Method for comprehensively evaluating fatigue performance of spacer of power transmission line in simulated natural environment

Abstract

The invention discloses a power transmission line spacer fatigue performance comprehensive evaluation method under a simulated natural environment, and belongs to the technical field of power transmission line detection, and the method comprises the steps: S10, carrying out the simulation of related environments, including climate, wind power and vibration, of a spacer; the climate comprises environment temperature, air humidity and sunlight intensity; and S20, a monitoring interval is set based on the climate, the monitoring interval comprises setting of climate changes with a basic value as a setting target, and the basic value comprises the environment temperature of 0 DEG C. By simulating climate (temperature, humidity and sunlight), wind power, vibration and other conditions in the natural environment, the stress condition and fatigue performance of the spacer in actual operation can be reflected more truly, and then the feature change of the fatigue crack on the surface of the spacer can be analyzed in detail so as to accurately predict the initiation and extension path of the crack and the fatigue life.

Description

Technical Field

[0001] This invention relates to the field of power transmission line testing technology, and in particular to a comprehensive evaluation method for the fatigue performance of power transmission line spacers under simulated natural conditions. Background Technology

[0002] Transmission line spacers are crucial components used to secure transmission conductors and prevent them from colliding with each other. In natural environments, spacers are constantly exposed to various factors such as wind, temperature changes, and vibration, making them prone to fatigue damage and consequently affecting the safe operation of transmission lines. Therefore, it is necessary to evaluate the fatigue performance of spacers.

[0003] In the field of power transmission line testing technology, there are many methods for evaluating the fatigue performance of power components or auxiliary parts, and the fatigue performance evaluation of spacers is one of them.

[0004] Regarding this research, application CN202210149825.4 provides a method for assessing the fatigue of insulated operating rods used in live-line work. The specific technical solution involves: setting working conditions, types of insulated operating rods, and grip distances; conducting preliminary tests; determining the optimal target muscle based on the results; collecting bioelectrical signals of the optimal target muscle under each working condition and grip distance for each type of insulated operating rod; extracting feature values; selecting feature parameters; establishing a fatigue assessment model; labeling the feature parameters according to muscle state; and using this label to establish a training set for training the fatigue assessment model. This technical solution can obtain the optimal target muscle through preliminary tests and conduct muscle fatigue assessment based on its surface bioelectrical signals, effectively improving detection accuracy and efficiency.

[0005] Another application, CN202210153226.X, provides a method for estimating fatigue damage of transmission line conductors and ground wires. This technical solution includes selecting the transmission line conductors and ground wires to be evaluated, combining the line's SN characteristic curve, and comparing the calculation results with operational data. This technical solution combines the conductor and ground wire fatigue performance SN curve and the transmission line OPGW vibration event data feedback, and uses the Miner damage accumulation criterion to evaluate the cumulative fatigue damage and risk of the transmission line, thereby scientifically assessing the service life of the conductors and ground wires and providing a basis for decision-making for operation and maintenance personnel.

[0006] However, the fatigue performance evaluation of the above-mentioned technical solutions for power components or auxiliary parts is based on laboratory static tests, which are difficult to truly reflect the actual working conditions of power components or auxiliary parts in natural environments. Summary of the Invention

[0007] In view of the problems existing in the field of power transmission line testing technology, the present invention is proposed.

[0008] Therefore, one of the objectives of this invention is to provide a comprehensive evaluation method for the fatigue performance of transmission line spacers under simulated natural environments. By simulating conditions such as climate (temperature, humidity, sunshine), wind force, and vibration in the natural environment, it can more realistically reflect the stress and fatigue performance of spacers in actual operation. Furthermore, through various means such as dynamic load application, strain analysis, and numerical simulation (finite element analysis), it can analyze in detail the characteristic changes of fatigue cracks on the surface of spacers, so as to accurately predict the initiation, propagation path, and fatigue life of cracks.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention provides a comprehensive evaluation method for the fatigue performance of transmission line spacers under simulated natural conditions, comprising the following steps: S10: Simulate the relevant environment for the spacer bar, including climate, wind, and vibration; the climate includes ambient temperature, air humidity, and solar radiation intensity. S20: Based on the climate, a monitoring interval is set, wherein the monitoring interval includes setting the climate change with a base value as the target, wherein the base value includes an ambient temperature of 0°C; S30: In the monitoring interval, the air humidity and solar radiation intensity are simultaneously reduced by lowering the ambient temperature, including reducing the ambient temperature from 0°C to -30°C, and the changes of the spacer are acquired in the monitoring interval, including fatigue cracks appearing on the surface of the spacer. S40: When the ambient temperature is reduced, a dynamic load is applied to the spacer bar. The dynamic load is set according to the actual conductor tension of the transmission line and the applied range is 1kN to 100kN. Within the applied range, the characteristic changes of fatigue cracks on the surface of the spacer bar are analyzed. S50: Divide the spacer bar into fulcrums based on the described feature changes, wherein the fulcrum division includes dividing the spacer bar into fulcrums. , ,..., ;in, Indicates the division of the first Calculate the maximum conductor tension that can be withstood at each of the several support points.

[0010] In a preferred embodiment of the present invention, in step S40, the characteristic changes of fatigue cracks on the surface of the spacer bar are analyzed within the applied range. The analysis includes strain analysis, which includes strain peak value, strain distribution, and strain cycle characteristics. The strain peak value is the maximum strain value of the spacer bar under different load magnitudes; The strain distribution is used to analyze the distribution of strain on the surface of the spacer bar; The strain cyclic characteristics are used to obtain the cyclic variation law of strain over time; The characteristic changes of fatigue cracks on the surface of the spacer bar are analyzed within the applied range. The analysis method also includes numerical simulation and analysis, including finite element analysis. The finite element analysis includes stress-strain distribution, crack propagation path prediction, and fatigue life assessment. The stress-strain distribution is used to analyze the stress-strain distribution on the surface and inside of the spacer to determine the stress concentration area of ​​the spacer. The crack propagation path prediction involves simulating the propagation path of a crack corresponding to a fatigue crack under different load magnitudes, and then predicting the crack propagation direction and rate based on the propagation path. The fatigue life assessment involves constructing a fatigue life prediction model based on the predicted crack propagation direction and rate, calculating the fatigue life of the spacer under different loads, and predicting the time of crack initiation and propagation based on the fatigue life.

[0011] In a preferred embodiment of the present invention, in step S50, the maximum conductor tension that different support points can withstand is calculated using the following formula: ;in, This represents the maximum conductor tension that can be withstood among the multiple support points; In the formula, This indicates the maximum total load that the spacer can withstand. This indicates the number of fulcrums on the spacer bar. Indicates the first The stiffness of the aforementioned support points.

[0012] In a preferred embodiment of the present invention, calculating the maximum conductor tension that different support points can withstand further includes calculating it according to the following formula: ;in, This indicates the maximum stress that can be withstood among the multiple support points; In the formula, This indicates the maximum conductor tension that can be withstood among the multiple support points; Indicates the first The length of each of the aforementioned fulcrums, Indicates the first The cross-sectional area of ​​each of the aforementioned fulcrums.

[0013] In a preferred embodiment of the present invention, the fatigue life of the spacer bar under different load magnitudes is calculated according to the following formula: ;in, Indicates the first Fatigue life of the aforementioned fulcrum; In the formula, This indicates the maximum stress that can be withstood among the multiple support points. This indicates the fatigue limit of the material used to manufacture the spacer bar. This indicates the fatigue index of the material.

[0014] In a preferred embodiment of the present invention, wind force and vibration are applied to each support point according to the calculated maximum conductor tension that different support points can withstand. When applying wind force and vibration to each support point, the support point is divided into a lateral force point and an intermediate force point. The maximum wind force and maximum vibration that the lateral force point and the intermediate force point corresponding to the support point can withstand when the support point is subjected to the maximum conductor tension are calculated. When the spacer is used in a real natural environment, when the support point has been subjected to the maximum conductor tension, the wind force magnitude and vibration frequency experienced by the lateral force point and the intermediate force point of the corresponding support point are collected. If the wind force magnitude and vibration frequency experienced do not reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, it is determined that the spacer will not develop fatigue cracks; otherwise, it is determined that the spacer will develop fatigue cracks and an early warning is issued. When the fulcrum is not subjected to the maximum conductor tension, if the wind force and vibration frequency experienced by the lateral force point and the intermediate force point corresponding to the fulcrum reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, then it is determined that the spacer will not develop fatigue cracks.

[0015] In a preferred embodiment of the present invention, when the fulcrum has already borne the maximum conductor tension, if the wind force and vibration frequency experienced by the lateral force point and the intermediate force point corresponding to the fulcrum reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, then the deflection angle of the wind force experienced at the center of the spacer is collected. If the deflection angle is opposite to the angle at which the fulcrum is located on the spacer, then it is determined that fatigue cracks on the surface of the spacer will not appear on the side deflected towards the fulcrum.

[0016] In a preferred embodiment of the present invention, the maximum wind force and maximum vibration that the lateral force point and the intermediate force point corresponding to the fulcrum can withstand when the fulcrum is subjected to the maximum conductor tension are calculated according to the following formula: In the formula, Indicates the maximum wind force; In the formula, Indicates air density, This indicates the maximum wind speed. Indicates the wind force coefficient. This represents the windward area of ​​the fulcrum. ; In the formula, Indicates the maximum vibration acceleration. Indicates the maximum vibration frequency. This indicates the mass of the fulcrum.

[0017] A terminal includes a processor, an input interface, an output interface, and a memory, which are interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to invoke the program instructions to execute the method described above.

[0018] A computer-readable storage medium storing a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the method as described above.

[0019] Beneficial effects: 1. This invention uses a variety of methods, such as dynamic load application, strain analysis, and numerical simulation (finite element analysis), to analyze in detail the characteristic changes of fatigue cracks on the surface of spacer bars, including strain peak, strain distribution, strain cycle characteristics, etc. This method can accurately predict crack initiation, propagation path and fatigue life, and can more effectively obtain the working conditions of spacer bars in natural environments. 2. By calculating the maximum conductor tension and stress that different support points can withstand, the support point distribution and structural design of the spacer can be optimized, which helps to rationally distribute the load, reduce stress concentration, and thus improve the overall fatigue performance and service life of the spacer. 3. This invention applies wind force and vibration to the fulcrum and collects relevant data. When the maximum conductor tension that the fulcrum can withstand reaches its limit, if the wind force and vibration frequency exceed the maximum value that the fulcrum can withstand, an early warning is issued, indicating that fatigue cracks may occur. This early warning mechanism can detect potential safety hazards in advance and avoid accidents. 4. When the fulcrum is subjected to the maximum conductor tension, if the wind deflection angle is opposite to the angle of the fulcrum, it is determined that the crack will not appear on the side deflected towards the fulcrum. This invention can predict the possible location of the crack based on the wind deflection angle, thus improving the efficiency and accuracy of the spacer evaluation. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the process structure of an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0022] Because existing technologies for evaluating the fatigue performance of power components or auxiliary parts rely on static laboratory tests, these tests cannot accurately reflect the actual operating conditions of power components or auxiliary parts in natural environments.

[0023] Based on this, the present invention proposes a comprehensive evaluation method for the fatigue performance of transmission line spacers under simulated natural environments. By simulating conditions such as climate (temperature, humidity, sunshine), wind force, and vibration in the natural environment, it can more realistically reflect the stress and fatigue performance of spacers in actual operation. Furthermore, through various means such as dynamic load application, strain analysis, and numerical simulation (finite element analysis), it can analyze in detail the characteristic changes of fatigue cracks on the surface of spacers, so as to accurately predict the initiation, propagation path, and fatigue life of cracks.

[0024] The present solution will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0025] Reference Figures 1 to 2 As one embodiment of the present invention, this embodiment provides a comprehensive evaluation method for the fatigue performance of transmission line spacer bars under simulated natural conditions, including the following steps: S10: Simulate the relevant environment for the spacer bar, including climate, wind, and vibration; climate includes ambient temperature, air humidity, and solar radiation intensity. In this embodiment, in one feasible implementation, the spacer to be tested is installed on the experimental device simulating the conductor of a transmission line to ensure that its installation method is consistent with that of an actual transmission line. The climate simulation includes simulating temperature changes (-20℃ to +50℃) and humidity changes (10% to 90% relative humidity) in the natural environment using temperature and humidity controllers, cooling and heating equipment, and humidification and dehumidification devices. At the same time, ultraviolet lamps are used to simulate sunlight, simulating solar radiation intensity of 300W / m² to 1000W / m². The simulation of wind force includes using an adjustable-speed blower to simulate natural wind force, with a wind speed range of 0.5m / s to 30m / s. By changing the wind direction and speed, the effect of wind of different directions and intensities on the spacer is simulated. The simulation of vibration includes using a vibration table to simulate the vibration of transmission line conductors, with a vibration frequency range of 0.1Hz to 100Hz and a vibration acceleration range of 0.1g to 10g, in order to simulate the vibration of conductors in actual operation. S20: Based on climate setting, the monitoring interval includes setting climate change with a base value as the target. The base value includes an ambient temperature of 0°C. S30: Simultaneously reduce air humidity and solar radiation intensity in the monitoring range by lowering the ambient temperature, including reducing the ambient temperature from 0°C to -30°C, and obtain changes in the spacer bars in the monitoring range, including fatigue cracks appearing on the surface of the spacer bars. In this embodiment, in reality, steel has the characteristic of high temperature resistance. Under normal temperature and high temperature conditions, the performance of steel will not be negatively affected. Furthermore, extreme high temperature conditions (such as above 200°C) are rare. Therefore, in this embodiment, in combination with the actual situation, the rise in ambient temperature is not used as the fatigue assessment of the spacer bar. This approach has practical significance. It should be noted that reducing air humidity and solar intensity in a way that lowers the ambient temperature includes reducing air humidity and solar intensity in a way that is consistent with the decrease in ambient temperature. S40: Apply dynamic load to the spacer bar when the ambient temperature decreases. The dynamic load is set according to the conductor tension of the actual transmission line and the range of application is 1kN to 100kN. Analyze the characteristic changes of fatigue cracks on the surface of the spacer bar within the applied range. S50: Divide the spacer into fulcrums based on characteristic changes. This fulcrum division includes dividing the spacer into fulcrums... , ,..., ;in, Indicates the division of the first Calculate the maximum conductor tension that can be withstood at each of the following support points; In this embodiment, the fulcrum is the fulcrum on the spacer bar that fixes and supports the wire; It should be emphasized that this embodiment covers multiple steps, from environmental simulation, monitoring range setting, environmental parameter adjustment to fatigue crack characteristic change analysis on the spacer surface, making the evaluation process more scientific, systematic and comprehensive, and helping to fully understand the fatigue performance changes of the spacer under different environmental conditions. By simulating various relevant environmental factors such as climate, wind, and vibration, the stress and fatigue performance of spacers in actual natural environments can be more realistically reflected. This overcomes the limitations of traditional laboratory static testing, which cannot fully simulate actual working conditions, and provides a more realistic basis for the performance evaluation of spacers. In S40, the characteristic changes of fatigue cracks on the surface of the spacer bar are analyzed within the applied range. The analysis methods include strain analysis, which includes strain peak, strain distribution and strain cycle characteristics. It should be noted that, in one feasible implementation, strain gauges are installed on the surface of the spacer to monitor the strain changes of the spacer under dynamic loads in real time. By analyzing the strain data, the stress state of the spacer under different load levels can be understood. Peak strain is the maximum strain value of the spacer bar under different load magnitudes. In this embodiment, the maximum strain value of the strain gauge is recorded under different load levels. As the load increases, the strain peak value also increases. When fatigue cracks occur, the strain peak value may change abruptly. Strain distribution is used to analyze the distribution of strain on the surface of the spacer bar; In this embodiment, fatigue cracks usually initiate in stress concentration areas, so changes in strain distribution can provide clues to the location of cracks. Strain cyclic characteristics are used to obtain the cyclic variation law of strain over time. In this embodiment, the strain cycle may exhibit nonlinear changes during the fatigue crack propagation stage; The characteristic changes of fatigue cracks on the surface of the spacer bar are analyzed within the applied range. The analysis methods also include numerical simulation and analysis, including finite element analysis. Finite element analysis includes stress-strain distribution, crack propagation path prediction, and fatigue life assessment. Stress-strain distribution is used to analyze the stress-strain distribution on the surface and inside of the spacer to determine the stress concentration areas of the spacer. Crack propagation path prediction involves simulating the propagation path of a fatigue crack under different load conditions, and then predicting the crack propagation direction and rate based on the propagation path. Fatigue life assessment involves constructing a fatigue life prediction model based on the predicted crack propagation direction and rate, calculating the fatigue life of the spacer bar under different loads, and predicting the time of crack initiation and propagation based on the fatigue life. It should be noted that, in order to construct a numerical model of the spacer, dynamic loads are applied to the numerical model to simulate the stress-strain distribution and crack propagation of the spacer under different load magnitudes. For fatigue life assessment, in one feasible implementation, a fatigue life prediction model can be constructed based on the fatigue performance data of the material used to manufacture the spacer and the combination of the predicted crack propagation direction and rate, to assess the fatigue life of the spacer under different load levels. It is important to emphasize that by employing various methods such as strain analysis and numerical simulation and analysis, and analyzing the characteristic changes of fatigue cracks on the surface of spacer bars from multiple dimensions such as strain peak value, strain distribution, and strain cycle characteristics, we can gain a more comprehensive and in-depth understanding of the formation and development laws of cracks, and provide richer information for accurately evaluating the fatigue performance of spacer bars. In S50, the maximum conductor tension that different support points can withstand is calculated using the following formula: ;in, This indicates the maximum conductor tension that can be withstood among multiple supports; In the formula, This indicates the maximum total load that the spacer can withstand. Indicates the number of fulcrums on the spacer bar. Indicates the first Stiffness of each support point; In this embodiment, the maximum conductor tension that different support points can withstand is calculated by formula, and the force-bearing capacity of the support points is quantified. This provides clear quantitative indicators for the design and optimization of the spacer, which helps to rationally distribute the force on the support points, optimize the layout and structural design of the support points, and improve the overall load-bearing capacity and fatigue performance of the spacer. Furthermore, the stiffness factor of the support points is introduced into the calculation formula, taking into account the possible stiffness differences of different support points, making the calculation results more consistent with the actual situation and more accurately reflecting the actual stress situation of each support point, thus providing a basis for the personalized design and optimization of spacers. Calculating the maximum conductor tension that different support points can withstand also includes calculations based on the following formula: ;in, This indicates the maximum stress that can be withstood among multiple support points; In the formula, This indicates the maximum conductor tension that can be withstood among multiple supports; Indicates the first The length of each fulcrum Indicates the first Cross-sectional area of ​​each fulcrum; In this embodiment, based on the above calculation formula, the maximum stress of the fulcrum is further calculated, and the stress situation of the fulcrum is analyzed in more detail from the perspective of stress, so that the assessment of the fulcrum's stress capacity is more comprehensive and in-depth, and the safety and reliability of the fulcrum in actual use can be judged more accurately. By calculating the maximum stress at the support, the structural design of the support can be optimized. For example, parameters such as the cross-sectional area or length of the support can be adjusted to reduce the stress level of the support, improve the load-bearing capacity and fatigue resistance of the support, thereby optimizing the structural design of the entire spacer. The fatigue life of the spacer bar under different loads is calculated using the following formula: ;in, Indicates the first Fatigue life of each fulcrum; In the formula, This indicates the maximum stress that can be withstood among multiple support points. This indicates the fatigue limit of the material used to manufacture the spacer bars. Indicates the fatigue index of the material; In this embodiment, the fatigue life of the support is calculated by formula, which can quantitatively evaluate the fatigue performance of the support under different loads, making the fatigue life prediction of the spacer more specific and accurate. This helps to formulate maintenance and replacement plans in advance and avoid spacer damage and transmission line failure caused by support fatigue failure. Furthermore, the fatigue limit and fatigue index of the material are introduced into the calculation formula, which fully considers the influence of the material's fatigue characteristics on the fatigue life of the support, making the calculation results more consistent with the actual fatigue behavior of the material, and providing a more accurate reference for the material selection and design optimization of the spacer bar. Based on the calculated maximum conductor tension that different support points can withstand, wind force and vibration are applied to each support point. When applying wind force and vibration to each support point, any support point is divided into lateral force points and intermediate force points. The maximum wind force and maximum vibration that the corresponding lateral force points and intermediate force points can withstand when the support point is under maximum conductor tension are calculated. When the spacer is used in a real natural environment, when the support point has already been under maximum conductor tension, the wind force magnitude and vibration frequency experienced by the corresponding lateral force points and intermediate force points of the support point are collected. If the wind force magnitude and vibration frequency experienced do not reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, it is determined that the spacer will not develop fatigue cracks; otherwise, it is determined that the spacer will develop fatigue cracks and an early warning is issued. When the fulcrum is not subjected to the maximum conductor tension, if the wind force and vibration frequency experienced by the lateral force point and the intermediate force point corresponding to the fulcrum reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, it is determined that the spacer will not develop fatigue cracks. It should be noted that in actual use, the wind force experienced by the spacer is not uniform. The reasons for this uneven wind force include the influence of terrain and micro-meteorological conditions, as well as the arrangement of the conductors and the installation position of the spacer. In terms of terrain factors, transmission lines often cross different terrains, such as valleys, ridges, and plains. In valleys, the wind speed may increase due to the funnel effect; while on ridges, the wind speed may decrease due to terrain obstruction. This difference in terrain will cause the spacer to experience different wind forces at different locations. Furthermore, local meteorological conditions (such as local airflow and eddies) can also lead to uneven wind speeds. For example, near buildings or trees, wind speeds may change due to obstruction by obstacles. The arrangement of conductors (such as horizontal, vertical, and triangular) will affect the distribution of wind force on the spacers. For example, vertical and triangular conductors have a better effect on suppressing wind force after spacers are installed, while horizontal conductors are less effective at suppressing wind force. The installation position of spacers also affects their wind resistance. Installing spacers at different locations on the conductor may result in different wind resistance. For example, installing spacers in the middle of the conductor may result in stronger winds, while installing them closer to the tower may result in relatively weaker winds. Changes in wind direction also affect the wind force on the spacers. When the wind direction is perpendicular to the direction of the conductor arrangement, the spacers experience the greatest wind force; while when the wind direction is parallel to the direction of the conductor arrangement, the spacers experience relatively less wind force. It should be emphasized that, based on the consideration of the maximum conductor tension borne by the support point, wind force and vibration are further applied to the support point, and the influence of wind force and vibration on the fatigue performance of the spacer is comprehensively considered, making the evaluation results more comprehensive and accurate, and able to more realistically reflect the stress and fatigue state of the spacer in actual operation. By collecting the wind force and vibration frequency experienced by the lateral and intermediate stress points of the fulcrum and comparing them with the maximum wind force and maximum vibration that the fulcrum can withstand, an early warning function for fatigue cracks in the spacer is realized. When the wind force and vibration experienced exceed the bearing capacity of the fulcrum, an early warning can be issued in time to remind relevant personnel to take measures to avoid further expansion of fatigue cracks and damage to the spacer. When the fulcrum has been subjected to the maximum conductor tension, if the wind force and vibration frequency experienced by the lateral force point and the intermediate force point corresponding to the fulcrum reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, then the deflection angle of the wind force experienced at the center of the spacer is collected. If the deflection angle is opposite to the angle of the fulcrum on the spacer, then it is determined that the fatigue crack on the surface of the spacer will not appear on the side deflected towards the fulcrum. It should be noted that, according to the applicant's research experience, there is a certain relationship between the wind deflection angle and fatigue cracks. When the surface of the spacer bar is blown by strong wind, the wind will generate pressure distribution on the surface. If the wind deflection angle is uneven, it will cause stress concentration in some areas. These stress concentration areas are usually high-risk areas for fatigue crack initiation. If the wind deflection angle causes stress concentration in a certain direction, then the crack will initiate along the direction corresponding to that stress direction. Therefore, if the deflection angle is opposite to the angle at which the fulcrum is located on the spacer, it is determined that fatigue cracks on the surface of the spacer will not appear on the side deflected towards the fulcrum. This determination in this embodiment has practical significance. It is important to emphasize that when the fulcrum is subjected to the maximum conductor tension and the wind force and vibration frequency reach their maximum values, by collecting the deflection angle of the wind force at the center of the spacer, it is possible to determine whether the crack will appear on the side deflected towards the fulcrum, providing a new idea and method for crack detection and prevention. This method can, to some extent, narrow the scope of crack detection, avoid comprehensive inspection of the entire spacer, thereby improving the efficiency of crack detection, reducing detection costs and workload, and also helps to more accurately locate the crack, providing guidance for subsequent repair and maintenance. The maximum wind force and maximum vibration that the lateral and intermediate stress points corresponding to the fulcrum can withstand under the condition of maximum conductor tension at the fulcrum are calculated using the following formula: In the formula, Indicates the maximum wind force; In the formula, Indicates air density, This indicates the maximum wind speed. Indicates the wind force coefficient. This represents the windward area of ​​the fulcrum. ; In the formula, Indicates the maximum vibration acceleration. Indicates the maximum vibration frequency. Indicates the mass of the fulcrum; In this embodiment, the wind force coefficient is related to the shape of the support point, and is usually taken as 0.8 to 1.2; The quantitative indicators such as the maximum wind force and maximum vibration acceleration obtained by calculation can intuitively reflect the wind force and vibration tolerance limit of the support point under the maximum conductor tension, making the wind force and vibration assessment of the support point more specific and accurate, and providing strong support for the design, selection and operation and maintenance of spacers.

[0026] A terminal includes a processor, an input interface, an output interface, and a memory, which are interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to invoke the program instructions to execute the method described above.

[0027] A computer-readable storage medium storing a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the method as described above.

[0028] In summary, this application, by simulating natural environmental conditions such as climate (temperature, humidity, sunshine), wind force, and vibration, can more realistically reflect the stress and fatigue performance of the spacer bar in actual operation. Furthermore, through various methods such as dynamic load application, strain analysis, and numerical simulation (finite element analysis), it can analyze in detail the characteristic changes of fatigue cracks on the surface of the spacer bar, so as to accurately predict the crack initiation, propagation path, and fatigue life.

[0029] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A comprehensive evaluation method for fatigue performance of transmission line spacer bars under simulated natural conditions, characterized in that, Includes the following steps: S10: Simulate the relevant environment for the spacer bar, including climate, wind, and vibration; the climate includes ambient temperature, air humidity, and solar radiation intensity. S20: Based on the climate, a monitoring interval is set, wherein the monitoring interval includes setting the climate change with a base value as the target, wherein the base value includes an ambient temperature of 0°C; S30: In the monitoring interval, the air humidity and solar radiation intensity are simultaneously reduced by lowering the ambient temperature, including reducing the ambient temperature from 0°C to -30°C, and the changes of the spacer are acquired in the monitoring interval, including fatigue cracks appearing on the surface of the spacer. S40: When the ambient temperature is reduced, a dynamic load is applied to the spacer bar. The dynamic load is set according to the actual conductor tension of the transmission line and the applied range is 1kN to 100kN. Within the applied range, the characteristic changes of fatigue cracks on the surface of the spacer bar are analyzed. S50: Divide the spacer bar into fulcrums based on the described feature changes, wherein the fulcrum division includes dividing the spacer bar into fulcrums. , ,..., ;in, Indicates the division of the first Calculate the maximum conductor tension that can be withstood at each of the several support points.

2. The comprehensive evaluation method for fatigue performance of transmission line spacer bars under simulated natural environment as described in claim 1, characterized in that, In S40, the characteristic changes of fatigue cracks on the surface of the spacer bar are analyzed within the applied range. The analysis method includes strain analysis, which includes strain peak, strain distribution and strain cycle characteristics. The strain peak value is the maximum strain value of the spacer bar under different load magnitudes; The strain distribution is used to analyze the distribution of strain on the surface of the spacer bar; The strain cyclic characteristics are used to obtain the cyclic variation law of strain over time; The characteristic changes of fatigue cracks on the surface of the spacer bar are analyzed within the applied range. The analysis method also includes numerical simulation and analysis, including finite element analysis. The finite element analysis includes stress-strain distribution, crack propagation path prediction, and fatigue life assessment. The stress-strain distribution is used to analyze the stress-strain distribution on the surface and inside of the spacer to determine the stress concentration area of ​​the spacer. The crack propagation path prediction involves simulating the propagation path of a crack corresponding to a fatigue crack under different load magnitudes, and then predicting the crack propagation direction and rate based on the propagation path. The fatigue life assessment involves constructing a fatigue life prediction model based on the predicted crack propagation direction and rate, calculating the fatigue life of the spacer under different loads, and predicting the time of crack initiation and propagation based on the fatigue life.

3. The comprehensive evaluation method for fatigue performance of transmission line spacer bars under simulated natural environment as described in claim 1, characterized in that, In step S50, the maximum conductor tension that different support points can withstand is calculated using the following formula: ;in, This represents the maximum conductor tension that can be withstood among the multiple support points; In the formula, This indicates the maximum total load that the spacer can withstand. This indicates the number of fulcrums on the spacer bar. Indicates the first The stiffness of the aforementioned support points.

4. The comprehensive evaluation method for fatigue performance of transmission line spacer bars under simulated natural environment as described in claim 3, characterized in that, Calculating the maximum conductor tension that different support points can withstand also includes calculations based on the following formula: ;in, This indicates the maximum stress that can be withstood among the multiple support points; In the formula, This represents the maximum conductor tension that can be withstood among the multiple support points; Indicates the first The length of each of the aforementioned fulcrums, Indicates the first The cross-sectional area of ​​each of the aforementioned fulcrums.

5. The comprehensive evaluation method for fatigue performance of transmission line spacer bars under simulated natural environment as described in claim 2, characterized in that, The fatigue life of the spacer bar under different loads was calculated using the following formula: ;in, Indicates the first Fatigue life of the aforementioned fulcrum; In the formula, This indicates the maximum stress that can be withstood among the multiple support points. This indicates the fatigue limit of the material used to manufacture the spacer bar. This indicates the fatigue index of the material.

6. The comprehensive evaluation method for fatigue performance of transmission line spacer bars under simulated natural conditions as described in any one of claims 3 and 4, characterized in that, Based on the calculated maximum conductor tension that different support points can withstand, wind force and vibration are applied to each support point. When applying wind force and vibration to each support point, any support point is divided into a lateral force point and an intermediate force point. The maximum wind force and maximum vibration that the lateral force point and intermediate force point corresponding to the support point can withstand when the support point is subjected to the maximum conductor tension are calculated. When the spacer is used in a real natural environment, when the support point has been subjected to the maximum conductor tension, the wind force magnitude and vibration frequency experienced by the lateral force point and intermediate force point of the corresponding support point are collected. If the wind force magnitude and vibration frequency experienced do not reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, it is determined that the spacer will not develop fatigue cracks. Conversely, if the spacer bar does not show signs of fatigue cracking, an early warning will be issued. When the fulcrum is not subjected to the maximum conductor tension, if the wind force and vibration frequency experienced by the lateral force point and the intermediate force point corresponding to the fulcrum reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, then it is determined that the spacer will not develop fatigue cracks.

7. The comprehensive evaluation method for fatigue performance of transmission line spacer bars under simulated natural environment as described in claim 6, characterized in that, When the fulcrum has already borne the maximum conductor tension, if the wind force and vibration frequency experienced by the lateral force point and the intermediate force point corresponding to the fulcrum reach the wind force and vibration corresponding to the maximum wind force and maximum vibration, then the deflection angle of the wind force experienced at the center of the spacer is collected. If the deflection angle is opposite to the angle at which the fulcrum is located on the spacer, then it is determined that fatigue cracks on the surface of the spacer will not appear on the side deflected towards the fulcrum.

8. The comprehensive evaluation method for fatigue performance of transmission line spacer bars under simulated natural environment as described in claim 6, characterized in that, The maximum wind force and maximum vibration that the lateral and intermediate stress points corresponding to the fulcrum can withstand under the condition that the fulcrum is subjected to the maximum conductor tension are calculated using the following formula: In the formula, Indicates the maximum wind force; In the formula, Indicates air density, This indicates the maximum wind speed. Indicates the wind force coefficient. This represents the windward area of ​​the fulcrum. ； In the formula, Indicates the maximum vibration acceleration. Indicates the maximum vibration frequency. This indicates the mass of the fulcrum.

9. A terminal, characterized in that, The system includes a processor, an input interface, an output interface, and a memory, which are interconnected. The memory is used to store a computer program, which includes program instructions. The processor is configured to invoke the program instructions to execute the method as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the method as described in any one of claims 1 to 8.

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