Wind power bolt strength online evaluation method and system

Abstract

The invention discloses a wind power bolt strength online evaluation method and system, and relates to the technical field of online evaluation, and the method comprises the following steps: S1, analyzing the accumulated damage value of a bolt, S2, analyzing the flexibility of the wind power bolt, S3, dividing the combination state of the bolt, and S4, evaluating the strength state of the bolt. According to the method, the associated damage values under the load levels of different stages are analyzed, and the associated damage values are combined with the original accumulated damage values, so that the actual accumulated damage values under the load levels of different stages are obtained, and as the external force is applied to the wind power bolt every time, the wind power bolt can be damaged to different degrees, and the reliability of the wind power bolt is improved. The damage can be further deepened by the superposed external force, so that the direct damage value when different external forces are applied is determined, and the deepening of the damage part is analyzed, so that the final damage value can better fit the actual condition, and the analysis of the strength state of the wind power bolt can be more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of online evaluation, and specifically provides an online evaluation method and system for the strength of wind power bolts. Background Art

[0002] The online evaluation system for the strength of wind power bolts is mainly to help wind power operators monitor the bolt status in real time, avoid frequent failures, and thus improve the safety and operation efficiency of wind farms. In the invention patent with the application number 202311339751.1, "A load equivalent method, system, device and medium for evaluating bolt loosening, which relates to the technical field of bolt evaluation, includes solving the bending moment and lateral external load according to Castigliano's theorem, and establishing the first model as the equivalent model of bolt external load and screw load; establishing the second model according to the first model, and the second model is the equivalent relationship model between screw load and thread load; establishing the third model as the equivalent model of thread load and thread root stress; converting the load-time history of the bolt in the third model into the stress-time history of the thread root, and evaluating the loosening life of the bolt connection based on rain flow counting and Miner damage linear cumulative theory. The beneficial effect of the present invention provides technical support for the safe service of vehicle bolt connection equipment and the guarantee of driving safety, and has important scientific value and engineering significance for optimizing bolt connection parameters, preventing bolt loosening failure and ensuring the safe and stable operation of vehicles."

[0003] The above-mentioned prior art solves problems such as avoiding bolt loosening and falling off and affecting normal use. However, during operation, since the actual cumulative damage value under different levels of load is not analyzed, once the bolt breaks, it will affect the safety of the equipment. At the same time, this method can only evaluate the loosening life and cannot analyze the force distribution and strength state of the bolt. It is difficult for maintenance personnel to take timely measures for intervention based on the existing data. Therefore, it cannot ensure the stable operation of the equipment. Summary of the Invention

[0004] The purpose of the present invention is to provide an online evaluation method and system for the strength of wind power bolts to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: An online evaluation method for the strength of wind power bolts, including the following steps:

[0006] S1. Analyze the cumulative damage value of bolts: Determine the maximum damage value, actual usage times, and maximum damage usage times of wind power bolts under different levels of load series. Analyze the maximum damage value, actual usage times, and maximum damage usage times of overuse to obtain the original cumulative damage value under different levels of load series. Statistically analyze the influence coefficient values and usage indices of wind power bolts under different levels of load series. Use the influence coefficient values, usage indices, and the actual cumulative damage value at the previous level of load series to analyze the associated damage value at the next level of load series. Add the original cumulative damage value and the associated damage value at the same level of load series, and store the result as the actual cumulative damage value at the current level of load series. Repeat the operation until the actual cumulative damage values at all levels of load series are calculated;

[0007] S2. Analyze the flexibility of wind power bolts: After constructing an equivalent model of wind power bolts using ANSYS simulation software, statistically analyze the component length data of wind power bolts. Then, analyze the flexibility of the bolt head, connection section, rod section, and thread section based on the length data. Add the flexibility of the bolt head, connection section, rod section, and thread section to obtain the total flexibility of the wind power bolts;

[0008] S3. Divide the bolt combination states: Determine the relative stiffness of wind power bolts and divide the combination states of wind power bolts and connectors into three types, namely the initial state, contact state, and stress state. The relative displacements, reverse forces, pre-tightening forces, clamping forces, and external pressures corresponding to different combination states are different;

[0009] S4. Evaluate the bolt strength state: After determining the maximum load value of wind power bolts under different combination states, transmit the maximum load value of wind power bolts to the equivalent model of wind power bolts for analysis to obtain the load results of wind power bolts in the limit state. After obtaining the real-time data of wind power bolts, use neural network technology to analyze the real-time data, the actual cumulative damage value of wind power bolts, and the load results in the equivalent model of wind power bolts to determine the current strength state of wind power bolts.

[0010] Preferably, the step S1 specifically includes the following steps:

[0011] S101. Determine the maximum damage value of overuse of wind power bolts under different levels of load series The actual usage times m1, m2,..., m i ,..., m r and the maximum damage usage times M1, M2,..., M i ,..., M r under different levels of load series, where i represents the series number and r represents the total number of series. The maximum damage value of overuse at the i-th level of load series The actual number of usage times m at the i-th level of load i and the maximum damaged number of usage times M at the i-th level of load i are combined and analyzed to obtain the cumulative damage value at the i-th level of load where

[0012] S102. Statistically analyze the load level values Z1, Z2,..., Z k ,..., Z n of the wind power bolts. After that, according to the maximum damage value the actual number of usage times m1 and the maximum number of usage times M1 at the first level of load, determine that the original cumulative damage value at the first level of load is After that, take as the actual cumulative damage value at the first level of load Calculate the corresponding influence coefficient value θ1 by using the load level value Z1 of the first level and the load level value Z2 of the second level, where

[0013] Preferably, step S1 specifically further includes the following steps:

[0014] S103. After obtaining the influence coefficient value θ1 at the first level of load, the maximum damaged number of usage times M1 at the first level of load, and the maximum damaged number of usage times M2 at the second level of load, calculate the usage index h2 at the second level of load according to the maximum damaged number of usage times M1 at the first level of load and the maximum damaged number of usage times M2 at the second level of load. Use the influence coefficient value θ1 at the first level of load, the usage index h2 at the second level of load, and the actual cumulative damage value at the first level of load to analyze the associated damage value at the second level of load where

[0015] S104. According to the maximum damage value the actual number of usage times m2 and the maximum number of usage times M2 at the second level of load, determine that the original cumulative damage value at the second level of load is where Take and add them together, and use the obtained result as the actual cumulative damage value at the second level of load for storage;

[0016] S105. Repeat the operation until the associated damage value at the r-th level of load is analyzed and the original cumulative damage value at the r-th load level is Add and together, and use the resulting value as the actual cumulative damage value at the r-th load level where

[0017] Preferably, step S2 specifically includes the following steps:

[0018] S201. After constructing an equivalent model of the wind power bolt according to the structural geometric relationship using ANSYS simulation software, count the lengths of the bolt assemblies that are inside the connector and meshed with the connector, the lengths of the bolt assemblies that are inside the connector and not meshed with the connector, the length of the bolt top, the length of the bolt assembly without a threaded section outside the connector, and the length of the bolt assembly with a threaded section outside the connector when the wind power bolt is combined with the connector. Transmit all the length data to the corresponding database for storage;

[0019] S202. After determining the inner diameter length, outer diameter length, and material deformation coefficient of the wind power bolt, calculate the corresponding inner cross-section and outer cross-section according to the inner diameter length and outer diameter length. Analyze the flexibility of the bolt top based on the length of the bolt top, the material deformation coefficient, and the inner cross-sectional area. Combine and analyze the lengths of the bolt assemblies that are inside the connector and meshed with the connector, the lengths of the bolt assemblies that are inside the connector and not meshed with the connector, the material deformation coefficient, and the inner cross-section to obtain the flexibility of the current wind power bolt connection section.

[0020] Preferably, step S2 specifically further includes the following steps:

[0021] S203. Use the length of the bolt assembly without a threaded section outside the connector, the material deformation coefficient, and the inner cross-section to calculate and determine the flexibility of the current bolt rod part. Analyze through the length of the bolt assembly with a threaded section outside the connector, the material deformation coefficient, and the outer cross-section to obtain the flexibility of the current bolt threaded section;

[0022] S204. Add the flexibilities of the bolt top, connection section, rod part, and threaded section to obtain the total flexibility of the wind power bolt.

[0023] Preferably, step S3 specifically includes the following steps:

[0024] S301. After counting the flexibility when the center lines of the connector and the bolt do not overlap and when they overlap, determine the load coefficient of the wind power bolt, and calculate the relative stiffness of the wind power bolt according to the load coefficient and the flexibility of the connector;

[0025] S302. Divide the combined state of the wind power bolt and the connector into three types, namely the initial state, the contact state, and the stressed state;

[0026] S303. When the combined state between the wind power bolt and the connector is the initial state, the relative displacement of the wind power bolt is zero;

[0027] S304. When the combined state between the wind power bolt and the connector is the contact state, both the wind power bolt and the connector have relative displacements, and the reverse force, pre-tightening force, and clamping force of the bolt are all equal;

[0028] S305. When the combined state between the wind power bolt and the connector is the stressed state, both the wind power bolt and the connector are subjected to external pressure, and the actual external pressure values of the wind power bolt and the connector are calculated according to the relative stiffness of the bolt.

[0029] Preferably, the step S4 specifically includes the following steps:

[0030] S401. After determining the maximum load value of the wind power bolt in different combined states, transmit the maximum load value of the wind power bolt to the wind power bolt equivalent model for analysis to obtain the load result of the wind power bolt in the limit state;

[0031] S402. After counting the load amplitude, average load value, and tensile strength of the wind power bolt, use the optimization coefficient analysis algorithm to analyze the load amplitude, average load value, and tensile strength of the wind power bolt to obtain the optimized average load value. The optimization coefficient analysis algorithm is specifically:

[0032]

[0033] Among them, λ′ represents the optimized average load value, λ0 represents the load amplitude, τ represents the tensile strength, represents the average load value;

[0034] S403. Analyze the actual cumulative damage value under different levels of load using the optimized average load value to obtain the optimized actual cumulative damage value;

[0035] S404. After obtaining the real-time data of the wind power bolt, use neural network technology to analyze the real-time data, the optimized actual cumulative damage value of the wind power bolt, and the load result in the wind power bolt equivalent model to determine the strength state of the current wind power bolt.

[0036] The on-line strength evaluation system for a wind power bolt includes an actual damage analysis unit, a bolt parameter calculation unit, a combined state determination unit, and a strength state output unit;

[0037] The actual damage analysis unit determines the maximum damage value, actual usage times, and maximum damage usage times of the wind power bolt under different levels of load, analyzes the maximum damage value, actual usage times, and maximum damage usage times of overuse, obtains the original cumulative damage value under different levels of load, counts the influence coefficient values and usage indices of the wind power bolt under different levels of load, analyzes the associated damage value under the next level of load using the influence coefficient value, usage index, and actual cumulative damage value under the previous level of load, adds the original cumulative damage value and the associated damage value under the same level of load, stores the result as the actual cumulative damage value under the current level of load, and repeats the operation until the actual cumulative damage values under all levels of load are calculated;

[0038] After the bolt parameter calculation unit constructs an equivalent model of the wind power bolt using ANSYS simulation software, it counts the component length data of the wind power bolt, analyzes the flexibility of the bolt head, connection section, rod part, and thread section according to the length data, and adds the flexibility of the bolt head, connection section, rod part, and thread section to obtain the total flexibility of the wind power bolt;

[0039] The combined state determination unit determines the relative stiffness of the wind power bolt, divides the combined state of the wind power bolt and the connector into three types, namely the initial state, contact state, and stress state, and the relative displacement, reverse force, pre-tightening force, clamping force, and external pressure of the wind power bolt are different for different combined states;

[0040] After the strength state output unit determines the maximum load value of the wind power bolt in different combined states, it transmits the maximum load value of the wind power bolt to the equivalent model of the wind power bolt for analysis to obtain the load result of the wind power bolt in the limit state. After obtaining the real-time data of the wind power bolt, it uses neural network technology to analyze the real-time data, the actual cumulative damage value of the wind power bolt, and the load result in the equivalent model of the wind power bolt to determine the current strength state of the wind power bolt.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] By analyzing the associated damage values under different levels of load series, the present invention combines the associated damage values with the original cumulative damage values to obtain the actual cumulative damage values under different levels of load series. Since applying an external force to a wind power bolt each time will cause varying degrees of damage to it, and the superimposed external forces will further deepen this damage, this method not only determines the direct damage values when different external forces are applied, but also analyzes the deepening of the damaged part, making the final damage value more in line with the actual situation, ensuring more accurate analysis of the strength state of the wind power bolt. Moreover, this method constructs an equivalent model for the wind power bolt and refines the flexibility of different components on the bolt, making the force analysis of the wind power bolt more convenient, providing data support for the current analysis of the strength state of the wind power bolt, and ensuring the accuracy of subsequent evaluation results. Description of the Drawings

[0043] Figure 1 It is a flowchart of the overall method provided by an embodiment of the present invention. Detailed Embodiment

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] Please refer to Figure 1 , the present invention provides a technical solution: an online evaluation method for the strength of a wind power bolt, including the following steps:

[0046] S1. Analyze the cumulative damage value of the bolt: Determine the maximum damage value of overuse, the actual number of uses, and the maximum number of uses with damage of the wind power bolt under different levels of load series. Analyze the maximum damage value of overuse, the actual number of uses, and the maximum number of uses with damage to obtain the original cumulative damage values under different levels of load series. Statistically analyze the influence coefficient values and usage indices of the wind power bolt under different levels of load series, and use the influence coefficient values, usage indices, and the actual cumulative damage value at the previous level of load series to analyze the associated damage value at the next level of load series. Add the original cumulative damage value and the associated damage value at the same level of load series, and store the result as the actual cumulative damage value at the current level of load series. Repeat the operation until the actual cumulative damage values at all levels of load series are calculated;

[0047] S2. Analyze the flexibility of wind power bolts: After constructing an equivalent model of wind power bolts using ANSYS simulation software, and after statistically analyzing the component length data of the wind power bolts, the flexibility of the bolt head, connection section, rod section, and thread section is analyzed according to the length data. Then, the flexibility of the bolt head, connection section, rod section, and thread section is added together to obtain the total flexibility of the wind power bolts;

[0048] S3. Divide the bolt combination states: Determine the relative stiffness of the wind power bolts, and divide the combination states of the wind power bolts and the connectors into three types, namely the initial state, the contact state, and the stressed state. The relative displacements, reverse forces, pre-tightening forces, clamping forces, and external pressures of the wind power bolts corresponding to different combination states are different;

[0049] S4. Evaluate the bolt strength state: After determining the maximum load values of the wind power bolts in different combination states, the maximum load values of the wind power bolts are transmitted to the equivalent model of the wind power bolts for analysis to obtain the load results of the wind power bolts in the limit state. After obtaining the real-time data of the wind power bolts, neural network technology is used to analyze the real-time data, the actual cumulative damage value of the wind power bolts, and the load results in the equivalent model of the wind power bolts to determine the current strength state of the wind power bolts.

[0050] Step S1 specifically includes the following steps:

[0051] S101. Determine the maximum damage value of overuse of wind power bolts under different levels of load The actual usage times m1, m2,..., m i ,…,m r and the maximum damaged usage times M1, M2,…, M i ,…,M r under different levels of load, where i represents the series number and r represents the total number of series. Combine and analyze the maximum damage value of overuse the actual usage times m i at the i-th level of load and the maximum damaged usage times M i at the i-th level of load to obtain the cumulative damage value at the i-th level of load, where

[0052] S102. After statistically analyzing the load level values Z1, Z2,..., Z k ,...,Z n of the wind power bolts at different levels, according to the maximum damage value the actual usage times m1 and the maximum usage times M1 at the first level of load, determine that the original cumulative damage value at the first level of load is After that, As the actual cumulative damage value at the first-stage load level Using the load level value Z1 of the first stage and the load level value Z2 of the second stage, calculate the corresponding influence coefficient value θ1, where

[0053] Step S1 specifically further includes the following steps:

[0054] S103. After obtaining the influence coefficient value θ1 at the first-stage load level, the maximum number of damaged uses M1 at the first-stage load level, and the maximum number of damaged uses M2 at the second-stage load level, calculate the usage index h2 at the second-stage load level according to the maximum number of damaged uses M1 at the first-stage load level and the maximum number of damaged uses M2 at the second-stage load level. Using the influence coefficient value θ1 at the first-stage load level, the usage index h2 at the second-stage load level, and the actual cumulative damage value at the first-stage load level Analyze the associated damage value at the second-stage load level Where

[0055] S104. According to the maximum damage value at the second-stage load level The original cumulative damage value at the second-stage load level is determined based on the actual number of uses m2 and the maximum number of uses M2 at the second-stage load level as Where Add And The result obtained by adding them is used as the actual cumulative damage value at the second-stage load level Store it;

[0056] S105. Repeat the operation until the associated damage value at the rth-stage load level And the original cumulative damage value at the rth-stage load level is Add And The result obtained by adding them is used as the actual cumulative damage value at the rth-stage load level Where

[0057] Step S2 specifically includes the following steps:

[0058] S201. After constructing an equivalent model of the wind power bolt according to the structural geometric relationship using ANSYS simulation software, count the lengths of the bolt assemblies that are inside the connector and meshed with the connector, the lengths of the bolt assemblies that are inside the connector and not meshed with the connector, the length of the bolt top, the length of the bolt assembly without a threaded section outside the connector, and the length of the bolt assembly with a threaded section outside the connector when the wind power bolt is combined with the connector. Transmit all the length data to the corresponding database for storage;

[0059] S202. After determining the inner diameter length, outer diameter length, and material deformation coefficient of the wind power bolt, calculate the corresponding inner cross-section and outer cross-section according to the inner diameter length and outer diameter length. Analyze the flexibility of the bolt top based on the length of the bolt top, material deformation coefficient, and inner cross-sectional area. Combine and analyze the length of the bolt assembly that is inside the connector and meshed with the connector, the length of the bolt assembly that is inside the connector and not meshed with the connector, the material deformation coefficient, and the inner cross-section to obtain the flexibility of the current wind power bolt connection section;

[0060] Step S2 specifically further includes the following steps:

[0061] S203. Use the length of the bolt assembly without a threaded section outside the connector, material deformation coefficient, and inner cross-section for calculation to determine the flexibility of the current bolt rod part. Analyze through the length of the bolt assembly with a threaded section outside the connector, material deformation coefficient, and outer cross-section to obtain the flexibility of the current bolt threaded section;

[0062] S204. Add the flexibilities of the bolt top, connection section, rod part, and threaded section to obtain the total flexibility of the wind power bolt;

[0063] Step S3 specifically includes the following steps:

[0064] S301. After counting the flexibility when the center line of the connector and the center line of the bolt do not overlap and when they overlap, determine the load coefficient of the wind power bolt, and calculate the relative stiffness of the wind power bolt according to the load coefficient and the flexibility of the connector;

[0065] S302. Divide the combined state of the wind power bolt and the connector into three types, namely the initial state, the contact state, and the stressed state;

[0066] S303. When the combined state between the wind power bolt and the connector is the initial state, the relative displacement of the wind power bolt is zero;

[0067] S304. When the combined state between the wind power bolt and the connector is the contact state, both the wind power bolt and the connector have relative displacements, and the reverse force, pre-tightening force, and clamping force of the bolt are equal;

[0068] S305. When the combined state between the wind power bolt and the connector is in a stressed state, both the wind power bolt and the connector are subjected to external pressure, and the actual external pressure values of the wind power bolt and the connector are calculated according to the relative stiffness of the bolt.

[0069] Step S4 specifically includes the following steps:

[0070] S401. After determining the maximum load value of the wind power bolt in different combined states, the maximum load value of the wind power bolt is transmitted to the wind power bolt equivalent model for analysis to obtain the load result of the wind power bolt in the limit state.

[0071] S402. After statistically analyzing the load amplitude, average load value, and tensile strength of the wind power bolt, the load amplitude, average load value, and tensile strength of the wind power bolt are analyzed using the optimization coefficient analysis algorithm to obtain the optimized average load value. The optimization coefficient analysis algorithm is specifically as follows:

[0072]

[0073] Among them, λ′ represents the optimized average load value, λ0 represents the load amplitude, τ represents the tensile strength, represents the average load value;

[0074] S403. Analyze the actual cumulative damage value at different load levels using the optimized average load value to obtain the optimized actual cumulative damage value.

[0075] S404. After obtaining the real-time data of the wind power bolt, use neural network technology to analyze the real-time data, the optimized actual cumulative damage value of the wind power bolt, and the load result in the wind power bolt equivalent model to determine the strength state of the current wind power bolt.

[0076] An on-line evaluation system for the strength of a wind power bolt, comprising an actual damage analysis unit 1, a bolt parameter calculation unit 2, a combined state determination unit 3, and a strength state output unit 4;

[0077] The actual damage analysis unit 1 determines the maximum damage value, actual usage times, and maximum damage usage times of the wind power bolt under different levels of load, analyzes the maximum damage value, actual usage times, and maximum damage usage times of overuse, obtains the original cumulative damage value under different levels of load, counts the influence coefficient value and usage index of the wind power bolt under different levels of load, and analyzes the associated damage value under the next level of load using the influence coefficient value, usage index, and the actual cumulative damage value under the previous level of load. Add the original cumulative damage value and the associated damage value under the same level of load, and store the result as the actual cumulative damage value under the current level of load. Repeat the operation until the actual cumulative damage values under all levels of load are calculated;

[0078] After the bolt parameter calculation unit 2 constructs an equivalent model of the wind power bolt using ANSYS simulation software, it counts the component length data of the wind power bolt, analyzes the flexibility of the bolt head, connection section, rod part, and thread section based on the length data, and adds the flexibility of the bolt head, connection section, rod part, and thread section to obtain the total flexibility of the wind power bolt;

[0079] The combined state determination unit 3 determines the relative stiffness of the wind power bolt and divides the combined state of the wind power bolt and the connector into three types, namely the initial state, contact state, and stress state. The relative displacement, reverse force, pre-tightening force, clamping force, and external pressure of the wind power bolt are different for different combined states;

[0080] After the strength state output unit 4 determines the maximum load value of the wind power bolt in different combined states, it transmits the maximum load value of the wind power bolt to the equivalent model of the wind power bolt for analysis to obtain the load result of the wind power bolt in the limit state. After obtaining the real-time data of the wind power bolt, it uses neural network technology to analyze the real-time data, the actual cumulative damage value of the wind power bolt, and the load result in the equivalent model of the wind power bolt to determine the current strength state of the wind power bolt.

[0081] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0082] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An on-line evaluation method for the strength of wind power bolts, characterized in that, The method includes the following steps: S1. Analyze the cumulative damage value of the bolt: Determine the maximum damage value, the actual number of uses, and the maximum number of uses with damage of the wind power bolt under different levels of load. Analyze the maximum damage value, the actual number of uses, and the maximum number of uses with damage to obtain the original cumulative damage value under different levels of load. Statistically analyze the influence coefficient value and the usage index of the wind power bolt under different levels of load. Use the influence coefficient value, the usage index, and the actual cumulative damage value at the previous level of load to analyze the associated damage value at the next level of load. Add the original cumulative damage value and the associated damage value at the same level of load, and store the result as the actual cumulative damage value at the current level of load. Repeat the operation until the actual cumulative damage values at all levels of load are calculated; S2. Analyze the flexibility of the wind power bolt: After constructing an equivalent model of the wind power bolt using ANSYS simulation software, statistically analyze the component length data of the wind power bolt. Then, analyze the flexibility of the bolt head, connection section, rod section, and thread section based on the length data. Add the flexibility of the bolt head, connection section, rod section, and thread section to obtain the total flexibility of the wind power bolt; S3. Divide the bolt combination state: Determine the relative stiffness of the wind power bolt, and divide the combination state of the wind power bolt and the connector into three types, namely the initial state, the contact state, and the stressed state. The relative displacement, reverse force, pre-tightening force, clamping force, and external pressure of the wind power bolt are different for different combination states; S4. Evaluate the bolt strength state: After determining the maximum load value of the wind power bolt in different combination states, transmit the maximum load value of the wind power bolt to the equivalent model of the wind power bolt for analysis to obtain the load result of the wind power bolt in the limit state. After obtaining the real-time data of the wind power bolt, use neural network technology to analyze the real-time data, the actual cumulative damage value of the wind power bolt, and the load result in the equivalent model of the wind power bolt to determine the current strength state of the wind power bolt.

2. The online evaluation method for the strength of a wind power bolt according to claim 1, characterized in that: The specific steps of step S1 include the following steps: S101. Determine the maximum damage value of overuse of wind power bolts at different levels of load The actual usage times m1, m2, …, m at different levels of load i ,..., m r And the maximum damage usage times M1, M2, …, M at different levels of load i ,..., M r , where i represents the serial number of the level, r represents the total number of levels, and the maximum damage value of overuse at the i-th level of load The actual usage times m at the i-th level of load i And the maximum damage usage times M at the i-th level of load i Are combined and analyzed to obtain the cumulative damage value at the i-th level of load Where S102. Statistically analyze the load level values Z1, Z2,..., Z k ,..., Z n After that, according to the maximum damage value under the first-level load level, the actual usage times m1 and the maximum usage times M1 are used to determine the original cumulative damage value under the first-level load level as After that, is used as the actual cumulative damage value under the first-level load level Calculate the corresponding influence coefficient value θ1 by using the load level value Z1 of the first level and the load level value Z2 of the second level, where 3. The on-line evaluation method for the strength of a wind power bolt according to claim 1, wherein: The specific steps of step S1 further include the following steps: After obtaining the influence coefficient value θ1 at the first-level load level, the maximum number of damaged uses M1 at the first-level load level, and the maximum number of damaged uses M2 at the second-level load level, calculate the usage index h2 at the second-level load level according to the maximum number of damaged uses M1 at the first-level load level and the maximum number of damaged uses M2 at the second-level load level. Then, use the influence coefficient value θ1 at the first-level load level, the usage index h2 at the second-level load level, and the actual cumulative damage value at the first-level load level to analyze the associated damage value at the second-level load level where S104. Determine the original cumulative damage value at the second-level load level according to the maximum damage value, the actual number of usage times m2, and the maximum number of usage times M2 at the second-level load level. The original cumulative damage value at the second-level load level is determined as where Add and together, and use the resulting value as the actual cumulative damage value at the second-level load level and store it. S105. Repeat the operation until the associated damage value at the r-th level of load is analyzed and the original cumulative damage value at the r-th level of load is Add and together, and use the result as the actual cumulative damage value at the r-th level of load where 4. The on-line evaluation method for the strength of a wind power bolt according to claim 1, characterized in that: The specific steps of step S2 include the following steps: S201. After constructing an equivalent model of the wind power bolt using ANSYS simulation software according to the structural geometric relationship, statistically analyze the length of the bolt components that are inside the connector and meshed with the connector, the length of the bolt components that are inside the connector and not meshed with the connector, the length of the bolt head, the length of the bolt components that are outside the connector and have no thread section, and the length of the bolt components that are outside the connector and have a thread section when the wind power bolt is combined with the connector. Transmit all the length data to the corresponding database for storage; After determining the inner diameter length, outer diameter length, and material deformation coefficient of the wind power bolt, calculate the corresponding inner cross-section and outer cross-section based on the inner diameter length and outer diameter length. Analyze the flexibility of the bolt head according to the bolt head length, material deformation coefficient, and inner cross-sectional area. Combine and analyze the length of the bolt assembly inside the connector and meshing with the connector, the length of the bolt assembly inside the connector and not meshing with the connector, the material deformation coefficient, and the inner cross-section to obtain the flexibility of the current wind power bolt connection section.

5. The on-line evaluation method for the strength of a wind power bolt according to claim 1, characterized in that: The specific steps of step S2 further include the following steps: S203. Calculate using the length of the bolt assembly outside the connector and without a threaded section, the material deformation coefficient, and the inner cross-section to determine the flexibility of the current bolt rod part. Analyze through the length of the bolt assembly outside the connector and with a threaded section, the material deformation coefficient, and the outer cross-section to obtain the flexibility of the current bolt threaded section. S204. Add the flexibilities of the bolt head, connection section, rod part, and threaded section to obtain the total flexibility of the wind power bolt.

6. The on-line evaluation method for the strength of a wind power bolt according to claim 1, characterized in that: The specific steps of step S3 include the following steps: S301. After counting the flexibility when the centerlines of the connector and the bolt do not overlap and when they overlap, determine the load coefficient of the wind power bolt, and calculate the relative stiffness of the wind power bolt according to the load coefficient and the flexibility of the connector. S302. Divide the combined state of the wind power bolt and the connector into three types, namely the initial state, the contact state, and the stressed state. S303. When the combined state between the wind power bolt and the connector is the initial state, the relative displacement of the wind power bolt is zero. S304. When the combined state between the wind power bolt and the connector is the contact state, both the wind power bolt and the connector have relative displacements, and the reverse force, pre-tightening force, and clamping force of the bolt are equal. S305. When the combined state between the wind power bolt and the connector is the stressed state, both the wind power bolt and the connector are subjected to external pressure, and calculate the actual external pressure values of the wind power bolt and the connector according to the relative stiffness of the bolt.

7. The on-line evaluation method for the strength of a wind power bolt according to claim 1, characterized in that: The specific steps of step S4 include the following steps: S401. After determining the maximum load value of the wind power bolt in different combined states, transmit the maximum load value of the wind power bolt to the wind power bolt equivalent model for analysis to obtain the load result of the wind power bolt in the limit state. S402. After counting the load amplitude, average load value, and tensile strength of the wind power bolt, use the optimization coefficient analysis algorithm to analyze the load amplitude, average load value, and tensile strength of the wind power bolt to obtain the optimized average load value. S403. Analyze the actual cumulative damage value under different levels of load using the optimized average load value to obtain the optimized actual cumulative damage value. S404. After obtaining the real-time data of the wind power bolt, use neural network technology to analyze the real-time data, the optimized actual cumulative damage value of the wind power bolt, and the load result in the wind power bolt equivalent model to determine the strength state of the current wind power bolt.

8. An on-line evaluation system for the strength of wind power bolts, characterized in that, The online evaluation system is applicable to an online evaluation method for the strength of a wind power bolt described in any one of claims 1-7, and includes an actual damage analysis unit (1), a bolt parameter calculation unit (2), a combined state determination unit (3), and a strength state output unit (4); The actual damage analysis unit (1) determines the maximum damage value, the actual number of uses, and the maximum number of uses with damage of the wind power bolt under different levels of load, analyzes the maximum damage value, the actual number of uses, and the maximum number of uses with damage, obtains the original cumulative damage value under different levels of load, counts the influence coefficient value and the usage index of the wind power bolt under different levels of load, analyzes the associated damage value under the next level of load using the influence coefficient value, the usage index, and the actual cumulative damage value under the previous level of load, adds the original cumulative damage value and the associated damage value under the same level of load, stores the result as the actual cumulative damage value under the current level of load, and repeats the operation until the actual cumulative damage values under all levels of load are calculated; After constructing an equivalent model of the wind power bolt using ANSYS simulation software, the bolt parameter calculation unit (2) counts the component length data of the wind power bolt, analyzes the flexibility of the bolt head, the connection section, the rod part, and the thread section according to the length data, and adds the flexibility of the bolt head, the connection section, the rod part, and the thread section to obtain the total flexibility of the wind power bolt; The combined state determination unit (3) determines the relative stiffness of the wind power bolt, and divides the combined state of the wind power bolt and the connector into three types, namely the initial state, the contact state, and the stressed state. Different combined states correspond to different relative displacements, reverse forces, pre-tightening forces, clamping forces, and external pressures of the wind power bolt; After determining the maximum load value of the wind power bolt in different combined states, the strength state output unit (4) transmits the maximum load value of the wind power bolt to the equivalent model of the wind power bolt for analysis, obtains the load result of the wind power bolt in the limit state, obtains the real-time data of the wind power bolt, and uses neural network technology to analyze the real-time data, the actual cumulative damage value of the wind power bolt, and the load result in the equivalent model of the wind power bolt to determine the strength state of the current wind power bolt.

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