A test method for stiffness of large carbon fiber blades

Abstract

The present invention discloses a large carbon fiber blade stiffness test method, comprising the following steps: preparing a test device and a large carbon fiber blade to be tested; installing the blade on the test device, and fixing a displacement sensor for detecting the deformation of the blade to the outer edge of the top of the blade; using the test device to load a set load for forward stretching in a front-to-rear direction of the blade step by step, after each loading is completed, the load is unloaded to zero, and after a set time of unloading, it is loaded again until the load is loaded to a set first maximum resultant force, and the swing stiffness test is completed; using the test device to load a set load for upward stretching in a height direction of the blade step by step, after each loading is completed, the load is unloaded to zero, and after a set time of unloading, it is loaded again until the load is loaded to a second maximum resultant force, and the flapping stiffness test is completed; using the present invention to implement a swing stiffness test and a flapping stiffness test of a large carbon fiber blade, can accurately and scientifically obtain test data.

Description

Technical Field

[0001] The invention relates to the technical field of blade stiffness testing, in particular to a method for testing the stiffness of a large carbon fiber blade. Background Art

[0002] Carbon fiber composites are increasingly used in aerospace due to their high modulus, low density, high strength, excellent high-temperature performance, and good formability. Currently, carbon fiber composites are widely used in blades. To ensure their strength, blades require mechanical testing. However, existing test fixtures are not suitable for testing large blades. Furthermore, the outer edge of the blade is a non-uniform surface, making it difficult to apply loads uniformly across different sections. Summary of the Invention

[0003] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0004] In view of the above and / or existing problems in the preparation of existing ship cabin outer plates, the present invention is proposed.

[0005] Therefore, the purpose of the present invention is to provide a large carbon fiber blade stiffness test method. The present invention can realize the swing stiffness test and flapping stiffness test of large carbon fiber blades, and gradually load the blades in multiple levels to obtain test data accurately and scientifically.

[0006] To solve the above technical problems, the present invention provides the following technical solution: a large carbon fiber blade stiffness test method, comprising the following steps:

[0007] S1. Prepare the test equipment and the large carbon fiber blade to be tested;

[0008] S2. Install the large carbon fiber blade onto the test equipment, and fix the displacement sensor used to detect the blade deformation to the outer edge of the blade top;

[0009] S3. Use the test equipment to gradually apply a set forward tensile load in the front-to-back direction of the blade. After each loading is completed, the load is unloaded to zero. After unloading for a set time, it is loaded again until the load reaches the set first maximum resultant force. The shimmy stiffness test is completed;

[0010] S4. Use the test equipment to gradually apply a set upward tensile load in the height direction of the blade. After each loading is completed, the load is unloaded to zero. After unloading for a set time, it is loaded again until the load reaches the second maximum resultant force. The flapping stiffness test is completed;

[0011] Each time loading is performed, the load value and blade deformation are recorded in real time.

[0012] As a preferred solution of the stiffness test method for medium and large carbon fiber blades of the present invention, the test equipment includes a test base, an end seat is fixedly connected to the upper side of one end of the test base in the length direction, and a position-adjustable stiffness test frame is connected to the test base, a support seat is fixedly connected to the upper side of the test base between the end seat and the stiffness test frame, the support ring of the blade is rotatably connected to the support seat, and the end of the blade is connected to the end seat so that the blade cannot rotate; a deformation test frame is provided on the right side of the stiffness test frame, and two pull-wire displacement sensors are fixedly connected to the deformation test frame, and the sensing ends of the two pull-wire displacement sensors are respectively fixedly connected to the blade tops.

[0013] As a preferred solution of the stiffness test method for large carbon fiber blades of the present invention, the end seat is fixedly connected with clamping columns spaced apart in the front-to-back direction, and the two clamping columns clamp the root joint of the blade to prevent it from twisting.

[0014] As a preferred solution of the stiffness test method for medium and large carbon fiber blades of the present invention, the test equipment also includes a swing stiffness actuator cylinder fixedly connected to the upper end of the stiffness test frame, the swing stiffness actuator cylinder is connected to a swing stiffness test rod extending downward and capable of reciprocating linear motion, the lower end of the swing stiffness test rod is connected to a swing stiffness connecting lever assembly, and the lower end of the swing stiffness connecting lever assembly is connected to the blade.

[0015] As a preferred solution of the stiffness test method for medium and large carbon fiber blades of the present invention, the test equipment also includes a swing stiffness actuator cylinder fixedly connected to the front end of the stiffness test frame, and the swing stiffness actuator cylinder is connected to a swing stiffness test rod extending downward and capable of reciprocating linear motion, the lower end of the swing stiffness test rod is connected to a swing stiffness connecting lever assembly, and the rear end of the swing stiffness connecting lever assembly is connected to the blade.

[0016] As a preferred solution of the stiffness test method for medium and large carbon fiber blades of the present invention, wherein: a plurality of tape strips spaced apart in the left-right direction are bonded to the upward end of the blade, a first connecting strip and a second connecting strip spaced apart in the front-back direction are fixed to the upper end of the tape strip, the first connecting strip has a first plug interface at the center in the left-right direction, the first connecting strip has a first plug hole on the left and right sides of the first plug interface, the second connecting strip has a second plug interface at the center in the left-right direction, and the first connecting strip has a second plug hole on the left and right sides of the second plug interface.

[0017] As a preferred solution of the stiffness test method for large carbon fiber blades of the present invention, the swing stiffness connecting lever assembly includes an upper swing stiffness connecting lever fixedly connected to the lower end of the swing stiffness test rod, and a plurality of first plug-in rods corresponding to the first connecting belt. The lower end of the upper swing stiffness connecting lever is fixedly connected to the upper swing stiffness test connecting beam, and the left and right ends of the upper swing stiffness test connecting beam are respectively fixedly connected to the left middle swing stiffness connecting lever and the first right middle swing stiffness connecting lever extending downward. The lower end of the first left middle swing stiffness connecting lever is connected to the first lower swing stiffness test connecting beam, and the lower end of the first lower swing stiffness test connecting beam is connected to two first lower swing stiffness connecting levers. The lower end of the first lower swing stiffness connecting lever is fixed with a first lower swing stiffness connecting lever plugged in at the corresponding plug interface. A swing stiffness test connecting ring, a first connecting rod is plugged into the first swing stiffness test connecting ring, the two first connecting rods at the leftmost end are respectively inserted into the corresponding first connecting holes and plugged into the corresponding first swing stiffness test connecting ring, the lower end of the first right middle swing stiffness connecting lever is fixedly connected to the middle swing stiffness test connecting beam, a number of second right middle swing stiffness connecting levers are arranged at the lower end of the middle swing stiffness test connecting beam, the lower end of the second right middle swing stiffness connecting lever is fixedly connected to the second lower swing stiffness test connecting beam, two second lower swing stiffness connecting levers are fixedly connected to the second swing stiffness test connecting ring, the lower end of the second lower swing stiffness connecting lever is fixed with the second swing stiffness test connecting ring, and a number of first connecting rods on the right side of the first lower swing stiffness test connecting beam are respectively plugged into the corresponding second swing stiffness test connecting ring.

[0018] As a preferred solution of the stiffness test method for medium and large carbon fiber blades of the present invention, wherein: the swing stiffness connecting lever assembly includes a front swing stiffness connecting lever fixedly connected to the rear end of the swing stiffness test rod, a plurality of second plug-in rods corresponding one to one with the second connecting belt, the rear end of the front swing stiffness connecting lever is fixedly connected to the front swing stiffness test connecting beam, the left and right ends of the front swing stiffness test connecting beam are respectively fixedly connected to the left middle swing stiffness connecting lever and the first right middle swing stiffness connecting lever extending backward, the rear end of the left middle swing stiffness connecting lever is connected to the first rear swing stiffness test connecting beam, the rear end of the first rear swing stiffness test connecting beam is connected to two first rear swing stiffness connecting levers, the rear end of the first rear swing stiffness connecting lever is fixed with the first swing stiffness test connecting beam plugged in at the corresponding plug interface The connecting ring has a first swing stiffness test connecting rod connected to the front of the first swing stiffness test connecting ring, and the two second connecting rods are respectively connected to the two second connecting belts on the left end through the two first connecting holes on the left end. The rear end of the first right middle swing stiffness connecting lever is fixedly connected to the middle swing stiffness test connecting beam, and a number of second right middle swing stiffness connecting levers are arranged at the rear end of the middle swing stiffness test connecting beam. The rear end of the second right middle swing stiffness connecting lever is fixedly connected to the second rear swing stiffness test connecting beam, and the rear end of the second rear swing stiffness test connecting beam is fixedly connected to two second rear swing stiffness connecting levers. The rear end of the second rear swing stiffness connecting lever is fixed with a second swing stiffness test connecting ring, and a number of second connecting rods on the right side of the first rear swing stiffness test connecting beam are respectively connected to the corresponding second swing stiffness test connecting rings.

[0019] As a preferred solution of the large carbon fiber blade stiffness test method of the present invention, wherein: the step S3 is specifically,

[0020] S301: First load the shimmy stiffness test at 20% of the maximum resultant force, with a load ramp-up time of 30 seconds and a load hold time of 60 seconds, eliminating mechanical clearance.

[0021] S302, unload to zero, wait 150s, then load step by step according to 20% of the maximum resultant force of the shimmy stiffness test, with each load increasing time of 20s and holding time of 60s;

[0022] After each loading in S303 is completed, the load is unloaded to zero. After 120 to 150 seconds of unloading, the second test is allowed to proceed until the load reaches the set load of the shimmy stiffness test;

[0023] Among them, the maximum resultant force of the shimmy stiffness test is 26000N.

[0024] As a preferred solution of the large carbon fiber blade stiffness test method of the present invention, wherein: the step S4 is specifically,

[0025] S401: First load the swing stiffness test at 20% of the maximum resultant force, with a load ramp-up time of 30 seconds and a load hold time of 60 seconds to eliminate mechanical backlash.

[0026] S402, unload to zero, wait 150s, then load step by step according to 20% of the maximum resultant force of the swing stiffness test, with each load increasing time of 20s and holding time of 60s;

[0027] After each loading in S403, the load is unloaded to zero. After 120 to 150 seconds of unloading, the second test is allowed until the load reaches the set load of the flapping stiffness test.

[0028] The maximum resultant force of the loading swing stiffness test is 35600N.

[0029] Compared with the prior art, the present invention has the following technical effects: the maximum aerodynamic load during blade operation is simplified and distributed on the blade, adhesive tape is adhered to different sections, and the adhesive tape is connected to the corresponding actuator through the swing stiffness connecting lever assembly and the swing stiffness connecting lever assembly, thereby realizing the swing stiffness and swing stiffness test, and applying a uniform load to each section of the blade, thereby improving the accuracy of the test data; by setting a clamping column, the torsion of the blade is limited, and the accuracy of the test is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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. Among them:

[0031] Figure 1 This is a front view of the blade in the present invention installed on the test equipment.

[0032] Figure 2 The three-dimensional structure of the blade installed on the test equipment in the present invention Figure 1 .

[0033] Figure 3 for Figure 2 A partial enlarged view of point A in the middle.

[0034] Figure 4 The three-dimensional structure of the blade installed on the test equipment in the present invention Figure 2 .

[0035] Figure 5 for Figure 4 A partial enlarged view of point B in the middle.

[0036] Figure 6 for Figure 4 A partial enlarged view of point C in the middle.

[0037] Figure 7 This is a schematic diagram of the adhesive tape being bonded to various cross-sectional locations on the blade.

[0038] Figure 8 Layout diagram of displacement measurement points for blade stiffness test.

[0039] Figure 9 This is the deformation diagram of the blade in the direction of 26000N tension during the swing stiffness test.

[0040] Figure 10 This is the deformation diagram of the blade in the direction of 35600N tension during the flapping stiffness test.

[0041] In the figure: 1 blade, 101 support ring, 2 support seat, 3 clamping column, 4 end seat, 5 stiffness test frame, 501 sliding connecting plate, 6 swing stiffness connecting lever assembly, 601 first lower swing stiffness test connecting beam, 602 left middle swing stiffness connecting lever, 603 upper swing stiffness test connecting beam, 603-1 upper opening, 604 fastening bolt, 605 upper swing stiffness connecting lever, 606 first right middle swing stiffness connecting lever, 607 middle swing stiffness test connecting beam, 608 second lower swing stiffness test connecting beam, 609 second right middle swing stiffness connecting lever, 610 second lower swing stiffness connecting lever, 610-1 second swing stiffness test connecting ring, 611 first lower swing stiffness connecting lever, 611-1 first lower swing stiffness connecting lever, 7 swing stiffness connecting lever assembly, 701 front swing stiffness connecting lever Connecting lever, 702 left middle swing stiffness connecting lever, 703 first rear swing stiffness test connecting beam, 704 second rear swing stiffness test connecting beam, 705 second right middle swing stiffness connecting lever, 706 middle swing stiffness test connecting beam, 707 first right middle swing stiffness connecting lever, 708 front swing stiffness test connecting beam, 709 first rear swing stiffness connecting lever, 709-1 first swing stiffness test connecting ring, 710 second rear swing stiffness connecting lever, 710-1 second swing stiffness test connecting ring, 8 deformation test frame, 9 test base, 10 swing stiffness actuator, 11 swing stiffness actuator, 12 adhesive tape, 1201 second connecting belt, 1201-1 second plug hole, 1202 first connecting belt, 1202-1 first plug hole, 13 second plug rod, 14 first plug rod, 15 swing stiffness test rod, 16 shimmy stiffness test rod, 17 wire-type displacement sensor. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0044] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0045] Example 1: Reference Figure 2 , which is the first embodiment of the present invention, provides a large carbon fiber blade stiffness test method, which can reliably realize the detection test of the flapping stiffness and shimmy stiffness of the large carbon fiber blade 1 with accurate measurement.

[0046] A large carbon fiber blade stiffness test method comprises the following steps:

[0047] S1. Prepare the test equipment and the large carbon fiber blade 1 to be tested;

[0048] S2. Install the large carbon fiber blade 1 onto the test equipment, and fix the displacement sensor for detecting the deformation of the blade 1 to the outer edge of the top of the blade 1;

[0049] S3. Use the test equipment to gradually apply a set forward tensile load in the front-to-back direction of the blade 1. After each loading is completed, the load is unloaded to zero. After unloading for a set time, the load is applied again until the load reaches the set first maximum resultant force. This completes the shimmy stiffness test.

[0050] S4. Use the test equipment to gradually apply a set upward tensile load in the height direction of the blade 1. After each loading is completed, the load is unloaded to zero. After unloading for a set time, it is loaded again until the load reaches the second maximum resultant force. The flapping stiffness test is completed;

[0051] Each time loading is performed, the load value and the deformation of blade 1 are recorded in real time.

[0052] Step S3 specifically includes:

[0053] S301: First load the shimmy stiffness test at 20% of the maximum resultant force, with a load ramp-up time of 30 seconds and a load hold time of 60 seconds, eliminating mechanical clearance.

[0054] S302, unload to zero, wait 150s, then load step by step according to 20% of the maximum resultant force of the shimmy stiffness test, with each load increasing time of 20s and holding time of 60s;

[0055] After each loading in S303 is completed, the load is unloaded to zero. After 120 to 150 seconds of unloading, the second test is allowed to proceed until the load reaches the set load of the shimmy stiffness test;

[0056] Among them, the maximum resultant force of the shimmy stiffness test is 26000N.

[0057] Step S4 is specifically as follows:

[0058] S401: First load the swing stiffness test at 20% of the maximum resultant force, with a load ramp-up time of 30 seconds and a load hold time of 60 seconds to eliminate mechanical backlash.

[0059] S402, unload to zero, wait 150s, then load step by step according to 20% of the maximum resultant force of the swing stiffness test, with each load increasing time of 20s and holding time of 60s;

[0060] After each loading in S403, the load is unloaded to zero. After 120 to 150 seconds of unloading, the second test is allowed until the load reaches the set load of the flapping stiffness test.

[0061] Among them, the maximum combined force of the loading swing stiffness test is 35600N.

[0062] The specific values of the flapping stiffness test load and the shimmy stiffness test load are shown in Table 1 and Table 2, respectively.

[0063] Table 1 Blade flapping stiffness test load table

[0064]

[0065] Table 2 Blade shimmy stiffness test load table

[0066]

[0067] refer to Figure 8 , when measuring displacement: the displacement measurement point of blade 1 swing stiffness test is as follows Figure 8 As shown, two measuring points are selected on the blade tip, and a pull-rope displacement sensor is used. The measuring points are distributed on the front and rear sides of the axis of blade 1, and the front and rear measuring points are 150 mm away from the axis of blade 1.

[0068] Example 2: Figures 1 to 8 , which is the second embodiment of the present invention, and provides a large carbon fiber blade stiffness test method, which further realizes the testing of the flapping stiffness and shimmy stiffness of the large carbon fiber blade 1.

[0069] Specifically, the test equipment includes a test base 9, which is fixedly connected to an end seat 4 on the upper side of one end in the longitudinal direction, and a position-adjustable stiffness test frame 5 is connected to the test base 9, and the stiffness test frame 5 is slidably connected to the test base 9. A sliding connecting plate 501 is fixed to the bottom of the stiffness test frame 5, and the sliding connecting plate 501 slides on the upper side of the test base 9. The sliding connecting plate 501 is provided with a plurality of connecting holes. When the stiffness test frame 5 is adjusted to a suitable position left and right, fasteners such as fastening bolts 604 are screwed into the connecting holes and the test base to fix the stiffness test frame 5 on the test base 9; a support base 2 is fixedly connected to the upper side of the test base 9 between the end seat 4 and the stiffness test frame 5, and the support ring 101 of the blade 1 is rotatably connected to the support base 2, and the end of the blade 1 is connected to the end seat 4 so that the blade 1 cannot rotate; a deformation test frame 8 is provided on the right side of the stiffness test frame 5, and two pull-wire displacement sensors 17 are fixedly connected to the deformation test frame 8, and only the pull-wire displacement sensors 17 are drawn in the figure. The schematic diagram of the linear displacement sensor 17 does not affect the understanding of the solution by those skilled in the art. The sensing ends of the two wire-type displacement sensors 17 are respectively fixedly connected to the blade top of the blade 1. The end seat 4 is fixedly connected with the clamping columns 3 arranged at intervals in the front-to-back direction. The two clamping columns 3 clamp the root joint of the blade 1 to prevent it from twisting. The upper end of the stiffness test frame 5 is fixedly connected to the swing stiffness actuator 11, and the front end of the stiffness test frame 5 is fixedly connected to the swing stiffness actuator 10. The movable cylinder 11 is connected to a swing stiffness test rod 15 that extends downward and can perform reciprocating linear motion. The lower end of the swing stiffness test rod 15 is connected to a swing stiffness connecting lever assembly 6. The lower end of the swing stiffness connecting lever assembly 6 is connected to the blade 1. The swing stiffness actuator cylinder 10 is connected to a swing stiffness test rod 16 that extends downward and can perform reciprocating linear motion. The lower end of the swing stiffness test rod 16 is connected to the swing stiffness connecting lever assembly 7. The rear end of the swing stiffness connecting lever assembly 7 is connected to the blade 1.

[0070] An upward tensile load is applied to the blade 1 through the flap stiffness actuator 11 , and a forward pulling load is applied to the blade 1 through the shimmy stiffness actuator 10 . Both the flap stiffness actuator 11 and the shimmy stiffness actuator 10 are hydraulic cylinders.

[0071] When installing the carbon fiber blade 1, the support ring 101 of the blade 1 passes through the support seat 2 and is inserted into the end seat 4. The inclined surface of one end of the clamping column 3 is set according to the installation angle of the blade 1. The support ring 101 of the blade 1 is in contact with the right side of the end seat 4. The front and rear two clamping columns 3 and the front and rear sides of the support ring 101 of the clamping column 3 prevent the blade 1 from twisting, further improving the accuracy of the data during the test. Then the rear end of the swing stiffness connecting lever assembly 7 is connected to the forward end of the blade 1, and the lower end of the swing stiffness connecting lever assembly 6 is connected to the upward end of the blade 1.

[0072] In order to further facilitate the connection between each lever assembly and the blade 1 and to simplify and evenly distribute the aerodynamic load of the blade 1 during operation, a plurality of adhesive tapes 12 are bonded to the upper end of the blade 1 at intervals in the left and right directions. Specifically, adhesive tapes 12 are bonded to the eight sections of the blade 1 in the longitudinal direction at 0.6R-0.65R, 0.65R-0.7R, 0.7R-0.75R, 0.75R-0.8R, 0.8R-0.85R, 0.85R-0.9R, 0.9R-0.95R, and 0.95R-1R, and the adhesive tapes 12 are bonded to the eight sections at 0.6R-0.65R, 0.65R-0.7R, 0.7R-0.75R, 0.75R-0.8R, 0.8R-0.85R, 0.85R-0.9R, 0.9R-0.95R, and 0.95R-1R, respectively. The swing stiffness test load and the flapping stiffness test load are loaded on the section at 7R and the axial position of the blade 1. The upper end of the tape 12 is fixed with a first connecting belt 1202 and a second connecting belt 1201 spaced apart in the front-to-back direction. The first connecting belt 1202 has a first plug interface at the center in the left-right direction, and the first connecting belt 1202 on the left and right sides of the first plug interface has a first plug hole 1202-1. The second connecting belt 1201 has a second plug interface at the center in the left-right direction, and the first connecting belt 1202 on the left and right sides of the second plug interface has a second plug hole 1201-1.

[0073] In order to further realize the connection between the actuator and the tape 12, the swing stiffness connecting lever assembly 6 includes an upper swing stiffness connecting lever 605 fixedly connected to the lower end of the swing stiffness test rod 15, and a plurality of first connecting rods 14 corresponding to the first connecting belt 1202. The lower end of the upper swing stiffness connecting lever 605 is fixedly connected to the upper swing stiffness test connecting beam 603. The left and right ends of the upper swing stiffness test connecting beam 603 are respectively fixedly connected to the left middle swing stiffness connecting lever 602 and the first right middle swing stiffness connecting lever 606 extending downward. The lower end of the first left middle swing stiffness connecting lever 602 is connected to the first lower swing stiffness test connecting beam 601. The lower end of the first lower swing stiffness test connecting beam 601 is connected to two first lower swing stiffness connecting levers 611-1611. The lower ends of the first lower swing stiffness connecting levers 611-1611 are fixed with first swing stiffness test connecting levers plugged in at the corresponding plug-in interfaces. Test connecting ring, a first plug-in rod 14 is plugged into the first swing stiffness test connecting ring, and the two first plug-in rods 14 at the leftmost end are respectively inserted into the corresponding first plug-in holes 1202-1 and plugged into the corresponding first swing stiffness test connecting ring. The lower end of the first right middle swing stiffness connecting lever 606 is fixedly connected to the middle swing stiffness test connecting beam 607, and a plurality of second right middle swing stiffness connecting levers 609 are arranged at the lower end of the middle swing stiffness test connecting beam 607. The lower end of the second right middle swing stiffness connecting lever 609 is fixedly connected to the second lower swing stiffness test connecting beam 608, and two second lower swing stiffness connecting levers 610 are fixedly connected to the second lower swing stiffness test connecting ring 610-1. The plurality of first plug-in rods 14 on the right side of the first lower swing stiffness test connecting beam 601 are respectively plugged into the corresponding second swing stiffness test connecting ring 610-1.The swinging stiffness connecting lever assembly 6 includes a front swinging stiffness connecting lever 701 fixedly connected to the rear end of the swinging stiffness test rod 15, and a plurality of second plug-in rods 13 corresponding to the second connecting belt 1201. The rear end of the front swinging stiffness connecting lever 701 is fixedly connected to a front swinging stiffness test connecting beam 708. The left and right ends of the front swinging stiffness test connecting beam 708 are respectively fixedly connected to a left middle swinging stiffness connecting lever 702 and a first right middle swinging stiffness connecting lever 707 extending backward. The rear end of the left middle swinging stiffness connecting lever 702 is connected to a first rear swinging stiffness test connecting beam 703. The rear end of the first rear swinging stiffness test connecting beam 703 is connected to two first rear swinging stiffness connecting levers 709. The rear end of the first rear swinging stiffness connecting lever 709 is fixed with a first swinging stiffness test connecting ring 709-1 plugged in at the corresponding plug-in interface. The first swinging stiffness test connecting ring 709-1 is plugged in at the front. A swing stiffness test plug-in rod. Two second plug-in rods 13 are plugged into the two second connecting straps 1201 on the left end through the two first plug-in holes 1202-1 on the left end. The rear end of the first right intermediate swing stiffness test connecting lever 707 is fixedly connected to the intermediate swing stiffness test connecting beam 706. Several second right intermediate swing stiffness test connecting levers 705 are arranged at the rear end of the intermediate swing stiffness test connecting beam 706. The rear end of the second right intermediate swing stiffness test connecting lever 705 is fixedly connected to the second rear swing stiffness test connecting beam 704. The rear end of the second rear swing stiffness test connecting beam 704 is fixedly connected to two second rear swing stiffness test connecting levers 710. The rear end of the second rear swing stiffness test connecting lever 710 is fixed to a second swing stiffness test connecting ring 710-1. The several second plug-in rods 13 to the right of the first rear swing stiffness test connecting beam 703 are respectively plugged into the corresponding second swing stiffness test connecting ring 710-1.

[0074] Step S1 also includes the step of installing the large carbon fiber blade 1 on the testing equipment, and the specific steps are as follows:

[0075] S101. After the support ring 101 of the blade 1 partially passes through the support seat 2, the support ring 101 of the blade 1 is brought close to the clamping column 3. The blade 1 is rotated so that the support ring 101 of the blade 1 is aligned with the two clamping columns 3. The blade 1 is moved horizontally. The left end of the support ring 101 of the blade 1 abuts against the right side of the end seat 4. The front and rear two clamping columns 3 clamp the front and rear sides of the support ring 101 of the clamping column 3 to prevent the blade 1 from twisting.

[0076] S102, sticking adhesive tape 12 on eight sections of the blade 1 along the length direction, namely 0.6R-0.65R, 0.65R-0.7R, 0.7R-0.75R, 0.75R-0.8R, 0.8R-0.85R, 0.85R-0.9R, 0.9R-0.95R, and 0.95R-1R;

[0077] S103. Install all stiffness connecting lever assemblies except the first plug-in rod 14 and the second plug-in rod 13 at appropriate positions on the test frame. Plug all stiffness test connecting rings into the corresponding connecting strip's plug-in interface. Insert the first plug-in rod 14 into the first plug-in hole 1202-1 on one side of the first plug-in interface and then pass it through the swing stiffness test connecting ring. Then, plug the first plug-in rod 14 into the first plug-in hole 1202-1 on the other side of the first plug-in interface. Insert the second plug-in rod 13 into the second plug-in hole 1201-1 on one side of the second plug-in interface and then pass it through the swing stiffness test connecting ring. Then, plug the second plug-in rod 13 into the second plug-in hole 1201-1 on the other side of the second plug-in interface. The central axes of the front swing stiffness connecting lever 701 and the upper swing stiffness connecting lever 605 are at the cross-section of the blade 10.7R.

[0078] Taking the main view as a reference, in this application, the position of 0R is on the left of the test base 9, the straight-line distance between the position of 0R and the right side of the support base 2 is 4200mm, the straight-line distance between the position of OR and the right side of the blade 1 is 7000mm, and the position of the tape 12 on the 8 sections and the load loading position are referenced. Figure 7 .

[0079] The joint arrangement of the adhesive tape 12 and the lever assembly facilitates the connection between the blade 1 and the stiffness connection lever, and the load is gradually applied in five levels on the section at 0.7R and the axis position of the blade 1, so that the test data can be accurately and scientifically obtained.

[0080] Example 3: Reference Figure 3 , which is the third embodiment of the present invention. The difference between this embodiment and embodiment 2 is that it can further facilitate the test of the connection between the connecting beam and the corresponding connecting lever, and is more convenient for disassembly and assembly.

[0081] Specifically, an upper opening 603-1 is provided on the upper swing stiffness test connecting beam 603, which runs through the upper and lower parts. The lower end of the upper swing stiffness connecting lever 605 is just inserted into the upper opening 603-1. An upper connecting hole is provided on the lower part of the upper swing stiffness connecting lever 605. Several upper fixing holes are arranged in the length direction of the upper swing stiffness test connecting beam 603. A fixing bolt is screwed into the upper fixing hole on the front side of the upper opening 603-1 and then passes through the upper connecting hole and the upper fixing hole on the rear side of the upper opening 603-1. Then, a fixing nut is screwed on the fixing bolt on the rear side of the upper swing stiffness test connecting beam 603, and the fixing nut is pressed tightly on the rear side of the upper swing stiffness test connecting beam 603.

[0082] The overall structures of the various connecting levers are similar, differing only in length. The overall structures of the various test connecting beams are also similar, differing only in length. Therefore, the connection structures between the intermediate swing stiffness connecting levers and the corresponding intermediate swing stiffness test connecting beams 607, the connection structures between the upper ends of the lower swing stiffness connecting levers and the corresponding lower swing stiffness test connecting beams, the connection structures between the intermediate shimmy stiffness connecting levers and the corresponding intermediate shimmy stiffness test connecting beams 706, the connection structures between the rear shimmy stiffness connecting levers and the corresponding rear shimmy stiffness test connecting beams, and the connection structures between the front shimmy stiffness connecting levers 701 and the front shimmy stiffness test connecting beams 708 are similar to the connection structures between the upper swing stiffness connecting levers 605 and the upper swing stiffness test connecting beams 603, and are not further described here.

[0083] Example 4: Reference Figure 9 and Figure 10 This embodiment is the third embodiment of the present invention. The difference between this embodiment and embodiments 1 and 2 is that scientific experiments are used to verify that the present invention can accurately detect the stiffness of a large carbon fiber blade 1.

[0084] Shimmy stiffness test:

[0085] ABAQUS software was used to calculate the displacement deviation under the same load. The calculated and measured values were summarized in Table 3, and the errors between the calculated and measured values were compared.

[0086] Table 3 Comparison of measured and calculated displacements after blade shimmy stiffness test load loading

[0087]

[0088] After comparing the calculated results with the measured results, it can be seen from the table data that the shimmy stiffness meets the design requirements.

[0089] Flapping stiffness test:

[0090] ABAQUS software was used to calculate the displacement deviation under the same load. The calculated and measured values were summarized in Table 4, and the errors between the calculated and measured values were compared.

[0091] Table 4 Comparison of measured and calculated displacements after blade flapping stiffness test load loading

[0092]

[0093] After comparing the calculated results with the measured results, it can be seen from the table data that the flapping stiffness meets the design requirements.

[0094] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A large carbon fiber blade stiffness test method, characterized by: The following steps are included: S1. Prepare the test equipment and the large carbon fiber blade to be tested (1); S2. The large carbon fiber blade (1) is mounted on the test equipment, and a displacement sensor for detecting the deformation of the large carbon fiber blade (1) is fixed to the outer edge of the top of the large carbon fiber blade (1); S3, using the test equipment to load the large carbon fiber blade (1) with a set forward tensile load in a step-by-step manner in the front-to-back direction, after each loading is completed, the load is unloaded to zero, and after the unloading time is set, the load is loaded again until the load reaches the set first maximum resultant force, and the shimmy stiffness test is completed; S4, using the test equipment to load the set upward tensile load step by step in the height direction of the large carbon fiber blade (1), after each loading is completed, the load is unloaded to zero, and after the unloading set time, it is loaded again until the load is loaded to the second maximum resultant force, and the flapping stiffness test is completed; Each time loading is performed, the load value and deformation of the large carbon fiber blade (1) are recorded in real time; The test equipment comprises a test base (9), wherein the upper side of one end of the test base (9) in the longitudinal direction is fixedly connected to an end seat (4), a position-adjustable stiffness test frame (5) is connected to the test base (9), a support seat (2) is fixedly connected to the upper side of the test base (9) between the end seat (4) and the stiffness test frame (5), a support ring (101) of the large carbon fiber blade (1) is rotatably connected to the support seat (2), and the end of the large carbon fiber blade (1) is connected to the end seat (4) so that the large carbon fiber blade (1) cannot rotate; a deformation test frame (8) is provided on the right side of the stiffness test frame (5), and two wire-type displacement sensors (17) are fixedly connected to the deformation test frame (8), and the sensing ends of the two wire-type displacement sensors (17) are respectively fixedly connected to the blade top of the large carbon fiber blade (1); The test equipment further comprises a swing stiffness actuator cylinder (11) fixedly connected to the upper end of the stiffness test frame (5); a swing stiffness test rod (15) extending downward and capable of reciprocating linear motion is connected to the swing stiffness actuator cylinder (11); the lower end of the swing stiffness test rod (15) is connected to a swing stiffness connecting lever assembly (6); and the lower end of the swing stiffness connecting lever assembly (6) is connected to the large carbon fiber blade (1); The test equipment further comprises a shimmy stiffness actuator cylinder (10) fixedly connected to the front end of the stiffness test frame (5); a shimmy stiffness test rod (16) extending downward and capable of reciprocating linear motion is connected to the shimmy stiffness actuator cylinder (10); a shimmy stiffness connecting lever assembly (7) is connected to the lower end of the shimmy stiffness connecting lever assembly (7); and a rear end of the shimmy stiffness connecting lever assembly (7) is connected to the large carbon fiber blade (1); A plurality of adhesive tapes (12) arranged at intervals in the left-right direction are bonded to an upward end of the large carbon fiber blade (1); a first connecting tape (1202) and a second connecting tape (1201) arranged at intervals in the front-back direction are fixed to the upper end of the adhesive tape (12); the first connecting tape (1202) has a first plug interface at the center in the left-right direction, and the first connecting tape (1202) on the left and right sides of the first plug interface has first plug holes (1202-1); the second connecting tape (1201) has a second plug interface at the center in the left-right direction, and the first connecting tape (1202) on the left and right sides of the second plug interface has second plug holes (1201-1).

2. The large carbon fiber blade stiffness test method according to claim 1, wherein: The end seat (4) is fixedly connected to clamping columns (3) spaced apart in the front-rear direction, and the two clamping columns (3) clamp the blade root joint of the large carbon fiber blade (1) to prevent it from twisting.

3. The large carbon fiber blade stiffness test method according to claim 1 or 2, characterized in that: The swing stiffness connecting lever assembly (6) comprises an upper swing stiffness connecting lever (605) fixedly connected to the lower end of the swing stiffness test rod (15), and a plurality of first plug-in rods (14) corresponding one to one with the first connecting belt (1202). The lower end of the upper swing stiffness connecting lever (605) is fixedly connected to an upper swing stiffness test connecting beam (603), and the left and right ends of the upper swing stiffness test connecting beam (603) are respectively fixedly connected to a left middle swing stiffness connecting lever (603) extending downward. 2) and a first right middle swing stiffness connecting lever (606), the lower end of the left middle swing stiffness connecting lever (602) is connected to a first lower swing stiffness test connecting beam (601), the lower end of the first lower swing stiffness test connecting beam (601) is connected to two first lower swing stiffness connecting levers (611-1) (611), the lower end of the first lower swing stiffness connecting lever (611-1) (611) is fixed with a first swing stiffness test connecting ring plugged into the corresponding plug interface, A first plug-in rod (14) is plugged into a swing stiffness test connection ring, and the two first plug-in rods (14) at the leftmost end respectively pass through the corresponding first plug-in holes (1202-1) and are plugged into the corresponding first swing stiffness test connection ring. The lower end of the first right middle swing stiffness connection lever (606) is fixedly connected to the middle swing stiffness test connection beam (607), and the lower end of the middle swing stiffness test connection beam (607) is arranged with a plurality of second right middle swing stiffness connection levers (609). The lower end of the intermediate swing stiffness connecting lever (609) is fixedly connected to the second lower swing stiffness test connecting beam (608), to which two second lower swing stiffness connecting levers (610) are fixedly connected. The lower end of each of the second lower swing stiffness connecting levers (610) is fixed to a second swing stiffness test connecting ring (610-1), and a plurality of first plug-in rods (14) on the right side of the first lower swing stiffness test connecting beam (601) are respectively plugged into corresponding second swing stiffness test connecting rings (610-1).

4. The large carbon fiber blade stiffness test method according to claim 3, characterized in that: The swing stiffness connecting lever assembly (6) comprises a front swing stiffness connecting lever (701) fixedly connected to the rear end of the swing stiffness test rod (15), and a plurality of second plug-in rods (13) corresponding to the second connecting belt (1201). The rear end of the front swing stiffness connecting lever (701) is fixedly connected to a front swing stiffness test connecting beam (708). The left and right ends of the front swing stiffness test connecting beam (708) are respectively fixedly connected to a left middle swing stiffness connecting lever (702) extending backward and a first right middle swing stiffness connecting lever ( 707), the rear end of the left middle shimmy stiffness connecting lever (702) is connected to the first rear shimmy stiffness test connecting beam (703), the rear end of the first rear shimmy stiffness test connecting beam (703) is connected to two first rear shimmy stiffness connecting levers (709), the rear end of the first rear shimmy stiffness connecting lever (709) is fixed with a first shimmy stiffness test connecting ring (709-1) plugged into the corresponding plug interface, the front of the first shimmy stiffness test connecting ring (709-1) is plugged with a first shimmy stiffness test plug rod, and two second plug rods ( 13) are respectively connected to the two second connecting belts (1201) on the left end through the two first plug holes (1202-1) on the left end, the rear end of the first right middle swing stiffness connecting lever (707) is fixedly connected to the middle swing stiffness test connecting beam (706), and the rear end of the middle swing stiffness test connecting beam (706) is arranged with a plurality of second right middle swing stiffness connecting levers (705). In this application, the rear end of the middle swing stiffness test connecting beam (706) is arranged with three second right middle swing stiffness connecting levers (705). The rear end of the stiffness connecting lever (705) is fixedly connected to a second rear oscillation stiffness test connecting beam (704), the rear end of the second rear oscillation stiffness test connecting beam (704) is fixedly connected to two second rear oscillation stiffness connecting levers (710), the rear ends of the second rear oscillation stiffness connecting levers (710) are fixed to a second oscillation stiffness test connecting ring (710-1), and a plurality of second plug-in rods (13) on the right side of the first rear oscillation stiffness test connecting beam (703) are respectively plugged into corresponding second oscillation stiffness test connecting rings (710-1).

5. The large carbon fiber blade stiffness test method according to claim 4, characterized in that: The step S3 is specifically as follows: S301: First load the shimmy stiffness test at 20% of the maximum resultant force, with a load ramp-up time of 30 seconds and a load hold time of 60 seconds, eliminating mechanical clearance. S302, unload to zero, wait 150s, then load step by step according to 20% of the maximum resultant force of the shimmy stiffness test, with each load increasing time of 20s and holding time of 60s; S303. After each loading is completed, the load is unloaded to zero. After 120 to 150 seconds of unloading, a second test is allowed until the load reaches the set load for the shimmy stiffness test. Among them, the maximum resultant force of the shimmy stiffness test is 26000N.

6. The large carbon fiber blade stiffness test method according to claim 5, characterized in that: The step S4 is specifically as follows: S401: First load the swing stiffness test at 20% of the maximum resultant force, with a load ramp-up time of 30 seconds and a load hold time of 60 seconds to eliminate mechanical backlash. S402, unload to zero, wait 150s, then load step by step according to 20% of the maximum resultant force of the swing stiffness test, with each load increasing time of 20s and holding time of 60s; S403. After each loading is completed, the load is unloaded to zero. After 120 to 150 seconds of unloading, the second test is allowed to proceed until the load reaches the set load for the flapping stiffness test; The maximum resultant force of the loading swing stiffness test is 35600N.

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