first support plate 321 is fixedly connected to the outermost second support plate 341, so that the first support plate 321 and the second support plate 341 can move synchronously; the two rotating rods 323 are rotatably connected to the first support plate 321 on the upper support frame 31 through bearings and are symmetrically distributed front and back. The two rotating rods 323 are connected by a transmission assembly to achieve synchronous rotation; the transmission assembly can adopt a synchronous belt and synchronous pulley transmission structure; the lower end of the rotating rod 323 is provided with a thread 324, and a screw sleeve 325 that cooperates with the thread 324 is fixedly installed on the first support plate 321 of the lower support frame 31; the adjusting motor 322 is fixedly connected to the first support plate 321, and the output end of the adjusting motor 322 is fixedly connected to any rotating rod 323;

[0058] The lateral support assembly 33 includes a connecting sleeve 331 and a baffle 332. The connecting sleeve 331 is rotatably mounted on the first support plate 321 via a bearing. The baffle 332 is fixedly mounted between the connecting sleeves 331. The baffle 332 is used to abut against the side of the blade specimen 1.

[0059] In the present invention, by adjusting the motor 322 to drive the rotating rod 323 to rotate, the two support frames 31 are moved toward or relative to each other under the cooperation of the thread 324 and the screw sleeve 325, so as to adjust the distance between the two support frames 31 and adapt to the parts of the blade specimen 1 with different thicknesses; the servo push rod 343 pushes the first support plate 321 and the second support plate 341 to move synchronously along the length direction of the blade specimen 1, so that the rotating rods 323 of the lateral support assemblies 33 on both sides of the support frame 31 are close to or away from each other until the baffles 332 on both sides are against the two sides of the blade specimen 1 to adapt to the parts of the blade specimen 1 with different widths; at the same time, under the action of the scissor bracket 342, all the second support plates 341 are moved equidistantly, so that the floating support assemblies are always evenly distributed along the width direction of the blade specimen 1, ensuring the uniformity of the support effect;

[0060] When the force application point on the blade specimen 1 needs to be changed, the second push cylinder 347 drives the support roller 348 to move vertically until the reading of the pressure sensor 346 at the end of the second push cylinder 347 reaches the set value. The output end of the second push cylinder 347 stops moving, so that each support roller 348 is in contact with the outer wall of the blade specimen 1 and the force is balanced. The fixed moving wheel 352 is controlled by the moving motor 351 to rotate to drive the support frame 31 to move along the length direction of the blade specimen 1.

[0061] When the support frame 31 moves to the force application point of the blade specimen 1, the first push cylinder 344 drives the arc support plate 345 to move vertically. The arc support plate 345 will automatically rotate after contacting the outer wall of the blade specimen 1, and its angle is adjusted to maximize the contact area between the arc support plate 345 and the outer wall of the blade specimen 1. When the readings of the pressure sensors 346 at both ends of the arc support plate 345 reach the set value, the output end of the first push cylinder 344 stops moving, so that the forces on each arc support plate 345 are balanced, thereby achieving the tightening effect of the blade specimen 1.

[0062] The composite swing amplitude control mechanism 4 includes a bracket 41, a longitudinal swing assembly, a lateral swing assembly, a linkage rod 48 and a third push cylinder 49. The longitudinal swing assembly is arranged on the lower side of the blade specimen 1, the bracket 41 is arranged on the left or right side of the blade specimen 1, and the top of the bracket 41 is installed with a lateral swing assembly. The two ends of the linkage rod 48 are hinged to the movable ends of the longitudinal swing assembly and the lateral swing assembly respectively; the third push cylinder 49 is fixedly installed at the upper end of the bracket 41, and the output end of the third push cylinder 49 is fixedly connected to the movable end of the lateral swing assembly; the movable ends of the longitudinal swing assembly and the lateral swing assembly are respectively connected to the bottom and side of the support frame 31, and are used to control the swing of the blade specimen 1 in the swing direction and the swinging direction respectively;

[0063] See also Figure 3-Figure 5 The lateral swing assembly includes a lateral slide 42, a lateral slide 43 and a lateral connecting rod 44. The lateral slide 42 is fixedly connected to the top of the bracket 41, the lateral slide 43 is slidingly connected to the lateral slide 42, and the two ends of the lateral connecting rod 44 are respectively hinged to the side of the support frame 31 and the lateral slide 43; the output end of the third push cylinder 49 is fixedly connected to the lateral slide 43;

[0064] The longitudinal swing assembly includes a longitudinal slide rod 45, a longitudinal slide 46 and a longitudinal connecting rod 47. The lower end of the longitudinal slide rod 45 is fixed to the ground or the support platform, the longitudinal slide 46 is connected to the longitudinal slide rod 45 in a limited sliding manner, and the ends of the longitudinal connecting rod 47 are respectively hinged to the lower end of the support frame 31 and the longitudinal slide 46;

[0065] The two ends of the linkage rod 48 are hinged to the transverse slide 43 and the longitudinal slide 46 respectively. The linkage rod 48 adopts a telescopic rod structure. By changing the length of the linkage rod 48, the swing trajectory of the blade specimen 1 can be changed, thereby realizing the life test of the blade specimen 1 under different torsion conditions;

[0066] In the present invention, under the action of the linkage rod 48, when the transverse slide 43 approaches the blade specimen 1, the longitudinal slide 46 synchronously moves away from the blade specimen 1, and when the transverse slide 43 moves away from the blade specimen 1, the longitudinal slide 46 synchronously approaches the blade specimen 1, so that under the drive of a power source of the third push cylinder 49, the blade specimen 1 can be controlled to swing in the swing direction and the swinging direction. The two are combined to realize the elliptical motion of the blade specimen 1, achieve a more practical simulation effect, and ensure the accuracy of the prediction results. In addition, the transverse slide 43 or the longitudinal slide 46 only increases the power required by the third push cylinder 49 when it moves away from the blade specimen 1, and the approach and distance of the transverse slide 43 and the blade specimen 1, as well as the longitudinal slide 46 and the blade specimen 1, are opposite, and will not cause a large load on the third push cylinder 49.

[0067] Embodiment 2: In some embodiments, as Figures 1-10 As shown, as a preferred embodiment of the present invention, a prediction method of a wind turbine blade strength prediction device includes the following steps:

[0068] Step 1: Install sensors such as strain gauges, displacement meters, and accelerometers on the surface and inside of the blade specimen 1 along the length of the blade specimen 1 at a set interval, for example, every meter;

[0069] Step 2: Install the movable blade fixture 3 in the middle of the blade specimen 1, and adjust the distance between the upper and lower support frames 31 through the distance adjustment component 32 so that the movable components 35 on the two support frames 31 always fit the upper and lower side walls of the blade specimen 1 and adapt to the different thickness parts of the blade specimen 1;

[0070] Step 3: Use the servo push rod 343 to push the first support plate 321 and the second support plate 341 to move synchronously along the length direction of the blade specimen 1, so that the baffles 332 on both sides always abut against the two sides of the blade specimen 1 to adapt to the parts of the blade specimen 1 with different widths;

[0071] Step 4: The second push cylinder 347 drives the support rollers 348 to move vertically until the reading of the pressure sensor 346 at the end of the second push cylinder 347 reaches the set value. The output end of the second push cylinder 347 stops moving, so that each support roller 348 is in contact with the outer wall of the blade specimen 1 and the force is balanced. The fixed moving wheel 352 is controlled to rotate by the moving motor 351 to drive the support frame 31 to move along the length direction of the blade specimen 1 to the force application point;

[0072] Step 5: After the support frame 31 moves to the force application point of the blade specimen 1, the first push cylinder 344 drives the arc-shaped support plate 345 to move vertically. After the arc-shaped support plate 345 contacts the outer wall of the blade specimen 1, it automatically rotates and adjusts its angle to maximize the contact area between the arc-shaped support plate 345 and the outer wall of the blade specimen 1. When the readings of the pressure sensors 346 at both ends of the arc-shaped support plate 345 reach the set value, the output end of the first push cylinder 344 stops moving, so that the forces on each arc-shaped support plate 345 are balanced, thereby fastening the support frame 31 to the blade specimen 1.

[0073] Step 6: The third push cylinder 49 drives the transverse slide 43 to reciprocate in the horizontal direction. The transverse slide 43 drives the longitudinal slide 46 to reciprocate in the vertical direction synchronously through the linkage rod 48. The transverse slide 43 and the longitudinal slide 46 move closer and farther away from the blade specimen 1 in opposite directions. The combination of the two realizes the elliptical motion of the blade specimen 1. After the test is completed, the first push cylinder 344 drives the arc support plate 345 to reset.

[0074] Step 7: Check whether the readings of each sensor are consistent with the set values;

[0075] Step 8: Repeat steps 4 to 7 until fatigue testing is performed on multiple points in the middle and tip of the blade specimen 1, and a comprehensive judgment is made on the strength of the blade specimen 1 based on the readings of the sensors.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A wind turbine blade strength prediction device, comprising a specimen support mechanism (2) for being connected and fixed to the blade root of a blade specimen (1) and a movable blade fixture (3) fixed to the outside of the blade specimen (1), characterized in that: The movable blade tooling (3) comprises a support frame (31), a spacing adjustment component (32), a lateral support component (33) and an adaptive support component (34), wherein the two support frames (31) are symmetrically arranged on the upper and lower sides of the blade specimen (1), a moving component (35) is arranged in the middle of the support frame (31), and the moving component (35) is used to drive the support frame (31) to move along the length direction of the blade specimen (1); the adaptive support components (34) are symmetrically arranged on both sides of the support frame (31), and the adaptive support components (34) are used to fit with the upper and lower outer walls of the blade specimen (1) so that the support frame (31) remains horizontal on the blade specimen (1); a spacing adjustment component (32) is arranged between the two ends of the two support frames (31), and the spacing adjustment component (32) is used to adjust the spacing between the upper and lower support frames (31); each support frame (31) is further provided with a lateral support component (33) at the movable end, and the lateral support component (33) is used to limit the left and right outer walls of the blade specimen (1); A composite swing amplitude control mechanism (4) is provided on the lower side of the movable blade fixture (3); an output end of the composite swing amplitude control mechanism (4) is connected to a support frame (31); the composite swing amplitude control mechanism (4) dynamically applies force to the blade specimen (1) in a swinging direction and a swinging direction through a single power source; and the composite swing amplitude control mechanism (4) is fastened to the ground or a support platform; The adaptive support assembly (34) includes a second support plate (341), a scissor bracket (342), a servo push rod (343) and a floating support assembly. The second support plate (341) is provided with a plurality of scissor brackets (342) and is evenly distributed along the length direction of the blade specimen (1). The second support plate (341) is connected to the cross bar (311) by limited sliding. Each second support plate (341) is provided with a floating support assembly that conforms to the side wall of the blade specimen (1). The servo push rod (343) is fixedly connected to the end of the cross bar (311), and the output end of the servo push rod (343) is fixedly connected to the second support plate (341). The scissor bracket (342) is provided on the second support plate (341), so that the second support plate (341) can be expanded or contracted along the length direction of the cross bar (311) with the connecting plate (312) as the starting point. The spacing adjustment assembly (32) includes a first support plate (321), an adjustment motor (322) and a rotating rod (323), wherein the first support plate (321) is connected to the cross bar (311) in a limited sliding manner, and the first support plate (321) is fixedly connected to the outermost second support plate (341); the two rotating rods (323) are rotatably connected to the first support plate (321) on the upper support frame (31) through bearings and are symmetrically distributed front to back, and the two rotating rods (323) are connected by a transmission assembly to achieve synchronous rotation, the lower end of the rotating rod (323) is provided with a thread (324), and a screw sleeve (325) that cooperates with the thread (324) is fixedly installed on the first support plate (321) of the lower support frame (31); the adjustment motor (322) is fixedly connected to the first support plate (321), and the output end of the adjustment motor (322) is fixedly connected to any rotating rod (323); The composite swing amplitude control mechanism (4) comprises a bracket (41), a longitudinal swing component, a transverse swing component, a linkage rod (48) and a third push cylinder (49), wherein the longitudinal swing component is arranged on the lower side of the blade specimen (1), the bracket (41) is arranged on the left or right side of the blade specimen (1), the top of the bracket (41) is provided with a transverse swing component, and the two ends of the linkage rod (48) are respectively hinged to the movable ends of the longitudinal swing component and the transverse swing component; the third push cylinder (49) is fixedly mounted on the upper end of the bracket (41), and the output end of the third push cylinder (49) is fixedly connected to the movable end of the transverse swing component; the movable ends of the longitudinal swing component and the transverse swing component are respectively connected to the bottom and side of the support frame (31), and are respectively used to control the swing of the blade specimen (1) in the swing direction and the waving direction.

2. The wind turbine blade strength prediction device according to claim 1, characterized in that: The support frame (31) is composed of two parallel cross bars (311) and a connecting plate (312) fixedly installed between the middle parts of the cross bars (311); the moving assembly (35) includes a moving motor (351) and fixed moving wheels (352); one end of the connecting plate (312) close to the blade specimen (1) is rotatably mounted with two fixed moving wheels (352) that are rollingly connected to the outer wall of the blade specimen (1); the fixed moving wheels (352) are distributed along the length direction of the blade specimen (1); the other end of the connecting plate (312) is fixedly mounted with a moving motor (351); the output end of the moving motor (351) is transmission-connected to any of the fixed moving wheels (352) through a transmission assembly.

3. The wind turbine blade strength prediction device according to claim 2, characterized in that: The floating support assembly is composed of a plurality of groups of movable floating support structures and fixed floating support structures staggered on the second support plate (341), wherein the movable floating support structure is used to fit with the outer wall of the blade specimen (1) when the support frame (31) moves on the blade specimen (1) so as to keep the support frame (31) balanced, and the fixed floating support structure is used to fit with the outer wall of the blade specimen (1) when the support frame (31) needs to be fixed on the outside of the blade specimen (1) so as to keep the support frame (31) and the blade specimen (1) fastened.

4. The wind turbine blade strength prediction device according to claim 3, characterized in that: The fixed floating support structure comprises a first push cylinder (344), an arc-shaped support plate (345) and a pressure sensor (346); the first push cylinder (344) is fixedly connected to the second support plate (341); the output end of the first push cylinder (344) is hinged to the arc-shaped support plate (345); and the arc-shaped support plate (345) is restricted in rotation by a hinge seat so that the rotation range of the arc-shaped support plate (345) is from 45 degrees to 135 degrees; an anti-slip rubber layer for increasing friction is provided on the arc-shaped support plate (345); and pressure sensors (346) are provided at both ends of the arc-shaped support plate (345).

5. The wind turbine blade strength prediction device according to claim 4, characterized in that: The mobile floating support structure includes a second push cylinder (347), a support roller (348) and a pressure sensor (346). The second push cylinder (347) is fixedly connected to the second support plate (341). The output end of the second push cylinder (347) is installed with the pressure sensor (346), and the lower end of the pressure sensor (346) is installed with the support roller (348).

6. The wind turbine blade strength prediction device according to claim 5, characterized in that: The lateral support assembly (33) comprises a connecting sleeve (331) and a baffle (332); the connecting sleeve (331) is rotatably mounted on each of the first support plates (321) via a bearing; the baffle (332) is fixedly mounted between the connecting sleeves (331); the baffle (332) is used to abut against the side surface of the blade specimen (1).

7. A prediction method, using the wind turbine blade strength prediction device according to claim 6, characterized in that: The following steps are involved: Step 1: Installing strain gauges, displacement gauges, and accelerometers on the surface and inside of the blade specimen (1) along the length of the blade specimen (1) at set intervals; Step 2: Install the movable blade fixture (3) at the middle of the blade specimen (1), and adjust the distance between the upper and lower support frames (31) by using the distance adjustment component (32) so that the movable components (35) on the two support frames (31) always fit the upper and lower side walls of the blade specimen (1) to adapt to the different thickness parts of the blade specimen (1); Step 3: Pushing the first support plate (321) and the second support plate (341) to move synchronously along the length direction of the blade specimen (1) by means of the servo push rod (343), so that the baffles (332) on both sides always abut against both sides of the blade specimen (1) to adapt to portions of different widths of the blade specimen (1); Step 4: The second push cylinder (347) drives the supporting roller (348) to move vertically until the reading of the pressure sensor (346) at the end of the second push cylinder (347) reaches the set value, and the output end of the second push cylinder (347) stops moving, so that each supporting roller (348) is in contact with the outer wall of the blade specimen (1) and the force is balanced, and the fixed moving wheel (352) is controlled to rotate by the moving motor (351) to drive the supporting frame (31) to move along the length direction of the blade specimen (1) to the force application point; Step 5: After the support frame (31) moves to the force application point of the blade specimen (1), the first push cylinder (344) drives the arc support plate (345) to move vertically. After the arc support plate (345) contacts the outer wall of the blade specimen (1), it automatically rotates and adjusts its angle so that the contact area between the arc support plate (345) and the outer wall of the blade specimen (1) is maximized. When the readings of the pressure sensors (346) at both ends of the arc support plate (345) reach the set value, the output end of the first push cylinder (344) stops moving, so that the forces on each arc support plate (345) are balanced, thereby fastening the support frame (31) to the blade specimen (1); Step 6: The third push cylinder (49) drives the lateral swing component moving end to move back and forth in the horizontal direction, and the lateral swing component moving end drives the longitudinal swing component moving end to move back and forth synchronously in the vertical direction through the linkage rod (48), and the approach and distance between the lateral swing component moving end and the blade specimen (1) and between the longitudinal swing component moving end and the blade specimen (1) are opposite, and the two are combined to realize the elliptical motion of the blade specimen (1); after the test is completed, the first push cylinder (344) drives the arc support plate (345) to reset; Step 7: Check whether the readings of the strain gauge, displacement meter and accelerometer are consistent with the set values; Step 8: Repeat steps 4 to 7 until fatigue testing is performed on multiple points in the middle and tip of the blade specimen (1), and a comprehensive judgment is made on the strength of the blade specimen (1) through the readings of the sensors.

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