Method, system, device and medium for calculating tower slope force under lightning impact

Abstract

The present application relates to the technical field of power transmission line engineering and geotechnical engineering, and discloses a method, system, device and medium for calculating the stress of a tower slope under lightning impact, which collects lightning current waveform data of the tower under lightning impact, calculates the power density of Joule heat source, and establishes a three-dimensional slope geometric model corresponding to the influence range of lightning impact on the slope soil body; the power density of the Joule heat source is input into the three-dimensional transient heat conduction equation, and combined with the established geometric model, the maximum temperature rise value of the slope soil body under lightning impact is determined, so as to convert the temperature change into soil stress and obtain the initial lightning impact stress value; the correction coefficient is determined by the lightning current waveform data and multi-dimensional influence data to correct the initial lightning impact stress value, and the transient stress value of the tower slope under lightning impact is obtained; the present application fully considers the coupling of electric-thermal-mechanical multi-physical fields and the microsecond-level transient effect, and greatly improves the calculation accuracy of the transient stress of the tower slope under lightning impact.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of power transmission line engineering and geotechnical engineering, and in particular to a method, system, equipment and medium for quantifying the stress on tower slopes under lightning impact, applicable to the stability analysis of tower slopes threatened by lightning impact in power transmission line corridors. Background Technology

[0002] Transmission lines are often erected in mountainous and hilly areas with complex terrain, and the tower foundations are often located on excavated or filled slopes. During the rainy season, towers are more likely to be struck by lightning. When lightning current is discharged into the ground through the tower body and grounding device, it generates intense physical processes in the soil around the grounding electrode: on the one hand, the impact current of tens of kiloamperes generates Joule heating on the soil resistance, causing the soil temperature to rise rapidly within microseconds, leading to the vaporization and expansion of pore water; on the other hand, the extremely high electric field strength can cause soil ionization, forming plasma channels and generating shock wave pressure. These effects work together to generate transient stress waves in the slope soil, which may induce local instability or even overall slope collapse. Currently, there is a lack of dedicated methods for calculating slope stress under lightning impact in engineering practice. Existing technologies are mostly based on quasi-static assumptions or single-physics field analysis, simplifying lightning impact into an equivalent current field or steady-state heat source, which makes it difficult to accurately describe the strong coupling effect of multiple physics fields in extreme time domains, resulting in insufficient accuracy in calculating transient stress on slopes under lightning impact.

[0003] Therefore, how to solve the problem of low accuracy in calculating transient stress on slopes under lightning impact using existing technologies has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This invention provides a method, system, equipment, and medium for quantifying the stress on the slope of a tower under lightning impact, solving the problem of low accuracy in calculating transient stress on slopes under lightning impact in existing technologies.

[0005] To address the aforementioned technical problems, the first aspect of this invention provides a method for quantifying the stress on the slope of a tower under lightning impact, comprising: Acquire the size and location data of the tower, as well as the lightning current waveform data, current diffusion data, and multidimensional impact data of the slope soil under the lightning impact; Based on the lightning current waveform data and the current diffusion data, the electrical energy in the lightning impact is converted into the transient heat source intensity of the slope soil to obtain the Joule heat source power density. Based on the size and location data, the influence range of the lightning impact on the slope soil is determined, and a three-dimensional slope geometric model of the influence range is constructed. The power density of the Joule heat source is input into the three-dimensional transient heat conduction equation, and combined with the three-dimensional slope geometric model and the multi-dimensional influence data, the maximum temperature rise of the slope soil under the lightning impact is determined. Based on the maximum temperature rise value, the temperature change of the tower under the lightning strike is converted into soil stress to obtain the initial value of lightning strike stress. The correction coefficient is determined by the lightning current waveform data and the multidimensional influence data, and the initial value of the lightning impact stress is corrected by the correction coefficient to obtain the transient stress value of the tower slope under lightning impact.

[0006] As one preferred embodiment, the multidimensional influence data includes thermal parameters, mechanical parameters, and operating condition parameters.

[0007] As one preferred embodiment, the step of inputting the Joule heat source power density into the three-dimensional transient heat conduction equation, and combining the three-dimensional slope geometric model and the multi-dimensional influence data to determine the maximum temperature rise of the slope soil under the lightning impact, includes: The Joule heat source power density is used as an internal heat source term and substituted into the three-dimensional transient heat conduction equation. Combined with the three-dimensional slope geometric model and the thermal parameters, the spatiotemporal distribution of the temperature field inside the slope soil under lightning impact is obtained by solving the finite element method. The highest temperature value is extracted from the spatiotemporal distribution of the temperature field, and combined with the preset environmental reference temperature value, the maximum temperature rise of the slope soil under the lightning impact is calculated.

[0008] As one preferred embodiment, the step of converting the temperature change of the tower under the lightning strike into soil stress based on the maximum temperature rise value to obtain the initial value of the lightning strike stress includes: The relationship between the maximum temperature rise and the boiling point of pore water is determined, and based on the determination result, the temperature change of the tower under the lightning impact is converted into soil stress using a linear thermal expansion model or a phase change equivalent thermal strain model, thus obtaining the initial value of the lightning impact stress.

[0009] As one preferred embodiment, the step of determining the relationship between the maximum temperature rise and the boiling point of pore water, and based on the determination result, using a linear thermal expansion model or a phase transition equivalent thermal strain model to convert the temperature change of the tower under the lightning impact into soil stress, thereby obtaining the initial value of the lightning impact stress, includes: When the maximum temperature rise is lower than the boiling point of pore water, the temperature change of the tower under the lightning impact is converted into soil stress by the linear thermal expansion model combined with the generalized Hooke's law, and a first stress value is obtained as the initial value of the lightning impact stress. When the maximum temperature rise is not lower than the boiling point of pore water, the phase transition equivalent thermal strain model is constructed based on the first stress value, the working condition parameters and the elastic constitutive relationship of the slope soil. The temperature change of the tower under the lightning impact is converted into soil stress through the phase transition equivalent thermal strain model to obtain the initial value of the lightning impact stress.

[0010] As one preferred embodiment, the operating parameters include soil resistivity; wherein, The construction of the phase transition equivalent thermal strain model based on the first stress value, the working condition parameters, and the elastic constitutive relationship of the slope soil includes: The equivalent thermal expansion coefficient is determined based on the first stress value and the spatiotemporal distribution of the temperature field. Based on the Joule heat source power density, the thermal parameters and the equivalent thermal expansion coefficient, the stress change of the slope soil during pore water vaporization and gas expansion is determined, and a second stress value is obtained. The bulk modulus of the slope soil is determined based on the mechanical parameters, and the phase transition equivalent thermal strain model is constructed based on the equivalent thermal expansion coefficient, the first stress value, the second stress value, the soil resistivity, and the bulk modulus.

[0011] As one preferred embodiment, the lightning current waveform data includes the peak value of the lightning current; the operating parameters include soil moisture content; wherein... The process of determining correction coefficients using the lightning current waveform data and the multidimensional influence data, and then using these correction coefficients to correct the initial value of the lightning impact stress to obtain the transient stress value of the tower slope under lightning impact, includes: The correction coefficient is determined based on the peak lightning current and the soil moisture content; Multiplying the correction coefficient by the initial value of the lightning impact stress yields the transient stress value of the tower slope under lightning impact.

[0012] A second aspect of the present invention provides a system for quantifying the stress on a tower slope under lightning impact, comprising: The data acquisition module is used to acquire the size and location data of the tower, as well as the lightning current waveform data, current diffusion data, and multidimensional impact data of the slope soil under the lightning impact. An electrothermal coupling module is used to convert the electrical energy in the lightning impact into the transient heat source intensity of the slope soil based on the lightning current waveform data and the current diffusion data, so as to obtain the Joule heat source power density. The three-dimensional modeling module is used to determine the impact range of the lightning impact on the slope soil based on the size and location data, and to construct a three-dimensional slope geometric model of the impact range; The temperature calculation module is used to input the power density of the Joule heat source into the three-dimensional transient heat conduction equation, and combine the three-dimensional slope geometric model and the multi-dimensional influence data to determine the maximum temperature rise of the slope soil under the lightning impact. The thermal conversion module is used to convert the temperature change of the tower under the lightning strike into soil stress based on the maximum temperature rise value, so as to obtain the initial value of the lightning strike stress. The stress quantification module is used to determine the correction coefficient through the lightning current waveform data and the multidimensional influence data, and to use the correction coefficient to correct the initial value of the lightning impact stress to obtain the transient stress value of the tower slope under lightning impact.

[0013] A third aspect of the present invention provides an electronic device including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the method for quantifying the stress on the slope of a tower under lightning impact as described above.

[0014] A fourth aspect of the present invention provides a computer-readable storage medium comprising a stored computer program, wherein when the device containing the computer-readable storage medium executes the computer program, it implements the method for quantifying the stress on the slope of a tower under lightning impact as described above.

[0015] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows: By organically combining the transient electrothermal effect of lightning current with soil temperature rise and thermal stress expansion, this approach overcomes the shortcomings of traditional slope stability analysis, which only considers conventional loads such as rainfall and excavation while neglecting the thermal impact of lightning strikes. By constructing an "electricity → heat → force" transmission path, it can realistically reflect the physical process of soil pore water vaporization and strength attenuation caused by lightning strike current. The maximum temperature rise inside the soil is calculated using a three-dimensional transient heat conduction equation and converted into an initial value of thermal expansion stress. Then, the stress is corrected by combining waveform characteristics and multi-dimensional soil impact data, revealing the hidden damage mechanism of lightning on slopes and providing a new dimension for tower foundation protection design. By determining the correction coefficient through lightning current waveform data and its multi-dimensional impact data on slope soil, the rough estimation of a uniform safety factor is avoided. The initial value of lightning impact stress is then corrected using the correction coefficient, achieving accurate calculation of transient stress on transmission line corridor slopes under the influence of lightning strikes and effectively improving the accuracy of slope stress calculation under extreme weather conditions. Attached Figure Description

[0016] To more clearly illustrate the technical solution of the present invention, the drawings used in 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.

[0017] Figure 1 This is a flowchart of a method for quantifying the stress on a tower slope under lightning impact, provided in a certain embodiment of the present invention; Figure 2 This is a structural diagram of a stress quantification system for tower slopes under lightning impact, provided in a certain embodiment of the present invention. Figure 3 This is a structural diagram of an electronic device provided in a certain embodiment of the present invention; Figure label: Among them, 10 is the data acquisition module; 20 is the electrothermal coupling module; 30 is the 3D modeling module; 40 is the temperature calculation module; 50 is the thermal conversion module; 60 is the stress quantification module; 5000 is the electronic equipment; 5001 is the processor; 5002 is the bus; 5003 is the memory; and 5004 is the transceiver. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings and examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this application, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art will be able to understand the specific meaning of the above terms in this application according to the specific circumstances.

[0020] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is merely for describing specific embodiments and is not intended to limit the invention. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0021] In one embodiment, such as Figure 1 As shown, the first aspect of the present invention provides a method for quantifying the stress on the slope of a tower under lightning impact, comprising: S1. Obtain the size and location data of the tower and its lightning current waveform data, current diffusion data, and multi-dimensional influence data of the slope soil under the lightning impact; the multi-dimensional influence data includes thermal parameters, mechanical parameters, and working condition parameters; the working condition parameters include soil resistivity and soil moisture content; the lightning current waveform data includes the peak value of the lightning current; Specifically, the dimensions of the tower leg root opening, the foundation column burial depth, and the grounding device layout of the area to be tested are extracted from the tower structure design drawings. A total station or RTK is used to measure the topographic contour lines of the slope at the tower location to determine the horizontal distance from the tower base center to the slope shoulder, and the relative height difference between the foundation bottom and the potential sliding surface. Information on slope soil layering, slope topography, and the geometric dimensions, location, and grounding resistance of the tower base are collected from the geological survey report and used as the tower's dimensional and positional data. A lightning location system is installed at the tower grounding point to measure the lightning current amplitude, waveform, peak value, lightning strike start, and duration. A double exponential function is used to fit the lightning current waveform data. For cases where actual measurement is not possible, a standard lightning current waveform (such as an 8 / 20μs double exponential wave) can be used. Electromagnetic transient simulation software (such as CDEGS) is used to establish a calculation model based on the actual dimensions of the grounding device and the soil resistivity. The aforementioned double exponential lightning current is input as the excitation source, and the current diffusion density distribution and diffusion area volume of each grounding conductor segment are simulated as current diffusion data. By consulting geotechnical engineering investigation reports, on-site sampling and laboratory tests, or relevant specifications and manuals, obtain the thermal parameters (density ρ, specific heat capacity c, thermal conductivity k), mechanical parameters (elastic modulus E, Poisson's ratio ν, where cohesive soil is 0.3~0.4, sand is 0.25~0.35, and saturated clay can be taken as 0.49), and working condition parameters (soil resistivity, soil moisture content) of the soil near the tower location.

[0022] S2. Based on the lightning current waveform data and the current diffusion data, the electrical energy in the lightning impact is converted into the transient heat source intensity of the slope soil to obtain the Joule heat source power density. This invention establishes an electro-thermal coupling relationship by converting the electrical energy of lightning current into the transient heat source intensity of the slope soil. Then, based on the Joule heating calculation formula, and using lightning current waveform data and current diffusion data as input, it outputs the heat source power density of the Joule heat generated by the lightning current in the slope soil. This process is expressed by the following formula: In the formula, i(t) represents the instantaneous value of the lightning current at time t; R represents the tower grounding resistance; t represents the duration of the lightning strike; V represents the volume of the heat source, which is also the volume of the diffusion region formed by the current spreading approximately in a hemispherical shape around the grounding point; q v (t) represents the instantaneous value of the heat source power density at time t, which generates Joule heat in the slope soil due to lightning current.

[0023] S3. Determine the impact range of the lightning strike on the slope soil based on the size and location data, and construct a three-dimensional slope geometric model of the impact range; Based on the obtained tower foundation dimensions, grounding electrode arrangement (horizontal rays, vertical grounding electrodes, etc.) and their burial depth, determine the impact range of lightning strikes (usually the slope area within 5m around the tower foundation and within 3m in depth), and use 3D modeling software (such as AutoCAD, SolidWorks) to create a geometric solid model of the area—a 3D slope geometric model. This model should include details such as the tower foundation structure, grounding electrodes, and interfaces between different soil layers.

[0024] S4. Input the power density of the Joule heat source into the three-dimensional transient heat conduction equation, and combine the three-dimensional slope geometric model and the multi-dimensional influence data to determine the maximum temperature rise of the slope soil under the lightning impact. In one embodiment, step S4 includes: The Joule heat source power density is used as an internal heat source term and substituted into the three-dimensional transient heat conduction equation. Combined with the three-dimensional slope geometric model and the thermal parameters, the spatiotemporal distribution of the temperature field inside the slope soil under lightning impact is obtained by solving the finite element method. The highest temperature value is extracted from the spatiotemporal distribution of the temperature field, and combined with the preset environmental reference temperature value, the maximum temperature rise of the slope soil under the lightning impact is calculated.

[0025] Specifically, this invention calculates the global temperature field of a slope under lightning strike transients using three-dimensional transient heat conduction calculations, obtains the temperature basis for thermal strain, and completes the thermal field solution.

[0026] First, the constructed three-dimensional slope geometric model is imported into finite element thermal analysis software (such as the heat transfer module of ANSYS MechanicalAPDL or COMSOL Multiphysics). The material thermal parameters are configured according to the layered structure of the model, and tetrahedral elements are used for spatial discretization. The maximum mesh size of the soil surrounding the grounded circular steel surface and within a 0.5m radius is set to 0.02m to accurately capture the severe temperature gradient generated by the Joule heat source in this area. The mesh size of the soil more than 10m away from the tower base is widened to 1.0m to control the total amount of calculation, thus obtaining several positional elements, i.e., the mesh.

[0027] The coordinates of the spatial sampling points and the corresponding Joule heat source power density obtained from the electromagnetic simulation are exported. In the thermal analysis software, the "volume load interpolation mapping" function is used to assign the discrete Joule heat source power density to the nearest element integration point. A time function is defined based on the double exponential current waveform to describe the normalized waveform change of the heat source intensity during the duration of the lightning current. In the finite element software, the "table load" of the transient analysis is set, the total analysis time is set to [0,10] seconds, and the time function is densely interpolated in the microsecond range. For any element, the product of the Joule heat source power density value and the time function is used as the transient heat source term.

[0028] The computational domain is assumed to have a uniform temperature field at the initial moment. Based on this scenario, convective heat transfer boundary conditions and adiabatic boundary conditions are applied. Combining thermal parameters, the three-dimensional transient heat conduction equations are solved for isotropic soil elements in a Cartesian coordinate system as follows: In the formula, This indicates the density of the soil on the tower base slope; This indicates the specific heat capacity of the soil on the tower base slope; T This indicates the temperature distribution of the soil on the tower base slope; k This represents the thermal conductivity of the soil on the slope of the tower base.

[0029] The equations are solved using the backward difference method (BDF) time integration method (other finite element / finite difference numerical methods can also be used). Because of its good stability for rigid heat conduction problems, the spatiotemporal distribution of the temperature field inside the slope soil under lightning impact is obtained (i.e., the coordinates of all nodes of the slope soil and their corresponding three-dimensional transient temperature distribution).

[0030] The highest temperature value is extracted from the spatiotemporal distribution of the temperature field. The preset environmental reference temperature value (293.15K) is subtracted from the highest temperature value to locate the point of most severe temperature change, lock the location of maximum slope stress, and obtain the maximum temperature rise value of the slope soil under lightning impact.

[0031] This invention uses the microsecond-level variation of Joule thermal power density as the source term to drive the three-dimensional transient heat conduction equation, which can accurately capture the dynamic changes of the soil internal temperature field throughout the entire process of lightning current from peak to decay. By combining a real three-dimensional slope geometric model and specific soil thermal parameters, and using the finite element method to solve the problem, it avoids the limitations of simplifying the soil as an infinitely large homogeneous medium or a one-dimensional semi-infinite body. It can accurately reflect the influence of terrain on the heat dissipation path, thereby obtaining a temperature distribution cloud map with practical physical meaning. This enables the deep coupling and utilization of multi-source heterogeneous data and provides high-precision quantitative indicators to guide engineering decisions.

[0032] S5. Based on the maximum temperature rise value, the temperature change of the tower under the lightning impact is converted into soil stress to obtain the initial value of lightning impact stress. In one embodiment, step S5 includes: The relationship between the maximum temperature rise and the boiling point of pore water is determined, and based on the determination result, either a linear thermal expansion model or a phase change equivalent thermal strain model is used to convert the temperature change of the tower under the lightning strike into soil stress, thus obtaining the initial value of the lightning strike stress. Specifically, this invention abandons the simplistic treatment of using a constant thermal expansion coefficient in all traditional methods, and innovatively introduces a temperature rise threshold judgment mechanism. Depending on whether a phase change of pore water occurs, different calculation models are used: a linear thermal expansion model is used based on the judgment result to reflect the conventional mechanical behavior of the soil skeleton under thermal elastic expansion, converting the temperature change of the tower under the lightning strike into soil stress, thus obtaining the initial value of the lightning strike stress; or a phase change equivalent thermal strain model is used to accurately capture the more than 1,000-fold volume expansion effect generated by the instantaneous vaporization of liquid water, converting the temperature change of the tower under the lightning strike into soil stress, thus obtaining the initial value of the lightning strike stress. This avoids the problem of severely underestimating the initial stress value due to ignoring the phase change pressure, making the evaluation results closer to the real physical phenomenon of soil cracking and loosening near the lightning strike point.

[0033] In one embodiment, determining the relationship between the maximum temperature rise and the boiling point of pore water, and converting the temperature change of the tower under the lightning strike into soil stress using a linear thermal expansion model or a phase transition equivalent thermal strain model based on the determination result, to obtain the initial value of the lightning strike stress, includes: When the maximum temperature rise is lower than the boiling point of pore water, the temperature change of the tower under the lightning impact is converted into soil stress by the linear thermal expansion model combined with the generalized Hooke's law, and a first stress value is obtained as the initial value of the lightning impact stress. When the maximum temperature rise is not lower than the boiling point of pore water, the phase transition equivalent thermal strain model is constructed based on the first stress value, the working condition parameters and the elastic constitutive relationship of the slope soil. The temperature change of the tower under the lightning impact is converted into soil stress through the phase transition equivalent thermal strain model to obtain the initial value of the lightning impact stress.

[0034] Specifically, when the maximum temperature rise is below the boiling point of pore water, it is determined that the slope soil undergoes thermal expansion, and the volume change of the soil is relatively small. Since thermal expansion is directly proportional to the temperature rise, the linear thermal strain of the tower frame under lightning strike, calculated using a linear thermal expansion model, is: In the formula, Linear thermal strain; The linear thermal expansion coefficient of the soil skeleton is preferably [value missing]. ; This represents the maximum temperature rise.

[0035] According to the generalized Hooke's law, for an isotropic elastic body, thermal stress is proportional to volume strain. Through derivation, a simplified expression for the initial value of the lightning impact stress can be obtained as follows: In the formula, This represents the first stress value of the tower slope under lightning impact before phase change, which is the theoretical constraint stress caused only by the thermal expansion of the soil skeleton when the water vaporization phase change effect is not considered. K Indicates the bulk modulus of soil; Indicates soil resistivity; r 1 is the calculated value. The maximum distance between the grounding point and the grounding point; E The elastic modulus of the soil; The value is Poisson's ratio for the soil.

[0036] When the maximum temperature rise is not lower than the boiling point of pore water, the pore water in the soil begins to boil and vaporize. After the water turns into water vapor, its volume expands thousands of times under normal pressure, indicating a phase transition. However, the soil is strongly constrained by the surrounding medium, and the water vapor pressure forces some gas to escape along micro-cracks, so a fixed expansion factor cannot be directly applied. That is, when the temperature rises above the boiling point of pore water, the pore water rapidly vaporizes, changing from liquid water to gaseous water vapor. The Joule heating-induced vaporization of pore water needs to be equivalent to thermal strain to calculate the soil stress changes caused by water vaporization and rapid gas expansion. Based on this, this invention uses a phase transition equivalent thermal strain model constructed with the first stress value, working parameters, and the elastic constitutive relationship of the slope soil to convert the temperature change of the tower under lightning impact into soil stress, thus obtaining the initial value of the lightning impact stress.

[0037] This invention introduces a clear physical threshold criterion (boiling point temperature rise of pore water) to enable adaptive computation. When the lightning strike energy is low and no phase change occurs in the soil, the linear thermal expansion model is directly used to output the first stress value, resulting in simple and efficient calculations. When the lightning strike energy is intense enough to cause the pore water to boil, the system automatically switches to a phase change equivalent thermal strain model, superimposing the phase change additional stress effect on top of the first stress value. This hierarchical processing mechanism avoids unnecessary complex calculations in the absence of phase change while ensuring the physical accuracy of the assessment of high-energy lightning strike events, achieving a harmonious balance between computational economy and scientific rigor.

[0038] In one embodiment, constructing the phase transition equivalent thermal strain model based on the first stress value, the working condition parameters, and the elastic constitutive relation of the slope soil includes: The equivalent thermal expansion coefficient is determined based on the first stress value and the spatiotemporal distribution of the temperature field. Based on the Joule heat source power density, the thermal parameters and the equivalent thermal expansion coefficient, the stress change of the slope soil during pore water vaporization and gas expansion is determined, and a second stress value is obtained. The bulk modulus of the slope soil is determined based on the mechanical parameters, and the phase transition equivalent thermal strain model is constructed based on the equivalent thermal expansion coefficient, the first stress value, the second stress value, the soil resistivity, and the bulk modulus.

[0039] When pore water vaporizes, its volume expands dramatically, exerting additional pressure on the soil. This invention equates this effect to thermal strain and introduces an equivalent thermal expansion coefficient that varies with temperature, calculated based on the first stress value and the spatiotemporal distribution of the temperature field. In the formula, It is the equivalent thermal expansion coefficient.

[0040] Subsequently, by combining the equivalent thermal expansion coefficient, Joule heat source power density, thermal parameters, and the equivalent thermal expansion coefficient, the stress changes in the slope soil during pore water vaporization and gas expansion were calculated, which is the additional change caused by the phase transition: In the formula, The second stress value; t b The starting time for reaching the boiling point of pore water.

[0041] Based on the generalized Hooke's law and mechanical parameters, the bulk modulus of the slope soil is determined. Combined with the equivalent thermal expansion coefficient, the first stress value, the second stress value, and the soil resistivity, a phase transition equivalent thermal strain model is constructed. This model is expressed by the following equation: In the formula, This represents the combined stress on the tower slope under lightning impact during phase transition.

[0042] It should also be noted that when the comprehensive stress calculated by the phase transformation equivalent thermal strain model (i.e., the initial value of lightning impact stress, the additional changes caused by the thermal expansion of the skeleton and the phase transformation) exceeds the ultimate constraint stress of the soil, the ultimate constraint stress is used as the initial value of the effective stress.

[0043] This invention uses the linear calculation result (first stress value) under sub-boiling point conditions as the benchmark reference stress for constructing the phase transition model. Even under high-temperature conditions where phase transition occurs, the thermoelastic expansion of the soil skeleton still objectively exists and contributes to the foundation stress components. Starting from the first stress value, the additional changes caused by the elastic constitutive relation ensure a smooth numerical transition of the stress field on both sides of the threshold interface, avoiding stress jumps or non-physical abrupt changes caused by model switching, and improving the reliability of stress input in slope stability analysis. By deeply integrating the working condition parameters and the elastic constitutive relation into the phase transition model, the matching degree of engineering scenarios is improved, and the shortcomings of traditional empirical formulas that cannot consider soil stiffness differences are solved, providing a precise basis for the differentiated design of tower foundations under complex geological conditions.

[0044] S6. Determine the correction coefficient using the lightning current waveform data and the multidimensional influence data, and use the correction coefficient to correct the initial value of the lightning impact stress to obtain the transient stress value of the tower slope under lightning impact. In one embodiment, step S6 includes: The correction coefficient is determined based on the peak lightning current and the soil moisture content; Multiplying the correction coefficient by the initial value of the lightning impact stress yields the transient stress value of the tower slope under lightning impact.

[0045] Specifically, this invention determines a correction coefficient based on the peak lightning current and soil moisture content, and then multiplies the correction coefficient by the initial value of lightning impact stress to correct the initial value, thus obtaining the final transient stress value of the tower slope under lightning impact. This process is expressed by the following formula: In the formula, This represents the transient stress value of the tower slope under the final lightning impact. This is a correction factor; I 0 represents the peak value of the lightning current; This refers to the soil moisture content of the slope.

[0046] This invention uses peak lightning current and soil moisture content as the core variables for determining the correction coefficient, abandoning the crude approach of correcting with a single empirical constant. Peak lightning current directly determines the total energy input to the soil, while soil moisture content simultaneously affects heat capacity, latent heat of vaporization consumption, and the development of pore pressure. By constructing a correction coefficient expression based on these two key parameters, it can accurately reflect the essential difference between the dramatic increase in the proportion of phase transformation stress under "high current, high moisture content" conditions and the dominance of pure thermoelastic stress under "low current, low moisture content" conditions, making the corrected transient stress value more realistically approximate the actual field conditions. It achieves a scientific reduction of lightning impact stress from theoretical initial value to practical engineering value, quantifying the comprehensive effect of energy dissipation and constraint release. Utilizing easily obtainable field monitoring parameters to drive the correction process ensures the operability and promotional value of the method.

[0047] To verify the effectiveness of the solution described in this invention, the following comparative experiment was conducted. A certain region was used as the verification area, and the relevant parameters were set as follows: heat source volume V (m²) 3 The value is 16.76, and the duration of the lightning current is 2 × 10⁻⁶. -6 Density of soil on the base slope ρ (g / m 3 The specific heat capacity of the soil on the tower base slope is 1.9, the specific heat capacity c (kJ / (kg×K)) is 1.5, the thermal conductivity k (W / (m×K)) of the soil on the tower base slope is 1, and the coefficient of thermal expansion α (1 / K) of the soil when the temperature has not reached the boiling point of pore water is 1×10. -5 The soil's elastic modulus E (MPa) is 20, and the soil's Poisson's ratio is... v The value is 0.3, and the lightning current waveform function i(t)(A) is 10000(e -11800t -e -625000t The tower grounding resistance (Ω) is 10, and the soil resistivity p e (Q×m) is 100, soil moisture content The value is 0.28. Based on these data, the uncorrected stress is calculated to be 11.9 × 10⁻⁸.3 (kPa), while the stress modified in this invention is 13×10 3 (kPa), thus, the quantitative results of the scheme used in this invention have been improved. Based on the above data, the stress value calculated by the existing patent "Method for Limit Equilibrium Assessment of Tower Foundation Slope Stability under Lightning Impact Conditions" (publication number CN119413993A) is 0.33. This indicates that its method of using a conversion coefficient to derive the relationship between Joule heat generated by lightning current flowing into the slope soil and stress change is too simplistic. Furthermore, this invention considers the transient effects and coupling of electro-thermal-mechanical multi-physics fields in the slope soil under lightning impact, comprehensively considering the influence of peak lightning current and soil moisture content on the stress change of the slope soil. The scheme that corrects the initial value of the calculated stress change is more accurate and reasonable.

[0048] This application addresses the issue of low accuracy in calculating transient stress on slopes under lightning impact using existing technologies. It proposes a method for quantifying stress on tower slopes under lightning impact, organically combining the transient electrothermal effect of lightning current with soil temperature rise and thermal stress propagation. This overcomes the shortcomings of traditional slope stability analysis, which only considers conventional loads such as rainfall and excavation while neglecting the thermal impact of lightning. By constructing an "electricity → heat → force" transmission path, it can accurately reflect the physical processes of soil pore water vaporization and strength attenuation caused by lightning current. The method utilizes a three-dimensional transient heat conduction equation to calculate the maximum internal temperature rise of the soil and converts it into... The initial value of thermal expansion stress was used, and the stress was corrected by combining waveform characteristics and multidimensional influence data of soil. This revealed the hidden damage mechanism of lightning to slopes and provided a new dimension for the protection design of tower foundations. The correction coefficient was determined by lightning current waveform data and its multidimensional influence data on slope soil, avoiding the rough estimation of a uniform safety factor. The initial value of lightning impact stress was then corrected by the correction coefficient, which greatly improved the accuracy of transient stress calculation of slopes under lightning impact. At the same time, all input parameters can be obtained through conventional geotechnical engineering investigation or simple experiments, without the need for expensive or complex testing equipment, which facilitates engineering promotion and application.

[0049] It should be noted that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order requirement for the execution of these steps, and they can be executed in other orders.

[0050] In another embodiment, such as Figure 2 As shown, a second aspect of the present invention provides a system for quantifying the stress on a tower slope under lightning impact, comprising: Data acquisition module 10 is used to acquire the size and location data of the tower and its lightning current waveform data, current diffusion data and multidimensional impact data of the slope soil under the lightning impact. The electrothermal coupling module 20 is used to convert the electrical energy in the lightning impact into the transient heat source intensity of the slope soil based on the lightning current waveform data and the current diffusion data, so as to obtain the Joule heat source power density. The three-dimensional modeling module 30 is used to determine the influence range of the lightning impact on the slope soil based on the size and location data, and to construct a three-dimensional slope geometric model of the influence range; The temperature calculation module 40 is used to input the power density of the Joule heat source into the three-dimensional transient heat conduction equation, and combine the three-dimensional slope geometric model and the multi-dimensional influence data to determine the maximum temperature rise of the slope soil under the lightning impact. The thermal conversion module 50 is used to convert the temperature change of the tower under the lightning strike into soil stress based on the maximum temperature rise value, so as to obtain the initial value of the lightning strike stress. The stress quantification module 60 is used to determine the correction coefficient through the lightning current waveform data and the multidimensional influence data, and to use the correction coefficient to correct the initial value of the lightning impact stress to obtain the transient stress value of the tower slope under lightning impact.

[0051] It should be noted that each module in the aforementioned system for quantifying the stress on a tower slope under lightning impact can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module. For specific limitations regarding the system for quantifying the stress on a tower slope under lightning impact, please refer to the limitations regarding the method for quantifying the stress on a tower slope under lightning impact mentioned above; both have the same function and role, and will not be repeated here.

[0052] A third aspect of the present invention provides an electronic device comprising: Processor, memory, and bus; The bus is used to connect the processor and the memory; The memory is used to store operation instructions; The processor is configured to execute the operation instructions by calling the operation instructions, thereby causing the processor to perform the operation corresponding to the method for quantifying the stress on the slope of a tower under lightning impact as shown in the first aspect of this application.

[0053] In one alternative embodiment, an electronic device is provided, such as Figure 3 As shown, Figure 3The illustrated electronic device 5000 includes a processor 5001 and a memory 5003. The processor 5001 and the memory 5003 are connected, for example, via a bus 5002. Optionally, the electronic device 5000 may also include a transceiver 5004. It should be noted that in practical applications, the transceiver 5004 is not limited to one type, and the structure of this electronic device 5000 does not constitute a limitation on the embodiments of this application.

[0054] Processor 5001 may be a CPU, a general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 5001 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0055] Bus 5002 may include a path for transmitting information between the aforementioned components. Bus 5002 may be a PCI bus or an EISA bus, etc. Bus 5002 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 3 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0056] The memory 5003 may be a ROM or other type of static storage device capable of storing static information and instructions, RAM or other type of dynamic storage device capable of storing information and instructions, or it may be an EEPROM, CD-ROM or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0057] The memory 5003 is used to store application code that executes the scheme of this application, and its execution is controlled by the processor 5001. The processor 5001 is used to execute the application code stored in the memory 5003 to implement the content shown in any of the foregoing method embodiments.

[0058] Among them, electronic devices include, but are not limited to: mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), and in-vehicle terminals (such as in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers.

[0059] The fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for quantifying the stress on a tower slope under lightning impact, as shown in the first aspect of this application.

[0060] Another embodiment of this application provides a computer-readable storage medium storing a computer program that, when run on a computer, enables the computer to execute the corresponding content in the aforementioned method embodiments.

[0061] Furthermore, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0062] In summary, this invention relates to the interdisciplinary field of power transmission line engineering and geotechnical engineering, and discloses a method, system, equipment, and medium for quantifying the stress on tower slopes under lightning strikes. The method involves collecting lightning current waveform data of the tower under lightning strikes, calculating the Joule heat source power density, and establishing a three-dimensional geometric model of the slope corresponding to the influence range of the lightning strike on the slope soil. The Joule heat source power density is input into the three-dimensional transient heat conduction equation, and combined with the constructed geometric model, the maximum temperature rise of the slope soil under lightning strikes is determined to convert the temperature change into soil stress, obtaining the initial value of the lightning strike stress. Correction coefficients are determined using lightning current waveform data and multidimensional influence data to correct the initial value of the lightning strike stress, thus obtaining the transient stress value of the tower slope under lightning strikes. This invention fully considers the coupling of multiple physical fields (electric, thermal, and mechanical) and microsecond-level transient effects, and significantly improves the calculation accuracy of the transient stress on the tower slope under lightning strikes.

[0063] The various embodiments in this specification are described in a progressive manner. For directly identical or similar parts of the embodiments, refer to each other. Each embodiment focuses on its differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0064] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A method for quantifying the stress on the slope of a tower under lightning impact, characterized in that, include: Acquire the size and location data of the tower, as well as the lightning current waveform data, current diffusion data, and multidimensional impact data of the slope soil under the lightning impact; Based on the lightning current waveform data and the current diffusion data, the electrical energy in the lightning impact is converted into the transient heat source intensity of the slope soil to obtain the Joule heat source power density. Based on the size and location data, the influence range of the lightning impact on the slope soil is determined, and a three-dimensional slope geometric model of the influence range is constructed. The power density of the Joule heat source is input into the three-dimensional transient heat conduction equation, and combined with the three-dimensional slope geometric model and the multi-dimensional influence data, the maximum temperature rise of the slope soil under the lightning impact is determined. Based on the maximum temperature rise value, the temperature change of the tower under the lightning strike is converted into soil stress to obtain the initial value of lightning strike stress. The correction coefficient is determined by the lightning current waveform data and the multidimensional influence data, and the initial value of the lightning impact stress is corrected by the correction coefficient to obtain the transient stress value of the tower slope under lightning impact.

2. The method for quantifying the stress on the slope of a tower under lightning impact according to claim 1, characterized in that, The multidimensional influence data includes thermal parameters, mechanical parameters, and operating condition parameters.

3. The method for quantifying the stress on the slope of a tower under lightning impact according to claim 2, characterized in that, The step of inputting the Joule heat source power density into the three-dimensional transient heat conduction equation, and combining the three-dimensional slope geometric model and the multi-dimensional influence data to determine the maximum temperature rise of the slope soil under the lightning impact, includes: The Joule heat source power density is used as an internal heat source term and substituted into the three-dimensional transient heat conduction equation. Combined with the three-dimensional slope geometric model and the thermal parameters, the spatiotemporal distribution of the temperature field inside the slope soil under lightning impact is obtained by solving the finite element method. The highest temperature value is extracted from the spatiotemporal distribution of the temperature field, and combined with the preset environmental reference temperature value, the maximum temperature rise of the slope soil under the lightning impact is calculated.

4. The method for quantifying the stress on the slope of a tower under lightning impact according to claim 3, characterized in that, Based on the maximum temperature rise value, the temperature change of the tower under the lightning strike is converted into soil stress to obtain the initial value of the lightning strike stress, including: The relationship between the maximum temperature rise and the boiling point of pore water is determined, and based on the determination result, the temperature change of the tower under the lightning impact is converted into soil stress using a linear thermal expansion model or a phase change equivalent thermal strain model, thus obtaining the initial value of the lightning impact stress.

5. The method for quantifying the stress on the slope of a tower under lightning impact according to claim 4, characterized in that, The process of determining the relationship between the maximum temperature rise and the boiling point of pore water, and using a linear thermal expansion model or a phase transition equivalent thermal strain model based on the determination result to convert the temperature change of the tower under the lightning impact into soil stress, thereby obtaining the initial value of the lightning impact stress, includes: When the maximum temperature rise is lower than the boiling point of pore water, the temperature change of the tower under the lightning impact is converted into soil stress by the linear thermal expansion model combined with the generalized Hooke's law, and a first stress value is obtained as the initial value of the lightning impact stress. When the maximum temperature rise is not lower than the boiling point of pore water, the phase transition equivalent thermal strain model is constructed based on the first stress value, the working condition parameters and the elastic constitutive relationship of the slope soil. The temperature change of the tower under the lightning impact is converted into soil stress through the phase transition equivalent thermal strain model to obtain the initial value of the lightning impact stress.

6. The method for quantifying the stress on the slope of a tower under lightning impact according to claim 5, characterized in that, The operating parameters include soil resistivity; wherein... The construction of the phase transition equivalent thermal strain model based on the first stress value, the working condition parameters, and the elastic constitutive relationship of the slope soil includes: The equivalent thermal expansion coefficient is determined based on the first stress value and the spatiotemporal distribution of the temperature field. Based on the Joule heat source power density, the thermal parameters and the equivalent thermal expansion coefficient, the stress change of the slope soil during pore water vaporization and gas expansion is determined, and a second stress value is obtained. The bulk modulus of the slope soil is determined based on the mechanical parameters, and the phase transition equivalent thermal strain model is constructed based on the equivalent thermal expansion coefficient, the first stress value, the second stress value, the soil resistivity, and the bulk modulus.

7. The method for quantifying the stress on the slope of a tower under lightning impact according to claim 2, characterized in that, The lightning current waveform data includes the peak value of the lightning current; the operating parameters include soil moisture content; wherein... The process of determining correction coefficients using the lightning current waveform data and the multidimensional influence data, and then using these correction coefficients to correct the initial value of the lightning impact stress to obtain the transient stress value of the tower slope under lightning impact, includes: The correction coefficient is determined based on the peak lightning current and the soil moisture content; Multiplying the correction coefficient by the initial value of the lightning impact stress yields the transient stress value of the tower slope under lightning impact.

8. A system for quantifying the stress on the slope of a tower under lightning impact, characterized in that, include: The data acquisition module is used to acquire the size and location data of the tower, as well as the lightning current waveform data, current diffusion data, and multidimensional impact data of the slope soil under the lightning impact. An electrothermal coupling module is used to convert the electrical energy in the lightning impact into the transient heat source intensity of the slope soil based on the lightning current waveform data and the current diffusion data, so as to obtain the Joule heat source power density. The three-dimensional modeling module is used to determine the impact range of the lightning impact on the slope soil based on the size and location data, and to construct a three-dimensional slope geometric model of the impact range; The temperature calculation module is used to input the power density of the Joule heat source into the three-dimensional transient heat conduction equation, and combine the three-dimensional slope geometric model and the multi-dimensional influence data to determine the maximum temperature rise of the slope soil under the lightning impact. The thermal conversion module is used to convert the temperature change of the tower under the lightning strike into soil stress based on the maximum temperature rise value, so as to obtain the initial value of the lightning strike stress. The stress quantification module is used to determine the correction coefficient through the lightning current waveform data and the multidimensional influence data, and to use the correction coefficient to correct the initial value of the lightning impact stress to obtain the transient stress value of the tower slope under lightning impact.

9. An electronic device, characterized in that, The system includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the method for quantifying the stress on the tower slope under lightning impact as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein when the device containing the computer-readable storage medium executes the computer program, it implements the method for quantifying the stress on the slope of a tower under lightning impact as described in any one of claims 1 to 7.

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