A method and system for predicting the service life of transmission towers

Abstract

This application provides a method and system for predicting the service life of transmission towers. The method includes: establishing a macroscopic finite element model of the transmission tower; based on the established finite element model, performing load simulation analysis on the service performance of an uncorroded transmission tower under extreme conditions to identify the weak components of the transmission tower under stress; establishing a microscopic electrochemical corrosion simulation model for the materials of the weak components; based on the established electrochemical corrosion simulation model, obtaining quantitative analysis results of corrosion loss in the weak components; and combining the quantitative analysis results of corrosion loss in the weak components with the established macroscopic finite element model to obtain a prediction conclusion on the service life of the transmission tower. This application predicts the service performance changes and service life of transmission towers under atmospheric corrosion conditions, providing a scientific basis for the formulation of differentiated anti-corrosion strategies for power systems, and has important theoretical and practical significance for ensuring the safe, stable, and efficient operation of power systems.

Description

Technical Field

[0001] This application relates to the field of corrosion resistance research technology for transmission towers, specifically to a method and system for predicting the service life of transmission towers. Background Technology

[0002] Transmission towers are critical supporting structures for power transmission lines, essential for the normal operation of power systems. However, during service, transmission towers are frequently damaged by corrosion, leading to tower collapses and line breaks, which can cause power safety accidents. The safe and reliable operation of power systems has a significant impact on socio-economic development and daily life. With the rapid expansion of the power grid, the working environment of transmission towers is becoming increasingly harsh, making them more susceptible to corrosion from complex environments and increasing the risk of damage to vulnerable parts. Transmission towers are exposed to the natural atmosphere and are subject to long-term atmospheric corrosion, causing gradual corrosion on their surfaces. Various corrosive media accumulate on the surface of transmission tower components, forming electrolyte solutions that trigger electrochemical corrosion. Humidity, temperature, and pollutant concentrations in the atmospheric environment all affect the corrosion of transmission towers. High temperatures and high humidity also accelerate the reaction rate between metals and oxygen and pollutants, exacerbating corrosion. When the materials of transmission tower components are weakened by corrosion to a certain extent, or when exposed to extreme conditions such as snow, ice, or typhoons, sudden failures may occur, seriously affecting the safe operation of transmission lines.

[0003] The State Grid Corporation of China spends approximately 6-8 billion yuan annually on direct costs for atmospheric corrosion protection, with 20%-30% allocated to corrosion maintenance, repair, and reinforcement during operation to prevent equipment damage from corrosion. However, in recent years, accidents caused by material failure due to environmental corrosion have been increasing, indicating that current corrosion protection measures are not ideal. This accumulated corrosion damage can easily lead to safety hazards in power grid equipment. Atmospheric corrosion of transmission towers is one of the main causes of failure of key components under long-term normal operating conditions, and it also results in the actual corrosion protection life of transmission towers being lower than their design life.

[0004] Because the impact of environmental factors on the corrosion degree of transmission towers varies significantly across different regions, the implementation of anti-corrosion measures should fully consider regional characteristics to achieve precise implementation. Therefore, accurately selecting protective materials based on environmental corrosivity characteristics and service conditions, rapidly evaluating the corrosion resistance and lifespan of equipment materials, identifying corrosion sites as early as possible, predicting their development trend and carrying out timely technical treatment, and proposing clear corrosion resistance requirements for the service environment in material selection and technical specifications can improve the current anti-corrosion situation and provide technical support for differentiated anti-corrosion work. Summary of the Invention

[0005] This application provides a method and system for predicting the service life of transmission towers, which can solve the technical problem in the prior art of lacking research on the environmental corrosive characteristics of transmission towers and making service life predictions accordingly.

[0006] In a first aspect, this application provides a method for predicting the service life of a transmission tower, comprising the following steps:

[0007] Establish a macroscopic finite element model of the transmission tower;

[0008] Based on the established finite element model of the transmission tower, the service performance of the uncorroded transmission tower under extreme conditions is simulated and analyzed to identify the weak components of the transmission tower under stress.

[0009] Establish an electrochemical corrosion simulation model for weak component materials at the microscale;

[0010] Based on the established electrochemical corrosion simulation model, quantitative analysis results of corrosion loss of weak components were obtained;

[0011] Based on the quantitative analysis results of corrosion loss of weak components and the established macroscopic finite element model of the transmission tower, the service life prediction conclusion of the transmission tower is obtained.

[0012] In conjunction with the first aspect, in one implementation method, establishing a macroscopic-scale finite element model of a transmission tower specifically includes the following steps:

[0013] Based on the single-line diagram and engineering drawings of the transmission tower, the indirect modeling method was adopted to establish the geometric model of the structure in the order of points, lines, surfaces and volumes, so as to obtain the macroscopic finite element model of the transmission tower.

[0014] In conjunction with the first aspect, in one implementation, the extreme conditions in the step of performing load simulation analysis on the service performance of the uncorroded transmission tower under extreme conditions based on the established finite element model of the transmission tower, and obtaining the weak components of the transmission tower under stress, include high wind conditions, one-phase ground wire breakage conditions, and one-phase conductor breakage conditions.

[0015] In conjunction with the first aspect, in one implementation, after performing load simulation analysis on the service performance of an uncorroded transmission tower under extreme conditions based on the established finite element model of the transmission tower to identify the weak components of the transmission tower under stress, the method further includes the following steps:

[0016] The effectiveness of the established finite element model of the transmission tower is verified based on the stress conditions of the finite element model under extreme conditions and the actual collapse of the transmission tower in the field.

[0017] In conjunction with the first aspect, in one embodiment, establishing an electrochemical corrosion simulation model for microscale weak component materials specifically includes the following steps:

[0018] Based on corrosion mechanisms and electrochemical principles, and using electrochemical kinetic parameters and environmental parameters as boundary conditions, a corrosion development model for weak component materials under atmospheric conditions is developed, resulting in an electrochemical corrosion simulation model under atmospheric conditions.

[0019] In conjunction with the first aspect, in one implementation, after modeling the corrosion development of weak component materials under atmospheric conditions based on corrosion mechanisms and electrochemical principles, using electrochemical kinetic parameters and environmental parameters as boundary conditions, and obtaining a carbon steel corrosion development model under atmospheric conditions, the method further includes the following steps:

[0020] The experimental parameters of the neutral salt spray test were substituted into the electrochemical corrosion simulation model under atmospheric conditions to verify the effectiveness of the model.

[0021] In conjunction with the first aspect, in one embodiment, after verifying the effectiveness of the carbon steel corrosion development model under atmospheric conditions by substituting the test parameters of the neutral salt spray test into the model, the method further includes the following steps:

[0022] Based on the validated electrochemical corrosion simulation model, simulated values ​​of corrosion thickness loss of weak components were obtained.

[0023] Obtain the true value of corrosion thickness loss in atmospheric exposure tests of carbon steel for weak structural members;

[0024] By comparing the simulated corrosion loss values ​​and the actual corrosion loss values ​​of weak components, the electrochemical corrosion simulation model after its effectiveness verification is corrected based on the comparison results.

[0025] In conjunction with the first aspect, in one implementation method, obtaining the quantitative analysis results of corrosion thickness loss of weak components based on the established electrochemical corrosion simulation model specifically includes the following steps:

[0026] Input the environmental parameters of the carbon steel atmospheric exposure test into the electrochemical corrosion simulation model, and solve for the current density of the electrolyte on the electrode surface of the weak component;

[0027] The current density is converted to the corrosion rate;

[0028] By integrating the corrosion rate, the simulated corrosion loss value of the weak component is obtained.

[0029] Secondly, this application provides a transmission tower service life prediction system, comprising:

[0030] The finite element model building module is used to build finite element models of transmission towers at the macroscopic scale.

[0031] The weak component acquisition module is communicatively connected to the finite element model establishment module. It is used to perform load simulation analysis on the service performance of the uncorroded transmission tower under extreme conditions based on the established finite element model of the transmission tower, and to acquire the weak components of the transmission tower under stress.

[0032] The corrosion model establishment module is communicatively connected to the weak component acquisition module and is used to establish an electrochemical corrosion simulation model of the weak component material at the microscale.

[0033] The corrosion loss simulation module is communicatively connected to the weak component acquisition module and the corrosion model establishment module, and is used to obtain the quantitative analysis results of corrosion loss of the weak component based on the established electrochemical corrosion simulation model.

[0034] The transmission tower life prediction module is communicatively connected to the corrosion loss simulation module. It is used to obtain the service life prediction conclusion of the transmission tower based on the quantitative analysis results of corrosion loss of the weak components and the established macroscopic finite element model of the transmission tower.

[0035] In conjunction with the second aspect, in one embodiment, the corrosion thickness loss simulation module includes:

[0036] The current density acquisition unit is connected in communication with the weak component acquisition module and the corrosion model establishment module. It is used to input the environmental parameters of the carbon steel atmospheric exposure test into the electrochemical corrosion simulation model and solve for the current density of the electrolyte on the electrode surface of the weak component.

[0037] The corrosion rate acquisition unit is communicatively connected to the current density acquisition unit and is used to convert the current density into corrosion rate.

[0038] The corrosion loss simulation unit is communicatively connected to the corrosion rate acquisition unit and is used to perform integral calculations on the corrosion rate to obtain the simulated corrosion loss value of the weak component.

[0039] The beneficial effects of the technical solutions provided in this application include at least the following:

[0040] By establishing a macroscopic transmission tower model and a microscopic electrochemical corrosion simulation model, and combining the mechanical property degradation law of weak components of transmission towers under corrosive environments, this study explores the influence of the remaining thickness of weak components on the ultimate stress of the structure under extreme conditions. Finally, by integrating the electrochemical corrosion simulation model to predict the corrosion development of weak components over time under atmospheric conditions and to assess the lifespan of the galvanized layer, this study predicts the changes in service performance and service life of transmission towers under atmospheric corrosion conditions. This provides a scientific basis for the formulation of differentiated anti-corrosion strategies for power systems and has important theoretical and practical significance for ensuring the safe, stable, and efficient operation of power systems. Attached Figure Description

[0041] Figure 1 A flowchart illustrating a method for predicting the service life of a transmission tower, as provided in this application embodiment;

[0042] Figure 2 (a) is an equivalent stress cloud diagram of the entire uncorroded transmission tower under high wind conditions provided in an embodiment of this application; Figure 2 (b) is an equivalent stress cloud diagram of the uncorroded transmission tower leg under high wind conditions provided in the embodiments of this application;

[0043] Figure 3 A 24x magnified deformation cloud image of an uncorroded transmission tower under high wind conditions, provided in an embodiment of this application.

[0044] Figure 4 (a) is a stress cloud diagram of the main beams of the four tower legs of an uncorroded transmission tower under high wind conditions, provided in an embodiment of this application. Figure 4 (b) is a scatter plot and linear fitting diagram of stress variation on the main beams of the four tower legs of the uncorroded transmission tower under high wind conditions provided in the embodiments of this application;

[0045] Figure 5 (a) is one of the equivalent stress cloud diagrams of an uncorroded transmission tower under the condition of a single-phase conductor failure, provided in an embodiment of this application; Figure 5 (b) is the second equivalent stress cloud diagram of an uncorroded transmission tower under the condition of a single-phase conductor failure, provided in the embodiments of this application; Figure 5 (c) is the third equivalent stress cloud diagram of an uncorroded transmission tower under the condition of a single-phase conductor failure, provided in the embodiments of this application;

[0046] Figure 6 (a) is one of the equivalent stress cloud diagrams of an uncorroded transmission tower under the condition of a single-phase ground wire failure, provided in an embodiment of this application; Figure 6 (b) is the second equivalent stress cloud diagram of an uncorroded transmission tower under the condition of a single-phase ground wire failure, provided in the embodiments of this application;

[0047] Figure 7 Image (a) is one of the multi-location transmission tower collapse case illustrations provided in the embodiments of this application; Figure 7 Figure (b) is a second example of multiple transmission tower collapse cases provided in the embodiments of this application; Figure 7 Figure (c) is the third example of multiple transmission tower collapse cases provided in the embodiments of this application;

[0048] Figure 8 (a) is a two-dimensional cross-sectional geometric model diagram provided in an embodiment of this application; Figure 8 (b) is a schematic diagram of the mesh generation of the two-dimensional cross-sectional geometric model provided in the embodiments of this application;

[0049] Figure 9(a) is an electrolyte potential diagram of simulated carbon steel in a neutral salt spray environment at 0 h, provided in the embodiment of this application; Figure 9 (b) is an electrolyte potential diagram of simulated carbon steel in a neutral salt spray environment at 1800 h, provided in an embodiment of this application. Figure 9 (c) is a current density diagram of simulated carbon steel in a neutral salt spray environment at the 0th hour, provided in the embodiments of this application; Figure 9 (d) is a current density diagram of simulated carbon steel in a neutral salt spray environment at 1800 h, provided in the embodiments of this application;

[0050] Figure 10 (a) is a graph showing the corrosion rate of carbon steel in a neutral salt spray environment as provided in the embodiments of this application; Figure 10 (b) Corrosion loss diagram of medium (b) carbon steel in neutral salt spray environment test and simulation;

[0051] Figure 11 (a) is a comparison chart of the actual and simulated corrosion loss values ​​of carbon steel at the Beijing atmospheric exposure test station provided in the embodiments of this application; Figure 11 (b) is a comparison chart of the actual and simulated corrosion loss values ​​of carbon steel at the Qingdao atmospheric exposure test station provided in the embodiments of this application; Figure 11 (c) is a comparison chart of the actual and simulated corrosion loss values ​​of Wuhan carbon steel at an atmospheric exposure test station, provided in the embodiments of this application. Figure 11 (d) is a comparison chart of the actual and simulated corrosion loss values ​​of carbon steel at the Jiangjin atmospheric exposure test station provided in the embodiments of this application; Figure 11 (e) is a comparison chart of the actual and simulated corrosion loss values ​​of carbon steel at the Guangzhou atmospheric exposure test station provided in the embodiments of this application; Figure 11 (f) is a comparison chart of the actual and simulated corrosion loss values ​​of carbon steel at the Qionghai atmospheric exposure test station provided in the embodiments of this application;

[0052] Figure 12 A comparison chart of errors between the actual and simulated values ​​of corrosion loss of carbon steel at atmospheric exposure test stations in various regions, provided for embodiments of this application;

[0053] Figure 13 The annual corrosion rate diagram of carbon steel at the atmospheric exposure test station provided in the embodiments of this application;

[0054] Figure 14 (a) is a comparison chart of the actual corrosion loss value and the corrected simulated corrosion loss value of carbon steel at the Beijing atmospheric exposure test station provided in the embodiments of this application; Figure 14 (b) is a comparison chart of the actual corrosion loss value and the corrected simulated corrosion loss value of carbon steel at the Qingdao atmospheric exposure test station provided in the embodiments of this application; Figure 14(c) is a comparison chart of the actual corrosion loss value and the corrected simulated corrosion loss value of carbon steel at the Wuhan atmospheric exposure test station provided in the embodiments of this application; Figure 14 (d) is a comparison chart of the actual value and the corrected simulated value of corrosion thickness loss of carbon steel at the Jiangjin test station under atmospheric exposure, provided in the embodiments of this application; Figure 14 (e) is a comparison chart of the actual corrosion loss value and the corrected simulated corrosion loss value of carbon steel at the Guangzhou atmospheric exposure test station provided in the embodiments of this application; Figure 14 (f) is a comparison chart of the actual value and the corrected simulated value of corrosion loss of carbon steel at the Qionghai atmospheric exposure test station provided in the embodiments of this application;

[0055] Figure 15 Comparison chart of actual corrosion loss and simulated corrosion loss values ​​of carbon steel in various regions after error correction, provided in the embodiments of this application. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0057] Firstly, please refer to Figure 1 This application provides a method for predicting the service life of transmission towers, including the following steps:

[0058] Step S1: Establish a macroscopic finite element model of the transmission tower;

[0059] Step S3: Based on the established finite element model of the transmission tower, perform load simulation analysis on the service performance of the uncorroded transmission tower under extreme conditions to obtain the weak components of the transmission tower under stress.

[0060] Step S5: Establish an electrochemical corrosion simulation model for weak component materials at the microscale;

[0061] Step S8: Based on the established electrochemical corrosion simulation model, obtain the quantitative analysis results of corrosion thickness loss of weak components;

[0062] Step S9: Based on the quantitative analysis results of corrosion loss of weak components and the established macroscopic finite element model of the transmission tower, obtain the prediction conclusion of the service life of the transmission tower.

[0063] This application establishes a macroscopic transmission tower model and a microscopic electrochemical corrosion simulation model. Combining the mechanical property degradation law of weak components of transmission towers under corrosive environments, it explores the influence of the remaining thickness of weak components on the ultimate stress of the structure under extreme conditions. Finally, it uses the electrochemical corrosion simulation model to predict the corrosion development of weak components over time under atmospheric conditions and to assess the lifespan of the galvanized layer. It also predicts the service performance changes and service life of transmission towers under atmospheric corrosion conditions, providing a scientific basis for the formulation of differentiated anti-corrosion strategies for power systems. This has important theoretical value and practical significance for ensuring the safe, stable, and efficient operation of power systems.

[0064] In one embodiment, step S1: establishing a macroscopic-scale finite element model of the transmission tower specifically includes the following steps:

[0065] Based on the single-line diagram and engineering drawings of the transmission tower, the indirect modeling method was adopted to establish the geometric model of the structure in the order of points, lines, surfaces and volumes, so as to obtain the macroscopic finite element model of the transmission tower.

[0066] In a more specific embodiment, straight-line transmission towers account for a larger proportion of transmission towers in power transmission lines. Therefore, this application selects the cat-head straight-line transmission tower 1A3-ZM1 as the research object for mechanical finite element simulation. The tower has a height of 20.5m and a nominal height of 15m. At present, the mainstream material for transmission towers is Q355 steel, and Table 1 lists its main material parameters. Due to the complex structure of the cat-head transmission tower, involving a large number of point, line, surface, and volume elements, the direct modeling method used to solve general material mechanics and structural mechanics problems is not applicable when modeling transmission towers. Step S1: Establishing a macroscopic finite element model of the transmission tower is specifically implemented as follows:

[0067] An indirect modeling method was adopted, and a geometric model was established by referring to the transmission tower structure in the order of points, lines, surfaces, and volumes.

[0068] Based on the segment numbers on the single-line diagram or engineering drawings of the transmission tower, the transmission tower is decomposed into tower head module, tower body module and tower leg module, and modeled block by block. This segmented modeling method can better handle complex structures and make the modeling process more controllable and accurate.

[0069] Considering the stress of the tower material section and the division of the element mesh, the transmission tower is simplified as a beam structure and modeled using BEAM188 solid beam elements;

[0070] Based on the structural characteristics of the transmission tower, different specifications of load-bearing components are selected in its design. Specifically, the angle steel selected for the 1A3-ZM1 transmission tower includes 12 different specifications of equal-sided and equal-thickness angle steel (L40×3, L50×4, L63×5, etc.).

[0071] The orientation of angle steel affects the mechanical analysis structure of the finite element model of the transmission tower. When modeling angle steel, the orientation of angle steel is determined by the direction of the line connecting I and J and the orientation of the key control point Z. The orientation of each angle steel is strictly determined according to the design drawings when modeling the finite element model of the transmission tower.

[0072] Table 1 Main material parameters of the finite element model

[0073]

[0074] In one specific embodiment, step S1: establishing a macroscopic-scale finite element model of the transmission tower, specifically implemented as follows:

[0075] Based on the engineering drawings, while ensuring the overall dimensions are uniform, the common nodes of the angle steel of the transmission towers are simplified.

[0076] The key point coordinates are obtained by creating a wireframe model in 3D CAD software, and then the point coordinates are input into the finite element software to form a lattice model of the transmission tower. The points are then connected to form a linear model of the transmission tower.

[0077] Based on the stress of the tower material section and the division of the unit grid, the transmission tower is simplified into a beam structure;

[0078] Strictly follow the design drawings, assign the model the corresponding size of the angle steel section and adjust the orientation of the angle steel;

[0079] Complete the finite element modeling of the entire transmission tower to obtain a macroscopic finite element model of the transmission tower.

[0080] In one embodiment, the established finite element model of the transmission tower only considers the modeling of angle steel and ignores non-angle steel components such as connecting steel plates and bolts in the transmission tower structure. After establishing the macroscopic finite element model of the transmission tower in step S1, the following steps are also included:

[0081] Step S2: Perform quality correction on the established macroscopic finite element model of the transmission tower.

[0082] In one embodiment, step S2: quality correction of the established macroscopic-scale finite element model of the transmission tower specifically includes the following steps:

[0083] Step S21: Based on the actual drawings of the transmission tower, obtain the mass ratio of the structural connectors of the transmission tower, whereby the mass ratio is the proportion of the weight of the connectors to the actual weight M of the transmission tower.

[0084] Step S22: Based on the obtained mass ratio of the structural connectors of the transmission tower, calculate the mass amplification factor by calculating the obtained tower foot support reaction force F and the actual mass M of the transmission tower according to formula (1). :

[0085] Equation (1)

[0086] Step S23: Based on the calculated mass magnification factor, the material density is increased by a factor of k to match the actual self-weight of the transmission tower in subsequent simulations. This process corrects the mass of the established macroscopic finite element model of the transmission tower, thereby reducing errors.

[0087] In one embodiment, during the simulation of the transmission tower, the internal and external loads borne by the transmission tower need to be considered: the internal load refers to the weight of the transmission tower itself, while the external load encompasses various dynamic and static forces that affect the tower structure. External loads mainly include: the forces exerted by the conductors and ground wires on the transmission tower's hanging points, the forces generated by the insulator's self-weight, wind loads, ice loads, and asymmetric loads when the conductors and ground wires break. Step S3: Based on the established finite element model of the transmission tower, a load simulation analysis is performed on the service performance of the uncorroded transmission tower under extreme conditions to obtain the weakest components of the transmission tower under stress. The extreme conditions in this step include high wind conditions, single-phase ground wire breakage conditions, and single-phase conductor breakage conditions; specifically implemented as follows:

[0088] (a) High Wind Conditions: For transmission tower design, it is crucial to consider load combinations under extreme conditions – high wind conditions (basic wind speed). Standards specify that the basic wind speed is based on the annual maximum wind speed averaged over 10 minutes at local meteorological stations (using an extreme value type I distribution as the probability model). Generally, the height at which the statistical wind speed is measured for transmission lines should be 10 m above the ground. The design maximum wind speed for a 110 kV line, converted to a wind speed at 10 m above the ground, is approximately 28 m / s, equivalent to a Force 10 gale. When the wind direction is perpendicular to the line (i.e., a 90° wind angle), and assuming no ice accumulation and intact conductors and ground wires, the maximum load combination under these conditions needs to be evaluated. The basic wind speed, as the benchmark for wind-resistant design of the structure, is a key load factor that must be considered when assessing the stability and safety of transmission towers. Permanent loads under these conditions include the gravity loads of conductors and ground wires, insulators and their accessories, and the transmission tower structure. Variable loads include wind loads on conductors and ground wires perpendicular to the line direction and wind loads on the transmission tower itself. This must be fully considered in the design and stability analysis of transmission towers;

[0089] In the design of transmission towers, their ability to resist longitudinal loads must be fully considered. For straight transmission towers, it is also crucial to consider the unbalanced tension when one phase ground wire or one phase conductor is broken. Since transmission towers are equipped with three phase conductors and two phase ground wires, there are five potential breakage scenarios, each corresponding to a load model. The load conditions of the transmission tower are analyzed under the following two conditions:

[0090] (b) Extreme conditions: Under the condition of -5°C and ice cover, assuming no wind, if a phase conductor breaks while the ground wire remains intact, the permanent load is the gravity load of the conductor and ground wire, insulators and their accessories, transmission tower structure, etc., and the variable load is the tension difference between the two sides of the conductor.

[0091] (c) Extreme conditions: Under the same conditions of -5°C and ice cover, assuming no wind, if one phase ground wire breaks while the conductor remains intact, the permanent load is the gravity load of the conductor and ground wire, insulators and their accessories, transmission tower structure, etc., and the variable load is the tension difference on both sides of the ground wire.

[0092] In one specific embodiment, the load parameters of the transmission tower under the extreme conditions of high wind, single-phase ground wire breakage, and single-phase conductor breakage are shown in Table 2:

[0093] Table 2 Load parameters (N) of transmission towers under three extreme conditions

[0094]

[0095] The simulation results of the transmission tower's service performance under three extreme conditions are analyzed as follows:

[0096] (1) Under strong wind conditions:

[0097] Equivalent stress distribution cloud map of transmission tower under high wind conditions is shown below. Figure 2 (a) and Figure 2 As shown in (b), the four main beams bear a greater equivalent stress. Analysis of the uncorroded transmission tower shows that its maximum equivalent stress is 194.69 MPa (this numerical result is consistent with the data inside the power grid), which does not exceed the yield limit of the material, and this stress value occurs at the tower foot.

[0098] Under high wind conditions, the calculated maximum total displacement of the transmission tower is 90.002 mm. Figure 3 This is a 24x magnified image of the deformation cloud. The deformation starts at the top of the tower and gradually decreases downwards along the tower body, showing a linear decreasing trend. Furthermore, the entire tower body is deflected towards the windward side (tension side).

[0099] Then, solve the stress cloud diagrams on the main beams of the four tower legs separately, as shown below. Figure 4 As shown in (a), the maximum value of the equivalent stress is also located at the tower foot. Further investigation of the specific stress conditions on the main beam of each tower leg is conducted, and the trend of its equivalent stress variation is plotted as follows. Figure 4As shown in Figure (b), the horizontal axis represents the numerical values ​​of the finite element model coordinate points along the vertical Z-axis, while the vertical axis represents the equivalent stress values ​​at the corresponding coordinate points. The stress decreases linearly upwards from the tower legs and exhibits a symmetrical distribution across the tower body. Axes 1 and 3, located closer to the tilt direction of the transmission tower, generate greater stress; while axes 2 and 4, located further away from the tilt direction, generate less stress.

[0100] (2) Under the condition of one phase conductor failure:

[0101] Next, the structural response of the transmission tower under the condition of three-phase conductor fracture (one phase of the three phases breaking) is analyzed. Finite element simulation was used to simulate different conductor fracture scenarios, obtaining the equivalent stress distribution of the transmission tower under three different conditions. Analysis shows that in all conductor fracture scenarios, the four main beams of the transmission tower bear higher equivalent stress than the auxiliary beams. However, the equivalent stress values ​​do not exceed the yield strength of the material, indicating that the structure has sufficient safety margin in its design. Further observation revealed that the location of the conductor fracture significantly affects the stress distribution. When one phase conductor on the left or right side fractures, a larger equivalent stress is generated on the tension side and near the conductor's hanging point on that side (e.g., ...). Figure 5 (a) and Figure 5 As shown in (c)). When the conductor breaks at the middle position, a larger equivalent stress is generated on the tension side near the suspension point at the middle position (e.g. Figure 5 (As shown in (b)). However, due to the symmetrical stress on the transmission tower after fracture, the overall structural stability of the transmission tower is slightly better in this case. Therefore, the transmission tower still has a certain degree of structural integrity and stability when one phase conductor is broken; in operation and maintenance, the influence of the conductor fracture location on stress distribution can be considered.

[0102] (3) One-phase ground wire disconnection condition:

[0103] Finally, the structural response of the transmission tower under the condition of two-phase ground wire breakage (one of the two phases is broken) was analyzed. Finite element simulation was used to simulate different ground wire breakage scenarios, and the equivalent stress distribution of the transmission tower under two different conditions was obtained. The results show that under the condition of one-phase ground wire breakage, the four main beams of the transmission tower generated greater equivalent stress than the auxiliary beams, and the stress in all areas did not exceed the yield limit of the material, indicating that the design safety was guaranteed. Further observation revealed that the upper part of the transmission tower is the key area bearing a large equivalent stress, especially on the side where the ground wire is broken (e.g., ...). Figure 6(As shown). Furthermore, the location of the ground wire breakage also leads to differences in the equivalent stress distribution. Since the cross-sectional area of ​​the ground wire is generally larger than that of the conductor, its breakage results in a greater weight imbalance, thus significantly affecting the unbalanced tension of the transmission tower. This unbalanced tension may have a more significant impact on the overall stability of the transmission tower. When the ground wire breaks, the unbalanced tension on the transmission tower is greater, and the impact on the tower's stability is also greater. Therefore, during the operation and maintenance of transmission towers, attention should be paid to the impact of ground wire breakage on structural stability, and effective measures should be taken to improve the transmission tower's resistance to unbalanced tension when the ground wire breaks, to ensure the safe and stable operation of the power grid.

[0104] Analysis of simulation results of transmission tower service performance under three extreme conditions yielded the following results:

[0105] Under strong wind conditions, the weakest components of the transmission tower are located in the tower legs, especially the tower feet.

[0106] The weakest component of the transmission tower under the condition of one phase conductor failure in a three-phase transmission tower is that the transmission tower still has a certain degree of structural integrity and stability when one phase conductor fails. In operation and maintenance, the influence of the conductor failure location on stress distribution can be considered.

[0107] When a ground wire breaks in a two-phase grounding tower, the unbalanced tension on the tower is greater, which has a greater impact on the tower's stability. Therefore, during the operation and maintenance of the tower, attention should be paid to the impact of ground wire breakage on structural stability.

[0108] In summary, by constructing a macroscopic finite element model of the transmission tower and setting the load conditions of the overhead transmission line under extreme conditions according to the current industry standards, the finite element simulation of the transmission tower was conducted. The results showed that the weak stress area of ​​the transmission tower is located in the tower legs, especially the tower feet. The components of the tower legs and tower feet are all made of carbon steel.

[0109] In one embodiment, the above-mentioned load simulation analysis of the service performance of the uncorroded transmission tower under three extreme conditions yielded reasonable and expected results from the three finite element models of the transmission tower, and they mutually verified each other. However, it is still necessary to further verify the effectiveness of the model by combining it with the actual tower collapse situation. Step S3: After conducting load simulation analysis of the service performance of the uncorroded transmission tower under extreme conditions based on the established finite element model of the transmission tower and obtaining the weak components of the transmission tower under stress, the following steps are also included:

[0110] Step S4: Verify the effectiveness of the established finite element model of the transmission tower based on the stress conditions of the finite element model of the transmission tower under extreme conditions and the actual collapse of the transmission tower on site.

[0111] In one embodiment, step S4: verifying the effectiveness of the established finite element model of the transmission tower based on the stress conditions of the finite element model under extreme conditions and the actual collapse of the transmission tower on site, specifically implemented as follows:

[0112] Under strong wind conditions, the weakest points of transmission towers are mainly concentrated near the tower legs, where the equivalent stress generated by the main beam under load is particularly significant. Therefore, in severe convective weather conditions that often last from several minutes to several hours, the ambient wind speed is generally higher than the design wind speed, making transmission towers more prone to bending and toppling at the tower legs. Furthermore, investigations at multiple accident sites have confirmed that transmission towers often collapse at the tower legs. Photos of the case sites are shown below. Figure 7 As shown, the effectiveness of the finite element model described above can be verified. In subsequent research, we will further simulate the corrosion behavior of the weakly stressed components of the transmission tower legs to investigate the impact of corrosion thinning on its service life.

[0113] The effectiveness of the finite element model of the transmission tower was verified by comparing the simulation results with the case of tower collapse in the field; at the same time, the weak stress area of ​​the transmission tower also coincides with the common corrosion sites in the corrosion survey of transmission towers, which are all located in the tower leg.

[0114] In one embodiment, step S5: establishing an electrochemical corrosion simulation model for the microscale weak component material specifically includes the following steps:

[0115] Based on corrosion mechanisms and electrochemical principles, and using electrochemical kinetic parameters and environmental parameters as boundary conditions, a corrosion development model for weak component materials under atmospheric conditions is constructed, resulting in an electrochemical corrosion simulation model under atmospheric conditions. The electrochemical kinetic parameters include anodic exchange current density, cathodic exchange current density, anodic equilibrium potential, cathodic equilibrium potential, anodic Tafel slope, and cathodic Tafel slope. The environmental parameters include annual average temperature (T), annual average humidity (RH), sulfate deposition rate (Pd), and chloride ion deposition rate (Sd).

[0116] Since the tower legs and bases of the transmission tower are made of carbon steel, the electrochemical corrosion simulation model for the micro-scale weak component material established in this application is a carbon steel electrochemical corrosion simulation model.

[0117] The corrosion of weak structural components in an atmospheric environment is a complex system affected by numerous climatic variables, among which the formation and transformation of corrosion products during liquid film evaporation and condensation are particularly complex. To construct a more reasonable electrochemical corrosion simulation model, this application proposes the following assumptions:

[0118] (1) Neglect of liquid film evaporation and condensation: The electrochemical corrosion simulation model assumes that the thickness of the liquid film on the carbon steel surface remains stable and does not involve evaporation and condensation processes. Therefore, the salt concentration in the liquid film is also considered to be a constant value.

[0119] (2) Simplified corrosion product transformation: Considering the complex transformation process of corrosion products of carbon steel under alternating wet and dry conditions, and the lack of kinetic data of related intermediate reactions, this process was simplified in the electrochemical corrosion simulation model, focusing only on the generation of the first-order reaction Fe(OH)2.

[0120] (3) Ignore electrochemical activity: It is assumed that the corrosion products do not have electrochemical activity in the electrochemical corrosion simulation model, and their influence on the subsequent corrosion process of the substrate is not considered.

[0121] In one embodiment, step S5: Based on corrosion mechanisms and electrochemical principles, using electrochemical kinetic parameters and environmental parameters as boundary conditions, a corrosion development model for weak component materials under atmospheric conditions is performed to obtain an electrochemical corrosion simulation model under atmospheric conditions. Specifically, this is implemented as follows:

[0122] Based on corrosion mechanisms and electrochemical principles, this study utilizes the "Corrosion, Secondary Current" physics field interface of COMSOL software, inputting electrochemical kinetic parameters and environmental parameters as boundary conditions to model the corrosion development of carbon steel under atmospheric conditions. In certain situations, the two-dimensional model of COMSOL Multiphysics is an effective simplification of the three-dimensional problem. This is particularly true in the following two cases: when the three-dimensional model has infinite width and the variation in the width direction is almost negligible; or when the three-dimensional model is relatively wide, but the results remain unchanged along the width direction in the middle region, while the results near the edges are not the focus of the study. In this application, the focus is mainly on the corrosion development and evolution of carbon steel at the microscale, and the results near the edges are not the focus of the study. Therefore, considering the need to save computational resources and time, a two-dimensional profile model is established for this study, thereby balancing simulation accuracy and computational cost, and achieving simplified modeling of complex problems.

[0123] This application utilizes COMSOL software to establish a microscale electrochemical corrosion simulation model for carbon steel with weak structural members. By inputting electrochemical kinetic parameters and environmental parameters, the electrolyte current density on the carbon steel electrode surface under various atmospheric conditions was calculated. The obtained current density was then converted into corrosion rate and corrosion loss, enabling the prediction of corrosion development of carbon steel over time under different atmospheric environments.

[0124] In this application, the "Corrosion, Secondary Current" interface provided by the electrochemistry module in COMSOL Multiphysics was selected to define the physical field. This interface can describe the current and potential distributions in a corrosion cell. A key assumption in the model is the stability of the electrolyte composition, i.e., it is assumed that its changes have negligible effects on the current and potential distributions. To study the time-varying trend of corrosion behavior, the model employs a transient analysis method based on initial conditions. The model inputs include environmental parameters from the atmospheric exposure test station (including temperature, humidity, pollutant concentration, etc.) and electrochemical kinetic parameters of carbon steel, all of which are derived from actual measurements.

[0125] The electrolyte current density on the electrode surface can be initially calculated using an electrochemical corrosion simulation model. The calculated current density can be converted into the corrosion rate using equation (2), and the corrosion loss can be obtained by integrating the corrosion rate. This conversion process is based on the quantitative relationship between corrosion rate and current density. The area in the corrosion rate-time graph also reflects the change in corrosion amount over the corresponding time, thus obtaining the simulated value of corrosion loss. When the carbon steel electrode comes into contact with the electrolyte film covering its surface, a potential difference will be formed between the two.

[0126] Equation (2)

[0127] In the formula, A is ampere, a is year, and mm / a represents the annual corrosion amount.

[0128] Under atmospheric conditions, chloride ions (Cl...) - ) and sulfate ions (SO4) 2- The presence of oxygen promotes the formation of a low-potential anodic region on the carbon steel surface, thereby accelerating the corrosion process. Based on the above corrosion mechanism, this application establishes an electrochemical corrosion simulation model for carbon steel. A thin electrolyte film above the carbon steel surface serves as the computational domain, with the carbon steel substrate immediately below this film. The intermediate boundary of the computational domain, i.e., the electrode surfaces of oxygen and iron, is the key region where local electrochemical reactions occur. Here, the dissolution reaction of carbon steel at the anode and the reduction reaction of oxygen at the cathode are considered. To quantitatively analyze these processes, a two-dimensional cross-sectional geometric model is constructed as follows: Figure 8 As shown, a fine mesh was applied to the model, and the simulated corrosion loss of carbon steel was calculated for each mesh to ensure the accuracy and reliability of the simulation results.

[0129] In one embodiment, it is considered that the environmental parameters in the atmosphere are constantly changing, but the application uses the annual average environmental parameters as input parameters to simulate corrosion behavior. However, the parameters of the standard neutral salt spray test are constant, and the simulation results correspond to the effects of real environmental parameters. Therefore, the environmental parameters of the neutral salt spray condition are input into the carbon steel electrochemical corrosion simulation model to preliminarily verify the effectiveness of the established model. Step S5: Based on the corrosion mechanism and electrochemical principles, using electrochemical kinetic parameters and environmental parameters as boundary conditions, a corrosion development model of weak component materials under atmospheric conditions is performed. After obtaining the carbon steel corrosion development model under atmospheric conditions, the following steps are also included:

[0130] Step S6: Substitute the test parameters of the neutral salt spray test into the electrochemical corrosion simulation model under atmospheric conditions to verify the effectiveness of the model.

[0131] In one specific embodiment, the carbon steel is Q355 steel.

[0132] In one embodiment, step S6: substituting the test parameters of the neutral salt spray test into the electrochemical corrosion simulation model under atmospheric conditions, and validating the model, specifically includes the following steps:

[0133] According to the standard "Artificial Atmosphere Corrosion Test - Salt Spray Test" (GB / T 10125-2012), a series of indoor accelerated corrosion tests were conducted on Q355 steel under a neutral salt spray environment. Plate-shaped Q355 steel specimens with dimensions of 100 mm × 50 mm × 5 mm were prepared. The test consisted of 10 corrosion cycles: 5, 10, 15, 20, 25, 35, 45, 55, 65, and 75 days. The testing equipment used was a CASSER-TTR-TS0-2F from SUGA Corporation, Japan. A 5 wt% (pH 7.0) NaCl solution was used, and the ambient temperature was controlled within the range of 35℃ ± 1℃. Before the test, all specimens underwent careful processing, including drilling and numbering, deburring, cleaning of oil stains, weighing, and dimensional measurement to ensure accurate analysis of the test results. After the test, the samples were derusted, dried, and cooled; and weighed to calculate the average weight loss of the material after corrosion.

[0134] The corrosion rate and corrosion loss data for the carbon steel electrochemical corrosion simulation model validated by salt spray testing were based on the calculated average values ​​of three carbon steel samples over an 1800-hour period. The environmental parameters of the neutral salt spray test were substituted into the carbon steel electrochemical corrosion simulation model as boundary conditions, and a solution step size of 1 hour was set to simulate the corrosion behavior of the carbon steel samples over 1800 hours. The electrolyte potential and electrolyte current density of carbon steel at 0 hours and 1800 hours under neutral salt spray conditions are shown below. Figure 9As shown, the corrosion rate exhibits a continuous dynamic change trend. Comparing the corrosion rates from neutral salt spray tests and simulations with the corresponding corrosion loss data, for example... Figure 10 As shown, both exhibit an upward trend. Corrosion loss increases approximately linearly over time. Although the simulation and experimental corrosion rates and corrosion loss results differ in their growth trends, the overall values ​​are not significantly different, and the corrosion loss results at the final 1800 h are also quite similar, which preliminarily verifies the effectiveness of the carbon steel electrochemical corrosion simulation model.

[0135] This application preliminarily verifies the effectiveness of the model by substituting relevant parameters from the neutral salt spray test into the model. Then, environmental parameters from the carbon steel atmospheric exposure test are input into the model. Based on the error between the simulated and actual values ​​of carbon steel corrosion loss, the model is corrected by adjusting the limiting current density parameter in segments. After correction, the error between the simulated and actual values ​​of carbon steel corrosion loss is reduced from 29.3% to 14.7%, thus constructing the final carbon steel electrochemical corrosion simulation model.

[0136] In one embodiment, after step S6: substituting the test parameters of the neutral salt spray test into the carbon steel corrosion development model under atmospheric conditions and verifying the effectiveness of the model, the following steps are also included:

[0137] Step S7: Correct the electrochemical corrosion simulation model after validity verification.

[0138] In one embodiment, step S7: modifying the electrochemical corrosion simulation model after effectiveness verification, specifically includes the following steps:

[0139] Based on the validated electrochemical corrosion simulation model, simulated values ​​of corrosion thickness loss of weak components were obtained.

[0140] Obtain the true value of corrosion thickness loss in atmospheric exposure tests of carbon steel for weak structural members;

[0141] By comparing the simulated corrosion loss values ​​and the actual corrosion loss values ​​of weak components, the electrochemical corrosion simulation model after its effectiveness verification is corrected based on the comparison results.

[0142] In one specific embodiment, step S7: modifying the electrochemical corrosion simulation model after effectiveness verification, specifically implemented as follows:

[0143] Step S71: Convert the electrolyte current density on the electrode surface into corrosion rate using equation (2), and then calculate the growth trend of corrosion loss by integrating it.

[0144] Step S72: Compare the simulated corrosion loss values ​​of carbon steel at the atmospheric exposure test station with the actual corrosion loss values. Figure 11 As shown;

[0145] The results show that although the model can simulate the corrosion development trend of carbon steel, its accuracy still needs improvement: in the early stage of corrosion, the simulated value is lower than the actual value; while in the later stage of corrosion, the simulated value is higher than or close to the actual value. From the slope of the carbon steel corrosion thickness loss curve, the pre-correction electrochemical corrosion simulation model failed to effectively simulate the inhibitory effect of corrosion products on the corrosion process, and the increase in corrosion thickness loss did not show an inflection point. The errors between the simulated and actual values ​​of carbon steel corrosion thickness loss at each test station were calculated and statistically analyzed as follows: Figure 12 As shown, the average error is 29.3%. In subsequent work, step S73: the carbon steel electrochemical corrosion simulation model is modified to reduce the error and improve the model accuracy.

[0146] In one embodiment, the annual corrosion rate of carbon steel can be obtained by differentiating the corrosion loss of carbon steel, and its trend over time is as follows: Figure 13 As shown. In the six test stations, the annual corrosion rate of carbon steel showed a decreasing trend. In the first two years, the corrosion rate decreased sharply; from 2 to 8 years, the decreasing trend gradually slowed until a relatively low corrosion rate was reached; from 8 to 16 years, the carbon steel continued to corrode at this lower rate. This change in corrosion rate is mainly due to the impact of corrosion product accumulation on the corrosion process. Corrosion products gradually accumulate on the surface of carbon steel, forming a protective layer, thereby slowing down further corrosion. Therefore, in order to more accurately simulate the actual atmospheric corrosion behavior of carbon steel, step S73 is specifically implemented as follows:

[0147] The electrochemical corrosion simulation model for carbon steel is segmented by adjusting the limiting current density in stages based on actual corrosion conditions. The segmentation is based on the corrosion rate. Specifically, when the actual corrosion rate of carbon steel exceeds a preset rate, a first limiting current density is used for simulation; when the actual corrosion rate is less than the preset rate, a second limiting current density is used, where the first limiting current density is greater than the second. For example, a higher limiting current density is used during the 0-8 year period due to the higher corrosion rate, while a lower limiting current density is used during the 8-16 year period due to the lower and more stable corrosion rate. This segmented simulation method better simulates the corrosion behavior of carbon steel at different stages, thereby improving the accuracy and reliability of the model.

[0148] After performing segmented simulations of the corrosion behavior of carbon steel and smoothing the simulated corrosion thickness loss values, a comparison with the actual corrosion thickness loss values ​​was obtained. Figure 14As shown, the corrected simulated corrosion loss values ​​are obtained based on the corrected electrochemical corrosion simulation model. In the early stages of corrosion, the simulated values ​​are mostly still smaller than the actual values. This may be because the corrosion rate is faster and more influencing factors occur in the early stages, leading to some deviation in the simulation model. However, in the later stages of corrosion, the curves of the simulated and actual values ​​gradually converge, indicating that the segmented simulation method can better reflect the corrosion behavior of carbon steel in the later stages of corrosion. The change in the slope of the graph reflects that the corrected model can indeed demonstrate the inhibitory effect of corrosion products on the corrosion process. As corrosion products accumulate, the corrosion rate gradually decreases, and the increase in corrosion loss gradually slows down. The errors between the simulated and actual values ​​of carbon steel corrosion loss at each test station are calculated and statistically analyzed as follows: Figure 15 As shown, the error at each test station is within 20%. After correction, the average error of the carbon steel electrochemical corrosion simulation model decreased from 29.3% to 14.7%, and the corrected electrochemical corrosion simulation model can better simulate the corrosion behavior of carbon steel at different stages.

[0149] In one embodiment, step S8: obtaining quantitative analysis results of corrosion thickness loss of weak components based on the established electrochemical corrosion simulation model, specifically includes the following steps:

[0150] Input the environmental parameters of the carbon steel atmospheric exposure test into the electrochemical corrosion simulation model, and solve for the current density of the electrolyte on the electrode surface of the weak component;

[0151] The current density is converted to the corrosion rate;

[0152] By integrating the corrosion rate, the simulated corrosion loss value of the weak component is obtained.

[0153] In one embodiment, the service life prediction of transmission towers in different regions is achieved by combining the macroscopic mechanical model of the transmission tower with the microscopic carbon steel electrochemical corrosion simulation model of this chapter. Step S9: Based on the quantitative analysis results of corrosion loss of weak components and the established macroscopic finite element model of the transmission tower, the service life prediction conclusion of the transmission tower is obtained, which specifically includes the following steps:

[0154] Tensile tests were conducted to investigate the effects of different types of corrosion defects on the mechanical properties of Q355 steel under accelerated corrosion in neutral salt spray, SO2, and humid heat environments. The mechanical properties of corrosion pit defects were then simulated, and tensile tests of Q355 steel under different corrosion cycles were simulated to obtain the simulation results of tensile tests of Q355 steel under different corrosion cycles.

[0155] Based on the finite element model of the transmission tower, this study explores the extent to which the remaining thickness of the tower leg will exceed the yield strength of Q355 steel under extreme conditions, and obtains the thickness yield strength of the tower leg.

[0156] Based on the corrosion simulation model, the corrosion development of carbon steel over time under atmospheric corrosion environment is predicted and the life of galvanized layer is assessed to obtain the corrosion life of carbon steel and galvanized layer.

[0157] Based on the simulation results of tensile tests on Q355 steel under different corrosion cycles, the thickness yield strength of the tower legs, and the corrosion life of carbon steel and galvanized coating, the service life of transmission towers in different regions is predicted.

[0158] Secondly, this application provides a transmission tower service life prediction system, comprising:

[0159] The finite element model building module is used to build finite element models of transmission towers at the macroscopic scale.

[0160] The weak component acquisition module is communicatively connected to the finite element model establishment module. It is used to perform load simulation analysis on the service performance of the uncorroded transmission tower under extreme conditions based on the established finite element model of the transmission tower, and to acquire the weak components of the transmission tower under stress.

[0161] The corrosion model establishment module is communicatively connected to the weak component acquisition module and is used to establish an electrochemical corrosion simulation model of the weak component material at the microscale.

[0162] The corrosion loss simulation module is communicatively connected to the weak component acquisition module and the corrosion model establishment module, and is used to obtain the quantitative analysis results of corrosion loss of the weak component based on the established electrochemical corrosion simulation model.

[0163] The transmission tower life prediction module is communicatively connected to the corrosion loss simulation module. It is used to obtain the service life prediction conclusion of the transmission tower based on the quantitative analysis results of corrosion loss of the weak components and the established macroscopic finite element model of the transmission tower.

[0164] In one embodiment, the corrosion thickness loss simulation module includes:

[0165] The current density acquisition unit is connected in communication with the weak component acquisition module and the corrosion model establishment module. It is used to input the environmental parameters of the carbon steel atmospheric exposure test into the electrochemical corrosion simulation model and solve for the current density of the electrolyte on the electrode surface of the weak component.

[0166] The corrosion rate acquisition unit is communicatively connected to the current density acquisition unit and is used to convert the current density into corrosion rate.

[0167] The corrosion loss simulation unit is communicatively connected to the corrosion rate acquisition unit and is used to perform integral calculations on the corrosion rate to obtain the simulated corrosion loss value of the weak component.

[0168] Thirdly, embodiments of this application also provide a readable storage medium.

[0169] The present application has a readable storage medium storing a transmission tower service life prediction program, wherein when the transmission tower service life prediction program is executed by a processor, it implements the steps of the transmission tower service life prediction method as described above.

[0170] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for predicting service life of a power transmission tower, characterized in that, The method comprises the following steps: establishing a macro-scale power transmission tower finite element model; based on the established power transmission tower finite element model, performing load simulation analysis on the service performance of the un-corroded power transmission tower under extreme conditions to obtain a weak component of the power transmission tower under stress; establishing an electrochemical corrosion simulation model of the material of the weak component at a micro-scale; based on the established electrochemical corrosion simulation model, obtaining quantitative analysis results of the corrosion thickness loss of the weak component; based on the quantitative analysis results of the corrosion thickness loss of the weak component and the established macro-scale power transmission tower finite element model, obtaining a service life prediction conclusion of the power transmission tower; the step of establishing the electrochemical corrosion simulation model of the material of the weak component at a micro-scale comprises the following steps: based on the corrosion mechanism and electrochemical principle, taking electrochemical kinetic parameters and environmental parameters as boundary conditions, modeling the corrosion development of the material of the weak component in an atmospheric environment to obtain an electrochemical corrosion simulation model in an atmospheric environment; the electrochemical kinetic parameters include an anode exchange current density, a cathode exchange current density, an anode equilibrium potential, a cathode equilibrium potential, an anode Tafel slope and a cathode Tafel slope; the environmental parameters include an annual average temperature, an annual average humidity, a sulfate deposition rate and a chloride ion deposition rate; the step of obtaining quantitative analysis results of the corrosion thickness loss of the weak component based on the established electrochemical corrosion simulation model comprises the following steps: inputting environmental parameters of a carbon steel atmospheric exposure test to the electrochemical corrosion simulation model to obtain a current density of an electrolyte on the electrode surface of the weak component; converting the current density into a corrosion rate; integrally calculating the corrosion rate to obtain a corrosion thickness loss simulation value of the weak component.

2. The method of predicting the service life of a power transmission tower of claim 1, wherein, the step of establishing the macro-scale power transmission tower finite element model comprises the following steps: according to a single-line drawing and engineering drawings of the power transmission tower, using an indirect modeling method, sequentially establishing a geometric model of the structure in a point-line-surface-body mode to obtain the macro-scale power transmission tower finite element model.

3. The method of claim 1, wherein, the extreme conditions in the step of obtaining the weak component of the power transmission tower under stress based on the established power transmission tower finite element model include a strong wind working condition, a one-phase ground wire fracture working condition and a one-phase conductor fracture working condition.

4. The method of predicting the service life of a power transmission tower of claim 1, wherein, after the step of obtaining the weak component of the power transmission tower under stress based on the established power transmission tower finite element model, the method further comprises the following steps: verifying the effectiveness of the established power transmission tower finite element model according to the stress condition of the power transmission tower finite element model under the extreme conditions and the field power transmission tower tower collapse condition.

5. The method for predicting service life of a power transmission tower according to claim 1, wherein, after the step of modeling the corrosion development of the carbon steel in an atmospheric environment based on the corrosion mechanism and the electrochemical principle, taking the electrochemical kinetic parameters and the environmental parameters as the boundary conditions to obtain a carbon steel corrosion development model in an atmospheric environment, the method further comprises the following steps: inputting test parameters of a neutral salt spray test to the electrochemical corrosion simulation model in an atmospheric environment to verify the effectiveness of the model.

6. The method of predicting the service life of a power transmission tower of claim 5, wherein, The test parameters of the neutral salt spray test are substituted into the carbon steel corrosion development model in the atmospheric environment, and after verifying the effectiveness of the model, the following steps are further included: Based on the electrochemical corrosion simulation model after effectiveness verification, the corrosion thickness loss simulation value of the weak component is obtained; The corrosion thickness loss true value of the carbon steel atmospheric exposure test of the weak component is obtained; The corrosion thickness loss simulation value and the corrosion thickness loss true value of the weak component are compared, and the electrochemical corrosion simulation model after effectiveness verification is corrected according to the comparison result.

7. A system for service life prediction of a power transmission tower, the system comprising: It comprises: A finite element model establishing module for establishing a macro-scale transmission tower finite element model; A weak component obtaining module in communication connection with the finite element model establishing module, for performing load simulation analysis on the service performance of an uncorroded transmission tower under extreme conditions based on the established transmission tower finite element model, and obtaining a weak component of the transmission tower under stress; A corrosion model establishing module in communication connection with the weak component obtaining module, for establishing a micro-scale electrochemical corrosion simulation model of the material of the weak component; A corrosion thickness loss simulation module in communication connection with the weak component obtaining module and the corrosion model establishing module, for obtaining a quantitative analysis result of the corrosion thickness loss of the weak component based on the established electrochemical corrosion simulation model; A transmission tower service life prediction module in communication connection with the corrosion thickness loss simulation module, for obtaining a transmission tower service life prediction conclusion based on the quantitative analysis result of the corrosion thickness loss of the weak component and the established macro-scale transmission tower finite element model; The corrosion thickness loss simulation module comprises: A current density obtaining unit in communication connection with the weak component obtaining module and the corrosion model establishing module, for inputting environmental parameters of a carbon steel atmospheric exposure test into the electrochemical corrosion simulation model to obtain the current density of the electrode surface electrolyte of the weak component; A corrosion rate obtaining unit in communication connection with the current density obtaining unit, for converting the current density into a corrosion rate; A corrosion thickness loss simulation unit in communication connection with the corrosion rate obtaining unit, for integrating the corrosion rate to obtain a corrosion thickness loss simulation value of the weak component; The establishment of the micro-scale electrochemical corrosion simulation model of the material of the weak component comprises: Based on the corrosion mechanism and electrochemical principle, the electrochemical kinetics parameters and environmental parameters are taken as boundary conditions to model the corrosion development of the material of the weak component in the atmospheric environment, to obtain an electrochemical corrosion simulation model in the atmospheric environment; The electrochemical kinetics parameters include anode exchange current density, cathode exchange current density, anode equilibrium potential, cathode equilibrium potential, anode Tafel slope and cathode Tafel slope; and the environmental parameters include annual average temperature, annual average humidity, sulfate deposition rate and chloride ion deposition rate.

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