Device and method for testing torsional rigidity of wind power blade
The device addresses inaccuracies in wind turbine blade torsion tests by using a double-point method and gravity balancing to ensure accurate torsional stiffness measurements, overcoming issues of fixture deformation and load control.
Patent Information
- Application Number
- CN202411399409.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-09
- Publication Date
- 2024-12-13
AI Technical Summary
Existing blade torsion tests for wind turbine blades face challenges such as inability to balance the blade's own gravity, ensure fixture non-deformation, maintain the rotation center, and accurately control the applied load, leading to inaccurate stiffness measurements.
A testing device and method using two load-applying elements with an upper and lower double-point method to place the torsion center at the shear center, incorporate a gravity balancing device to counteract the blade's weight, and employ precise torque control through an electric cylinder, fisheye rod, wire rope, and force sensor setup.
Accurate measurement of torsional stiffness is achieved by avoiding bending-torsion coupling, balancing the blade's weight, and precise load control, allowing for reliable evaluation of blade structure under torsional stress.
Smart Images
Figure CN119124599A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of wind turbine blades, and in particular to a device and method for testing the torsional stiffness of wind turbine blades. Background Art
[0002] Blade torsion test is an important means to evaluate the torsion performance of wind turbine blades, especially in the design and verification stage, it is crucial to verify the reliability and safety of the blade structure. At present, the blade torsion test mainly fixes the blade on the test bench, applies load to the test fixture of the corresponding section through a crane or heavy objects, and calculates the stiffness deformation of the blade based on the angle sensor attached to the blade. However, the above test has many problems such as being unable to balance its own gravity, being unable to ensure that the fixture itself does not deform, the rotation center of the blade remains unchanged during the loading process, and being unable to accurately control the applied load. Summary of the invention
[0003] Based on this, it is necessary to provide a testing device and method for the torsional stiffness of wind turbine blades to address the above-mentioned problems. By setting two load applying elements and adopting an upper and lower double-point method to pull the blade segments in relative directions, the torsion center is placed at the shear center of the blade segment, thereby avoiding the bending-torsion coupling deformation of the blade segment and realizing pure torsion testing. At the same time, the weight can be balanced to avoid the influence of the blade segment's own weight on the test results, making the blade stiffness results more accurate.
[0004] According to a wind turbine blade torsional stiffness test device proposed in the present application, the test device comprises a loading end, a fixed end and a blade segment, the loading end and the fixed end are arranged opposite to each other, and the blade segment is placed between the loading end and the fixed end;
[0005] The loading end includes a reaction support, a clamping element 1, two load applying elements, a weighing sensor, a jack and a gravity balancing device. The reaction support includes two groups, each group of reaction supports is arranged on both sides of the clamping element 1, and the two load applying elements are connected to the clamping element 1 through a round clamp lifting ear, and the blade segment is pulled in relative directions by an upper and lower double-point method. The gravity balancing device is arranged below the clamping element 1, and the weighing sensor and the jack are arranged below the gravity balancing device;
[0006] The fixed end includes an oblique brace, a column, a crossbeam and a second clamping element. The crossbeam includes an upper crossbeam and a lower crossbeam. The second clamping element is arranged between the upper crossbeam and the lower crossbeam. The crossbeam is connected to the column, and the oblique brace is arranged on the side of the column.
[0007] In one embodiment, the clamping element 1 includes a wooden clamp fixing block, a round clamp, a wooden clamp and a screw rod 1, the round clamp includes an upper round clamp and a lower round clamp, the wooden clamp includes an upper wooden clamp and a lower wooden clamp, the wooden clamp is arranged between the round clamps, the wooden clamp fixing blocks are arranged at both ends of the wooden clamp and the wooden clamp fixing blocks are connected to the wooden clamp, and the wooden clamp fixing blocks are also connected to the round clamp, and the screw rod 1 passes through the upper round clamp and the lower round clamp.
[0008] In one embodiment, the load applying element includes a nose-type lifting ear, an electric cylinder, a fisheye rod, a wire rope, a fixed pulley set, a force sensor, and a D-type lifting ear. The electric cylinder is fixed to the reaction force bracket through the nose-type lifting ear, the electric cylinder is connected to the fisheye rod, the fisheye rod is connected to the wire rope, the fixed pulley set is fixed to the reaction force bracket, the wire rope passes through the fixed pulley to connect one end of the force sensor, and is connected to the other end of the force sensor through the D-type lifting ear, and then the wire rope is connected to the round clamp through the round clamp lifting ear.
[0009] In one embodiment, the clamping element 2 includes a wooden plywood, a second screw rod and a wooden plywood fixing block, the wooden plywood includes an upper wooden plywood and a lower wooden plywood, the wooden plywood fixing blocks are arranged at both ends of the wooden plywood and are connected to the wooden plywood, and the wooden plywood fixing blocks are also connected to the cross beam, and the second screw rod passes through the upper cross beam and the lower cross beam.
[0010] In one of the embodiments, the testing device further comprises a foundation, a plurality of grooves are arranged at intervals on the foundation, and the loading end and the fixed end are slidably connected to the foundation through the grooves.
[0011] In one embodiment, the loading end and the fixing end are connected to the foundation by a combination of anchor bolts and nuts.
[0012] In one embodiment, the reaction support at the loading end is connected to the foundation, and the column and the diagonal brace at the fixed end are both connected to the foundation.
[0013] In one embodiment, the columns are arranged in two groups, and each group has two columns arranged on both sides of the second clamping element.
[0014] In one of the embodiments, side supports are provided on the sides of the reaction support.
[0015] The present application also includes a testing method using a wind turbine blade torsional stiffness testing device, wherein the specific steps of the testing method include:
[0016] Fixing the root portion of the blade segment: clamping the root portion of the blade segment with a clamping element 2 at the fixed end;
[0017] Fixing the tip of the blade segment: clamping the tip of the blade segment with a clamping element at the loading end;
[0018] Install sensors: Place various sensors on the surface of the blade segment and stick them on the key parts of the blade segment at a predetermined interval. Before loading, the values of each sensor are reset to zero. After the torsional load is applied to the loading end, each sensor collects data. The sensor outputs an analog signal or a digital signal, which is output to the signal acquisition system through a transmitter. The data is then saved by the host computer and displayed on the display to monitor the force response characteristics of the blade segment in real time. Among them, the analog signal is voltage, current and resistance, and the digital signal is a binary signal.
[0019] Balancing blade weight: The tip weight of the blade is calculated by the load cell at the loading end, and then the weight of the blade is balanced using a jack and a gravity balance device;
[0020] Collect data: Ensure that the blade is at zero degree chordwise position before the test begins, and adopt a step-by-step loading and unloading method to predict the blade's springback and residual deformation;
[0021] Data processing: The torsional stiffness k of the blade is calculated by comparing the angles of each section of the blade before and after the force is applied. The calculation formula is: Where T is the pure torsional load applied to the tip of the blade segment, α l2 is the torsion value measured by the angle sensor at the position of the blade segment close to the blade tip, α l1 is the torsion value measured by the angle sensor at the position of the blade segment close to the blade root; further, the calculation formula of T is F is the axial force of the wire rope measured by the force sensor, and R is the sum of the radius of the circular clamp and the effective height of the circular clamp lifting lug.
[0022] Compared with the prior art, the present application has the following beneficial effects:
[0023] First, by setting up two load-applying elements and using the upper and lower double-point method to pull the blade segments in relative directions, the torsion center is placed at the shear center of the blade segment, avoiding the bending-torsion coupling deformation of the blade segment and achieving pure torsion testing. The test results are accurate, and the upper and lower double-point method can truly restore the posture of the blade itself, which is closer to a torsion state during the force-bearing process.
[0024] Second, by setting a gravity balance device at the bottom of the circular fixture at the loading end, the weighing sensor displays the current weight of the circular fixture and the blade segment. The load on the gravity balance device is controlled to be the total weight of the circular fixture and the blade segment to achieve gravity balance. By adjusting the balance weight in the early stage of loading, the influence of the blade segment's own weight on the test results can be avoided.
[0025] Third, by setting up a load application structure including an electric cylinder, a fisheye rod, a wire rope, a force sensor and a fixed pulley assembly, precise torque control can be performed, thereby achieving precise control of applied load.
[0026] Fourth, the test device is placed on the foundation, and the connection between the loading end and the fixed end of the test device and the foundation is set to a sliding connection. At the same time, the blade end is fixed by setting a frame-type clamping element, so that the blade segment can be clamped at any angle in the horizontal or vertical direction (the horizontal or vertical angle of the blade segment refers to the initial angle of the blade in the unloaded state). By adjusting the height of the crossbeam on the column, blade clamps of different heights can be clamped. The blade clamp fixing block can be moved on the crossbeam to fix the blade clamp of any width. Any angle of the blade is achieved by formulating a blade clamp of a specific angle. At the same time, the blade clamp, the screw rod and the blade clamp fixing block at the loading end can make corresponding adjustments following the fixed end. The test device can freely adjust the clamping size parameters of the loading end and the fixed end wooden clamp according to the test requirements to adapt to the sizes of samples of different specifications.
[0027] Fifth, various sensors are placed on the surface of the blade segment according to the area of the blade segment to be observed. The sensors measure the torsion angle of the selected cross section of the blade segment, and the torsional stiffness of the blade segment is calculated by a formula. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 This is a schematic diagram of the overall structure of a wind turbine blade torsional stiffness testing device proposed in this application.
[0029] Figure 2 This is a schematic diagram of the loading end structure of a wind turbine blade torsional stiffness testing device proposed in this application.
[0030] Figure 3 This is a schematic diagram of the fixed end structure of a wind turbine blade torsional stiffness testing device proposed in this application.
[0031] Illustrations: 1. Reaction bracket; 2. Nose-shaped lifting ear; 3. Electric cylinder; 4. Fisheye rod; 5. Wire rope; 6. Fixed pulley block; 7. Anchor bolt and nut combination; 8. Foundation; 9. Force sensor; 10. D-shaped lifting ear; 11. Weighing sensor; 12. Jack; 13. Gravity balance device; 14. Wooden clamp fixing block; 15. Round clamp lifting ear; 16. Round clamp; 17. Wooden clamp; 18. Screw rod one; 19. Diagonal brace; 20. Column; 21. Crossbeam; 22. Screw rod two; 23. Wooden plywood; 24. Wooden plywood fixing block. DETAILED DESCRIPTION
[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0033] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.
[0034] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0035] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0036] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0037] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.
[0038] See also Figures 1 to 3 , Figure 1 The overall structural schematic diagram of a wind turbine blade torsional stiffness testing device in an embodiment of the present application is shown. The wind turbine blade torsional stiffness testing device provided in an embodiment of the present application includes a loading end 31, a fixed end 32 and a blade segment 33. The loading end 31 and the fixed end 32 are arranged opposite to each other, and the blade segment 33 is placed between the loading end 31 and the fixed end 32.
[0039] The loading end 31 includes a reaction support 1, a clamping element 1, two load applying elements, a weighing sensor 11, a jack 12 and a gravity balancing device 13. The reaction support 1 includes two groups, each group of reaction supports 1 is arranged on both sides of the clamping element 1, the two load applying elements are connected to the clamping element 1 through a round clamp lifting ear 15, and the blade segment 33 is pulled in relative directions by an upper and lower double-point method, the gravity balancing device 13 is arranged below the clamping element 1, and the weighing sensor 11 and the jack 12 are arranged below the gravity balancing device 13;
[0040] The fixed end 32 includes a diagonal brace 19, a column 20, a crossbeam 21 and a second clamping element. The crossbeam 21 includes an upper crossbeam and a lower crossbeam. The second clamping element is arranged between the upper crossbeam and the lower crossbeam. The crossbeam 21 is connected to the column 20 and can move on the column 20 so that blade clamps of different heights can be clamped. The diagonal brace 19 is arranged on the side of the column 20.
[0041] The testing device also includes a foundation, on which a plurality of grooves are arranged at intervals, and the loading end 31 and the fixed end 32 are slidably connected to the foundation through the grooves, so that the clamping size parameters of the clamping elements of the loading end and the fixed end can be freely adjusted according to the test requirements to adapt to the sizes of samples of different specifications, and the loading end 31 and the fixed end 32 are both connected to the foundation using a combination of anchor bolts and nuts.
[0042] The side of the reaction support 1 is provided with a side support, and the reaction support 1 and the side support of the loading end 31 are both connected to the foundation. The combination of the reaction support 1 and the side support can achieve the force stability of the loading end 31 tooling.
[0043] The columns 20 are arranged in two groups, each group having two columns 20 arranged on both sides of the clamping element 2. The columns 20 and the diagonal braces 19 of the fixed end 32 are both connected to the foundation. The combination of the columns and the diagonal braces can achieve stable force on the fixed end tooling.
[0044] Combination Figure 2 As shown, Figure 2 The schematic diagram of the loading end structure of the wind turbine blade torsional stiffness test device in one embodiment of the present application is shown. In some embodiments, the clamping element 1 includes a wooden clamp fixing block 14, a round clamp 16, a wooden clamp 17 and a screw rod 18. The round clamp 16 includes an upper round clamp and a lower round clamp. The wooden clamp 17 includes an upper wooden clamp and a lower wooden clamp. The wooden clamp 17 is arranged between the round clamps 16. The wooden clamp fixing block 14 is arranged at both ends of the wooden clamp 17 and the wooden clamp fixing block 14 is connected to the wooden clamp 17. At the same time, the wooden clamp fixing block 14 is also connected to the round clamp 16. The screw rod 18 passes through the upper round clamp and the lower round clamp. The wooden clamp fixing block 14 can move on the round clamp 16 to adapt to blade segments of different widths.
[0045] The load applying element includes a nose-type lifting ear 2, an electric cylinder 3, a fisheye rod 4, a wire rope 5, a fixed pulley block 6, a force sensor 9 and a D-type lifting ear 10. The electric cylinder 3 is fixed to the reaction force bracket 1 through the nose-type lifting ear 2, the electric cylinder 3 is connected to the fisheye rod 4, the fisheye rod 4 is connected to the wire rope 5, the fixed pulley block 6 is fixed to the reaction force bracket 1, the wire rope 5 passes through the fixed pulley to connect one end of the force sensor 9, and is connected to the other end of the force sensor 9 through the D-type lifting ear 10, and then the wire rope 5 is connected to the round clamp 16 through the round clamp lifting ear 15.
[0046] The loading end 31 is fixed by a round clamp 16 and a wooden clamp 17 using a screw rod 18 to clamp the tip of the blade segment 33, so as to be fixed to the reaction support 1 on the foundation 8, and the load application element integrated in the reaction support 1 includes an electric cylinder 3, a fisheye rod 4, a wire rope 5, a force sensor 9 and a fixed pulley block 6, wherein the electric cylinder 3 is fixed to the reaction support 1 by bolts, the electric cylinder 3 is connected to the fisheye rod 4, the fisheye rod 4 is connected to the wire rope 5, the fixed pulley block 6 is fixed to the reaction support by bolts, and the wire rope 5 passes through the fixed pulley block 6. The wheel is connected to one end of the force sensor 9, and the other end of the force sensor 9 is connected to the wire rope 5 using a lifting lug, and then the wire rope 5 is connected to the round clamp 16 through the round clamp lifting lug 15, thereby forming a structure that can apply a load. The load application structure can accurately control the magnitude of the loading force value, and the measurement result is accurate. A pure torsional load T is applied to the tip of the blade segment to cause the blade segment to be torsional deformed, and then the torsional angle of the selected section of the blade segment is measured by the angle sensor on the surface of the blade segment, and finally the torsional stiffness k of the blade segment is calculated by the formula. The calculation formula is: Where T is the pure torsional load applied to the tip of the blade segment, α l2 is the torsion value measured by the angle sensor at the position of the blade segment close to the blade tip, α l1 It is the torsion value measured by the angle sensor at the position of the blade segment close to the blade root.
[0047] Combination Figure 3 As shown, Figure 3 The fixed end structure schematic diagram of the wind turbine blade torsional stiffness test device in an embodiment of the present application is shown. In some embodiments, the clamping element 2 includes a wooden plywood 23, a screw rod 22 and a wooden plywood fixing block 24. The wooden plywood 23 includes an upper wooden plywood and a lower wooden plywood. The wooden plywood fixing block 24 is arranged at both ends of the wooden plywood 23 and connected to the wooden plywood. At the same time, the wooden plywood fixing block 24 is also connected to the crossbeam 21. The wooden plywood fixing block 24 can move on the crossbeam 21. The screw rod 22 passes through the upper crossbeam and the lower crossbeam. The fixed end 32 is connected by the combination of the crossbeam 21 and the wooden plywood, and then the root part of the blade segment is clamped by the screw rod 22, and then the crossbeam 21 is connected to the column 20 by bolts. In order to improve the stability of the fixed end 32, a diagonal brace 19 is added to the side of the column 20 and fixed to the column 20 by bolts, and then fixed to the foundation by a combination of anchor bolts. By adjusting the height of the crossbeam 21 on the column 20, wooden plywood of different heights can be clamped. Since the wooden plywood fixing block 24 can move on the crossbeam 21, wooden plywood of any width can be fixed. Any angle of the blade can be achieved by making a blade clamp of a specific angle. At the same time, the blade clamp, screw rod 1 and blade clamp fixing block at the loading end can make corresponding adjustments following the fixing end, so as to achieve the clamping of the blade segment at any angle in the horizontal or vertical direction.
[0048] The present application also includes a test method using a wind turbine blade torsional stiffness test device, the test method mainly comprising: 1) fixing the root portion of the blade segment; 2) fixing the tip portion of the blade segment; 3) installing a sensor; 4) balancing the blade weight; 5) collecting data; 6) data processing; the specific operations are as follows:
[0049] Fix the root of the blade segment: first fix the device to the foundation 8 with a combination of anchor bolts and nuts, then use a wooden plywood to clamp the blade segment at the fixed end, the wooden plywood is positioned by a wooden plywood fixing block, and the wooden plywood and the blade segment are clamped by a combination of a lead screw and a nut. There are two groups of columns, each with two distributed on both sides of the wooden plywood, and each column is provided with a diagonal brace on the outside. The combination of the column and the diagonal brace finally achieves the stability of the force of the fixed end tooling.
[0050] The tip of the fixed blade segment: The loading end is mainly fixed by a circular fixture, and a force sensor 9 is installed on the wire rope to ensure that the upper and lower torques of the loading end remain consistent.
[0051] Install sensors: various sensors are placed on the surface of the blade segment 33 according to the area of the blade segment to be observed, including angle sensors, displacement sensors, etc., which are pasted on key positions such as the windward main beam, leeward main beam, and leading and trailing edges of the blade segment at predetermined intervals. The values of each sensor are reset before load loading. After the torsional load is applied at the loading end, each sensor collects data such as strain, displacement, and rotation angle. The sensor outputs analog signals (voltage, current, resistance) or digital signals (binary signals), which are output to the signal acquisition system through a transmitter, and then the data is saved by the host computer and displayed on the display to monitor the force response characteristics of the blade segment in real time.
[0052] Balancing blade weight: In order to reduce the test error caused by the deadweight of the blade segment, a gravity balancing device 13 is provided under the circular fixture. The load-bearing sensor displays the deadweight of the current circular fixture and the blade segment. The load on the gravity balancing device is controlled to be the total weight of the circular fixture and the blade segment to achieve gravity balance. The weight of the blade tip is calculated by the weighing sensor 11 at the loading end 31, and then the jack 12 and the gravity balancing device 13 are used to balance the weight of the blade. The imbalance of the blade weight may lead to uneven torque distribution during the test. By balancing the blade weight, the test data is made more reliable.
[0053] Collect data: Before the test begins, ensure that the blade is in the zero-degree chordal position. Use a step-by-step loading method, which can be 25%, 50%, 75%, 100% (recommended but not limited to), starting from a lower load level, which helps to detect the behavior of the blade under low stress levels and avoid sudden damage to the blade due to excessive load; use a step-by-step unloading method, which can be 100%, 75%, 50%, 25% (recommended but not limited to), after reaching the highest predetermined load, gradually reduce until completely unloaded, and predict the rebound amount and any residual deformation of the blade; use strain gauges, displacement sensors, angle sensors, etc. to monitor the strain, displacement, angle and other changes of the blade under torsional load in real time, and use data analysis software to perform steady-state, modal and other analyses based on the dynamic response data of the blade during the test, to help analyze the stress and strain distribution of the blade under specific loads and predict the rebound amount and residual deformation of the blade.
[0054] Data processing: Calculate the average angle, correction angle and deviation from the theoretical rotation angle of the windward main beam, leeward main beam and leading and trailing edges. The torsional stiffness k of the blade is calculated mainly by comparing the angles of each section of the blade before and after the force is applied. The calculation formula is: Where T is the pure torsional load applied to the tip of the blade segment, α l2 is the torsion value measured by the angle sensor at the position of the blade segment close to the blade tip, α l1 is the torsion value measured by the angle sensor at the position of the blade segment close to the blade root; the calculation formula of T is F is the axial force of the wire rope measured by the force sensor, and R is the sum of the radius of the circular clamp and the effective height of the circular clamp lifting lug.
[0055] There are two verification situations: supported and unsupported blade tips. By comparing the test data of the two blade tip forms with the finite element simulation data, it can be seen that the test values are basically consistent with the simulation analysis values; and the angles of each part of the blade are highly consistent during the supported torsion test, and the average deviation between the unsupported torsion test value of the blade tip and the theoretical value is small; in addition, the test device can be used as a device to verify the torsional stiffness of blades of various models.
[0056] In this test method, the devices in multiple parts can be adjusted according to actual conditions. For example, the reaction support 1 can be replaced by a mechanical or concrete load-bearing device or base capable of bearing lateral loads; the electric cylinder 3 can be replaced by a hydraulic cylinder, a winch, or a pneumatic cylinder; the fisheye rod 4 can be replaced by a hinge connector; and the diagonal brace 19 can be replaced by a retractable structural reinforcement device whose length is controlled by threads.
[0057] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0058] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A wind turbine blade torsional stiffness testing device, characterized in that: The testing device comprises a loading end, a fixed end and a blade segment, the loading end and the fixed end are arranged opposite to each other, and the blade segment is placed between the loading end and the fixed end; The loading end includes a reaction support, a clamping element 1, two load applying elements, a weighing sensor, a jack and a gravity balancing device. The reaction support includes two groups, each group of reaction supports is arranged on both sides of the clamping element 1, and the two load applying elements are connected to the clamping element 1 through a round clamp lifting ear, and the blade segment is pulled in relative directions by an upper and lower double-point method. The gravity balancing device is arranged below the clamping element 1, and the weighing sensor and the jack are arranged below the gravity balancing device; The fixed end includes an oblique brace, a column, a crossbeam and a second clamping element. The crossbeam includes an upper crossbeam and a lower crossbeam. The second clamping element is arranged between the upper crossbeam and the lower crossbeam. The crossbeam is connected to the column, and the oblique brace is arranged on the side of the column.
2. The wind turbine blade torsional stiffness testing device according to claim 1, characterized in that: The clamping element 1 includes a wooden clamp fixing block, a round clamp, a wooden clamp and a screw rod 1. The round clamp includes an upper round clamp and a lower round clamp. The wooden clamp includes an upper wooden clamp and a lower wooden clamp. The wooden clamp is arranged between the round clamps. The wooden clamp fixing blocks are arranged at both ends of the wooden clamp and the wooden clamp fixing blocks are connected to the wooden clamp. At the same time, the wooden clamp fixing blocks are also connected to the round clamp. The screw rod 1 passes through the upper round clamp and the lower round clamp.
3. The wind turbine blade torsional stiffness testing device according to claim 1, characterized in that: The load applying element includes a nose-shaped lifting ear, an electric cylinder, a fisheye rod, a wire rope, a fixed pulley block, a force sensor, and a D-shaped lifting ear. The electric cylinder is fixed to the reaction force bracket through the nose-shaped lifting ear, the electric cylinder is connected to the fisheye rod, the fisheye rod is connected to the wire rope, the fixed pulley block is fixed to the reaction force bracket, the wire rope passes through the fixed pulley to connect one end of the force sensor, and is connected to the other end of the force sensor through the D-shaped lifting ear, and then the wire rope is connected to the round clamp through the round clamp lifting ear.
4. The wind turbine blade torsional stiffness testing device according to claim 1, characterized in that: The second clamping element includes a wooden plywood, a second screw rod and a wooden plywood fixing block. The wooden plywood includes an upper wooden plywood and a lower wooden plywood. The wooden plywood fixing blocks are arranged at both ends of the wooden plywood and are connected to the wooden plywood. At the same time, the wooden plywood fixing blocks are also connected to the crossbeam. The second screw rod passes through the upper crossbeam and the lower crossbeam.
5. The wind turbine blade torsional stiffness testing device according to claim 1, characterized in that: The testing device also includes a foundation, on which a plurality of grooves are arranged at intervals, and the loading end and the fixing end are slidably connected to the foundation through the grooves.
6. The wind turbine blade torsional stiffness testing device according to claim 2, characterized in that: The loading end and the fixing end are connected to the foundation by a combination of anchor bolts and nuts.
7. The wind turbine blade torsional stiffness testing device according to claim 2, characterized in that: The reaction support at the loading end is connected to the foundation, and the column and the diagonal support at the fixed end are both connected to the foundation.
8. The wind turbine blade torsional stiffness testing device according to claim 1, characterized in that: The columns are arranged in two groups, and each group has two columns arranged on both sides of the second clamping element.
9. The wind turbine blade torsional stiffness testing device according to claim 1, characterized in that: Side supports are arranged on the sides of the reaction force bracket.
10. A testing method using the testing device according to any one of claims 1 to 9, characterized in that: The specific steps of the testing method include: Fixing the root portion of the blade segment: clamping the root portion of the blade segment with a clamping element 2 at the fixed end; Fixing the tip of the blade segment: clamping the tip of the blade segment with a clamping element at the loading end; Install sensors: Place various sensors on the surface of the blade segment and stick them on the key parts of the blade segment at a predetermined interval. Before loading, the values of each sensor are reset to zero. After the torsional load is applied to the loading end, each sensor collects data. The sensor outputs an analog signal or a digital signal, which is output to the signal acquisition system through a transmitter. The data is then saved by the host computer and displayed on the display to monitor the force response characteristics of the blade segment in real time. Among them, the analog signal is voltage, current and resistance, and the digital signal is a binary signal. Balancing blade weight: The tip weight of the blade is calculated by the load cell at the loading end, and then the weight of the blade is balanced using a jack and a gravity balance device; Collect data: Ensure that the blade is at zero degree chordwise position before the test begins, and adopt a step-by-step loading and unloading method to predict the blade's springback and residual deformation; Data processing: The torsional stiffness k of the blade is calculated by comparing the angles of each section of the blade before and after the force is applied. The calculation formula is: Where T is the pure torsional load applied to the tip of the blade segment, α l2 is the torsion value measured by the angle sensor at the position of the blade segment close to the blade tip, α l1 is the torsion value measured by the angle sensor at the position of the blade segment close to the blade root; further, the calculation formula of T is F is the axial force of the wire rope measured by the force sensor, and R is the sum of the radius of the circular clamp and the effective height of the circular clamp lifting lug.