A wind turbine blade embedded bolt sleeve interface performance test and evaluation method

Abstract

The present invention provides a method for testing and evaluating the performance of a pre-embedded bolt sleeve interface of a wind turbine blade, wherein the method comprises: obtaining blade root connection parameters of the pre-embedded bolt sleeve interface to be tested, and calculating the bolt axial force on a single bolt according to the blade root connection parameters; wherein the blade root connection parameters include: blade root fatigue load when R=-1 under 10 million times, number of bolts, blade root axial force, blade root limit load and blade root pitch circle diameter; calculating the static strength safety factor of the pre-embedded bolt sleeve interface according to the bolt axial force; obtaining a blade root fatigue load matrix of the pre-embedded bolt sleeve interface to be tested, and obtaining the corresponding fatigue strength according to the blade root fatigue load matrix; wherein the blade root fatigue load matrix includes: stress amplitude, stress mean and number of cycles; calculating the damage factor of the pre-embedded bolt sleeve interface according to the fatigue strength; and obtaining the test performance of the pre-embedded bolt sleeve interface according to the static strength safety factor and the damage factor of the pre-embedded bolt sleeve interface.

Description

Technical Field

[0001] The present invention relates to the technical field of bolt sleeve interface testing, and in particular to a method for testing and evaluating the interface performance of pre-embedded bolt sleeves for wind turbine blades. Background Art

[0002] As wind turbine power levels increase, wind turbine blades are also developing larger and longer. To meet the requirements of higher mechanical power and greater load transmission, the root connection of wind turbine blades is particularly important. Compared with T-bolts, embedded bolt sleeve connections can achieve multiple bolt connections with the same pitch diameter, meeting the requirements of higher blade root loads.

[0003] Before using the embedded bolt sleeve connection solution, it is necessary to evaluate whether the pull-out resistance and fatigue performance of the embedded bolt sleeve interface meet the blade root load requirements, so as to evaluate whether the embedded bolt sleeve connection solution is feasible. Summary of the Invention

[0004] Based on this, it is necessary to provide a wind turbine blade embedded bolt sleeve interface performance test and evaluation method to address the above technical issues.

[0005] A wind turbine blade embedded bolt sleeve interface performance test and evaluation method, characterized by comprising:

[0006] Obtain blade root connection parameters of the embedded bolt sleeve interface to be tested, and calculate the bolt axial force on a single bolt based on the blade root connection parameters; wherein the blade root connection parameters include: blade root fatigue load at R = -1 under 10 million cycles, number of bolts, blade root axial force, blade root limit load, and blade root pitch circle diameter;

[0007] Calculate the static strength safety factor of the embedded bolt sleeve interface according to the bolt axial force;

[0008] Obtaining a blade root fatigue load matrix of the embedded bolt sleeve interface to be tested, and obtaining corresponding fatigue strength according to the blade root fatigue load matrix; wherein the blade root fatigue load matrix includes: stress amplitude, stress mean, and number of cycles;

[0009] Calculating the damage factor of the embedded bolt sleeve interface based on the fatigue strength;

[0010] The test performance of the embedded bolt sleeve interface is obtained according to the embedded bolt sleeve interface combined with the static strength safety factor and the damage factor.

[0011] In one embodiment, obtaining blade root connection parameters of the embedded bolt sleeve interface to be measured, and calculating the bolt axial force on a single bolt based on the blade root connection parameters, includes:

[0012] The axial force on a single bolt is calculated using the following formula:

[0013]

[0014] Among them, F A Indicates the bolt axial force, M xy Indicates the blade root limit load, F Z represents the axial force at the blade root, D represents the pitch diameter of the blade root, and N represents the number of bolts.

[0015] In one embodiment, calculating the static strength safety factor of the embedded bolt sleeve interface according to the bolt axial force includes:

[0016] Acquire a plurality of pre-embedded bolt sleeve test pieces, and acquire characteristic values ​​of pull-out destructive force based on the plurality of pre-embedded bolt sleeve test pieces;

[0017] The static strength safety factor of the embedded bolt sleeve interface is calculated based on the characteristic value of the pull-out destructive force and the axial force of the bolt on the single bolt.

[0018] In one embodiment, a plurality of embedded bolt sleeve test pieces are obtained, and characteristic values ​​of the pull-out destructive force are obtained based on the plurality of embedded bolt sleeve test pieces, including:

[0019] Obtaining a pull-out destructive force of the embedded bolt sleeve test piece based on a plurality of embedded bolt sleeve test pieces;

[0020] The average pull-out force is calculated using the following formula:

[0021]

[0022] Among them, F a Indicates the average pull-out destructive force, n represents n embedded bolt sleeve test pieces, F i represents the pull-out destructive force of the i-th embedded bolt sleeve test piece;

[0023] The standard deviation of the pull-out force is calculated using the following formula:

[0024]

[0025] Where σ represents the standard deviation of the pull-out force, n represents the number of embedded bolt sleeve test pieces, and F i F represents the pull-out destructive force of the i-th embedded bolt sleeve test piece, a Indicates the average pull-out destructive force;

[0026] The coefficient of variation of the pull-out force is calculated using the following formula:

[0027]

[0028] Where μ represents the coefficient of variation of the pull-out failure force, σ represents the standard deviation of the pull-out failure force, and F a Indicates the average pull-out destructive force;

[0029] The characteristic value of the pull-out breaking force is calculated by the following formula:

[0030]

[0031] Among them, F char Indicates the characteristic value of the pull-out failure force, F a represents the average pull-out force, μ represents the coefficient of variation of the pull-out force, and n represents the number of embedded bolt sleeve test pieces.

[0032] In one embodiment, the static strength safety factor of the embedded bolt sleeve interface is calculated based on the characteristic value of the pull-out destructive force and the axial force of the bolt on the single bolt, including:

[0033] Calculate the static strength safety factor of the embedded bolt sleeve interface according to the following formula:

[0034]

[0035] Among them, S G Indicates the static strength safety factor of the embedded bolt sleeve interface, F char Indicates the characteristic value of the pull-out failure force, F A Indicates the axial force of the bolt.

[0036] In one embodiment, obtaining the corresponding fatigue strength according to the blade root fatigue load matrix includes:

[0037] According to the stress amplitude and the stress mean, the corresponding fatigue strength is obtained according to the Goodman equation.

[0038] In one embodiment, calculating the damage factor of the embedded bolt sleeve interface based on the fatigue strength includes:

[0039] Obtaining an S / N curve of the embedded bolt sleeve connection solution based on the blade root connection parameters;

[0040] The damage factor between the embedded bolt sleeve interface is obtained according to the fatigue strength and the S / N curve.

[0041] In one embodiment, obtaining an S / N curve of the embedded bolt sleeve connection solution based on the blade root connection parameters includes:

[0042] Calculate the equivalent fatigue load of a single bolt at R=-1 under 10 million cycles according to the following formula:

[0043]

[0044] Among them, F L It represents the equivalent fatigue load of a single bolt when R=-1 under 10 million cycles, M represents the blade root fatigue load when R=-1 under 10 million cycles, D represents the blade root pitch circle diameter, and N represents the number of bolts;

[0045] Calculate the equivalent fatigue load for the remaining times R=-1 according to the following formula:

[0046]

[0047] Among them, F ′ L Indicates the equivalent fatigue load when R=-1 under other times, T indicates the multiple of the number of times to be tested and 10 million times, F L Indicates the equivalent fatigue load of a single bolt when R=-1 under 10 million cycles;

[0048] The test load amplitude F of the equivalent fatigue load when the unit is actually running at R = -1 and the test load when R = 0.1 M and the test load mean F m The relationship is as follows:

[0049]

[0050]

[0051] The test load peak and test load valley values ​​at different cycle times are calculated according to the following formula:

[0052]

[0053]

[0054]

[0055] Among them, R = 0.1 represents the ratio of the test load peak value to the test load valley value, F M Indicates the test load amplitude when R=0.1, F m Indicates the mean test load when R=0.1, F max Indicates the test load peak, F min Indicates the test load valley value;

[0056] Several embedded bolt sleeve test pieces are tested at test load peaks and test load valleys at different cycle times to obtain the test cycle times, and an S / N curve of the embedded bolt sleeve connection solution is obtained according to the test cycle times.

[0057] In one embodiment, obtaining the damage factor between the embedded bolt sleeve interface according to the fatigue strength and the S / N curve includes:

[0058] The allowable number of cycles under the fatigue strength can be obtained through the S / N curve;

[0059] The damage factor between the bolt sleeve and the interface at each angle is obtained based on the linear damage theory and the allowable number of cycles.

[0060] In one embodiment, the test performance of the embedded bolt sleeve interface is obtained based on the static strength safety factor and the damage factor of the embedded bolt sleeve interface, including:

[0061] In response to the embedded bolt sleeve interface combined static strength safety factor being greater than a preset embedded bolt sleeve interface combined static strength safety factor value, the embedded bolt sleeve interface is safe and reliable under the test load;

[0062] In response to the damage factor being less than a preset damage factor, the embedded bolt sleeve interface meets preset standard requirements.

[0063] Compared with the existing technology, the advantages and beneficial effects of the present invention are: before the embedded bolt sleeve connection scheme is used, the present invention can evaluate whether the pull-out resistance and fatigue performance of the embedded bolt sleeve interface meet the blade root load requirements, reduce testing costs, avoid excessive material waste, and at the same time improve the quality of the embedded bolt sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 Schematic diagram of a flow chart of a method for testing and evaluating the interface performance of embedded bolt sleeves of wind turbine blades in one embodiment;

[0065] Figure 2A This is a schematic diagram of the external structure of a pre-embedded bolt sleeve connection solution in one embodiment;

[0066] Figure 2B This is a schematic diagram of the internal structure of a pre-embedded bolt sleeve connection solution in one embodiment;

[0067] Figure 3 Schematic diagram of a pre-buried bolt connection scheme in an embodiment. DETAILED DESCRIPTION

[0068] In order to make the objectives, technical solutions and advantages of this application more clear, this application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0069] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0070] Based on the existing technology and in response to the problems existing in the existing technology, in order to evaluate the pull-out performance and fatigue performance of the embedded bolt sleeve interface, the embodiment of the present application provides a wind turbine blade embedded bolt sleeve interface performance test and evaluation method. First, the pull-out performance of the embedded bolt sleeve interface is tested, and the blade root connection parameters of the embedded bolt sleeve interface to be tested are obtained. The bolt axial force on a single bolt is calculated based on the blade root connection parameters. Then, the static strength safety factor of the embedded bolt sleeve interface is calculated based on the bolt axial force. Based on the calculated static strength safety factor of the embedded bolt sleeve interface, it can be determined whether the pull-out performance of the bolt sleeve interface can meet the blade root load requirements. After testing the pull-out performance of the embedded bolt sleeve interface, the fatigue performance of the embedded bolt sleeve interface is tested, and the blade root fatigue load matrix of the embedded bolt sleeve interface to be tested is obtained. According to the blade root fatigue load matrix, the corresponding fatigue strength is obtained. The damage factor of the embedded bolt sleeve interface is calculated based on the fatigue strength. According to the damage factor, it is determined whether the fatigue performance meets the blade root load requirements.

[0071] The technical solution of the present application is further described in detail below through specific implementation methods.

[0072] First, the embodiment of the present application provides a wind turbine blade embedded bolt sleeve interface performance test and evaluation method, referring to Figure 1 , including the following steps:

[0073] Step S101: Obtain blade root connection parameters of the embedded bolt sleeve interface to be tested, and calculate the bolt axial force on a single bolt based on the blade root connection parameters; wherein the blade root connection parameters include: blade root fatigue load when R=-1 at 10 million times, number of bolts, blade root axial force, blade root limit load, and blade root pitch circle diameter.

[0074] Specifically, preset blade root connection parameters are obtained, including: blade root fatigue load at R=-1 under 10 million times, number of bolts, blade root axial force, blade root limit load, and blade root pitch circle diameter. Specifically, in one embodiment, the blade root connection parameters are shown in the following table:

[0075]

[0076] Table 1 Leaf-root connection parameters

[0077] On this basis, the blade root connection parameters of the embedded bolt sleeve interface to be tested are obtained, and the bolt axial force on a single bolt is calculated according to the blade root connection parameters, including:

[0078] The axial force on a single bolt is calculated using the following formula:

[0079]

[0080] Among them, F A Indicates the bolt axial force, M xy Indicates the blade root limit load, F Z represents the axial force at the blade root, D represents the pitch diameter of the blade root, and N represents the number of bolts.

[0081] Specifically, the bolt axial force represents the static limit load on a single bolt. When the blade root connection parameters are as shown in Table 1, the calculated bolt axial force is 366.9 kN.

[0082] Step S102: Calculate the static strength safety factor of the embedded bolt sleeve interface according to the bolt axial force.

[0083] Specifically, according to the material reduction factor in the GL2010 standard, the static strength safety factor S of the embedded bolt sleeve interface can be calculated. G Among them, the GL2010 standard requirement is the 2010 wind power standard.

[0084] On this basis, the static strength safety factor of the embedded bolt sleeve interface is calculated according to the bolt axial force, including:

[0085] Acquire a plurality of pre-embedded bolt sleeve test pieces, and acquire characteristic values ​​of pull-out destructive force based on the plurality of pre-embedded bolt sleeve test pieces;

[0086] The static strength safety factor of the embedded bolt sleeve interface is calculated based on the characteristic value of the pull-out destructive force and the axial force of the bolt on the single bolt.

[0087] Specifically, the blade root connection scheme is optimized by parametric finite element modeling and calculation to obtain the theoretically optimal design of the embedded bolt sleeve connection scheme. Specifically, the external structure diagram of a pre-embedded bolt sleeve connection scheme is as follows: Figure 2A , a schematic diagram of the internal structure of a pre-buried bolt sleeve connection scheme is as follows Figure 2B . According to the design Figure 3 Several embedded bolt sleeve test pieces were fabricated for the embedded bolt connection scheme shown. Characteristic values ​​for the pullout failure force were obtained from these multiple embedded bolt sleeve test pieces. The static strength safety factor for the embedded bolt sleeve interface was then calculated based on the characteristic values ​​for the pullout failure force and the axial force acting on a single bolt.

[0088] On this basis, several embedded bolt sleeve test pieces are obtained, and characteristic values ​​of the pull-out destructive force are obtained based on the multiple embedded bolt sleeve test pieces, including:

[0089] Obtaining a pull-out destructive force of the embedded bolt sleeve test piece based on a plurality of embedded bolt sleeve test pieces;

[0090] The average pull-out breaking force is calculated according to the pull-out breaking force using the following formula:

[0091]

[0092] Among them, F a Indicates the average pull-out destructive force, n represents n embedded bolt sleeve test pieces, F i represents the pull-out destructive force of the i-th embedded bolt sleeve test piece;

[0093] The standard deviation of the pull-out force is calculated using the following formula:

[0094]

[0095] Where σ represents the standard deviation of the pull-out force, n represents the number of embedded bolt sleeve test pieces, and F i F represents the pull-out destructive force of the i-th embedded bolt sleeve test piece, a Indicates the average pull-out destructive force;

[0096] The coefficient of variation of the pull-out force is calculated using the following formula:

[0097]

[0098] Where μ represents the coefficient of variation of the pull-out failure force, σ represents the standard deviation of the pull-out failure force, and F a Indicates the average pull-out destructive force;

[0099] The characteristic value of the pull-out breaking force is calculated by the following formula:

[0100]

[0101] Among them, F char Indicates the characteristic value of the pull-out failure force, F arepresents the average pull-out force, μ represents the coefficient of variation of the pull-out force, and n represents the number of embedded bolt sleeve test pieces.

[0102] Specifically, an axial tensile test is performed on a number of pre-embedded bolt sleeve test pieces to determine the ultimate pull-out destructive force of N pre-embedded bolt sleeve test pieces. In one embodiment, the specific test results of four pre-embedded bolt sleeve test pieces can be shown in Table 2:

[0103]

[0104] Table 2 Ultimate tensile test results of embedded bolt sleeve test pieces

[0105] According to the ultimate tensile test results F of the embedded bolt sleeve test piece in Table 2 i , the average pull-out force F can be calculated a =1139.4KN; standard deviation σ = 11.84; coefficient of variation μ = 0.01; characteristic value of the pulling-out force F char =1008KN.

[0106] On this basis, the static strength safety factor of the embedded bolt sleeve interface is calculated according to the characteristic value of the pull-out destructive force and the axial force of the bolt on the single bolt, including:

[0107] Calculate the static strength safety factor of the embedded bolt sleeve interface according to the following formula:

[0108]

[0109] Among them, S G Indicates the static strength safety factor of the embedded bolt sleeve interface, F char Indicates the characteristic value of the pull-out failure force, F A Indicates the axial force of the bolt.

[0110] Specifically, in one embodiment, the characteristic value of the pull-out destructive force is 1008KN; when the bolt axial force is 366.9KN, the static strength safety factor of the embedded bolt sleeve interface is S G =1.12.

[0111] In this embodiment, the pull-out destructive force of each embedded bolt sleeve test piece is obtained, and the characteristic value of the pull-out destructive force is obtained based on the pull-out destructive force. The static strength safety factor of the embedded bolt sleeve interface can be calculated based on this characteristic value, and the static strength safety factor of the embedded bolt sleeve interface can be accurately tested, thereby improving the accuracy of the embedded bolt sleeve interface performance test, and improving the embedded bolt sleeve interface based on the static strength safety factor of the embedded bolt sleeve interface.

[0112] Step S103 , obtaining a blade root fatigue load matrix of the embedded bolt sleeve interface to be tested, and obtaining corresponding fatigue strength according to the blade root fatigue load matrix; wherein the blade root fatigue load matrix includes stress amplitude, stress mean, and cycle number.

[0113] Specifically, the preset blade root fatigue load matrix is ​​a Markov matrix, which includes stress amplitude and stress mean. The corresponding fatigue strength can be calculated according to the Goodman equation.

[0114] On this basis, the corresponding fatigue strength is obtained according to the blade root fatigue load matrix, including:

[0115] According to the stress amplitude and the stress mean, the corresponding fatigue strength is obtained according to the Goodman equation.

[0116] Step S104, calculating the damage factor of the embedded bolt sleeve interface according to the fatigue strength

[0117] On this basis, the damage factor of the embedded bolt sleeve interface is calculated according to the fatigue strength, including:

[0118] Obtaining an S / N curve of the embedded bolt sleeve connection solution based on the blade root connection parameters;

[0119] The damage factor between the embedded bolt sleeve interface is obtained according to the fatigue strength and the S / N curve.

[0120] Specifically, the corresponding fatigue strength can be calculated based on the Goodman equation, and the allowable number of cycles under this fatigue strength can be obtained from the measured S / N curve. Finally, the damage factor between the bolt sleeve and the interface at various angles can be obtained based on linear damage theory. The linear damage theory can be the Palmgren-Miner theory, and the damage factor can be calculated based on this theory.

[0121] On this basis, the S / N curve of the embedded bolt sleeve connection solution is obtained based on the blade root connection parameters, including:

[0122] Calculate the equivalent fatigue load of a single bolt at R=-1 under 10 million cycles according to the following formula:

[0123]

[0124] Among them, F L It represents the equivalent fatigue load of a single bolt when R=-1 under 10 million cycles, M represents the blade root fatigue load when R=-1 under 10 million cycles, D represents the blade root pitch circle diameter, and N represents the number of bolts;

[0125] Calculate the equivalent fatigue load for the remaining times R=-1 according to the following formula:

[0126]

[0127] Among them, F ′ L Indicates the equivalent fatigue load when R=-1 under other times, T indicates the multiple of the number of times to be tested and 10 million times, F L Indicates the equivalent fatigue load of a single bolt when R=-1 under 10 million cycles;

[0128] The test load amplitude F of the equivalent fatigue load when the unit is actually running at R = -1 and the test load when R = 0.1 M and the test load mean F m The relationship is as follows:

[0129]

[0130]

[0131] The test load peak and test load valley values ​​at different cycle times are calculated according to the following formula:

[0132]

[0133]

[0134]

[0135] Among them, R = 0.1 represents the ratio of the test load peak value to the test load valley value, F M Indicates the test load amplitude when R=0.1, F m Indicates the mean test load when R=0.1, F max Indicates the test load peak, F min Indicates the test load valley value;

[0136] Several embedded bolt sleeve test pieces are tested at test load peaks and test load valleys at different cycle times to obtain the test cycle times, and an S / N curve of the embedded bolt sleeve connection solution is obtained according to the test cycle times.

[0137] Specifically, according to the blade root connection parameters in Table 1, the blade root fatigue load when R = -1 at 10 million cycles is 12000 kN / m; the blade root pitch circle diameter is 3200 mm; when the number of bolts is 128, the equivalent fatigue load of a single bolt at R = -1 at 10 million cycles is 117.2 kN.

[0138] In one embodiment, taking 2 million times as an example, T is The equivalent fatigue load of a single bolt when R=-1 under 2 million cycles is

[0139] After calculating the equivalent fatigue load under different number of cycles, the test load amplitude F M and the test load amplitude F m The test load peak value and the test load valley value can be calculated using the relationship formula and the test load peak value and test load valley value formulas.

[0140] Then the embedded bolt sleeve test piece is tested at the test load peak and test load valley. The test process is as follows:

[0141] 1) Test 4 samples at 10,000 cycles;

[0142] 2) Test 4 samples at 100,000 cycles;

[0143] 3) Test 4 samples at 2 million cycles;

[0144] 4) Test three samples at 10 million cycles;

[0145] According to the final test cycle number of each sample under different cycle numbers, the S / N curve of the embedded bolt sleeve test piece connection scheme is fitted.

[0146] On this basis, the damage factor between the embedded bolt sleeve interface is obtained according to the fatigue strength and the S / N curve, including:

[0147] The allowable number of cycles under the fatigue strength can be obtained through the S / N curve;

[0148] The damage factor between the bolt sleeve and the interface at each angle is obtained based on the linear damage theory and the allowable number of cycles.

[0149] Specifically, the S / N curve obtained from the test can be used to obtain the number of cycles under the fatigue strength, and finally the damage factor between the bolt sleeve and the interface at various angles can be obtained based on the linear damage theory.

[0150] Step S105 , obtaining the test performance of the embedded bolt sleeve interface according to the embedded bolt sleeve interface in combination with the static strength safety factor and the damage factor.

[0151] Specifically, the static strength safety factor and damage factor of the embedded bolt sleeve interface are combined with their own industry standards. The calculated static strength safety factor and damage factor of the embedded bolt sleeve interface are compared with their respective industry standards to obtain the performance of the embedded bolt sleeve interface.

[0152] On this basis, the test performance of the embedded bolt sleeve interface is obtained according to the embedded bolt sleeve interface combined with the static strength safety factor and the damage factor, including:

[0153] In response to the embedded bolt sleeve interface combined static strength safety factor being greater than a preset embedded bolt sleeve interface combined static strength safety factor value, the embedded bolt sleeve interface is safe and reliable under the test load;

[0154] In response to the damage factor being less than a preset damage factor, the embedded bolt sleeve interface meets preset standard requirements.

[0155] Specifically, the preset static strength safety factor value of the embedded bolt sleeve interface is a recognized standard in the industry. The specific preset static strength safety factor value of the embedded bolt sleeve interface can be 1.0. When the calculated static strength safety factor value of the embedded bolt sleeve interface is greater than 1.0, it indicates that the tested design embedded bolt sleeve connection scheme is safe and reliable under the load.

[0156] The preset damage factor value is an industry-recognized standard, which may be the GL2010 standard requirement. The specific preset damage factor value may be 1. If the damage factor is less than 1, the GL2010 standard requirement is met.

[0157] In this embodiment, the calculated pre-bolt sleeve interface is verified according to industry-recognized standards, combined with the static strength safety factor and damage factor, to conduct performance testing and evaluation of the pre-bolt sleeve interface for wind turbine blades. This reduces testing costs, facilitates improvements to the pre-bolt sleeve interface for wind turbine blades, and allows for multiple tests.

[0158] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Within the scope of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0159] In addition, to simplify the description and discussion, and so as not to obscure the embodiments of the present disclosure, known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided figures. In addition, devices may be shown in the form of block diagrams to avoid obscuring the embodiments of the present disclosure, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present disclosure are to be implemented (i.e., these details should be fully within the purview of those skilled in the art). Where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present disclosure, it will be apparent to those skilled in the art that the embodiments of the present disclosure may be implemented without these specific details or with variations in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0160] Although the present disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those skilled in the art based on the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0161] The embodiments of the present disclosure are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method, characterized in that: include: Obtain blade root connection parameters of the embedded bolt sleeve interface to be tested, and calculate the bolt axial force on a single bolt based on the blade root connection parameters; wherein the blade root connection parameters include: blade root fatigue load when R=-1 at 10 million times, number of bolts, blade root axial force, blade root ultimate load, and blade root pitch circle diameter; wherein R represents the ratio of the test load peak value to the test load valley value; Calculate the static strength safety factor of the embedded bolt sleeve interface according to the bolt axial force; Obtaining a blade root fatigue load matrix of the embedded bolt sleeve interface to be tested, and obtaining corresponding fatigue strength according to the blade root fatigue load matrix; wherein the blade root fatigue load matrix includes: stress amplitude, stress mean, and number of cycles; Calculating the damage factor of the embedded bolt sleeve interface based on the fatigue strength; Obtaining test performance of the embedded bolt sleeve interface according to the embedded bolt sleeve interface combined with the static strength safety factor and the damage factor; Calculating the static strength safety factor of the embedded bolt sleeve interface according to the bolt axial force includes: Acquire a plurality of pre-embedded bolt sleeve test pieces, and acquire characteristic values ​​of pull-out destructive force based on the plurality of pre-embedded bolt sleeve test pieces; The static strength safety factor of the embedded bolt sleeve interface is calculated based on the characteristic value of the pull-out destructive force and the axial force of the bolt on the single bolt.

2. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method according to claim 1, characterized in that: The step of obtaining blade root connection parameters of the embedded bolt sleeve interface to be measured and calculating the bolt axial force on a single bolt according to the blade root connection parameters includes: The axial force on a single bolt is calculated using the following formula: Among them, F A Indicates the bolt axial force, M xy Indicates the blade root limit load, F Z represents the axial force at the blade root, D represents the pitch diameter of the blade root, and N represents the number of bolts.

3. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method according to claim 1, characterized in that: The step of obtaining a plurality of pre-embedded bolt sleeve test pieces and obtaining characteristic values ​​of the pull-out destructive force based on the plurality of pre-embedded bolt sleeve test pieces includes: Obtaining a pull-out destructive force of the embedded bolt sleeve test piece based on a plurality of embedded bolt sleeve test pieces; The average pull-out force is calculated using the following formula: Among them, F a Indicates the average pull-out destructive force, n represents n embedded bolt sleeve test pieces, F i represents the pull-out destructive force of the i-th embedded bolt sleeve test piece; The standard deviation of the pull-out force is calculated using the following formula: Where σ represents the standard deviation of the pull-out force, n represents the number of embedded bolt sleeve test pieces, and F i F represents the pull-out destructive force of the i-th embedded bolt sleeve test piece, a Indicates the average pull-out destructive force; The coefficient of variation of the pull-out force is calculated using the following formula: Where μ represents the coefficient of variation of the pull-out failure force, σ represents the standard deviation of the pull-out failure force, and F a Indicates the average pull-out destructive force; The characteristic value of the pull-out breaking force is calculated by the following formula: Among them, F char Indicates the characteristic value of the pull-out failure force, F a represents the average pull-out force, μ represents the coefficient of variation of the pull-out force, and n represents the number of embedded bolt sleeve test pieces.

4. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method according to claim 3, characterized in that: The calculation of the static strength safety factor of the embedded bolt sleeve interface according to the characteristic value of the pull-out destructive force and the axial force of the bolt on the single bolt includes: Calculate the static strength safety factor of the embedded bolt sleeve interface according to the following formula: Among them, S G Indicates the static strength safety factor of the embedded bolt sleeve interface, F char Indicates the characteristic value of the pull-out failure force, F A Indicates the axial force of the bolt.

5. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method according to claim 1, characterized in that: Obtaining the corresponding fatigue strength according to the blade root fatigue load matrix includes: According to the stress amplitude and the stress mean, the corresponding fatigue strength is obtained according to the Goodman equation.

6. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method according to claim 5, characterized in that: Calculating the damage factor of the embedded bolt sleeve interface according to the fatigue strength includes: Obtaining an S / N curve of the embedded bolt sleeve connection solution based on the blade root connection parameters; The damage factor between the embedded bolt sleeve interface is obtained according to the fatigue strength and the S / N curve.

7. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method according to claim 5, characterized in that: The obtaining of the S / N curve of the embedded bolt sleeve connection solution based on the blade root connection parameters includes: Calculate the equivalent fatigue load of a single bolt at R=-1 under 10 million cycles according to the following formula: Among them, F L It represents the equivalent fatigue load of a single bolt when R=-1 under 10 million cycles, M represents the blade root fatigue load when R=-1 under 10 million cycles, D represents the blade root pitch circle diameter, and N represents the number of bolts; Calculate the equivalent fatigue load for the remaining times R=-1 according to the following formula: Among them, F ′ L Indicates the equivalent fatigue load when R=-1 under other times, T indicates the multiple of the number of times to be tested and 10 million times, F L Indicates the equivalent fatigue load of a single bolt when R=-1 under 10 million cycles; The test load amplitude F of the equivalent fatigue load when the unit is actually running at R = -1 and the test load when R = 0.1 M and the test load mean F m The relationship is as follows: The test load peak and test load valley values ​​at different cycle times are calculated according to the following formula: Where R represents the ratio of the test load peak value to the test load valley value, F M Indicates the test load amplitude when R=0.1, F m Indicates the mean test load when R=0.1, F max Indicates the test load peak, F min Indicates the test load valley value; Several embedded bolt sleeve test pieces are tested at test load peaks and test load valleys at different cycle times to obtain the test cycle times, and an S / N curve of the embedded bolt sleeve connection solution is obtained according to the test cycle times.

8. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method according to claim 6, characterized in that: The obtaining of the damage factor between the embedded bolt sleeve interface according to the fatigue strength and the S / N curve includes: The allowable number of cycles under the fatigue strength is obtained through the S / N curve; The damage factor between the bolt sleeve and the interface at each angle is obtained based on the linear damage theory and the allowable number of cycles.

9. A wind turbine blade embedded bolt sleeve interface performance test and evaluation method according to claim 1, characterized in that: The test performance of the embedded bolt sleeve interface is obtained according to the embedded bolt sleeve interface in combination with the static strength safety factor and the damage factor, including: In response to the embedded bolt sleeve interface combined static strength safety factor being greater than a preset embedded bolt sleeve interface combined static strength safety factor value, the embedded bolt sleeve interface is safe and reliable under the test load; In response to the damage factor being less than a preset damage factor, the embedded bolt sleeve interface meets preset standard requirements.

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