Grading ring pressing plate optimization design method and system based on fatigue reliability evaluation

Abstract

The invention discloses a grading ring pressing plate optimization design method and system based on fatigue reliability evaluation, and the method comprises the steps: building a grading ring finite element model, applying a wind load to a grading ring pressing plate, obtaining the stress of the grading ring pressing plate, determining the hot spot position fatigue damage of the grading ring pressing plate under the effect of the wind load based on the stress of the grading ring pressing plate, and determining the fatigue damage of the grading ring pressing plate. Determining the fatigue reliability of the grading ring pressing plate based on the hot spot position fatigue damage of the grading ring pressing plate under the wind load effect; the method comprises the following steps: establishing a target function by taking the cross section width and thickness of the grading ring pressing plate as design variables and taking the mass minimization of the grading ring pressing plate as a target, establishing a grading ring pressing plate optimization mathematical model by taking the fatigue reliability of the grading ring pressing plate as a constraint condition, and obtaining a final optimization design scheme of the grading ring pressing plate by utilizing the grading ring pressing plate optimization mathematical model. The method is used for solving the technical problem that an existing grading ring pressing plate lacks a wind-induced fatigue reliability evaluation and optimization method.

Description

Background Art

[0002] The grading ring is an indispensable part of the high-voltage power transmission system, and it is often used in transmission lines and substations. The basic working principle of the grading ring is to use the electric field distribution effect of the conductor to expand the concentrated electric field around the insulator and switch to the outside, so that the distribution of the surrounding electric field is more uniform, thereby preventing the occurrence of high-voltage system problems such as corona and flashover, while reducing the material aging rate and equipment failure rate. my country uses grading rings on high-voltage transmission lines of 110 kV and above to solve the problem of excessive concentration of electric fields in some special parts. However, since the current structural design of the grading ring only considers the impact on the electric field distribution, there is no method to evaluate and optimize the fatigue characteristics of the grading ring pressure plate under the action of wind load, which leads to a large number of engineering accidents in which fatigue fractures of the grading ring pressure plate occur under the action of wind load during the actual service of the grading ring, which has a bad impact on the stability of the power grid system. Under the action of continuous wind load, the grading ring will passively swing or vibrate, and the torsional force and bending force at the connection between the grading ring and the pressure plate are the most concentrated, so this position and its vicinity are most likely to cause fracture. Attachment Figure 1 This is a diagram of the fracture position of the pressure plate of a certain high-voltage power transmission project abroad under continuous wind load. From the damage, the bolt fastening position of the connecting plate is flat, and a loosening gasket is installed. There is no deformation, distortion or loosening of the screw hole, indicating that there is no improper construction during the installation. From the fracture location, the fracture of the pressure ring is close to the screw hole of the connecting plate. Figure 2 The fracture form of the equalizing ring plate is given. It can be seen that the fracture passes through the screw hole and is at a 45° angle with the long side, which is recorded as a type II fracture. A typical scanning electron microscope analysis of the sample fracture shows that there are several crack source areas at the edge of the sample fracture, indicating that the sample starts to crack from the edge, and the crack gradually expands inward until it breaks, as shown in Figure 3 (a). River-like patterns appear in the internal area of ​​the fracture, and secondary cracks exist, indicating that the sample is subjected to a large load before breaking and the fracture process is fast. In addition, a small amount of fatigue bands can be observed in some areas, as shown in Figure 3 (b), which is a typical morphological feature of fatigue fracture, indicating that fatigue fracture occurs in some areas of the sample under the action of alternating loads. Based on the above analysis, it is believed that the sample fractures in the form of overload / fatigue composite under multi-directional loads.

[0003] At present, the design and manufacture of the equalizing ring plate of the transmission line are based on the strength theory of materials. In addition to the description of the structural dimensions of the equalizing ring, the industry standard for the equalizing ring (DLT760.3-2012) puts forward the following requirements for its mechanical properties: the equalizing ring should meet the mechanical strength requirements of being able to withstand a static mechanical load of not less than 1000N, and the ring body and the bracket should not be loosened or fatigued due to vibration. The provisions of the industry standard for the equalizing ring (DLT760.3-2012) on its mechanical properties are relatively rough. It only puts forward that the equalizing ring should meet the mechanical strength requirements of being able to withstand a static mechanical load of not less than 1000N, and the ring body and the bracket should not be loosened or fatigued due to vibration. There are no relevant regulations on how to prevent fatigue fractures in the connection of the equalizing ring plate caused by wind-induced vibration, and no relevant solutions are proposed for what methods to take to solve the problem of fatigue damage of the equalizing ring plate. In addition, high-voltage transmission projects often use the method of increasing the strength of the equalizing ring plate to reduce the probability of wind-induced fatigue fractures. In order to increase the strength of the pressure equalizing ring pressure plate, the method of increasing the cross-sectional size of the pressure equalizing ring pressure plate and replacing the pressure equalizing ring pressure plate from aluminum material to iron material is often used in engineering.

[0004] At present, high-voltage power transmission projects have adopted the method of increasing the cross-sectional size of the equalizing ring pressure plate to reduce the probability of wind-induced fatigue fracture; however, fatigue fracture still occurs in the equalizing ring pressure plate after adopting this method, and the fracture problem cannot be fundamentally solved. This is due to the lack of wind-induced fatigue reliability assessment methods for the equalizing ring pressure plate, and the fatigue characteristics of the equalizing ring cannot be optimized for design. In addition, although the method of replacing the equalizing ring pressure plate with aluminum material can increase the strength of the equalizing ring pressure plate, since the main structure of the equalizing ring is aluminum, after using an iron pressure plate, the equalizing ring and the pressure plate are prone to dissimilar metal corrosion in the air, and the equalizing ring pressure plate is prone to fatigue fracture under the action of wind vibration. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method and system for optimizing the design of an equalizing ring pressure plate based on fatigue reliability assessment in response to the above-mentioned deficiencies in the prior art, so as to solve the technical problem that the current equalizing ring pressure plate lacks a method for evaluating and optimizing wind-induced fatigue reliability.

[0006] The present invention adopts the following technical solutions: The optimization design method of the pressure equalizing ring plate based on fatigue reliability evaluation includes the following steps: S1. Establish a finite element model of the pressure equalizing ring, apply wind load to the pressure equalizing ring plate, obtain the stress of the pressure equalizing ring plate, determine the fatigue damage of the hot spot position of the pressure equalizing ring plate under the wind load based on the stress of the pressure equalizing ring plate, and determine the fatigue reliability of the pressure equalizing ring plate based on the fatigue damage of the hot spot position of the pressure equalizing ring plate under the wind load; S2. Taking the cross-sectional width and thickness of the pressure equalizing ring pressure plate as design variables and minimizing the mass of the pressure equalizing ring pressure plate as the goal to establish an objective function, taking the fatigue reliability of the pressure equalizing ring pressure plate as a constraint condition, constructing an optimization mathematical model for the pressure equalizing ring pressure plate, and using the optimization mathematical model for the pressure equalizing ring pressure plate to obtain the final optimized design scheme for the pressure equalizing ring pressure plate.

[0007] Preferably, the wind load The calculation is as follows:

[0008] in, ρ is the air density, v cr is the wind speed, μ L is the cross-wind force coefficient, is the vortex shedding engineering frequency, is the cross-sectional diameter of the pressure equalizing ring, For time.

[0009] Preferably, the stress of the equalizing ring pressure plate is located at the bolt hole position at the root of the pressure plate flange.

[0010] Preferably, in the finite element model of the pressure equalizing ring, the vibration frequency of the pressure equalizing ring pressure plate is n i for:

[0011] in, is the annual vibration time of the pressure equalizing ring, It is the first-order vibration frequency of the pressure equalizing ring.

[0012] Preferably, in the finite element model of the pressure equalizing ring, the vibration resistance times of the pressure equalizing ring pressure plate are N for: The dynamic stress of the pressure plate under breeze vibration condition Substitute the vibration times of the pressure equalizing ring to calculate the equivalent stress of the pressure equalizing ring pressure plate. , and then the equivalent stress Substitute into the SN of the pressure ring plate to find the vibration resistance number of the pressure ring plate N ;Material of pressure ring pressure plate S - N According to the tensile strength of the pressure plate and elastic modulus are generated in the material library of the fatigue design software.

[0013] Preferably, the equivalent stress The calculation is as follows:

[0014] in, is the equivalent alternating stress; is the dynamic stress of the pressure plate of the equalizing ring under breeze vibration conditions; is the tensile strength of the pressure equalizing ring plate; is the static stress of the equalizing ring pressure plate.

[0015] Preferably, the fatigue damage at the hot spot position of the pressure equalizing ring pressure plate is specifically: The damage of the pressure plate material under the stress condition of level i is defined as D ami The damage caused by different stress levels can be linearly superimposed, thus obtaining the total damage of the pressure ring plate D am , fatigue life of the pressure plate Total damage D am The reciprocal of .

[0016] Preferably, the total damage of the pressure ring and pressure plate D am for:

[0017] in, n ( σ i ) The vibration frequency of the pressure equalizing ring, N ( σ i ) indicates the vibration resistance times of the pressure equalizing ring.

[0018] Preferably, the fatigue reliability of the pressure equalizing ring pressure plate is specifically: The cross-sectional dimensions of the pressure plate of the pressure equalizing ring are taken as the initial design value. X 0, and the design reliability R s ≥95% as a constraint; Gradually reduce the cross-sectional size of the pressure plate of the pressure equalizing ring, and use the RBF neural network response surface to calculate the state function Z i ; Calling the state function using the Monte-Carlo method Z i Calculation of the reliability of the pressure plate R ; According to the approximation method, the reliability of the pressure plate of the pressure equalizing ring is R Gradually approaching the design allowable reliability R s , get the initial optimal design point of the pressure equalizing ring and pressure plate; The sample data of the cross-sectional dimensions of the pressure-equalizing ring and the pressure plate are uniformly selected by comprehensive test method near the initial optimized design point, and the reliability of the pressure-equalizing ring and the pressure plate is calculated again. Ri And gradually make it close to the design allowable reliability R s ; Finally, the optimal design scheme of the pressure equalizing ring pressure plate is obtained by using the optimization mathematical model of the pressure equalizing ring pressure plate.

[0019] Preferably, the state function is calculated using the RBF neural network response surface Z i Specifically: Sample data obtained by finite number tests or finite element calculations; Then, the nonlinear mapping function of the RBF neural network is used to simulate the random design variables. X With the state function g ( X ) between explicit function expressions; When establishing the RBF neural network response surface model of the pressure equalizing ring plate, the random input variable cross-sectional width of the pressure equalizing ring plate is firstly X 1. Cross-sectional thickness of the pressure plate of the pressure equalizing ring X 2. Elastic modulus of the pressure plate of the pressure ring X 3. Wind speed X 4 as 4 nodes of the network input layer; Limit state equation function of fatigue part of pressure ring and platen As a node in the network output layer; A hidden layer is selected, and the number of nodes in the hidden layer is determined by the resource allocation network algorithm.

[0020] Preferably, the limit state equation function of the fatigue part of the pressure equalizing ring and platen is for:

[0021] in, D R is the damage limit of the pressure plate of the pressure equalizing ring ( D R ≤1); D ( X 1, X 2, X 3. X 4) is the damage value of the equalizing ring pressure plate.

[0022] Preferably, the optimized mathematical model of the pressure equalizing ring and pressure plate is as follows:

[0023] in, g (X) is the state function, X 1 is the cross-sectional width of the pressure plate of the pressure equalizing ring, X 2 is the cross-sectional thickness of the pressure plate of the pressure equalizing ring,R i is the reliability of the pressure-equalizing ring plate under wind load, R s is the fatigue reliability limit of the pressure plate of the equalizing ring, for, is the flange length of the upper pressure plate of the pressure equalizing ring, is the flange length of the lower pressure plate under the pressure equalizing ring, is the arc radius of the pressure plate of the pressure equalizing ring, is the density of the pressure equalizing ring plate.

[0024] In a second aspect, an embodiment of the present invention provides a pressure equalizing ring plate optimization design system based on fatigue reliability assessment, comprising: Stress module, establishes the finite element model of the pressure equalizing ring, calculates the wind load of the pressure equalizing ring body and the stress of the pressure equalizing ring pressure plate; Design module, calculate the wind vibration times of the equalizing ring, the vibration resistance times of the equalizing ring pressure plate, the fatigue damage of the hot spots of the equalizing ring pressure plate and the fatigue reliability of the equalizing ring, construct the optimization mathematical model of the equalizing ring pressure plate, and use the optimization mathematical model of the equalizing ring pressure plate to obtain the final optimization design scheme of the equalizing ring pressure plate.

[0025] In a third aspect, a computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for optimizing the design of the equalizing ring pressure plate based on fatigue reliability assessment when executing the computer program.

[0026] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, including a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for optimizing the design of an equalizing ring pressure plate based on fatigue reliability assessment.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects: The optimization design method of the pressure-equalizing ring plate based on fatigue reliability evaluation is given, and the wind-induced fatigue reliability evaluation and optimization design method of the pressure-equalizing ring plate are given; because there are many factors that affect the fatigue damage of the pressure-equalizing ring plate, it is difficult to give a clear analytical expression for the fatigue damage of the pressure-equalizing ring plate, which brings difficulties to the calculation of the fatigue reliability of the pressure-equalizing ring plate. To this end, the present invention organically combines neural network technology (NN) and stochastic simulation method (Monte-Carlo), and proposes an optimization design method of the pressure-equalizing ring plate based on fatigue reliability; by establishing an RBF neural network response surface model for the calculated fatigue hot spot damage sample data of the pressure-equalizing ring plate, and then using this model to approximately replace the implicit functional function of the fatigue damage of the pressure-equalizing ring plate, using the generalization ability of the neural network to obtain more functional function values, and then according to the Monte Carlo principle, the fatigue reliability of the pressure-equalizing ring plate is calculated, and finally the pressure-equalizing ring plate is optimized with the fatigue reliability of the pressure-equalizing ring plate as a constraint condition. Therefore, the method provided by the present invention for calculating the fatigue reliability of the equalizing ring by replacing the implicit function of fatigue damage of the equalizing ring platen with the RBF neural network response surface model can greatly reduce the amount of calculation for fatigue reliability analysis of the equalizing ring platen; on this basis, the present invention provides an optimization method for the equalizing ring platen based on fatigue reliability, which can optimize the geometric dimensions and materials of the equalizing ring platen, thereby reducing the probability of fatigue fracture of the equalizing ring platen under wind-induced vibration conditions, and ensuring the safe and stable operation of high-voltage transmission lines. In addition, the fatigue damage prediction model for the equalizing ring platen provided by the present invention can predict the fatigue damage performance of the fatigue hotspot position of the equalizing ring platen, significantly improve the calculation efficiency of fatigue damage at the fatigue hotspot position of the equalizing ring platen, provide sufficient sample data for fatigue reliability calculation of the fatigue hotspot position of the equalizing ring platen, and thus improve the accuracy of fatigue reliability calculation of the equalizing ring platen.

[0028] Furthermore, actual engineering and calculations show that the maximum stress of the pressure ring is located at the root bolt hole of the flange of the pressure plate. Therefore, this position is set as the fatigue hotspot of the pressure ring, and the results of fatigue calculation at this position can be used to accurately evaluate the fatigue life of the pressure ring pressure plate.

[0029] Furthermore, the hot spot of the pressure equalizing ring pressure plate is most prone to fatigue fracture, and this position is the most dangerous position of the pressure equalizing ring. Setting the hot spot of the pressure equalizing ring pressure plate at the root bolt hole of the pressure plate flange can accurately evaluate the fatigue damage of the pressure equalizing ring pressure plate.

[0030] Furthermore, the purpose of setting the fatigue reliability of the hotspot position of the pressure ring pressure plate is to evaluate the safety reliability of the pressure ring pressure plate against fatigue wind vibration. In addition, the fatigue reliability of the hotspot position of the pressure ring pressure plate can be used as a constraint condition of the pressure ring pressure plate optimization mathematical model to optimize the pressure ring pressure plate.

[0031] Furthermore, the RBF neural network response surface method is used to construct the fatigue reliability calculation state function of the pressure equalizing ring and platen. Z i and design variables X The relationship between. This method can transform the complex fatigue reliability calculation of the equalizing ring plate into a solvable mathematical problem, thereby improving the calculation efficiency of the fatigue reliability of the equalizing ring plate. A neural network model is established for the finite fatigue damage sample data obtained by the finite element numerical calculation of the fatigue of the equalizing ring plate, and then this neural network is used to approximately replace the implicit function function of the fatigue damage of the equalizing ring plate. By using the generalization ability of the neural network, more function function values ​​are obtained, and then the fatigue reliability of the equalizing ring plate is calculated according to the Monte Carlo principle. Finally, the fatigue reliability of the equalizing ring plate is optimized with the fatigue reliability of the equalizing ring plate as a constraint. Since it is based on finite element numerical analysis and the finite element model is replaced by an approximate analytical expression, the calculation amount of the fatigue reliability analysis of the equalizing ring plate is greatly reduced, and the fatigue optimization calculation problem of the equalizing ring plate under the implicit function function is successfully solved, which has important theoretical significance and engineering application value.

[0032] It can be understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. In summary, the present invention establishes a mathematical model for optimizing the fatigue temperature rise of the equalizing ring pressure plate based on reliability. After optimizing the design of the equalizing ring pressure plate using the mathematical model, the equalizing ring pressure plate can meet the allowable reliability control requirements. The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram showing the fracture position of the grading ring plate of a foreign high-voltage transmission project under continuous wind load; Figure 2 This is the fracture form diagram of the equalizing ring and pressure plate; Figure 3 is a diagram of the failure morphology of the pressure equalizing ring and pressure plate; FIG4 is a finite element model diagram of the pressure equalizing ring, wherein (a) is a three-dimensional solid geometric model of the pressure equalizing ring, and (b) is a finite element model; Figure 5 This is a schematic diagram of the first-order vibration mode and natural vibration period of the pressure equalizing ring after modal analysis; Figure 6 This is the location diagram of fatigue hot spots of the pressure equalizing ring; Figure 7 This is the fatigue damage assessment diagram of the pressure equalizing ring and pressure plate; Figure 8 It is the SN curve diagram of the pressure equalizing ring and pressure plate; Fig. 9 This is the fatigue life diagram of the pressure equalizing ring and pressure plate; Fig.10It is the topological structure diagram of fatigue reliability prediction model of equalizing ring and platen; Fig.11 This is a flow chart of reliability calculation of the pressure equalizing ring pressure plate of the present invention; Fig.12 A schematic diagram of a computer device provided by an embodiment of the present invention; Fig.13 The present invention is a block diagram of an electronic device provided according to an embodiment. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0036] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0037] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0038] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0039] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0040] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0041] The present invention provides an optimization design method for a pressure equalizing ring pressure plate based on fatigue reliability assessment, and provides a method for calculating the fatigue reliability of the pressure equalizing ring by replacing the implicit function of fatigue damage of the pressure equalizing ring pressure plate with the RBF neural network response surface model. This method can reduce the amount of calculation for fatigue reliability analysis of the pressure equalizing ring pressure plate; on this basis, the present invention patent provides an optimization method for the pressure equalizing ring pressure plate based on fatigue reliability, which can optimize the geometric dimensions and materials of the pressure equalizing ring pressure plate, thereby reducing the probability of fatigue fracture of the pressure equalizing ring pressure plate under wind-induced vibration conditions, and ensuring the safe and stable operation of high-voltage transmission lines. In addition, the fatigue damage prediction model for the pressure equalizing ring pressure plate provided by the present invention patent can predict the fatigue damage performance of the fatigue hotspot position of the pressure equalizing ring pressure plate, significantly improve the calculation efficiency of fatigue damage at the hotspot position of the pressure equalizing ring pressure plate, and provide sufficient sample data for fatigue reliability calculation of the fatigue hotspot position of the pressure equalizing ring pressure plate, thereby improving the accuracy of fatigue reliability calculation of the pressure equalizing ring pressure plate.

[0042] Theoretically, as long as the strength design of the pressure plate of the grading ring meets the standard requirements, the pressure plate of the grading ring will not be damaged. However, in areas with continuous and stable winds at home and abroad, fatigue fractures often occur in the pressure plate of the grading ring of high-voltage transmission lines. Such pressure plate is often less than the standard design strength of the pressure plate and fatigue fracture occurs. Therefore, in order to reduce the probability of fatigue fracture of the pressure plate of the grading ring of the transmission line in continuous and stable wind areas, it is necessary not only to check the strength of the pressure plate of the grading ring, but also to optimize the fatigue reliability design of its geometric dimensions and materials.

[0043] The present invention provides a method for optimizing the design of a pressure equalizing ring plate based on fatigue reliability evaluation, comprising the following steps: S1. Calculate the fatigue hot spot stress of the pressure plate of the pressure equalizing ring; S101, establishing a finite element model of a pressure equalizing ring; The material of the pressure equalizing ring is industrial aluminum alloy, and the specific parameters are shown in Table 1: Table 1 Material properties of pressure equalizing ring

[0044] The geometric model is established according to the structural characteristics and stress characteristics of the pressure equalizing ring. The pressure equalizing ring structure is established as a three-dimensional solid geometric model according to the solid unit, as shown in Figure 4 (a). The pressure equalizing ring body, bracket, pressure plate and bolts in the model are all modeled using solid units. The unit type is solid unit, which is used to simulate 3 D Solid structure. The unit is defined by 8 nodes, each node has 3 degrees of freedom, that is, along the node coordinate system x,y and z The unit model is a hexahedron. The geometric model is divided into units. The ring, support rod and connecting plate are all divided into hexahedron units using mapping mesh. The connection between the support rod and the pressure plate is divided into free mesh. The obtained finite element model is shown in Figure 4 (b). The boundary constraint between the pressure ring and the pressure plate is set as a fixed end connection.

[0045] S102. Calculate the wind load on the pressure equalizing ring; When the wind blows horizontally across the pressure equalizing ring, a stable Karman vortex is formed behind the pressure equalizing ring. When the Karman vortex shedding frequency is consistent with a certain order of natural frequency of the pressure equalizing ring, the pressure equalizing ring will vibrate with a certain amplitude in a breeze. The breeze vibration will have an adverse effect on the fatigue strength of the structure itself. The formation of the vortex is related to the Reynolds number and the structural cross-section. The Reynolds number is a dimensionless number that characterizes the flow of the fluid, which is expressed as follows: (1) in, R e is the Reynolds number; d is the diameter of the pressure equalizing ring; v is the wind speed.

[0046] Substituting the maximum wind speed once in n years into Formula 1, the Reynolds number of the pressure equalizing ring can be calculated. The pressure equalizing ring is a circular interface structure. For a circular cross-section structure. When the Reynolds number is less than 3×10 5 When the wind speed is in the subcritical range, the pressure equalizing ring may experience vortex-induced vibration. v cr Determine by the following formula: (2) in, T 1 is the natural vibration period of the pressure equalizing ring; S t is the Strouhal number, which is 0.2 for a circular cross section;d is the cross-sectional diameter of the pressure equalizing ring (m).

[0047] v cr The value is small, and the first vibration mode breeze resonance is very likely to occur. When the wind speed reaches the critical wind speed, the lateral wind force acting on the equalizing ring is: (3) in, ρ is the air density; μ L is the crosswind force coefficient. In the subcritical range, the lateral force coefficient of the circular cross-section structure should be 0.4. It is the vortex shedding engineering frequency, which is equal to the fundamental frequency of the pressure equalizing ring.

[0048] S103. Calculate the stress of the pressure plate of the equalizing ring.

[0049] When applying lateral wind load to the pressure equalizing ring structure, the lateral wind pressure F L The converted node pressure is applied to the ring body of the equalizing ring, and the lateral wind force applied to the node is perpendicular to the direction of the equalizing ring. The calculation parameters in formula 3 are It can be obtained by performing computational modal analysis on the pressure equalizing ring.

[0050] See also Figure 5 , the first-order vibration mode and natural vibration period of the pressure-equalizing ring plate after the modal analysis are given. The basic vibration mode of the overall structure of the pressure-equalizing ring plate is the horizontal shaking of the pressure-equalizing ring body in the direction perpendicular to the plate. By applying lateral wind loads to the pressure-equalizing ring body and performing dynamic time-history calculations, the stress distribution of the pressure-equalizing ring plate is obtained, and it can be seen that: The maximum stress of the pressure plate of the equalizing ring is located at the root bolt hole of the plate flange, such as Figure 6 As shown, fatigue fracture is most likely to occur here, which is consistent with the fracture location of the equalizing ring plate in actual engineering, indicating that the fatigue hotspot of the equalizing ring is located at the root bolt hole of the plate flange.

[0051] S2. Evaluate the fatigue reliability of the pressure equalizing ring pressure plate and optimize the design of the pressure equalizing ring pressure plate.

[0052] See also Figure 7 When the wind blows horizontally through the grading ring, the grading ring will generate breeze vibration; based on the response of breeze vibration, taking into account the differences in wind environment in various places, combined with the regional wind direction and wind speed probability distribution characteristics, the linear cumulative damage principle is used to evaluate the life of the grading ring of the high-voltage transmission line.

[0053] S201, calculating the number of wind vibrations of the pressure equalizing ring (n); The wind environment varies greatly in different regions and time periods, but there are statistical rules for wind speed and direction. In a specified region and time period, the average wind speed is considered to be a stable Gaussian random process. Many probability distribution models are used to estimate the distribution of wind speed. A large amount of field observation and test data show that the Weibull distribution is very reliable in fitting the wind speed distribution.

[0054] Commonly used two-parameter Weibull distribution function F ( v )for: (4) in, F ( v ) indicates that the wind speed is less than v The probability of k w represents the shape parameter, c w Represents the scale parameter.

[0055] Shape parameters k w According to formula 5, the calculation is simplified: (5) in, It represents the average wind speed over many years. The specific calculation is as follows: (6) Calculate the local 10m average wind speed according to formula 6 , converted into the average wind speed at the pressure equalizing ring height z: (7) Scale parameter Calculate as follows: (8) In formula 8, Γ(1+1 / k ) is the standard integral, , according to formula 4, wind speed v ϵ [ v low ~ v up The probability of ] is: (9) According to formula (8), the probability of wind speed causing breeze vibration is .

[0056] The breeze vibration of the pressure equalizing ring is not only affected by wind speed, but also by wind direction. When the angle between the wind direction and the pressure equalizing ring is between 45° and 90°, the pressure equalizing ring structure will vibrate stably. By counting the probability of wind direction when the angle between the local wind direction and the pressure equalizing ring is between 45° and 90°, the wind direction probability can be obtained. .

[0057] The joint probability of wind speed and wind direction is: (10) According to formula 10, the annual average time of breeze vibration of the equalizing ring is: t =3600×24×365× f ( v , d )(11) Vibration times of the pressure equalizing ring n i for: (12) The first vibration frequency of the pressure equalizing ring pressure plate.

[0058] S202, calculate the vibration resistance times of the pressure equalizing ring plate ( N ); Vibration resistance of pressure plate and pressure ring N The equivalent stress of the plate can be The equivalent stress of the pressure ring plate is calculated by the SN curve of the material of the pressure ring plate. Calculated according to Goodman's formula: (13) in, is the equivalent alternating stress; is the dynamic stress of the pressure plate of the equalizing ring under breeze vibration conditions; is the tensile strength of the pressure equalizing ring plate; is the static stress of the equalizing ring pressure plate.

[0059] See also Figure 8 , the dynamic stress of the pressure plate under breeze vibration condition Substitute into formula 12 to calculate the equivalent stress of the pressure ring plate , and then Substitute into the SN of the pressure ring plate to find the vibration resistance number of the pressure ring plate N ;Material of pressure ring pressure plate S - N According to the tensile strength of the pressure plate and elastic modulus are generated in the material library of the fatigue design software.

[0060] S203, calculating fatigue damage at hotspots of the pressure equalizing ring and pressure plate; See also Fig. 9 The fatigue damage of the pressure plate can be calculated using Miner's linear cumulative damage formula 14: First, the damage of the pressure plate material under the stress condition of level i is defined as D ami The damage caused by different stress levels can be linearly superimposed, thus obtaining the total damage of the pressure ring plate D am , the specific calculation is as follows: (14) in, n ( σ i ) The vibration times of the pressure equalizing ring are calculated according to formula 12; N ( σ i ) indicates the vibration resistance times of the pressure equalizing ring.

[0061] The fatigue life of the pressure plate is the inverse of its fatigue damage, that is: (15) Fatigue life of the equalizing ring plate calculated according to formula 15.

[0062] S204, calculating the fatigue reliability of the pressure equalizing ring; The fatigue reliability of the pressure equalizing ring plate is expressed as: (16) The state function in formula (16) g ( X ) is expressed as: (17) Among them, when the damage of the fatigue hot spot of the equalizing ring pressure plate approaches or exceeds the fatigue damage limit, it is in failure state.

[0063] According to formula 17, the fatigue reliability calculation limit state equation of the equalizing ring plate is expressed as: (18) in, D R is the damage limit of the pressure plate of the pressure equalizing ring ( D R ≤1); D ( X 1, X 2, X 3. X 4) is the damage value of the equalizing ring pressure plate, which is a random variable.

[0064] The key to solving the reliability of the pressure platen using Equation 16 is to construct the state function g ( X 1, X 2, X 3, X 4) and design variables X ( X 1, X 2, X 3. X 4), and to construct this mapping relationship, it is necessary to know the joint probability density function of the state function of the pressure equalizing ring and the pressure plate. This function has an implicit function relationship with the factors affecting the fatigue damage of the pressure equalizing ring and the pressure plate, which is difficult to calculate using traditional methods.

[0065] To this end, the present invention adopts RBF neural network response surface method to construct the fatigue reliability calculation state function of the equalizing ring plate g ( X ) and design variables X The relationship between them is specifically: Firstly, the sample data obtained by finite number tests or finite element calculations are used; Then, the nonlinear mapping function of the RBF neural network is used to simulate the random design variables. X With the state function g ( X ) between explicit function expressions; When establishing the RBF neural network response surface model for fatigue reliability calculation of the pressure equalizing ring plate, the random input variable cross-sectional width of the pressure equalizing ring plate ( X 1) Cross-sectional thickness of the pressure plate of the pressure equalizing ring ( X 2) Elastic modulus of the pressure plate of the pressure ring ( X 3) Wind speed ( X 4) 4 nodes as the network input layer; Limit state equation function of fatigue part of pressure ring and platen As a node in the network output layer; A hidden layer is selected, and the number of nodes in the hidden layer is determined by the resource allocation network algorithm.

[0066] The transfer function of the hidden layer unit is expressed as follows using the nonlinear radial basis function: (19) Among them, || xp-ci || is the Euclidean norm; i is the number of hidden layer nodes; For the p input samples, p =1,2,…,P, m The number of nodes in the neural network input layer;c i is the center of the Gauss function; σ is the variance of the Gauss function.

[0067] According to the structure of radial basis neural network, the output of RBF neural network is: (20) in, , p= 1,2,3,…, P,P is the total number of samples; n is the number of nodes in the output layer; c i is the center of the network hidden layer node ω ij is the connection weight from the hidden layer to the output layer; i =1,2,3,…, h is the number of hidden layer nodes; y j is the network corresponding to the input sample j The actual output of the output node.

[0068] set up d is the expected output value of the sample, and the variance of the basis function is expressed as: (twenty one) The RBF neural network learning algorithm is divided into two stages: The first is the self-organizing learning stage, which seeks the center and variance of the hidden layer basis function; The second is the tutored learning stage, which seeks the connection weights between the hidden layer and the output layer.

[0069] See also Fig.10 The parameters for training and learning the RBF neural network response surface model of the pressure equalizing ring and pressure plate in the present invention are set as follows: The learning rate is 0.1, the momentum factor is 0.9, and the learning target error is set to 10 -4 . Finally, the network topology is 4-31-1.

[0070] The RBF neural network established by the present invention gives the random design variables X ( X 1, X 2, X 3. X 4) With the state function g ( X 1, X 2, X 3. X4) between the explicit function, which can replace the finite element model of the pressure ring and plate. Since the time to calculate a function is much shorter than the finite element numerical calculation, this formula is used to improve the pressure ring and plate to improve the state function g ( X 1, X 2, X 3. X 4) Calculation efficiency, reducing the amount of calculation for reliability analysis of the pressure ring plate. In addition, this formula combines numerical analysis with stochastic simulation technology, and successfully solves the fatigue reliability analysis problem of the pressure ring plate under implicit function.

[0071] When the fatigue reliability of the pressure-equalizing ring plate is calculated using the RBF neural network, the numerical approximation method given by equation (22) is used to convert the reliability probability constraint with arbitrary distribution parameters in equation (16) into the following deterministic constraint: (twenty two) in, μ zi , σ zi is the state function g ( X )’s mean and standard deviation; B is the coefficient to be determined.

[0072] In order to ensure that equation (16) and equation (22) are equivalent, in the optimization process, B The calculation method of stepwise approximation is adopted, namely: (twenty three) in, , initial value and step length It is expressed as: (twenty four) (25) in, R i0 Design reliability of the pressure equalizing ring plate; β i0 is with R i0 Corresponding reliability indicators; Calculate the reliability of the pressure plate for the pressure equalizing ring; λi and ηi It is an adjustment parameter, which is usually around 1.

[0073] See also Fig.11 , the calculation process is as follows: S2041, its cross-sectional dimensions are taken as the initial design value X 0(X 01 , X 02 , X 03 , X 04 ), and the design allowable reliability ( R s ≥95%) as a constraint; Let the number of iterations k =0, select a suitable initial value and the initial value of the optimized design X 0( X 01 , X 02 , X 03 , X 04 ), using the response surface function mapping relationship of the RBF neural network to calculate a series of limit state functions of the pressure-equalizing ring and platen Z i value, and find its mean μ zi and variance σ zi as the data for the next step of analysis.

[0074] S2042, gradually reduce its cross-sectional size, and use RBF neural network response surface to calculate the state function Z i ; Using approximations , optimize the state functions in the design model g ( X ) is converted into deterministic constraints, and the optimization design is performed to obtain the initial optimization design point.

[0075] S2043, use the Monte-Carlo method to call this function to calculate the fatigue reliability of the pressure plate of the pressure ring R ; The Monte Carlo method is used to generate the corresponding distribution i Group random number X i ( X i1 , X i2 , X i3 , X i4 ) is substituted into the response surface function of the RBF neural network for simulation calculation to obtain the corresponding limit state function value Z i , then iThe probability analysis of the limit state function value is carried out to obtain the reliability of the pressure equalizing ring plate at the initial optimal design point. .

[0076] S2044. According to equation (24) and equation (25), the fatigue reliability of the pressure ring and plate is calculated by using the approximation method. R Gradually approaching the design allowable reliability R s , and obtain the initial optimal design point of the pressure equalizing ring pressure plate.

[0077] Determine whether the conditions are met. ,in, R s For design reliability, is the small error allowed. If the condition is met, the calculation ends. Otherwise, let n=n+1. = + , go to step S2042.

[0078] The sample data of the cross-sectional dimensions of the pressure-equalizing ring plate are uniformly selected by a comprehensive test method near the initial optimized design point, and the fatigue reliability of the pressure-equalizing ring plate is calculated again by the above method. R i And gradually make it close to the design allowable reliability R s Finally, the optimization model is used to obtain the final optimized design scheme of the pressure equalizing ring pressure plate.

[0079] S205, optimization of the pressure equalizing ring pressure plate.

[0080] The specific mathematical model for optimizing the pressure equalizing ring and pressure plate is: 1) Design variables The design variables of the pressure plate are: X ( X 1, X 2), where X 1 is the width of the pressure plate of the pressure equalizing ring, X 2 is the cross-sectional thickness of the pressure plate of the equalizing ring.

[0081] 2) Objective function The mass of the pressure plate of the pressure equalizing ring is the smallest, that is: (26) in, ρ is the density of the pressure ring plate, L 1 is the flange length of the upper pressure plate of the pressure equalizing ring, L 2 is the flange length of the lower pressure plate of the pressure equalizing ring, R is the arc radius of the pressure equalizing ring pressure plate.

[0082] 3) Constraints Fatigue reliability of pressure plate under wind load R i Greater than the fatigue reliability limit of the pressure plate of the pressure ring R s , as follows: (27) In summary, the optimization mathematical model of the pressure equalizing ring and pressure plate is further written as: (28) in, g (X) is the state function, and its design variables are X ( X 1, X 2, X 3. X 4), X 1 is the thickness of the pressure plate of the pressure equalizing ring, X 2 is the density of the pressure equalizing ring plate, X 3 is the elastic modulus of the pressure plate of the equalizing ring, X 4 is the wind speed.

[0083] It will be appreciated by those skilled in the art that various aspects of the present invention may be implemented as systems, methods or program products. Therefore, various aspects of the present invention may be specifically implemented in the following forms, namely: complete hardware implementation, complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software implementations, which may be collectively referred to herein as "circuits", "modules" or "platforms".

[0084] In still another embodiment of the present invention, a pressure equalizing ring pressure plate optimization design system based on fatigue reliability assessment is provided. The system can be used to implement the above-mentioned pressure equalizing ring pressure plate optimization design method based on fatigue reliability assessment. Specifically, the pressure equalizing ring pressure plate optimization design system based on fatigue reliability assessment includes a stress module and a design module.

[0085] Among them, the stress module establishes a finite element model of the pressure equalizing ring, applies wind load to the pressure equalizing ring plate, obtains the stress of the pressure equalizing ring plate, determines the fatigue damage of the hot spot position of the pressure equalizing ring plate under the action of wind load based on the stress of the pressure equalizing ring plate, and determines the fatigue reliability of the pressure equalizing ring plate based on the fatigue damage of the hot spot position of the pressure equalizing ring plate under the action of wind load; The design module takes the cross-sectional width and thickness of the pressure equalizing ring pressure plate as design variables and establishes an objective function with the goal of minimizing the mass of the pressure equalizing ring pressure plate. The fatigue reliability of the pressure equalizing ring pressure plate is used as a constraint condition to construct an optimization mathematical model for the pressure equalizing ring pressure plate. The final optimization design scheme of the pressure equalizing ring pressure plate is obtained using the optimization mathematical model for the pressure equalizing ring pressure plate.

[0086] In another embodiment of the present invention, a terminal device is provided, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the equalizing ring pressure plate optimization design method based on fatigue reliability evaluation, including: A finite element model of the pressure equalizing ring is established, and wind load is applied to the pressure equalizing ring pressure plate to obtain the stress of the pressure equalizing ring pressure plate. The fatigue damage of the hot spot position of the pressure equalizing ring pressure plate under the action of wind load is determined based on the stress of the pressure equalizing ring pressure plate. The fatigue reliability of the pressure equalizing ring pressure plate is determined based on the fatigue damage of the hot spot position of the pressure equalizing ring pressure plate under the action of wind load. An objective function is established with the cross-sectional width and thickness of the pressure equalizing ring pressure plate as design variables and the minimum mass of the pressure equalizing ring pressure plate as the goal. With the fatigue reliability of the pressure equalizing ring pressure plate as a constraint condition, an optimization mathematical model of the pressure equalizing ring pressure plate is constructed. The final optimization design scheme of the pressure equalizing ring pressure plate is obtained by using the optimization mathematical model of the pressure equalizing ring pressure plate.

[0087] In another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It is understandable that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device, and can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that more specific examples (non-exhaustive list) of the computer-readable storage medium here include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0088] Computer readable storage media also include data signals propagated in baseband or as part of a carrier wave, which carry readable program codes. Such propagated data signals can take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable storage medium can also be any readable medium other than a readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, device, or device. The program code contained on the readable storage medium can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above.

[0089] Program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0090] The processor may load and execute one or more instructions stored in a computer-readable storage medium to implement the corresponding steps of the above-mentioned embodiment of the method for optimizing the design of the equalizing ring platen based on fatigue reliability assessment; the processor may load and execute the following steps of one or more instructions in the computer-readable storage medium: A finite element model of the pressure equalizing ring is established, and wind load is applied to the pressure equalizing ring pressure plate to obtain the stress of the pressure equalizing ring pressure plate. The fatigue damage of the hot spot position of the pressure equalizing ring pressure plate under the action of wind load is determined based on the stress of the pressure equalizing ring pressure plate. The fatigue reliability of the pressure equalizing ring pressure plate is determined based on the fatigue damage of the hot spot position of the pressure equalizing ring pressure plate under the action of wind load. An objective function is established with the cross-sectional width and thickness of the pressure equalizing ring pressure plate as design variables and the minimum mass of the pressure equalizing ring pressure plate as the goal. With the fatigue reliability of the pressure equalizing ring pressure plate as a constraint condition, an optimization mathematical model of the pressure equalizing ring pressure plate is constructed. The final optimization design scheme of the pressure equalizing ring pressure plate is obtained by using the optimization mathematical model of the pressure equalizing ring pressure plate.

[0091] See also Fig.12 , the terminal device is a computer device. The computer device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the computer program 63 is executed by the processor 61, the equalizing ring and platen optimization design method based on fatigue reliability evaluation in the embodiment is implemented. To avoid repetition, it is not described here one by one. Alternatively, when the computer program 63 is executed by the processor 61, the functions of each model / unit in the equalizing ring and platen optimization design system based on fatigue reliability evaluation in the embodiment are implemented. To avoid repetition, it is not described here one by one.

[0092] The computer device 60 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will appreciate that Fig.12 This is only an example of the computer device 60 and does not constitute a limitation of the computer device 60. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device may also include input and output devices, network access devices, buses, etc.

[0093] The processor 61 may be a central processing unit (CPU), or other general-purpose processors, central processing units, graphics processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, data processing logic based on quantum computing, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0094] The memory 62 may be an internal storage unit of the computer device 60, such as a hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., equipped on the computer device 60.

[0095] Furthermore, the memory 62 may include both an internal storage unit of the computer device 60 and an external storage device. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store data that has been output or is to be output.

[0096] Any reference to a memory, database or other medium used in the embodiments provided in the present application may include at least one of a non-volatile and a volatile memory. Non-volatile memory may include a read-only memory (ROM), a magnetic tape, a floppy disk, a flash memory, an optical memory, a high-density embedded non-volatile memory, a resistive random access memory (ReRAM), a magnetic random access memory (MRAM), a ferroelectric random access memory (FRAM), a phase change memory (PCM), a graphene memory, etc. Volatile memory may include a random access memory (RAM) or an external cache memory, etc. As an illustration and not limitation, RAM may be in various forms, such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), etc.

[0097] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0098] See also Fig.13 The terminal device 600 is an electronic device, and the electronic device is in the form of a general computing device. The components of the electronic device may include but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including the storage unit 620 and the processing unit 610), a display unit 640, etc.

[0099] The storage unit stores program codes, which can be executed by the processing unit 610, so that the processing unit 610 performs the steps according to various exemplary embodiments of the present invention described in the above method section of this specification. For example, the processing unit 610 can perform the following steps: Figure 1 Follow the steps shown in .

[0100] The storage unit 620 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 6201 and / or a cache memory unit 6202 , and may further include a read-only memory unit (ROM) 6203 .

[0101] The storage unit 620 may also include a program / utility 6204 having a set (at least one) of program modules 6205, such program modules 6205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0102] Bus 630 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0103] The electronic device 600 may also communicate with one or more external devices 700 (e.g., keyboards, pointing devices, Bluetooth devices, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device 600, and / or communicate with any device that enables the electronic device 600 to communicate with one or more other computing devices (e.g., routers, modems, etc.). Such communication may be performed via an input / output (I / O) interface 650. Furthermore, the electronic device 600 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 660. The network adapter 660 may communicate with other modules of the electronic device 600 via a bus 630. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, etc.

[0104] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0105] See also Figure 1 , is a diagram of the fracture position of the pressure plate of a certain high-voltage power transmission project abroad under continuous wind load. From the damage, the bolt fastening position of the connecting plate is flat, and a loosening gasket is installed. The screw hole has no deformation, distortion, or bolt loosening, indicating that there is no improper construction during the construction and installation. From the fracture location, the fracture of the pressure ring is close to the screw hole of the connecting plate.

[0106] See also Figure 2 , the fracture form of the equalizing ring pressure plate is given. It can be seen that the fracture passes through the screw hole and forms an angle of 45° with the long side, which is recorded as type II fracture.

[0107] Please refer to Figure 3, which shows the failure morphology of the equalizing ring plate. It can be seen that there are several crack source areas at the edge of the sample fracture, indicating that the sample cracks from the edge, and the cracks gradually extend inward until it breaks, as shown in Figure 3 (a). River-like patterns appear in the internal area of ​​the fracture, and secondary cracks exist, indicating that the sample was subjected to a large load before breaking and the fracture process was fast. In addition, a small amount of fatigue bands can be observed in some areas, as shown in Figure 3 (b), which is a typical morphological feature of fatigue fracture, indicating that fatigue fracture occurs in some areas of the sample under the action of alternating loads. Based on the above analysis, it is believed that the sample fractures in the form of overload / fatigue composite under multi-directional loads.

[0108] Please refer to Figure 4. Figure 4 (a) shows the three-dimensional solid geometric model of the pressure equalizing ring. The pressure equalizing ring body, bracket, pressure plate and bolts in the model are all modeled using solid units. The unit type is solid unit, which is used to simulate 3 D Solid structure. The unit is defined by 8 nodes, each node has 3 degrees of freedom, that is, along the node coordinate system x,y and z The unit model is a hexahedron. The geometric model is divided into units. The ring, support rod and connecting plate are all divided into hexahedron units using mapping mesh. The connection between the support rod and the pressure plate is divided into free mesh. The obtained finite element model is shown in Figure 4 (b). The boundary constraint between the pressure ring and the pressure plate is set as a fixed end connection.

[0109] See also Figure 5 , the first-order vibration mode and natural vibration period of the pressure equalizing ring after the calculated modal analysis are given. It can be seen that the basic vibration mode of the overall structure of the pressure equalizing ring is the horizontal shaking of the pressure equalizing ring body in the direction perpendicular to the pressure plate.

[0110] See also Figure 6, the location of the fatigue hotspot of the equalizing ring is given. It can be seen that the maximum stress of the equalizing ring is located at the root bolt hole of the pressure plate flange, where fatigue fracture is most likely to occur. This is consistent with the fracture location of the equalizing ring pressure plate in actual engineering, indicating that the fatigue hotspot of the equalizing ring is located at the root bolt hole of the pressure plate flange.

[0111] See also Figure 7 , the calculation process of fatigue damage assessment of the pressure equalizing ring plate is given. The analysis process is as follows: first, the joint probability density of wind speed and wind direction is calculated, and then the linear damage theory is used to calculate the cumulative damage of the pressure equalizing ring plate. On this basis, the fatigue damage of the pressure equalizing ring plate is evaluated.

[0112] See also Figure 8 The SN curve of the pressure-equalizing ring plate is given, which can be used to evaluate the fatigue damage of the pressure-equalizing ring plate.

[0113] See also Fig. 9 , and the fatigue life of the equalizing ring and pressure plate is given.

[0114] See also Fig.10 , the topological structure of the fatigue reliability prediction model of the pressure ring plate is given. The input layer of the prediction model has four nodes, namely: the cross-sectional width of the pressure ring plate ( X 1) Cross-sectional thickness of the pressure plate of the pressure equalizing ring ( X 2) Elastic modulus of the pressure plate of the pressure ring ( X 3) Wind speed ( X 4); Limit state equation function of fatigue part of pressure ring and platen Z As a node of the network output layer; select a hidden layer, the number of nodes in the hidden layer can be determined by the resource allocation network algorithm. The transfer function of the hidden layer unit adopts a nonlinear radial basis function.

[0115] To sum up, the present invention provides an optimization design method and system for a pressure equalizing ring pressure plate based on fatigue reliability assessment, which greatly reduces the calculation amount of fatigue reliability analysis of the pressure equalizing ring pressure plate, ensures the safe and stable operation of high-voltage transmission lines, significantly improves the calculation efficiency of fatigue damage at fatigue hot spots of the pressure equalizing ring pressure plate, and provides sufficient sample data for fatigue reliability calculation of fatigue hot spots of the pressure equalizing ring pressure plate, thereby improving the accuracy of fatigue reliability calculation of the pressure equalizing ring pressure plate.

[0116] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0117] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0118] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0119] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0120] 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 on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0121] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0122] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0123] The present application is described with reference to the 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 process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, 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 device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0124] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0125] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0126] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. An optimization design method for a pressure equalizing ring plate based on fatigue reliability assessment is characterized in that: The following steps are involved: A finite element model of the pressure equalizing ring is established, and wind load is applied to the pressure equalizing ring plate to obtain the stress of the pressure equalizing ring plate. Based on the stress of the pressure equalizing ring plate, fatigue damage at the hot spot position of the pressure equalizing ring plate under wind load is determined. Based on the fatigue damage at the hot spot position of the pressure equalizing ring plate under wind load, fatigue reliability of the pressure equalizing ring plate is determined. An objective function is established with the cross-sectional width and thickness of the pressure equalizing ring pressure plate as design variables and the minimum mass of the pressure equalizing ring pressure plate as the goal. An optimization mathematical model for the pressure equalizing ring pressure plate is constructed with the fatigue reliability of the pressure equalizing ring pressure plate as a constraint condition. The final optimized design scheme of the pressure equalizing ring pressure plate is obtained using the optimization mathematical model for the pressure equalizing ring pressure plate.

2. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability evaluation according to claim 1 is characterized in that: Wind load The calculation is as follows: in, ρ is the air density, v cr is the wind speed, μ L is the cross-wind force coefficient, is the vortex shedding engineering frequency, is the cross-sectional diameter of the pressure equalizing ring, For time.

3. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 1 is characterized in that: The stress of the equalizing ring pressure plate is located at the bolt hole position at the root of the pressure plate flange.

4. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 1 is characterized in that: The vibration frequency of the pressure plate of the pressure ring in the finite element model of the pressure ring n i for: in, is the annual vibration time of the pressure equalizing ring, It is the first-order vibration frequency of the pressure equalizing ring.

5. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 1 is characterized in that: The vibration resistance of the pressure plate of the pressure ring in the finite element model of the pressure ring N for: The dynamic stress of the pressure plate under breeze vibration condition Substitute the vibration times of the pressure equalizing ring to calculate the equivalent stress of the pressure equalizing ring pressure plate. , and then the equivalent stress Substitute into the SN of the pressure ring plate to find the vibration resistance number of the pressure ring plate N ;Material of pressure ring pressure plate S - N According to the tensile strength of the pressure plate and elastic modulus are generated in the material library of the fatigue design software.

6. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 5 is characterized in that: Equivalent stress The calculation is as follows: in, is the equivalent alternating stress; is the dynamic stress of the pressure plate of the equalizing ring under breeze vibration conditions; is the tensile strength of the pressure equalizing ring plate; is the static stress of the equalizing ring pressure plate.

7. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 1 is characterized in that: The fatigue damage of the hot spot position of the pressure equalizing ring plate is as follows: The damage of the pressure plate material under the stress condition of level i is defined as D ami The damage caused by different stress levels can be linearly superimposed, thus obtaining the total damage of the pressure ring plate D am , fatigue life of the pressure plate Total damage D am The reciprocal of .

8. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 7 is characterized in that: Total damage of pressure plate D am for: in, n ( σ i ) The vibration frequency of the pressure equalizing ring, N ( σ i ) indicates the vibration resistance times of the pressure equalizing ring.

9. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 1 is characterized in that: The fatigue reliability of the equalizing ring plate is as follows: The cross-sectional dimensions of the pressure plate of the pressure equalizing ring are taken as the initial design value. X 0, and the design reliability R s ≥95% as a constraint; Gradually reduce the cross-sectional size of the pressure plate of the pressure equalizing ring, and use the RBF neural network response surface to calculate the state function Z i ; Calling the state function using the Monte-Carlo method Z i Calculation of the reliability of the pressure plate R ; According to the approximation method, the reliability of the pressure plate of the pressure equalizing ring R Gradually approaching the design allowable reliability R s , get the initial optimal design point of the pressure equalizing ring and pressure plate; The sample data of the cross-sectional dimensions of the pressure-equalizing ring and the pressure plate are uniformly selected by comprehensive test method near the initial optimized design point, and the reliability of the pressure-equalizing ring and the pressure plate is calculated again. R i And gradually make it close to the design allowable reliability R s ; Finally, the optimal design scheme of the pressure equalizing ring pressure plate is obtained by using the optimization mathematical model of the pressure equalizing ring pressure plate.

10. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 9 is characterized in that: Calculating state function using RBF neural network response surface Z i Specifically: Sample data obtained by finite number tests or finite element calculations; Then, the nonlinear mapping function of the RBF neural network is used to simulate the random design variables. X With the state function g ( X ) between explicit function expressions; When establishing the RBF neural network response surface model of the pressure equalizing ring plate, the random input variable cross-sectional width of the pressure equalizing ring plate is firstly X 1. Cross-sectional thickness of the pressure plate of the pressure equalizing ring X 2. Elastic modulus of the pressure plate of the pressure ring X 3. Wind speed X 4 as 4 nodes of the network input layer; Limit state equation function of fatigue part of pressure ring and platen As a node in the network output layer; A hidden layer is selected, and the number of nodes in the hidden layer is determined by the resource allocation network algorithm.

11. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 10, characterized in that: Limit state equation function of fatigue part of pressure ring and platen for: in, D R is the damage limit of the pressure ring plate ( D R ≤1); D ( X 1, X 2, X 3. X 4) is the damage value of the equalizing ring pressure plate.

12. The method for optimizing the design of the pressure equalizing ring and pressure plate based on fatigue reliability assessment according to claim 9 is characterized in that: The optimization mathematical model of the pressure equalizing ring and pressure plate is as follows: in, g (X) is the state function, X 1 is the cross-sectional width of the pressure plate of the pressure equalizing ring, X 2 is the cross-sectional thickness of the pressure plate of the pressure equalizing ring, R i is the reliability of the pressure-equalizing ring plate under wind load, R s is the fatigue reliability limit of the pressure plate of the equalizing ring, for, is the flange length of the upper pressure plate of the pressure equalizing ring, is the flange length of the lower pressure plate under the pressure equalizing ring, is the arc radius of the pressure plate of the pressure equalizing ring, is the density of the equalizing ring plate.

13. A pressure equalizing ring plate optimization design system based on fatigue reliability assessment, characterized in that: include: Stress module, establishes a finite element model of the pressure equalizing ring, applies wind load to the pressure equalizing ring plate, obtains the stress of the pressure equalizing ring plate, determines the fatigue damage of the hot spot position of the pressure equalizing ring plate under the action of wind load based on the stress of the pressure equalizing ring plate, and determines the fatigue reliability of the pressure equalizing ring plate based on the fatigue damage of the hot spot position of the pressure equalizing ring plate under the action of wind load; The design module takes the cross-sectional width and thickness of the pressure equalizing ring pressure plate as design variables and establishes an objective function with the goal of minimizing the mass of the pressure equalizing ring pressure plate. The fatigue reliability of the pressure equalizing ring pressure plate is used as a constraint condition to construct an optimization mathematical model for the pressure equalizing ring pressure plate. The final optimization design scheme of the pressure equalizing ring pressure plate is obtained using the optimization mathematical model for the pressure equalizing ring pressure plate.

14. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform the method of any one of claims 1 to 12.

15. A computing device, characterized in that: include: One or more processors, a memory and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include steps for executing the method according to any one of claims 1 to 12.

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