Reinforced concrete pole icing failure assessment method, system, equipment and medium

Abstract

The invention relates to the technical field of electric power engineering structure failure assessment, and discloses a reinforced concrete pole icing failure assessment method, system, device and medium, and the method comprises the steps: collecting the initial data of a pole, and assessing the stress distribution and potential crack position of the pole under a specific load based on the data. According to the stress distribution and the crack position, the expansion condition of the concrete crack is determined, and the stress state of the steel bar is analyzed. And based on the stress state, executing preliminary judgment. And establishing a relation model of the critical fracture value and the critical load of the steel bar in combination with the preliminary judgment result, and calculating the probability of overall failure of the electric pole. By analyzing the stress distribution and potential cracks of the electric pole under different loads, the actual stress state of the electric pole can be accurately predicted. Through fitting the joint distribution of the preset loads, the interaction between the loads is considered, and the evaluation precision is improved. The established relation model provides a basis for electric pole failure probability evaluation based on a preliminary judgment result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power engineering structure failure evaluation, and in particular to a reinforced concrete pole icing failure evaluation method, system, device and medium. BACKGROUND

[0002] The reinforced concrete pole is a common support structure in the distribution line, and its main function is to bear the weight of the line and external environmental loads such as wind load, ice load and earthquake force, and maintain the stability of the distribution system. However, under complex natural conditions, the reinforced concrete pole is often subjected to various dynamic and static loads, resulting in the generation and propagation of cracks, which may eventually cause the reinforcement to yield or break, and even lead to overall failure. In order to ensure the safe operation of the distribution line, accurately evaluating the fracture behavior and ultimate state of the reinforced concrete pole becomes a key technical problem.

[0003] The existing reinforced concrete structure evaluation method is mostly based on material mechanics or limit analysis theory, and can only describe the response behavior of the pole within the elastic range, but lacks precise evaluation means for the nonlinear mechanics process of crack initiation, propagation and final fracture. With the development of fracture mechanics theory, the evaluation method based on stress intensity factor and fracture toughness provides a reliable theoretical basis for the crack propagation of concrete. At the same time, as part of the composite material, the crack propagation behavior of the reinforcement can be described by an integral equation to describe the fatigue propagation rate, but how to combine the ductility characteristics of the reinforcement with the brittleness characteristics of the concrete is still a research difficulty.

[0004] In addition, the steel and concrete bear external force together through the bonding-slip effect, and this interface effect has an important influence on the crack propagation and final failure of the overall structure. However, the existing research describes the interface mechanics behavior roughly, and has not yet formed a systematic evaluation method, resulting in insufficient understanding and prediction of the fracture process of the reinforced concrete pole. SUMMARY

[0005] In view of the above existing problems, the present application is proposed.

[0006] Therefore, the present application provides a reinforced concrete pole icing failure evaluation method, system, device and medium, which can solve the limitations of the existing reinforced concrete structure evaluation method, especially for the nonlinear mechanics process of crack propagation.

[0007] To solve the above technical problems, the present application provides the following technical solutions:

[0008] In a first aspect, the present application provides a reinforced concrete pole icing failure evaluation method, comprising:

[0009] obtaining first data of a target electric pole, obtaining an electric pole stress distribution and a potential crack position of the target electric pole under a preset load based on the first data;

[0010] The first data includes geometric data and material data of the target electric pole.

[0011] According to the electric pole stress distribution and the potential crack position under the preset load, the expansion condition of the concrete crack in the target electric pole is determined.

[0012] According to the expansion condition, the stress state of the steel bar in the target electric pole is analyzed.

[0013] According to the stress state of the steel bar, a first judgment operation is performed, and the first judgment operation is used to judge whether the target electric pole is overall broken.

[0014] As a preferred scheme of the steel reinforced concrete electric pole icing failure evaluation method described in the application, wherein:

[0015] According to the related historical meteorological information of the target electric pole, the probability distribution characteristics of the preset load are obtained.

[0016] The joint distribution of the preset load is fitted, and a relationship model of the critical fracture value of the steel bar in the target electric pole and the critical load borne by the steel bar is established in combination with the first judgment operation result.

[0017] According to the relationship model, the probability of overall failure of the electric pole is calculated.

[0018] As a preferred scheme of the steel reinforced concrete electric pole icing failure evaluation method described in the application, wherein:

[0019] A preset steel bar yield strength is determined.

[0020] The actual value of the steel bar bearing tensile stress is obtained according to the stress state of the steel bar.

[0021] The actual value and the steel bar yield strength are subjected to a first judgment operation.

[0022] According to the first judgment operation result, it is judged whether the target electric pole is overall broken.

[0023] As a preferred scheme of the steel reinforced concrete electric pole icing failure evaluation method described in the application, wherein:

[0024] The plastic zone stress when the actual value is greater than the steel bar yield strength is determined.

[0025] A preset steel bar tensile strength is determined.

[0026] establishing an integral description of fracture mechanics when the stress in the plastic zone is greater than the tensile strength of the reinforcement;

[0027] analyzing the ultimate state of the reinforcement according to the integral description to determine the critical condition of crack propagation.

[0028] determining the critical fracture toughness of the reinforcement according to the first judgment operation result.

[0029] The preferred embodiment can more accurately assess the fracture risk of the reinforcement under stress, thereby more accurately determining the overall failure probability of the target pole. By determining the stress in the plastic zone, presetting the tensile strength of the reinforcement, and establishing an integral description of fracture mechanics, the stress state of the reinforcement can be analyzed in depth, and the critical condition of crack propagation can be further determined to provide more reliable data support for the failure assessment of the pole.

[0030] As a preferred scheme of the ice-coated reinforced concrete pole failure assessment method described in the present application, wherein: the stress state of the reinforcement in the target pole is analyzed according to the propagation condition, including:

[0031] The stress state of the reinforcement in the target pole is analyzed according to the propagation condition combined with the bond-slip characteristics between the concrete reinforcements.

[0032] The bond-slip characteristics are represented by a piecewise function, including an elastic stage, a softening stage, and a residual stage.

[0033] As a preferred scheme of the ice-coated reinforced concrete pole failure assessment method described in the present application, wherein: the propagation condition of the concrete crack in the target pole is determined according to the stress distribution of the pole under the preset load and the potential crack location, including:

[0034] The propagation condition of the concrete crack in the target pole is determined according to the stress distribution of the pole under the preset load and the potential crack location combined with the brittle fracture K criterion.

[0035] The brittle fracture K criterion includes a strength factor K, which is determined by considering the non-uniform stress distribution inside and outside the ring section, as well as the crack shape and location.

[0036] The fracture toughness value of the concrete material is preset, and the strength factor K is compared with the fracture toughness value of the concrete material to determine whether propagation occurs.

[0037] The fracture toughness value of the concrete material is the propagation condition of the concrete crack in the target pole.

[0038] As a preferred scheme of the ice-coated reinforced concrete pole failure assessment method described in the present application, wherein: the preset loads are not independent of each other.

[0039] In a second aspect, the application provides a reinforced concrete pole icing failure evaluation system, comprising:

[0040] a data acquisition and processing module configured to acquire first data of the target pole, and acquire a pole stress distribution and a potential crack position of the target pole under a preset load based on the first data;

[0041] the first data comprises geometric data and material data of the target pole;

[0042] an expansion condition acquisition module configured to determine an expansion condition of a concrete crack in the target pole according to the pole stress distribution and the potential crack position under the preset load;

[0043] an analysis module configured to analyze a steel stress state in the target pole according to the expansion condition;

[0044] a judgment module configured to perform a first judgment operation according to the steel stress state, the first judgment operation being configured to judge whether the target pole is integrally fractured.

[0045] In a third aspect, the application provides an electronic device, comprising a memory and a processor, the memory storing a computer program, and the processor implementing the steps of the method as described above when executing the computer program.

[0046] In a fourth aspect, the application provides a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the method as described above when executed by a processor.

[0047] Compared with the prior art, the application has the beneficial effects that the application provides a reinforced concrete pole icing failure evaluation method, first data of a target pole are acquired, pole stress distribution and potential crack position of the target pole under a preset load are acquired based on the first data, the first data includes geometric data and material data of the target pole, the extension condition of a concrete crack in the target pole is determined according to the pole stress distribution and the potential crack position under the preset load, the stress state of steel bars in the target pole is analyzed according to the extension condition, and a first judgment operation is performed according to the stress state of the steel bars, the first judgment operation is used to judge whether the target pole is integrally fractured. According to relevant historical meteorological information of the target pole, probability distribution characteristics of the preset load are acquired, a joint distribution of the preset load is fitted, a relationship model of a critical fracture value of the steel bars in the target pole and a critical load borne by the steel bars is established in combination with a result of the first judgment operation, and the probability of integral failure of the pole is calculated according to the relationship model. Through in-depth analysis of the stress distribution and the potential crack position of the target pole under a plurality of preset loads, in combination with historical meteorological information, the application can more accurately simulate and predict the stress state of the pole in an actual environment. The fitting of the joint distribution of the preset load not only considers the mutual influence between loads, but also further improves the evaluation accuracy. The relationship model established in combination with the result of the first judgment operation provides a scientific basis for evaluating the integral failure probability of the pole. The method is not only suitable for the icing failure evaluation of the reinforced concrete pole, but also can provide a reference for the failure evaluation of other similar structures, and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0049] Figure 1 A method flowchart of a reinforced concrete pole icing failure evaluation method provided by an embodiment of the application.

[0050] Figure 2 An internal structure diagram of an electronic device of a reinforced concrete pole icing failure evaluation method provided by an embodiment of the application. DETAILED DESCRIPTION

[0051] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should fall within the scope of protection of the present application.

[0052] Embodiment 1, refer to Figures 1-2 For the first embodiment of the present application, the embodiment provides a reinforced concrete pole icing failure evaluation method, comprising:

[0053] In the prior related art, there are some problems, for example, the failure evaluation of the reinforced concrete pole under extreme weather conditions is not accurate enough, especially in the icing condition. The traditional evaluation method is often based on a simplified mechanical model, which fails to fully consider the nonlinear process of crack propagation and the complex interaction between steel bars and concrete. This leads to a large uncertainty in the prediction of the fracture risk and overall failure probability of the pole in actual application.

[0054] The present application provides a method that can effectively solve the above-mentioned problems. Next, how to implement the reinforced concrete pole icing failure evaluation method will be described in detail in combination with multiple embodiments;

[0055] Figure 1 A method flowchart of a reinforced concrete pole icing failure evaluation method is shown, comprising:

[0056] S101, acquiring first data of a target pole, acquiring a pole stress distribution and a potential crack position of the target pole under a preset load based on the first data;

[0057] In an optional embodiment, in order to perform the reinforced concrete pole icing failure evaluation, the relevant data of the target pole needs to be acquired, and the acquired relevant data needs to be related to the pole icing, such as the geometric size of the pole, the material type, the steel bar configuration and the historical icing record. These data are the basis for subsequent analysis, which can ensure the accuracy and reliability of the evaluation.

[0058] It should be noted that based on the first data, the stress distribution of the target pole under the preset load can be calculated by using finite element analysis or other numerical methods, and the potential crack position can be predicted. These preset loads may include wind load, snow load, icing weight and temperature change, etc., which have an important influence on the stress state of the pole.

[0059] In the embodiments of the present application, the first data includes the geometric data and material data of the target pole.

[0060] In an optional embodiment, the stress distribution and potential crack location of the electric pole under the preset load are obtained by the geometric data of the target electric pole and the material data, which can include detailed information such as the diameter, wall thickness, length of the electric pole, and the layout of the steel bars, and the material data can include key parameters such as the strength and elastic modulus of the concrete and the steel bars. These detailed data provide a solid foundation for accurately evaluating the stress distribution and potential crack location of the electric pole.

[0061] In an optional embodiment, the preset load can include various types of ice load, wind load, snow load, and temperature change load, which can act on the electric pole alone or jointly, and have a complex effect on the stress distribution and crack propagation of the electric pole. In order to accurately evaluate the effect of these loads on the electric pole, the interaction between them and the time-varying characteristics need to be considered.

[0062] In the embodiments of the present application, the ice load and the wind load are selected as the preset load.

[0063] Specifically, the geometric and material parameters of the electric pole are obtained, and the stress distribution and potential crack location of the electric pole under the action of the ice load and the wind load are calculated according to the following specific steps:

[0064] Step 1.1, obtain the geometric and material parameters of the electric pole, including the outer diameter D, the inner diameter d of each section of the electric pole, and the tensile strength σ of the concrete material c .

[0065] Step 1.2, calculate the stress distribution under the action of the ice load and the wind load,

[0066] Only considering the self-weight of the conductor, the horizontal tension T of the electric pole under the conductor is:

[0067]

[0068] where w is the unit length self-weight of the conductor; L is the span; f is the sag.

[0069] In an optional embodiment, when the line is covered with ice, assuming that the ice cover is a ring-shaped uniform ice cover, the ice weight per unit length of the conductor can be calculated by the following formula:

[0070]

[0071] where D l is the outer diameter of the conductor; b is the thickness of the ice cover; ρ ice is the density of ice.

[0072] In an optional embodiment, the wind load per unit length of the electric pole body is calculated according to the following formula:

[0073] q=0.5·C d ·ρ·V2

[0074] where C d is the drag coefficient; p is the air density; and V is the wind speed.

[0075] In an alternative embodiment, for a concrete pole, the wind load can be equivalent to a resultant force applied at the top of the pole, calculated as follows:

[0076]

[0077] where D(z) is the outer diameter of the pole at height z; and h is the height of the pole.

[0078] Axial stress s axial :

[0079]

[0080] where F v is the axial force on the pole section, mainly the weight of the pole and the conductors under icing conditions; and A is the annular cross-sectional area. The formula is as follows:

[0081]

[0082] In an alternative embodiment, the bending stress s bending is caused by the bending moment of the section:

[0083]

[0084] where M is the bending moment of the section, determined by the resultant force and the vertical distance from the loading point to the selected section, and the formula is as follows:

[0085] M(z) = (T R +F h ) · (h - z)

[0086] where M(z) is the bending moment at height z; T R is the resultant force of the horizontal tension of the conductors on the pole.

[0087] c is the distance from the section to the neutral axis, taken as D / 2; and I is the moment of inertia of the section, calculated as follows:

[0088]

[0089] Total stress s:

[0090]

[0091] In an alternative embodiment, according to the stress calculation results, the potential crack location is determined, and when the local tensile stress exceeds the tensile strength of the concrete, a crack will occur:

[0092] σ > σ c

[0093] In the embodiments of the present application, the preset loads are not independent of each other.

[0094] It should be noted that obtaining the first data of the target electric pole, obtaining the electric pole stress distribution and the potential crack position of the target electric pole under the preset load based on the first data can provide accurate basic data for subsequent determination of the expansion condition of the concrete crack in the target electric pole, thereby ensuring the accuracy and reliability of the entire evaluation process. In specific implementation, these data will be input into a special evaluation system, and the system will automatically calculate the stress distribution and potential crack position of the electric pole according to the preset algorithm and model, thereby providing strong support for subsequent analysis and judgment. In addition, considering the complexity and diversity of the preset load, the system will also perform in-depth analysis and processing on these loads to ensure the comprehensiveness and accuracy of the evaluation results.

[0095] S102, determining the expansion condition of the concrete crack in the target electric pole according to the electric pole stress distribution and the potential crack position under the preset load;

[0096] In an optional embodiment, the expansion condition of the concrete crack is mainly affected by the mechanical properties of the concrete, the morphology of the crack, the characteristics of the preset load, and environmental factors. In order to accurately determine these conditions, the tensile strength, fracture toughness, and crack propagation rate of the concrete and other key parameters need to be considered comprehensively.

[0097] At the same time, it is also necessary to analyze the influence of the size, direction, and action time of the preset load on the crack propagation.

[0098] In addition, environmental factors such as temperature and humidity may also have an important influence on the propagation of the crack. Therefore, when determining the expansion condition of the concrete crack, various factors need to be considered comprehensively to ensure the accuracy and reliability of the evaluation results.

[0099] In specific implementation, advanced numerical simulation methods and experimental means can be used to conduct in-depth research and analysis on the propagation process of the crack, thereby obtaining more accurate evaluation results.

[0100] In the embodiments of the present application, determining the expansion condition of the concrete crack in the target electric pole according to the electric pole stress distribution and the potential crack position under the preset load comprises:

[0101] According to the electric pole stress distribution and the potential crack position under the preset load, and combining the brittle fracture K criterion, the expansion condition of the concrete crack in the target electric pole is determined;

[0102] In an optional embodiment, the brittle fracture K criterion includes a strength factor K, which is determined by considering the uneven stress distribution of the annular cross-section inner and outer layers, as well as the crack shape and position;

[0103] The fracture toughness value of the preset concrete material is compared with the strength factor K and the fracture toughness value of the concrete material to determine whether expansion occurs;

[0104] The fracture toughness value of the concrete material is the expansion condition of the concrete crack in the target pole.

[0105] Specifically, the specific steps of analyzing the expansion condition of the concrete crack in the pole based on the brittle fracture K criterion are as follows:

[0106] Step 2.1, the fitted brittle fracture K criterion, considering the uneven stress distribution of the annular cross-section inner and outer layers, as well as the crack shape and position on the stress intensity factor K, the modified formula is as follows:

[0107]

[0108] Where a is the crack depth; Y is the shape coefficient, which is related to the specimen geometry, crack shape and crack position, i.e.:

[0109]

[0110] Where f shape is the crack shape correction factor, which is 1.12; c is the crack length along the surface direction. For the root crack of the annular cross-section under the action of the bending moment, Y can be taken as 1.8.

[0111] Step 2.2, the expansion condition of the concrete crack in the pole, when the stress intensity factor K satisfies the following formula, the concrete crack expands:

[0112] K>K IC

[0113] Where K IC is the fracture toughness of the concrete material.

[0114] It should be noted that according to the stress distribution of the pole under the preset load and the potential crack position, the expansion condition of the concrete crack in the target pole can accurately evaluate the overall performance and safety of the pole under extreme weather conditions such as icing, and provide scientific basis for subsequent development of targeted maintenance strategies and preventive measures. The implementation of this step not only improves the accuracy and reliability of the evaluation, but also provides a strong guarantee for the stable operation of the power system.

[0115] S103, according to the expansion condition, analyze the stress state of the steel bar in the target pole;

[0116] It should be noted that analyzing the stress state of the steel bars in the target pole can further understand the overall stability and durability of the pole under extreme conditions such as icing. Steel bars are an important component of the pole structure, and their stress state directly affects the carrying capacity and safety of the pole. Therefore, accurately analyzing the stress state of the steel bars is of great significance for evaluating the failure risk of the pole.

[0117] In an optional embodiment, finite element analysis or other numerical methods can be used to simulate and analyze the stress state of the steel bars in the pole, combined with the determined concrete crack propagation conditions. This includes considering factors such as the diameter, number, layout, and material properties of the steel bars, as well as their stress distribution and deformation under the preset load. Through these analyses, the stress state of the steel bars, including tensile stress, compressive stress, and bending stress, can be obtained, and whether the steel bars are in a safe state can be evaluated.

[0118] In an optional embodiment, experimental methods can also be used to monitor and verify the stress state of the steel bars in the pole in real time. For example, sensors can be installed at key locations on the pole to monitor the stress changes of the steel bars in real time, and compared and analyzed with the numerical simulation results. This not only improves the accuracy and reliability of the evaluation, but also provides more accurate data support for subsequent maintenance strategies and preventive measures.

[0119] It should be noted that the present application analyzes the stress state of the steel bars in the target pole by extending the conditions, therefore, the operation needs to be performed as follows.

[0120] In the embodiments of the present application, according to the extension conditions, the stress state of the steel bars in the target pole is analyzed, including:

[0121] According to the extension conditions, the stress state of the steel bars in the target pole is analyzed in combination with the bond-slip properties between the concrete and the steel bars.

[0122] The bond-slip properties are represented by a piecewise function, which includes an elastic stage, a softening stage, and a residual stage.

[0123] Specifically, according to the bond-slip properties between the concrete and the steel bars, and in combination with crack propagation, the specific steps for analyzing the stress state of the steel bars are as follows:

[0124] Step 3.1, the bond-slip properties between the concrete and the steel bars, the CEB-FIP model is commonly used to describe the bond-slip relationship between the steel bars and the concrete, where the relationship between the bond stress τ and the slip s can be represented by a piecewise function, which includes an elastic stage, a softening stage, and a residual stage in turn:

[0125]

[0126] where k is the bond stiffness in elastic stage; s1, s2 are the slip at peak stress and residual stress, respectively; τ r is the residual bond strength.

[0127] Distribution of bond stress along the thickness direction:

[0128]

[0129] where r is the distance from the inner circle in the concrete section; β is the stress distribution coefficient, which can be calibrated by experiment.

[0130] The slip s is related to the position of the reinforcement in the annular section, and a correction coefficient γ(r steel ) can be introduced:

[0131]

[0132] where Δr is the position deviation of the reinforcement relative to the neutral layer.

[0133] Step 3.2, combined with crack propagation, the stress state of the reinforcement is analyzed. When cracks appear in the concrete, the cracks will weaken the restraining ability of the concrete around the reinforcement, resulting in a decrease in bond stress. As the crack depth a increases, the local damage of the concrete near the crack tip leads to an increase in the slip s of the reinforcement. According to the stress distribution of crack propagation, the expression of bond stress τ is corrected as:

[0134]

[0135] where a c is the critical crack length, beyond which the bond fails, which can be obtained from the stress intensity factor.

[0136] During the crack propagation process, the stress borne by the reinforcement can be expressed as:

[0137]

[0138] where l b is the effective bond length of the reinforcement, and d s is the diameter of the reinforcement.

[0139] At this time, the tensile stress intensity borne by the reinforcement is:

[0140]

[0141] where A s is the cross-sectional area of the reinforcement.

[0142] It should be noted that, according to the expansion condition, analyzing the stress state of the reinforcing steel in the target pole can more accurately evaluate the carrying capacity and safety of the pole under extreme conditions. Through in-depth analysis of the stress state of the reinforcing steel, the overall stability and durability of the pole structure can be further understood, thereby providing a scientific basis for subsequent maintenance decisions and reinforcement design. In addition, the implementation of this step also helps to optimize the design of the pole, improve its adaptability in harsh environments such as icing, and ensure the safe and stable operation of the power system. In specific implementation, the influence of crack expansion on the stress state of reinforcing steel and the bond slip characteristics between reinforcing steel and concrete need to be considered to ensure the accuracy and reliability of the analysis results.

[0143] In one optional embodiment, the first judgment operation is used to determine whether the target pole is in a state of overall fracture under the preset load and crack expansion condition. If the stress state of the reinforcing steel shows that the tensile stress, compressive stress, or bending stress it bears has approached or exceeded the strength limit of the material, and combined with the analysis of crack expansion, the crack has seriously weakened the overall structural strength of the pole, resulting in a risk of overall fracture of the pole, it is determined that the target pole may have approached or reached a failure state.

[0144] At this time, measures need to be taken in a timely manner to reinforce or replace the pole to prevent safety accidents and power system interruptions caused by pole fracture.

[0145] On the contrary, if the stress state of the reinforcing steel is good and the crack expansion has not caused serious impact on the overall structure of the pole, it is determined that the target pole is still in a safe state and can continue to operate and be monitored. This judgment operation is of great significance for timely discovering and handling potential failure risks of the pole, and helps to ensure the safe and stable operation of the power system.

[0146] In one optional embodiment, the first judgment operation can be implemented using a special evaluation software or system that has built-in judgment logic and algorithms. The software or system can automatically determine whether the target pole is in a state of overall fracture based on the input stress state of the reinforcing steel and the crack expansion condition. This not only improves the efficiency and accuracy of the judgment, but also reduces the interference of human factors, ensuring the objectivity and reliability of the evaluation results. In addition, the software or system can also provide detailed analysis reports and data support for subsequent processing and decision-making.

[0147] In the embodiments of the present application, the first judgment operation includes:

[0148] determining the plastic zone stress when the actual value is greater than the yield strength of the reinforcing steel;

[0149] determining the plastic zone stress when the actual value is greater than the yield strength of the reinforcing steel;

[0150] The preset tensile strength of the steel bar;

[0151] An integral description of fracture mechanics is established when the stress in the plastic zone is greater than the tensile strength of the steel bar;

[0152] According to the integral description, the limit state of the steel bar is analyzed, and the critical condition of crack propagation is determined.

[0153] According to the first judgment operation result, the critical fracture toughness of the steel bar is determined.

[0154] Specifically, the crack propagation of the steel bar is evaluated, the limit state of the steel bar is analyzed, and whether the overall fracture occurs is judged.

[0155] The specific steps are as follows:

[0156] Step 4.1, crack propagation of the steel bar, when the steel bar bears tensile stress reaching its yield strength σ y , that is:

[0157] σ s > σ y

[0158] The steel bar enters the plastic stage, in which part of the cross-sectional area enters plastic flow, and finally forms a plastic hinge, that is, a concentrated area of steel bar bending deformation. When the steel bar bending is further increased, the stress in the plastic zone exceeds the tensile strength σ u of the steel bar, the crack starts to propagate, and this process can be described by the J integral of fracture mechanics:

[0159]

[0160] Where K is the stress intensity factor; a s is the crack depth of the steel bar; and E is the elastic modulus of the steel bar.

[0161] Step 4.2, analysis of the limit state of the steel bar, and the critical condition of crack propagation:

[0162] J = J c

[0163] Where J c is the critical fracture toughness of the steel bar.

[0164] When the crack propagation reaches the critical length a sc of the steel bar, the steel bar loses its carrying capacity and overall fracture occurs.

[0165] In the embodiments of the present application, the probability distribution characteristics of the preset load are obtained according to the relevant historical meteorological information of the target pole;

[0166] The joint distribution of the preset load is fitted, and a relationship model between the critical fracture value of the steel bar in the target pole and the critical load borne by the steel bar is established in combination with the first judgment operation result.

[0167] According to the relationship model, the probability of the overall failure of the electric pole is calculated.

[0168] In summary, the application provides an ice-coating failure evaluation method for a reinforced concrete electric pole. First data of a target electric pole are obtained, and electric pole stress distribution and potential crack locations of the target electric pole under a preset load are obtained based on the first data. The first data includes geometric data and material data of the target electric pole. The propagation conditions of concrete cracks in the target electric pole are determined according to the electric pole stress distribution and the potential crack locations under the preset load. The stress state of the steel bars in the target electric pole is analyzed according to the propagation conditions. A first judgment operation is performed according to the stress state of the steel bars, and the first judgment operation is used to determine whether the target electric pole is overall broken. The probability distribution characteristics of the preset load are obtained according to relevant historical meteorological information of the target electric pole. The joint distribution of the preset load is fitted, and a relationship model between the critical breaking value of the steel bars in the target electric pole and the critical load borne by the steel bars is established in combination with the first judgment operation result. According to the relationship model, the probability of the overall failure of the electric pole is calculated. Through in-depth analysis of the stress distribution and potential crack locations of the target electric pole under various preset loads, in combination with historical meteorological information, the application can more accurately simulate and predict the stress state of the electric pole in the actual environment. By fitting the joint distribution of the preset load, not only the mutual influence between the loads is considered, but also the accuracy of the evaluation is further improved. The relationship model established in combination with the first judgment operation result provides a scientific basis for evaluating the overall failure probability of the electric pole. This method is not only suitable for ice-coating failure evaluation of reinforced concrete electric poles, but also can provide a reference for failure evaluation of other similar structures, and has a wide application prospect.

[0169] In a preferred embodiment of embodiment 2, according to the relevant historical meteorological information of the target electric pole, the probability distribution characteristics of the preset load are obtained, the joint distribution of the preset load is fitted, the relationship model between the critical breaking value of the steel bars in the target electric pole and the critical load borne by the steel bars is established in combination with the first judgment operation result, and the specific operation steps of calculating the probability of the overall failure of the electric pole according to the relationship model can be as follows:

[0170] Step 5.1, according to the historical meteorological information, the probability distribution characteristics of the ice load and the wind load are analyzed, and the Frank Copula is used to fit the joint distribution of the electric pole ice load and wind load. When ice coating occurs, the ice load and the wind load borne by the electric pole under the same meteorological condition are not independent of each other, so the Frank Copula is used to fit the joint distribution of the electric pole ice load and wind load.

[0171] For the ice load X, the marginal distribution function F X (x) can be expressed as:

[0172]

[0173] where θ x is the distribution shape parameter related to ice load.

[0174] For wind load Y, its marginal distribution function F Y (y) can be expressed as:

[0175]

[0176] where θ y is the distribution shape parameter related to wind load.

[0177] Then its Frank Copula joint distribution function is:

[0178]

[0179] where u=F X (x) and v=F Y (y) are the marginal distribution functions of ice load and wind load respectively, θ is the parameter of joint distribution function, which controls the correlation between them, and can be estimated by historical meteorological information.

[0180] Its joint density function f θ (u,v) can be obtained by the second order partial derivative of joint distribution function:

[0181]

[0182] Step 5.2, the critical fracture J integral of the steel bar in the electric pole corresponds to the critical load of the steel bar, for the steel bar with crack, the energy expression formula of J integral can be associated:

[0183]

[0184] Substituting the expression of stress intensity factor K, we get:

[0185]

[0186] When the crack propagates to the critical state a sc :

[0187] J=J c

[0188] Substitute J c into the formula:

[0189]

[0190] The critical stress intensity σ c is obtained by rearranging:

[0191]

[0192] Further, it is linked to the critical load, i.e.:

[0193]

[0194] Step 5.3, the model is used to calculate the probability of the overall failure of the electric pole,

[0195]

[0196] where P T is the load acting on the steel; P c is the critical load of the steel; f θ (u, v) is the joint density function of the ice load and the wind load of the electric pole.

[0197] In an alternative embodiment, the following steps can also be performed:

[0198] Step 6.1, a failure index vector composed of the K criterion, the bond-slip mechanism and the J integral is constructed, and a stage contribution factor matrix is introduced to map the index vector to the relative contribution weights of the three fracture mechanisms in different failure stages.

[0199] For each set of load samples, the structural response of the electric pole is calculated, and the following failure index vector is constructed:

[0200] R i = [R K,i , R bond,i , R J,i ]

[0201] where R K,i is the K criterion index vector corresponding to the concrete stress intensity factor; R bond,i is the slip index vector corresponding to the bond-slip amount; R J,i is the steel fracture index vector corresponding to the steel J integral.

[0202] According to the pre-set stage division logic, a stage contribution factor matrix is introduced to map the index vector to the relative contribution weights of the three mechanisms in each stage, which is as follows:

[0203]

[0204] where α K , α b , α J are the physical mechanism amplification weights of the stage; and the obtained is the relative contribution of K, slip and J in the jth stage of the sample.

[0205] This step aims to quantify the degree of influence of different fracture mechanisms on the structural failure process, allowing for more accurate prediction of the failure mode of the pole under icing conditions.

[0206] Step 6.2, repeat this process, and statistically analyze a large number of load samples to finally obtain the average contribution weight of the three stages under the action of ice wind load:

[0207]

[0208] This process helps to understand the importance of each fracture mechanism in the entire failure process, providing a basis for optimizing design and maintenance strategies.

[0209] Step 7.1, use Bayesian optimization to optimize the hyperparameters of XGBoost. The process is as follows: first, randomly sample several points in the hyperparameter space, train the model and calculate the objective function value. Then model the current known hyperparameter performance (θ i ,f(θ i )) with a Gaussian process. According to the current GP model, calculate the function to select the next point worth trying. Finally, evaluate the objective function value of the point, update the GP model, and repeat the above steps. This step is used to improve the generalization ability of the model, ensuring that the model not only performs well on the training data, but also gives reliable prediction results on unseen data sets.

[0210] Step 7.2, structure regularization principle, in gradient boosting, the prediction result of a single tree is f t (x), the overall model is:

[0211]

[0212] To prevent overfitting, a structural regularization term is introduced in the objective function of XGBoost at each step:

[0213]

[0214] where the regularization term Ω(f) is defined as:

[0215]

[0216] where T is the number of leaves, w j is the output weight of the jth leaf, γ controls the model complexity, and λ is the L2 regularization term coefficient, which controls the weight size penalty.

[0217] It should be noted that the present application proposes a three-stage failure contribution proportion model, which calculates the failure index of each stage of the main fracture mechanism, and generates a contribution weight by normalization, which is used to judge the degree of action of different mechanisms in the final destruction process of the structure. And the optimized gradient boosting tree model is used to train and predict the obtained tower failure samples, so as to improve the accuracy and generalization ability of the failure evaluation.

[0218] In this embodiment, a reinforced concrete electric pole icing failure evaluation system is also provided, comprising:

[0219] The data acquisition and processing module is configured to acquire first data of the target electric pole, and acquire the electric pole stress distribution and the potential crack position of the target electric pole under the preset load based on the first data.

[0220] The first data includes geometric data and material data of the target electric pole.

[0221] The expansion condition acquisition module is configured to determine the expansion condition of the concrete crack in the target electric pole according to the electric pole stress distribution and the potential crack position under the preset load.

[0222] The analysis module is configured to analyze the stress state of the steel bar in the target electric pole according to the expansion condition.

[0223] The judgment module is configured to perform a first judgment operation according to the stress state of the steel bar, and the first judgment operation is used to judge whether the target electric pole is broken as a whole.

[0224] The above-mentioned various unit modules can be embedded in or independent of the processor in the electronic device in hardware form, or can be stored in the memory in the electronic device in software form, so as to call and execute the operation corresponding to each module by the processor.

[0225] The present embodiment also provides an electronic device, which can be a terminal, and its internal structure diagram can be as shown in Figure 2The electronic device shown. The electronic device includes a processor, a memory, a communication interface, a display screen and an input device connected by a system bus. Among them, the processor of the electronic device is used to provide computing and control capability. The memory of the electronic device includes non-volatile storage medium, internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The communication interface of the electronic device is used for wired or wireless communication with external terminals. Wireless mode can be achieved through WIFI, operator network, NFC (near field communication) or other technologies. The computer program is executed by the processor to realize power engineering structure failure evaluation. The display screen of the electronic device can be a liquid crystal display screen or an electronic ink display screen. The input device of the electronic device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad provided on the shell of the electronic device, or an external keyboard, touchpad or mouse, etc.

[0226] The embodiment also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the following steps:

[0227] Obtain first data of the target pole, and obtain a pole stress distribution and a potential crack position of the target pole under a preset load based on the first data;

[0228] The first data includes geometric data and material data of the target pole;

[0229] According to the pole stress distribution and the potential crack position under the preset load, the expansion condition of the concrete crack in the target pole is determined;

[0230] According to the expansion condition, the stress state of the steel bar in the target pole is analyzed;

[0231] According to the stress state of the steel bar, a first judgment operation is performed, and the first judgment operation is used to judge whether the target pole is overall broken.

[0232] According to the related historical meteorological information of the target pole, the probability distribution characteristics of the preset load are obtained;

[0233] The joint distribution of the preset load is fitted, and a relationship model of the critical breaking value of the steel bar in the target pole and the critical load borne by the steel bar is established in combination with the first judgment operation result;

[0234] According to the relationship model, the probability of overall failure of the pole is calculated.

[0235] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalent replaced without departing from the spirit and scope of the present application, and all of them should be covered in the scope of claims of the present application.

[0236] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt a computer program product in the form of being implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes. The solutions in the embodiments of the present application can be implemented in various computer languages.

[0237] The present application is described with reference to flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0238] These computer program instructions can also be stored in a computer readable storage medium that can direct the computer or other programmable data processing devices to work in a specific manner, so that the instructions stored in the computer readable storage medium produce a product including instruction apparatus, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0239] These computer program instructions can also be loaded into a computer or other programmable data processing device, so that a series of operation steps are performed on the computer or other programmable data processing device to produce a computer implemented process, so that the instructions executed on the computer or other programmable device provide a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0240] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they have the benefit of the present disclosure without departing from the spirit and scope of the application. Accordingly, it is intended that such additions and modifications be included within the scope of the application. It is the following claims, including any amendments thereto, which define the scope of the application.

[0241] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method for assessing the icing failure of reinforced concrete utility poles, characterized in that, include: Acquire first data of the target pole, and based on the first data, obtain the pole stress distribution and potential crack locations under a preset load; The first data includes the geometric data and material data of the target pole; Based on the stress distribution of the pole under the preset load and the location of potential cracks, the propagation conditions of concrete cracks in the target pole are determined. Based on the aforementioned extended conditions, analyze the stress state of the reinforcing steel in the target pole; A first judgment operation is performed based on the stress state of the reinforcing steel bar, which is used to determine whether the target pole has broken as a whole.

2. The method for assessing icing failure of reinforced concrete utility poles as described in claim 1, characterized in that, Also includes: Based on the relevant historical meteorological information of the target pole, obtain the probability distribution characteristics of the preset load; The joint distribution of the preset load is fitted, and combined with the results of the first judgment operation, a relationship model between the critical fracture value of the steel bar in the target pole and the critical load on the steel bar is established. The probability of overall pole failure is calculated based on the aforementioned relationship model.

3. The method for assessing icing failure of reinforced concrete utility poles as described in claim 2, characterized in that, The first judgment operation based on the stress state of the reinforcing steel includes: Preset the yield strength of the steel reinforcement; The actual value of the tensile stress borne by the steel bar is obtained based on the stress state of the steel bar. The actual value is compared with the yield strength of the steel bar to perform a first judgment operation; Based on the result of the first judgment operation, determine whether the target pole is completely broken.

4. The method for assessing icing failure of reinforced concrete utility poles as described in claim 3, characterized in that, The first determination operation includes: Determine the stress in the plastic zone when the actual value is greater than the yield strength of the steel bar; Preset tensile strength of steel bars; An integral description of fracture mechanics is established when the stress in the plastic zone is greater than the tensile strength of the steel bar. Based on the integral description analysis of the limit state of the reinforcing steel, the critical conditions for crack propagation are determined. The critical fracture toughness of the reinforcing steel is determined based on the results of the first judgment operation.

5. The method for assessing icing failure of reinforced concrete utility poles as described in claim 4, characterized in that, The analysis of the stress state of the reinforcing steel in the target pole based on the extended conditions includes: Based on the aforementioned extended conditions and the bond-slip characteristics between concrete and steel reinforcement, the stress state of the steel reinforcement in the target pole is analyzed. The bond slip characteristics are represented by a piecewise function, which includes an elastic stage, a softening stage, and a residual stage.

6. The method for assessing icing failure of reinforced concrete utility poles as described in claim 5, characterized in that, The step of determining the propagation conditions of concrete cracks in the target pole based on the pole stress distribution and potential crack locations under the preset load includes: Based on the stress distribution of the pole under the preset load and the location of potential cracks, and combined with the K criterion for brittle fracture, the propagation conditions of concrete cracks in the target pole are determined. The brittle fracture K criterion includes a strength factor K, which is determined by taking into account the uneven stress distribution between the inner and outer layers of the annular cross-section, as well as the crack shape and location. The fracture toughness value of the preset concrete material is compared with the strength factor K to determine whether propagation occurs. The fracture toughness value of the concrete material is the condition for the propagation of concrete cracks in the target pole.

7. The method for assessing icing failure of reinforced concrete utility poles as described in claim 6, characterized in that, The preset loads are not independent of each other.

8. A system for assessing the icing failure of reinforced concrete utility poles, using the method described in any one of claims 1 to 7, characterized in that, include: The data acquisition and processing module is used to acquire the first data of the target pole, and based on the first data, to acquire the pole stress distribution and potential crack locations under a preset load. The first data includes the geometric data and material data of the target pole; The extended condition acquisition module is used to determine the extension conditions of concrete cracks in the target pole based on the pole stress distribution and potential crack locations under the preset load. The analysis module is used to analyze the stress state of the steel bars in the target pole based on the extended conditions. The judgment module is used to perform a first judgment operation based on the stress state of the steel bar, and the first judgment operation is used to determine whether the target pole is broken as a whole.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method for assessing icing failure of reinforced concrete poles according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for assessing icing failure of reinforced concrete poles according to any one of claims 1 to 7.

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