Method and device for predicting residual strength of transmission tower after fire

Abstract

The invention provides a method and device for predicting residual strength of a transmission tower after fire, and the method comprises the steps: carrying out a fire simulation experiment on a transmission tower sample according to an actual forest fire temperature rise curve of a target working environment, carrying out the material performance test of the transmission tower sample after the fire simulation experiment, and obtaining a performance test result; simulating the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, and performing structural analysis on a simulation result to obtain a numerical analysis result; and obtaining a residual strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result. According to the method, experimental testing and numerical analysis are combined to analyze the residual strength of the transmission tower after multiple fire disasters, and the actual influence of the fire disasters on the tower can be simulated more truly, so that the accuracy of residual strength calculation is improved, and the accuracy of a safety assessment result is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission line assessment, and particularly to a method and device for predicting the remaining strength of a transmission tower after a fire. Background Art

[0002] In recent years, the power infrastructure that the country has focused on investing in and building has achieved great development. The voltage level of transmission lines is getting higher and higher, and a backbone power grid at the 500 kV level has been formed. In order to further meet the strategic needs of economic development, energy allocation, and ecological environment protection, long-distance power transmission at high voltage or even ultra-high voltage has already started. With the increase in transmission voltage, the height of transmission towers has been continuously increasing, and the forms have also been continuously innovated. Considerable progress has been made in both design and manufacturing and installation. Therefore, the safety and stability of the transmission tower structure have become the main objectives of the design and maintenance of the entire power transmission system.

[0003] Currently, the focus is mainly on exploring the impact of natural disasters on overhead transmission line systems, usually paying attention to the entire transmission network or individual transmission conductors. There are relatively few dedicated studies on the impact of natural disasters on the structure of transmission towers. In the prior art, studies have explored the responses of transmission tower structures under the action of geological disasters such as wind vibration and landslides. However, in actual cases, in addition to wind loads and earthquakes that can damage the transmission towers, the transmission towers may experience multiple fire attacks. Research on the impact of fires, especially on the remaining strength of towers after repeated fire events, is still relatively scarce. Traditional strength assessment techniques cannot comprehensively consider the actual situation after a fire, thus unable to accurately predict the remaining strength of the towers, resulting in an inability to accurately evaluate the actual load-bearing performance of the towers. Summary of the Invention

[0004] The present invention provides a method and device for predicting the remaining strength of a transmission tower after a fire, to solve the defect of low accuracy in the prior art and achieve high-accuracy prediction of the remaining strength of a transmission tower after a fire.

[0005] The present invention provides a method for predicting the remaining strength of a transmission tower after a fire, including the following steps: Conduct a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, and perform a material performance test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; Simulate the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, and perform a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; Obtain the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result.

[0006] A method for predicting the remaining strength of a transmission tower after a fire provided by the present invention, wherein both the performance test results and the numerical analysis results include the weighted average remaining strength and the comprehensive strength reduction percentage; Correspondingly, performing a material performance test on the transmission tower sample after the fire simulation experiment to obtain performance test results, specifically including: Performing a tensile strength test on the transmission tower sample after the fire simulation experiment to obtain the tensile strength; performing a compressive strength test on the transmission tower sample after the fire simulation experiment to obtain the compressive strength; performing a shear test on the transmission tower sample after the fire simulation experiment to obtain the shear strength; Calculating the first weighted average remaining strength according to the tensile strength, the compressive strength, the shear strength, and the stress distribution and weight of the transmission tower in the target working environment; Calculating the first initial weighted average strength according to the initial value of the tensile strength, the initial value of the compressive strength, the initial value of the shear strength, and the stress distribution and weight; Calculating the first comprehensive strength reduction percentage according to the first weighted average remaining strength and the first initial weighted average strength, and further obtaining the performance test results according to the first weighted average remaining strength and the first comprehensive strength reduction percentage.

[0007] A method for predicting the remaining strength of a transmission tower after a fire provided by the present invention, wherein obtaining the remaining strength prediction result of the transmission tower sample according to the performance test results and the numerical analysis results specifically includes: Adjusting the parameters of the numerical model according to the performance test results and the numerical analysis results; Updating the numerical analysis results according to the adjusted numerical model to obtain the remaining strength prediction result.

[0008] A method for predicting the remaining strength of a transmission tower after a fire provided by the present invention, wherein adjusting the parameters of the numerical model according to the performance test results and the numerical analysis results specifically includes: Performing damage grading using the damage grading standard according to the performance test results and the visual inspection results of the transmission tower sample after the fire simulation experiment to obtain the first grading result; Performing damage grading using the damage grading rule according to the numerical analysis results to obtain the second grading result; Compare the first grading result with the second grading result. When the difference between the first grading result and the second grading result is greater than a preset threshold, adjust the parameters of the numerical model according to the tensile strength, the compressive strength, and the shear strength.

[0009] According to a method for predicting the remaining strength of a transmission tower after a fire provided by the present invention, after obtaining the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result, the method further includes: Perform damage grading on the basis of the remaining strength prediction result by using a damage grading standard to obtain a damage grading result; Evaluate the safety of the transmission tower in the target working environment according to the damage grading result.

[0010] According to a method for predicting the remaining strength of a transmission tower after a fire provided by the present invention, the numerical model is constructed according to the geometric shape, material properties, boundary conditions, and loading conditions of the transmission tower sample; Wherein, the material properties at least include elastic modulus and yield strength; the boundary conditions at least include fixed support conditions and suspension point conditions; the loading conditions at least include the fire situation.

[0011] The present invention also provides a device for predicting the remaining strength of a transmission tower after a fire, including the following modules: An experiment unit, configured to perform a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, and perform a material performance test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; A model unit, configured to simulate the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, and perform a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; A result unit, configured to obtain the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result.

[0012] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, where when the processor executes the program, the method for predicting the remaining strength of a transmission tower after a fire as described in any one of the above is implemented.

[0013] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method for predicting the remaining strength of a transmission tower after a fire as described in any one of the above is implemented.

[0014] The present invention also provides a computer program product, including a computer program, which when executed by a processor, implements the method for predicting the remaining strength of a transmission tower after a fire as described in any one of the above.

[0015] The method and device for predicting the remaining strength of a transmission tower after a fire provided by the present invention perform a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, and conduct a material property test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; simulate the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, and conduct a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; and obtain a prediction result of the remaining strength of the transmission tower sample according to the performance test result and the numerical analysis result. The present invention combines experimental testing and numerical analysis to analyze the remaining strength of a transmission tower after experiencing multiple fires, can more realistically simulate the actual impact of a fire on the tower, thereby improving the accuracy of the remaining strength calculation, and further improving the accuracy of the safety assessment result. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is one of the flow diagrams of the method for predicting the remaining strength of a transmission tower after a fire provided by the present invention.

[0018] Figure 2 is another flow diagram of the method for predicting the remaining strength of a transmission tower after a fire provided by the present invention.

[0019] Figure 3 is the structural diagram of the device for predicting the remaining strength of a transmission tower after a fire provided by the present invention.

[0020] Figure 4 is the structural diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] The following will describe Figure 1 - Figure 2 the method for predicting the remaining strength of a transmission tower after a wildfire, as Figure 1 shown. The method includes: Step 110: Conduct a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, and perform a material property test on the transmission tower sample after the fire simulation experiment to obtain a performance test result.

[0023] It should be noted that the target working environment is the working environment where the transmission tower to be tested is located. This environment has been invaded by a wildfire, and the mentioned wildfire temperature rise curve is the actual wildfire temperature rise curve. Further, the transmission tower sample has the same material and structure as the transmission tower to be tested.

[0024] On this basis, that is to say, the embodiments of the present invention simulate the process of a transmission tower to be tested located in the target working environment being invaded by a wildfire by means of a fire simulation experiment based on the transmission tower sample, more realistically simulating the actual impact of the fire on the tower.

[0025] It should be noted that during the process of conducting the fire simulation experiment, in some embodiments, a heating furnace is used to perform multiple heat treatments on the transmission tower sample based on the actual wildfire temperature rise curve to complete the simulation experiment. The present invention does not specifically limit the heating furnace, and the heating furnace can be selected or set according to the actual situation during the operation process. In a specific embodiment, a self-made heating furnace is used for heat treatment.

[0026] Further, in some embodiments, after completing the fire simulation experiment, record the actual temperature curve of the transmission tower sample during the experiment.

[0027] After completing the fire simulation experiment, perform a material property test on the transmission tower sample. It should be noted that the material property test mentioned in the embodiments of the present invention is a laboratory material property test.

[0028] In addition, it should be explained that the performance test result obtained by performing a material property test on the transmission tower sample is calculated based on the result of the material property test. More specifically, in some embodiments, the performance test result includes the weighted average remaining strength and the comprehensive strength reduction percentage.

[0029] It should be noted that, in order to distinguish the weighted average remaining strength in the performance test results from the weighted average remaining strength in the subsequent numerical analysis results, the weighted average remaining strength in the performance test results is denoted as the first weighted average remaining strength.

[0030] Furthermore, after obtaining the first weighted average remaining strength and the first comprehensive strength decrease percentage, they can be used as the performance test results.

[0031] Step 120: Simulate the fire simulation experiment according to the pre-constructed numerical model of the transmission tower sample, and perform a structural analysis on the results of the simulation to obtain numerical analysis results; the numerical model is used to describe the actual structure and material properties of the transmission tower sample.

[0032] In addition to experimental analysis, numerical analysis can also be performed on the transmission tower sample. Specifically, first, a numerical model of the transmission tower needs to be established, that is, the transmission tower sample is simulated using mathematical equations, and the complex physical, chemical, or biological processes are abstracted into a mathematical model. For example, the mathematical model abstracted from the actual structure and material properties of the transmission tower sample is used as the numerical model.

[0033] After that, based on the obtained numerical model, the fire simulation experiment is simulated. Specifically, the content of the simulation includes determining the possible changes in the material properties of the tower after the fire. In a specific embodiment, the possible changes in the material properties of the tower after the fire are determined according to the data in the literature.

[0034] After obtaining the simulation results including the possible changes in the material properties of the tower after the fire, a structural analysis is performed on the simulation results to obtain numerical analysis results. It should be noted that the structural analysis is used to determine the performance of the transmission tower when it is stressed. This includes the analysis of material selection, design, construction methods, and loading effects. In the specific analysis process, structural analysis software such as ANSYS and ABAQUS can be used to calculate the numerical model using the finite element method.

[0035] Furthermore, the weighted average remaining strength and the comprehensive strength decrease percentage can be obtained after the structural analysis. The structured numerical analysis using the numerical model in the embodiments of the present invention can more accurately reflect the performance of the tower under actual working conditions.

[0036] It should be noted that, in order to distinguish the weighted average remaining strength and the comprehensive strength decrease percentage in the numerical analysis results from the weighted average remaining strength and the comprehensive strength decrease percentage in the performance test results, the weighted average remaining strength in the numerical analysis results is denoted as the second weighted average remaining strength, and the comprehensive strength decrease percentage in the numerical analysis results is denoted as the second comprehensive strength decrease percentage.

[0037] After obtaining the second weighted average remaining strength and the second comprehensive strength decrease percentage, they can be used as the numerical analysis results.

[0038] In addition, it can be understood that in addition to calculating the performance of the transmission tower samples from the perspective of numerical analysis, the numerical analysis based on the numerical model can also provide information that is difficult to observe in experiments, such as the internal stress distribution and the microscopic failure process, which helps to more deeply understand the fire behavior and remaining strength of the structure.

[0039] Step 130: Obtain the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result.

[0040] When the difference between the performance test result and the numerical analysis result is not greater than the preset threshold, neither the performance test result nor the numerical analysis result needs to be adjusted, and either the performance test result or the numerical analysis result can be used as the remaining strength prediction result.

[0041] When the difference between the performance test result and the numerical analysis result is greater than the preset threshold, further processing needs to be performed according to the performance test result and the numerical analysis result to obtain the remaining strength prediction result. The present invention will illustrate how to obtain the remaining strength prediction result by further processing according to the performance test result and the numerical analysis result in the subsequent embodiments.

[0042] The present invention combines numerical analysis with experimental measurement, so that the obtained remaining strength prediction result has the advantages of both experimental measurement and numerical analysis, thereby enabling a more comprehensive evaluation of the remaining strength of the transmission tower after a fire and providing a scientific basis for the safety assessment of the structure and subsequent reinforcement design.

[0043] Further, in step 110, in order to more comprehensively analyze the transmission tower sample after the fire simulation experiment, in some embodiments, visual inspection is performed on the surface damage condition of the transmission tower sample after the fire simulation experiment, including phenomena such as cracks, melting, and peeling. It should be noted that the visual inspection can be carried out manually or by means of machine vision, and the present invention does not limit this.

[0044] Further, based on the above embodiments, after visually inspecting the surface damage condition of the transmission tower sample after the fire simulation experiment, for the suspected damage area, non-destructive testing techniques can also be used for further internal damage assessment. Correspondingly, the present invention embodiment does not specifically limit the manner of the non-destructive testing technique.

[0045] The following introduces the material performance test of the transmission tower sample after the fire simulation experiment in step 110 to obtain the performance test result: Specifically, in some embodiments, the test content of the material property test mainly includes at least one of a tensile strength test, a compressive strength test, and a shear test. The above-mentioned material property tests are respectively used to determine the tensile strength of the material of the transmission tower sample , compressive strength and shear strength .

[0046] Furthermore, in some embodiments, a tensile strength test, a compressive strength test, and a shear test are simultaneously performed on the transmission tower sample

[0047] After that, based on the tensile strength , compressive strength and shear strength , the weighted average remaining strength is calculated according to the distribution and importance of various stresses of the transmission tower simulated by the transmission tower sample in the actual working environment (i.e., the target working environment) .

[0048] It should be noted that the distribution and importance of various stresses are the above-mentioned stress distribution and weights, and the stress distribution and weights can be obtained through the actual working conditions of the transmission tower in the target working environment

[0049] Based on the above embodiments, the material property test is performed on the transmission tower sample after the fire simulation experiment to obtain the performance test result, which specifically includes Performing a tensile strength test on the transmission tower sample after the fire simulation experiment to obtain the tensile strength; performing a compressive strength test on the transmission tower sample after the fire simulation experiment to obtain the compressive strength; performing a shear test on the transmission tower sample after the fire simulation experiment to obtain the shear strength Calculating the first weighted average remaining strength according to the tensile strength, the compressive strength, the shear strength, and the stress distribution and weights of the transmission tower in the target working environment Calculating the first initial weighted average strength according to the initial value of the tensile strength, the initial value of the compressive strength, the initial value of the shear strength, and the stress distribution and weights Calculating the first comprehensive strength reduction percentage according to the first weighted average remaining strength and the first initial weighted average strength, and further obtaining the performance test result according to the first weighted average remaining strength and the first comprehensive strength reduction percentage

[0050] Specifically, a tensile strength test, a compressive strength test, and a shear test are respectively performed on the transmission tower sample after the fire simulation experiment to obtain the tensile strength , compressive strength and shear strength 。

[0051] Further, in a specific embodiment, the following first preset formula is used to calculate the first weighted average remaining strength according to the tensile strength, compressive strength, shear strength, stress distribution and weight of the transmission tower in the target working environment.

[0052] The first preset formula includes:

[0053] where is the remaining value of the th kind of strength, is the corresponding weight.

[0054] On this basis, the first initial weighted average strength can also be calculated according to the initial value of the tensile strength, the initial value of the compressive strength, the initial value of the shear strength, the stress distribution and the weight 。In a specific embodiment, the following second preset formula is used to calculate the first initial weighted average strength.

[0055] The second preset formula includes:

[0056] where is the initial strength value of the th kind of strength, is the corresponding weight.

[0057] After that, the comprehensive strength decrease percentage is calculated according to the calculated first weighted average remaining strength and the first initial weighted average strength 。It should be noted that, in order to distinguish the comprehensive strength decrease percentage in the performance test results from the comprehensive strength decrease percentage in the subsequent numerical analysis results, the comprehensive strength decrease percentage in the performance test results is denoted as the first comprehensive strength decrease percentage.

[0058] In a specific embodiment, the following third preset formula is used to calculate the first comprehensive strength decrease percentage.

[0059] The third preset formula includes:

[0060] It should be noted that the first, second, and third mentioned in the embodiments of the present invention are only for distinction and do not include the calculation order or other meanings.

[0061] Further, in order to make the meaning represented by the performance test results obtained in step 110 easier to understand, in some embodiments, the first weighted average remaining strength and the first comprehensive strength decrease percentage in the performance test results are combined with the results of visual inspection, and damage grading is performed using a damage grading standard. The obtained grading results are used as the performance test results. The present invention will describe the aforementioned damage grading in subsequent embodiments.

[0062] The numerical model in step 120 is further introduced as follows: In the prior art, in order to facilitate the feasibility of calculation and analysis, researchers often perform abstraction and simplification on complex transmission line and tower structures. However, this simplification will cause a deviation between the analysis results and the actual engineering situation, and the simplification of the transmission tower model will lead to insufficient accuracy in tower strength calculation.

[0063] Compared with the prior art, the embodiments of the present invention consider the physical, chemical or biological processes of the transmission tower in the target working environment more comprehensively, and construct a numerical model by comprehensively considering its geometric shape, material properties, boundary conditions and loading conditions.

[0064] Based on the above embodiments, the numerical model is constructed according to the geometric shape, material properties, boundary conditions and loading conditions of the transmission tower sample; Among them, the material properties at least include elastic modulus and yield strength; the boundary conditions at least include fixed support conditions and suspension point conditions; the loading conditions at least include the overfire situation.

[0065] Specifically, the numerical model mentioned in the embodiments of the present invention includes the geometric shape, material properties, boundary conditions and loading conditions of the transmission tower sample (or the transmission tower to be tested in the target working environment).

[0066] Specifically, the geometric shape refers to the external contour or structure of an object. For example, it can be described by mathematical attributes such as boundaries, curves, areas and volumes; The material properties refer to the characteristics and properties shown by the material when subjected to external actions. For example, they include mechanical properties such as elastic modulus and yield strength; The boundary conditions refer to the restrictions imposed on the variables or their derivatives on the boundaries of the solution region in the numerical model. These restrictions are derived from the actual situation and can be used to simulate various constraints in the real world, such as the fixed support conditions and suspension point conditions of the transmission tower to be tested in the target working environment.

[0067] The loading conditions refer to the external actions or forces applied to a system or structure in physics, engineering and materials science. These conditions can be static or dynamic, stable or unstable, and uniform or non-uniform. For example, overfire simulation.

[0068] Further, in step 120, in order to make the meaning represented by the numerical analysis result obtained in step 120 easier to understand, in some embodiments, according to the second weighted average remaining strength and the second comprehensive strength decrease percentage in the obtained numerical analysis result, damage grading is performed using the damage grading standard, and the obtained grading result is used as the numerical analysis result. The present invention will explain the aforementioned damage grading in subsequent embodiments.

[0069] Further, in step 130, when the difference between the performance test result and the numerical analysis result is greater than a preset threshold, further processing of the performance test result and the numerical analysis result is required to obtain the remaining strength prediction result. Specifically, in some embodiments, obtaining the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result specifically includes: Adjusting the parameters of the numerical model according to the performance test result and the numerical analysis result; Updating the numerical analysis result according to the adjusted numerical model to obtain the remaining strength prediction result.

[0070] Specifically, the purpose of comparing the result of numerical analysis with the result measured by actual experiment (performance test result) is to make the numerical model closer to the actual situation, so as to verify the accuracy and reliability of the model.

[0071] More specifically, comparing the result of numerical analysis with the performance test result, if the difference is greater than the preset threshold, then adjust the parameters in the numerical model.

[0072] In the specific adjustment process, as Figure 2 shown, according to the calculated tensile strength , compressive strength and shear strength adjust the geometric shape, material properties, boundary conditions and loading conditions in the numerical model to obtain the adjusted numerical model.

[0073] After that, update the numerical analysis result according to the adjusted numerical model, and use the updated numerical analysis result as the remaining strength prediction result.

[0074] In the embodiment of the present invention, the performance test result and the numerical analysis result are compared, and the numerical analysis result is updated when the difference is large, so that the obtained remaining strength prediction result is closer to the actual situation and has higher accuracy and reliability.

[0075] Based on the above embodiments, further illustrate the method of comparing the performance test result and the numerical analysis result and the method of parameter adjustment according to the comparison result: In some embodiments, adjusting the parameters of the numerical model according to the performance test results and the numerical analysis results specifically includes: According to the performance test results and the visual inspection results of the transmission tower samples after the fire simulation experiment, use the damage grading standard to perform damage grading to obtain the first grading result; According to the numerical analysis results, use the damage grading rule to perform damage grading to obtain the second grading result; Compare the first grading result and the second grading result. In the case where the difference between the first grading result and the second grading result is greater than a preset threshold, adjust the parameters of the numerical model according to the tensile strength, the compressive strength, and the shear strength.

[0076] Specifically, it should be noted first that the performance test results referred to in the embodiments of the present invention are the first weighted average remaining strength and the second comprehensive strength decrease percentage, and the numerical analysis results are the second weighted average remaining strength and the second comprehensive strength decrease percentage.

[0077] On this basis, perform damage grading according to the performance test results and the visual inspection results of the transmission tower samples after the fire simulation experiment to obtain the first grading result, and perform damage grading according to the numerical analysis results to obtain the second grading result.

[0078] It should be pointed out that the damage grading referred to in the embodiments of the present invention is all carried out using the damage grading standard. The damage grading standard stipulates the comprehensive strength decrease percentage and the damage level corresponding to the visual inspection results. In some embodiments, the damage levels include five levels: no significant damage, minor damage, moderate damage, severe damage, and catastrophic damage.

[0079] In a specific embodiment, the damage grading standard is shown in Table 1.

[0080] Table 1 Grading standard for the performance degradation of transmission towers after fire

[0081] Based on experimental tests and numerical analysis, the embodiments of the present invention further adjust the parameters of the numerical model used in the numerical analysis based on actual experiments.

[0082] It not only has high practicability and operability, but also can accurately evaluate the safety of the transmission tower after multiple fires, providing a scientific basis for the safe operation of the transmission tower. The embodiments of the present invention are based on experimental test-based fire damage assessment, performance test of the tower after the fire, calculation of the remaining strength based on numerical analysis, and combination of experiments and numerical analysis to obtain the final result, which not only has high practicability and operability, but also can accurately evaluate the safety of the transmission tower after multiple fires, providing a scientific basis for the safe operation of the transmission tower.

[0083] Further, in order to make the meaning represented by the remaining strength prediction result in step 130 easier to understand, the obtained remaining strength prediction result is further processed to explore the safety situation of its actual load-bearing performance. In some embodiments, after obtaining the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result, it further includes: Performing damage grading on the basis of the remaining strength prediction result by using the damage grading standard to obtain a damage grading result; Evaluating the safety of the transmission tower in the target working environment according to the damage grading result.

[0084] Specifically, damage grading is performed according to the remaining strength prediction result to evaluate the safety of the tower. In the specific evaluation process, if severe damage or catastrophic damage is reached, repair or reinforcement measures should be proposed. Repair measures may include local reinforcement, overall replacement, etc.; reinforcement measures may include adding supports and changing the structural layout.

[0085] The embodiments of the present invention further perform damage grading according to the remaining strength prediction result, and conduct a safety assessment for the damage grading result, and propose improvement methods for the cases with poor safety assessment results, providing a feasible operation guide for actual engineering.

[0086] The method for predicting the remaining strength of a transmission tower after a fire provided by the present invention performs a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, performs a material performance test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; simulates the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, performs a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; obtains the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result. The present invention combines experimental tests and numerical analysis to analyze the remaining strength of the transmission tower after multiple fires, can more realistically simulate the actual impact of the fire on the tower, thereby improving the accuracy of the remaining strength calculation, and further improving the accuracy of the safety assessment result.

[0087] The following describes the device for predicting the remaining strength of a transmission tower after a wildfire provided by the present invention. The device for predicting the remaining strength of a transmission tower after a wildfire described below can be correspondingly referred to the method for predicting the remaining strength of a transmission tower after a wildfire described above. As Figure 3 shown, the device includes the following modules: An experimental unit 310, configured to perform a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, and perform a material property test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; A model unit 320, configured to simulate the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, and perform a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; A result unit 330, configured to obtain a remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result.

[0088] According to a device for predicting the remaining strength of a transmission tower after a wildfire provided by the present invention, both the performance test result and the numerical analysis result include a weighted average remaining strength and a comprehensive strength decrease percentage; Correspondingly, the performing a material property test on the transmission tower sample after the fire simulation experiment to obtain a performance test result specifically includes: Performing a tensile strength experiment on the transmission tower sample after the fire simulation experiment to obtain a tensile strength; performing a compressive strength experiment on the transmission tower sample after the fire simulation experiment to obtain a compressive strength; performing a shear experiment on the transmission tower sample after the fire simulation experiment to obtain a shear strength; Calculating a first weighted average remaining strength according to the tensile strength, the compressive strength, the shear strength, and the stress distribution and weight of the transmission tower in the target working environment; Calculating a first initial weighted average strength according to the initial value of the tensile strength, the initial value of the compressive strength, the initial value of the shear strength, and the stress distribution and weight; Calculating a first comprehensive strength decrease percentage according to the first weighted average remaining strength and the first initial weighted average strength, and further obtaining a performance test result according to the first weighted average remaining strength and the first comprehensive strength decrease percentage.

[0089] According to a device for predicting the remaining strength of a transmission tower after a wildfire provided by the present invention, the obtaining a remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result specifically includes: Adjust the parameters of the numerical model according to the performance test results and the numerical analysis results; Update the numerical analysis results according to the adjusted numerical model to obtain the remaining strength prediction results.

[0090] According to a remaining strength prediction device for a transmission tower after a fire provided by the present invention, the adjusting the parameters of the numerical model according to the performance test results and the numerical analysis results specifically includes: According to the performance test results and the visual inspection results of the transmission tower samples after the fire simulation experiment, use the damage grading standard to perform damage grading to obtain the first grading result; According to the numerical analysis results, use the damage grading rule to perform damage grading to obtain the second grading result; Compare the first grading result and the second grading result. When the difference between the first grading result and the second grading result is greater than a preset threshold, adjust the parameters of the numerical model according to the tensile strength, the compressive strength, and the shear strength.

[0091] According to a remaining strength prediction device for a transmission tower after a fire provided by the present invention, after obtaining the remaining strength prediction results of the transmission tower samples according to the performance test results and the numerical analysis results, it further includes: According to the remaining strength prediction results, use the damage grading standard to perform damage grading to obtain the damage grading results; Evaluate the safety of the transmission tower in the target working environment according to the damage grading results.

[0092] According to a remaining strength prediction device for a transmission tower after a fire provided by the present invention, the numerical model is constructed according to the geometric shape, material properties, boundary conditions, and loading conditions of the transmission tower samples; Wherein, the material properties at least include elastic modulus and yield strength; the boundary conditions at least include fixed support conditions and suspension point conditions; the loading conditions at least include the fire situation.

[0093] The device for predicting the remaining strength of a transmission tower after a fire provided by the present invention conducts a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, performs a material property test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; simulates the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, conducts a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; and obtains the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result. The present invention combines experimental testing and numerical analysis to analyze the remaining strength of a transmission tower after multiple fires, can more realistically simulate the actual impact of a fire on the tower, thereby improving the accuracy of the remaining strength calculation, and further improving the accuracy of the safety assessment result.

[0094] Figure 4 An example of a schematic physical structure diagram of an electronic device is shown as Figure 4 shown. The electronic device may include: a processor 410, a communication interface 420, a memory 430, and a communication bus 440. Among them, the processor 410, the communication interface 420, and the memory 430 complete communication with each other through the communication bus 440. The processor 410 can call the logical instructions in the memory 430 to execute the method for predicting the remaining strength of a transmission tower after a fire. The method includes: conducting a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, performing a material property test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; simulating the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, conducting a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; and obtaining the remaining strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result.

[0095] In addition, when the logical instructions in the above-mentioned memory 430 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0096] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the method for predicting the remaining strength of a transmission tower after a wildfire provided by the above-mentioned various methods. The method includes: conducting a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, performing a material property test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; simulating the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, performing a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; obtaining a prediction result of the remaining strength of the transmission tower sample according to the performance test result and the numerical analysis result.

[0097] On another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the method for predicting the remaining strength of a transmission tower after a wildfire provided by the above-mentioned various methods. The method includes: conducting a fire simulation experiment on a transmission tower sample according to the actual wildfire temperature rise curve of the target working environment, performing a material property test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; simulating the fire simulation experiment according to a pre-constructed numerical model of the transmission tower sample, performing a structural analysis on the result of the simulation to obtain a numerical analysis result; the numerical model is used to describe the actual structure and material characteristics of the transmission tower sample; obtaining a prediction result of the remaining strength of the transmission tower sample according to the performance test result and the numerical analysis result.

[0098] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0099] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting the residual strength of a transmission tower after fire, characterized in that: include: Conducting a fire simulation experiment on a transmission tower sample according to an actual wildfire temperature rise curve of a target working environment, and conducting a material performance test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; Simulating the fire simulation experiment according to the pre-built numerical model of the transmission tower sample, performing structural analysis on the simulation results, and obtaining numerical analysis results; The numerical model is used to describe the actual structure and material properties of the transmission tower sample; The residual strength prediction result of the transmission tower sample is obtained according to the performance test result and the numerical analysis result.

2. The method for predicting residual strength of a transmission tower after fire according to claim 1, characterized in that: The performance test results and the numerical analysis results both include weighted average residual strength and comprehensive strength reduction percentage; Accordingly, the material performance test is performed on the transmission tower sample after the fire simulation experiment to obtain the performance test results, which specifically include: A tensile strength test is performed on the transmission tower sample after the fire simulation test to obtain the tensile strength; a compressive strength test is performed on the transmission tower sample after the fire simulation test to obtain the compressive strength; a shear test is performed on the transmission tower sample after the fire simulation test to obtain the shear strength; Calculating a first weighted average residual strength according to the tensile strength, the compressive strength, the shear strength and the stress distribution and weight of the transmission tower in the target working environment; Calculating a first initial weighted average strength according to the initial value of the tensile strength, the initial value of the compressive strength, the initial value of the shear strength, and the stress distribution and weight; A first comprehensive strength reduction percentage is calculated based on the first weighted average remaining strength and the first initial weighted average strength, and then a performance test result is obtained based on the first weighted average remaining strength and the first comprehensive strength reduction percentage.

3. The method for predicting residual strength of a transmission tower after fire according to claim 1, characterized in that: The residual strength prediction result of the transmission tower sample is obtained according to the performance test result and the numerical analysis result, specifically including: Adjusting parameters of the numerical model according to the performance test results and the numerical analysis results; The numerical analysis result is updated according to the adjusted numerical model to obtain a residual strength prediction result.

4. The method for predicting residual strength of a transmission tower after fire according to claim 3, characterized in that: The adjusting the parameters of the numerical model according to the performance test results and the numerical analysis results specifically includes: According to the performance test results and the visual inspection results of the transmission tower sample after the fire simulation experiment, damage classification is performed using a damage classification standard to obtain a first classification result; According to the numerical analysis result, damage classification is performed using the damage classification rule to obtain a second classification result; The first classification result is compared with the second classification result, and when a difference between the first classification result and the second classification result is greater than a preset threshold, the parameters of the numerical model are adjusted according to the tensile strength, the compressive strength and the shear strength.

5. The method for predicting residual strength of a transmission tower after fire according to claim 1, characterized in that: The method further comprises: obtaining the residual strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result, and then: According to the residual strength prediction result, damage classification is performed using a damage classification standard to obtain a damage classification result; The safety of the transmission tower in the target working environment is evaluated according to the damage classification result.

6. The method for predicting residual strength of a transmission tower after fire according to claim 1, characterized in that: The numerical model is constructed based on the geometric shape, material properties, boundary conditions and loading conditions of the transmission tower sample; Among them, the material properties include at least elastic modulus and yield strength; the boundary conditions include at least fixed support conditions and hanging point conditions; and the loading conditions include at least fire conditions.

7. A device for predicting residual strength of a transmission tower after fire, characterized in that: include: An experimental unit, used to perform a fire simulation experiment on a transmission tower sample according to an actual wildfire temperature rise curve of a target working environment, and to perform a material performance test on the transmission tower sample after the fire simulation experiment to obtain a performance test result; A model unit, used for simulating the fire simulation experiment according to a pre-built numerical model of the transmission tower sample, performing structural analysis on the simulation result, and obtaining a numerical analysis result; The numerical model is used to describe the actual structure and material properties of the transmission tower sample; A result unit is used to obtain the residual strength prediction result of the transmission tower sample according to the performance test result and the numerical analysis result.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for predicting the residual strength of a transmission tower after fire as claimed in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for predicting the residual strength of a transmission tower after fire as claimed in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for predicting the residual strength of a transmission tower after fire as claimed in any one of claims 1 to 6 is implemented.

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