Device and method suitable for testing surface of wind power blade under dynamic load

Abstract

The invention relates to the technical field of material testing equipment, in particular to a device and method suitable for testing the surface of a wind power blade under a dynamic load, and is suitable for a rain erosion / sand erosion test of the wind power blade under the dynamic load. According to the testing device, the connecting rod and the loading unit which are connected with the testing machine are arranged, and the reasonable arrangement of the jetting assembly is matched, so that a jetting rain erosion / sand erosion erosion test can be carried out while a dynamic load is applied to a sample, the service condition of a wind power blade can be truly restored, and the engineering representativeness and reliability of a test result are remarkably improved; according to the test method, rain erosion and sand erosion environments under various actual working conditions can be simulated, the rain erosion / sand erosion resistance of the wind power blade under the dynamic load can be accurately evaluated by collecting and analyzing test data in real time, and the test method is wide in application prospect and easy to popularize.

Description

Technical Field

[0001] The present invention relates to the technical field of material testing equipment, and in particular to a device and method suitable for surface testing of wind turbine blades under dynamic loads, and is suitable for rain erosion / sand erosion tests of wind turbine blades under dynamic loads. Background Art

[0002] With the rapid development of the wind power industry, wind turbine blades are growing in size and operating in increasingly complex environments. During their service life, the leading edge of wind turbine blades is constantly exposed to high wind speeds, raindrops, and sand impact, making them susceptible to rain and sand erosion damage, which in turn affects the blade's service life and production efficiency.

[0003] The rain erosion / sand erosion testing schemes widely used in existing technologies are mostly static tooling or rotating arm devices, which have many shortcomings: on the one hand, it is difficult to simulate the complex dynamic load environment that blades are subjected to during service, resulting in deviations between the test results and the actual situation; on the other hand, the existing testing methods are difficult to simultaneously consider the combined effects of rain erosion and sand erosion, and the control precision of the test parameters and the accuracy of the test results need to be improved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a device and method suitable for testing the surface of wind turbine blades under dynamic loads, which can realize the simultaneous application of dynamic mechanical loading and rain erosion / sand erosion conditions to simulate the actual operating conditions of wind turbine blades, thereby significantly improving the accuracy and reliability of test results.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: 1. A device suitable for testing the surface of wind turbine blades under dynamic loads The present invention provides a device suitable for testing the surface of a wind turbine blade under dynamic load, comprising a box 6, wherein an upper loading unit 2 and a lower loading unit 3 are respectively provided at the upper and lower parts of the inner cavity of the box 6, and a wind turbine blade sample 1 to be tested is clamped between the upper loading unit 2 and the lower loading unit 3; The top of the upper loading unit 2 is fixedly connected to an upper connecting rod 4, and the bottom of the lower loading unit 3 is fixedly connected to a lower connecting rod 5. The upper connecting rod 4 and the lower connecting rod 5 respectively pass through the top and bottom of the box 6 and are connected to the external loading device; A spray assembly 7 is installed on the side wall of the box 6. The input end of the spray assembly 7 is connected to a rainwater or sand supply device. The output nozzle of the spray assembly 7 is inserted into the inner cavity of the box 6 and faces the leading edge area of ​​the wind turbine blade sample 1.

[0006] Preferably, an inclined slope 8 is provided at the bottom of the inner cavity of the box body 6, and an inclined groove 9 is provided on one side of the inclined slope 8.

[0007] Preferably, the upper connecting rod 4 and the lower connecting rod 5 are both provided with a connecting hole 10, and are connected to corresponding loading ends of external loading equipment through the connecting hole 10 in cooperation with the connecting shaft.

[0008] Preferably, the upper loading unit 2 and the lower loading unit 3 are both clamping plates made of high-strength metal or composite materials.

[0009] Preferably, the upper loading unit 2 and the lower loading unit 3 are fixedly connected to the upper connecting rod 4 and the lower connecting rod 5 respectively through corresponding threaded connectors.

[0010] Preferably, the shapes of the clamping surfaces of the upper loading unit 2 and the lower loading unit 3 are respectively adapted to the upper surface and the lower surface of the wind turbine blade sample 1 .

[0011] Preferably, the box body 6 is made of transparent or translucent material.

[0012] Preferably, the side wall of the box body 6 is provided with a plurality of equipment mounting supports.

[0013] 2. A wind turbine blade surface testing method Based on the same inventive concept, the present invention further provides a method for testing the surface of a wind turbine blade, which is based on the above-mentioned device suitable for testing the surface of a wind turbine blade under dynamic load, and includes the following steps: Step S1, test preparation, clamping the wind turbine blade sample to be tested between the upper loading unit and the lower loading unit, and adjusting the direction of the output nozzle of the spray assembly so that it faces the leading edge area of ​​the wind turbine blade sample; Step S2, dynamic load application, starting the external loading device, applying a dynamic load of preset frequency and amplitude to the wind turbine blade sample through the upper loading unit and the lower loading unit, and monitoring the magnitude of the applied load in real time; Step S3, rain erosion / sand erosion simulation, starting the rain / sand supply device, spraying raindrops / sand at a preset temperature at a preset spray pressure and angle toward the leading edge of the wind turbine blade sample through the spray assembly, and monitoring the spray speed of the raindrops / sand in real time; Step S4, data collection and analysis, real-time collection and recording of the size of the load applied by the device and the injection speed of raindrops / sand particles within the preset time period T0, and measurement of the surface damage rate of the wind turbine blade sample within the preset time period T0, and then analysis and evaluation of the rain erosion / sand erosion resistance of the wind turbine blade sample based on the resistance evaluation algorithm, and production of an analysis result report, providing a reference basis for the subsequent optimization design and protection of wind turbine blades.

[0014] Preferably, the variation pattern of the dynamic load application frequency and amplitude is consistent with the variation pattern of the load parameter measurement value borne by the wind turbine blade under actual operating conditions within the preset time period T1; Preferably, the variation pattern of the raindrop / sand particle injection pressure and angle is consistent with the variation pattern of the measured value of the raindrop / sand particle impact parameter borne by the wind turbine blade under actual operating conditions within the preset time period T2; Preferably, the resistance evaluation algorithm is specifically as follows: determining whether the resistance evaluation value K0 of the wind turbine blade sample within a preset time period T0 is greater than a preset resistance evaluation value threshold K'; if so, determining that the rain erosion / sand erosion resistance performance of the wind turbine blade sample is qualified; otherwise, determining that it is unqualified; The resistance evaluation value K0=(F0×V0×C) / P0, wherein F0 and V0 are respectively the average value of the load applied by the device within the preset time period T0 and the average value of the raindrop / sand particle injection velocity, P0 is the surface damage rate of the wind turbine blade sample within the preset time period T0, C is the correction coefficient, and the resistance evaluation value threshold K' is an empirical value obtained from multiple tests.

[0015] Compared with the prior art, the present invention has the following main advantages: 1. The test device of the present invention, by providing a connecting rod and a loading unit connected to the testing machine and combining it with the rational arrangement of the spray assembly, can perform spray rain erosion / sand erosion tests on samples while applying dynamic loads. This can realistically restore the service conditions of wind turbine blades and significantly improve the engineering representativeness and reliability of the test results. 2. The bottom of the box of the present invention is provided with an inclined slope structure and an inclined groove, which is conducive to the discharge and collection of liquid and sand particles, can keep the experimental environment clean and tidy, and can effectively prevent the accumulation of liquid and sand particles from affecting the accuracy of the test; 3. The spray assembly of the present invention has a flexible layout, and the spray pressure, speed and additives can be easily adjusted to simulate different rainfall / sandblasting intensity conditions; 4. The testing method of the present invention can simulate rain erosion and sand erosion environments under various actual working conditions. By real-time collection and analysis of test data, it can accurately evaluate the anti-rain erosion / anti-sand erosion performance of wind turbine blades under dynamic loads. It has broad application prospects and is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is an overall schematic diagram of the device in an embodiment of the present invention; Figure 2 is a front view of the device in an embodiment of the present invention; Figure 3 is a side view of the device in an embodiment of the present invention; Figure 4 Flowchart of the testing method in an embodiment of the present invention.

[0017] In the figure: 1- wind turbine blade sample; 2- upper loading unit; 3- lower loading unit; 4- upper connecting rod; 5- lower connecting rod; 6- box; 7- injection assembly; 8- inclined slope; 9- inclined groove; 10- connecting hole. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0019] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0020] In the present invention, unless otherwise expressly specified or limited, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, for example, two, three, etc., unless otherwise expressly specified or limited.

[0021] Embodiment 1: This embodiment provides a device suitable for testing the surface of a wind turbine blade under dynamic load, such as Figures 1-3 As shown, it mainly includes: a wind turbine blade sample 1, an upper loading unit 2, a lower loading unit 3, an upper connecting rod 4, a lower connecting rod 5, a box 6 and a spray assembly 7; The upper and lower parts of the inner cavity of the box body 6 are respectively provided with an upper loading unit 2 and a lower loading unit 3, and the wind turbine blade sample 1 to be tested is clamped between the upper loading unit 2 and the lower loading unit 3; The top of the upper loading unit 2 is fixedly connected to an upper connecting rod 4, and the bottom of the lower loading unit 3 is fixedly connected to a lower connecting rod 5. The upper connecting rod 4 and the lower connecting rod 5 respectively pass through the top and bottom of the box 6 and are connected to the external loading device; A spray assembly 7 is installed on the side wall of the box 6. The input end of the spray assembly 7 is connected to a rainwater or sand supply device. The output nozzle of the spray assembly 7 is inserted into the inner cavity of the box 6 and faces the leading edge area of ​​the wind turbine blade sample 1.

[0022] Furthermore, an inclined slope 8 is provided at the bottom of the inner cavity of the box body 6, and an inclined groove 9 is provided on one side of the inclined slope 8.

[0023] Furthermore, the upper connecting rod 4 and the lower connecting rod 5 are both provided with a connecting hole 10, and the connecting hole 10 cooperates with the connecting shaft to connect with the corresponding loading end of the external loading device.

[0024] Furthermore, the upper loading unit 2 and the lower loading unit 3 are both clamping plates made of high-strength metal or composite materials.

[0025] Furthermore, the upper loading unit 2 and the lower loading unit 3 are fixedly connected to the upper connecting rod 4 and the lower connecting rod 5 respectively through corresponding threaded connectors.

[0026] Furthermore, the shapes of the clamping surfaces of the upper loading unit 2 and the lower loading unit 3 are respectively adapted to the upper surface and the lower surface of the wind turbine blade sample 1 .

[0027] Furthermore, the box body 6 is made of transparent or translucent material.

[0028] Furthermore, the side walls of the box body 6 are provided with a plurality of equipment mounting supports.

[0029] In a second embodiment, a device suitable for testing the surface of a wind turbine blade under dynamic load is provided. The sample is fixed between the loading units, and the loading units are arranged symmetrically in an upper and lower manner, with two units in total. One end of each loading unit is connected to a corresponding connecting rod, which passes through the top and bottom of the box respectively and is provided with a connecting hole for connecting to an external loading device to realize a loading force transmission path. The box is a closed structure, which contains samples and loading components. The bottom of the box is provided with an inclined slope structure to facilitate the flushing liquid and sand to flow into the lower part for collection and discharge. The spray assembly is fixedly installed on the side wall of the box and can spray liquid or sand particles to simulate rain or wind and sand to directionally flush the leading edge area of ​​the sample.

[0030] Furthermore, the connecting rod can be connected to the loading head of the fatigue testing machine via a connecting shaft, thereby achieving synchronous loading of dynamic loads (such as alternating tension, compression or bending) on ​​the sample.

[0031] Furthermore, the loading unit is made of high-strength metal or composite material, and its clamping surface is consistent with the shape of the sample to ensure uniform loading.

[0032] Furthermore, the box is made of transparent or translucent material to facilitate observation of the rain erosion / sand erosion process, and an imaging and recording device installation position is provided on the outer wall of the box.

[0033] Furthermore, the injection assembly can adjust the fluid pressure, speed, angle, temperature and additives. The fluid medium can be water, salt water and / or organic matter, and organic and / or inorganic particles, particles (solid form) and dissolved substances can be added to the fluid medium, or a mixture thereof can be used as a medium to simulate different rain erosion / sand erosion conditions.

[0034] Example 3: Based on the same inventive concept, this embodiment also provides a method for testing the surface of a wind turbine blade, based on the device for testing the surface of a wind turbine blade under dynamic load as described above, such as Figure 4 As shown, the following steps are included: Step S1, test preparation, clamping the wind turbine blade sample to be tested between the upper loading unit and the lower loading unit, and adjusting the direction of the output nozzle of the spray assembly so that it faces the leading edge area of ​​the wind turbine blade sample; Step S2, dynamic load application, starting the external loading device, applying a dynamic load of preset frequency and amplitude to the wind turbine blade sample through the upper loading unit and the lower loading unit, and monitoring the magnitude of the applied load in real time; Step S3, rain erosion / sand erosion simulation, starting the rain / sand supply device, spraying raindrops / sand at a preset temperature at a preset spray pressure and angle toward the leading edge of the wind turbine blade sample through the spray assembly, and monitoring the spray speed of the raindrops / sand in real time; Step S4, data collection and analysis, real-time collection and recording of the size of the load applied by the device and the injection speed of raindrops / sand particles within the preset time period T0, and measurement of the surface damage rate of the wind turbine blade sample within the preset time period T0, and then analysis and evaluation of the rain erosion / sand erosion resistance of the wind turbine blade sample based on the resistance evaluation algorithm, and production of an analysis result report, providing a reference basis for the subsequent optimization design and protection of wind turbine blades.

[0035] Furthermore, the variation pattern of the dynamic load application frequency and amplitude is consistent with the variation pattern of the load parameter measurement value borne by the wind turbine blade under actual operating conditions within the preset time period T1; Furthermore, the variation pattern of the raindrop / sand particle injection pressure and angle is consistent with the variation pattern of the measured value of the raindrop / sand particle impact parameter borne by the wind turbine blade under actual operating conditions within the preset time period T2; Furthermore, the resistance evaluation algorithm specifically comprises: determining whether the resistance evaluation value K0 of the wind turbine blade sample within a preset time period T0 is greater than a preset resistance evaluation value threshold K'; if so, determining that the rain erosion / sand erosion resistance performance of the wind turbine blade sample is qualified; otherwise, determining that the wind turbine blade sample is unqualified; The resistance evaluation value K0=(F0×V0×C) / P0, wherein F0 and V0 are respectively the average value of the load applied by the device within the preset time period T0 and the average value of the raindrop / sand particle injection velocity, P0 is the surface damage rate of the wind turbine blade sample within the preset time period T0, C is the correction coefficient, and the resistance evaluation value threshold K' is an empirical value obtained from multiple tests.

[0036] Furthermore, all parts of this application that are not described in detail are the same as the existing technology or are implemented using the existing technology.

[0037] In summary: 1. The test device of the present invention, by providing a connecting rod and a loading unit connected to the testing machine and combining it with the rational arrangement of the spray assembly, can perform spray rain erosion / sand erosion tests on samples while applying dynamic loads. This can realistically restore the service conditions of wind turbine blades and significantly improve the engineering representativeness and reliability of the test results. 2. The bottom of the box of the present invention is provided with an inclined slope structure and an inclined groove, which is conducive to the discharge and collection of liquid and sand particles, can keep the experimental environment clean and tidy, and can effectively prevent the accumulation of liquid and sand particles from affecting the accuracy of the test; 3. The spray assembly of the present invention has a flexible layout, and the spray pressure, speed and additives can be easily adjusted to simulate different rainfall / sandblasting intensity conditions; 4. The testing method of the present invention can simulate rain erosion and sand erosion environments under various actual working conditions. By real-time collection and analysis of test data, it can accurately evaluate the anti-rain erosion / anti-sand erosion performance of wind turbine blades under dynamic loads. It has broad application prospects and is easy to promote.

[0038] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0039] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0040] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device suitable for testing the surface of wind turbine blades under dynamic loads, characterized by: It comprises a box body (6), wherein an upper loading unit (2) and a lower loading unit (3) are respectively provided at the upper and lower parts of the inner cavity of the box body (6), and a wind turbine blade sample (1) to be tested is clamped between the upper loading unit (2) and the lower loading unit (3); The top of the upper loading unit (2) is fixedly connected to an upper connecting rod (4), and the bottom of the lower loading unit (3) is fixedly connected to a lower connecting rod (5). The upper connecting rod (4) and the lower connecting rod (5) respectively pass through the top and bottom of the box (6) and are connected to an external loading device. The side wall of the box (6) is installed with a spray assembly (7), the input end of the spray assembly (7) is connected to a rainwater or sand supply device, and the output nozzle of the spray assembly (7) is inserted into the inner cavity of the box (6) and faces the leading edge area of ​​the wind turbine blade sample (1).

2. The device for testing the surface of a wind turbine blade under dynamic load according to claim 1, characterized in that: An inclined slope (8) is provided at the bottom of the inner cavity of the box body (6), and an inclined groove (9) is provided on one side of the inclined slope (8).

3. The device for testing the surface of a wind turbine blade under dynamic load according to claim 1, characterized in that: The upper connecting rod (4) and the lower connecting rod (5) are both provided with a connecting hole (10), and are connected to corresponding loading ends of external loading equipment through the connecting hole (10) in conjunction with the connecting shaft.

4. The device for testing the surface of a wind turbine blade under dynamic load according to claim 1, characterized in that: The upper loading unit (2) and the lower loading unit (3) are both clamping plates made of high-strength metal or composite materials.

5. The device for testing the surface of a wind turbine blade under dynamic load according to claim 4, characterized in that: The upper loading unit (2) and the lower loading unit (3) are fixedly connected to the upper connecting rod (4) and the lower connecting rod (5) respectively via corresponding threaded connectors.

6. The device for testing the surface of a wind turbine blade under dynamic load according to claim 4, characterized in that: The shapes of the clamping surfaces of the upper loading unit (2) and the lower loading unit (3) are respectively adapted to the upper surface and the lower surface of the wind turbine blade sample (1).

7. The device for testing the surface of a wind turbine blade under dynamic load according to claim 1, characterized in that: The box body (6) is made of transparent or translucent material.

8. The device for testing the surface of a wind turbine blade under dynamic load according to claim 7, characterized in that: The side wall of the box body (6) is provided with a plurality of equipment mounting supports.

9. A method for testing the surface of a wind turbine blade, based on the device for testing the surface of a wind turbine blade under dynamic load according to any one of claims 1 to 8, characterized in that: The steps include: Step S1, test preparation, clamping the wind turbine blade sample to be tested between the upper loading unit and the lower loading unit, and adjusting the direction of the output nozzle of the spray assembly so that it faces the leading edge area of ​​the wind turbine blade sample; Step S2, dynamic load application, starting the external loading device, applying a dynamic load of preset frequency and amplitude to the wind turbine blade sample through the upper loading unit and the lower loading unit, and monitoring the magnitude of the applied load in real time; Step S3, rain erosion / sand erosion simulation, starting the rain / sand supply device, spraying raindrops / sand at a preset temperature at a preset spray pressure and angle toward the leading edge of the wind turbine blade sample through the spray assembly, and monitoring the spray speed of the raindrops / sand in real time; Step S4, data collection and analysis, real-time collection and recording of the size of the load applied by the device and the injection speed of raindrops / sand particles within the preset time period T0, and measurement of the surface damage rate of the wind turbine blade sample within the preset time period T0, and then analysis and evaluation of the rain erosion / sand erosion resistance of the wind turbine blade sample based on the resistance evaluation algorithm, and production of an analysis result report, providing a reference basis for the subsequent optimization design and protection of wind turbine blades.

10. The testing method according to claim 9, characterized in that: The variation pattern of the dynamic load application frequency and amplitude is consistent with the variation pattern of the load parameter measurement value borne by the wind turbine blade under actual operating conditions within the preset time period T1; The variation pattern of the raindrop / sand particle injection pressure and angle is consistent with the variation pattern of the measured values ​​of the raindrop / sand particle impact parameters to which the wind turbine blade is subjected under actual operating conditions within the preset time period T2; The resistance evaluation algorithm specifically comprises: determining whether the resistance evaluation value K0 of the wind turbine blade sample within a preset time period T0 is greater than a preset resistance evaluation value threshold K'; if so, determining that the rain erosion / sand erosion resistance performance of the wind turbine blade sample is qualified; otherwise, determining that the wind turbine blade sample is unqualified; The resistance evaluation value K0=(F0×V0×C) / P0, wherein F0 and V0 are respectively the average value of the load applied by the device within the preset time period T0 and the average value of the raindrop / sand particle injection velocity, P0 is the surface damage rate of the wind turbine blade sample within the preset time period T0, C is the correction coefficient, and the resistance evaluation value threshold K' is an empirical value obtained from multiple tests.

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