Cable laying simulation system based on finite element

Abstract

The invention relates to the technical field of electrical simulation, in particular to a finite element-based cable laying simulation system, which comprises a cable parameter acquisition module, a geometric material modeling module, a finite element unit discrete module, a load boundary determination module and a mechanical result calculation module. According to the method, structural parameters such as cable conductor twisting pitch and environmental parameters such as ground vehicle weight are collected, conductor equivalent stiffness parameters are calculated to construct a practical structural material model, and unit discrete density is adjusted according to the bending radius of a laying path to generate an adaptive discrete unit model; ground traffic load is converted into cable equivalent pressure to determine load boundary parameters, and mechanical data is calculated in combination with a fatigue damage threshold, so that the simulation process is integrated with the influence of cable structural characteristics and actual environment, the fitting degree of a simulation result and a real laying working condition is improved, and more accurate data support is provided for safety assessment of a cable laying scheme.

Description

Technical Field

[0001] This invention relates to the field of electrical simulation technology, and in particular to a cable laying simulation system based on the finite element method. Background Technology

[0002] The field of electrical simulation technology encompasses the simulation, analysis, and prediction of electrical equipment and related electrical processes. Its core content involves using mathematical modeling and numerical computation to reproduce the operating state, physical characteristics, and responses under various operating conditions of electrical systems in a virtual environment. The overall technological scope covers multiple aspects, including performance verification during the electrical equipment design phase, fault simulation during operation, and parameter optimization under different operating conditions. By constructing simulation models that conform to actual physical laws, it provides data support and theoretical basis for product development, engineering applications, and technological improvements in the electrical field. It involves multiple sub-application scenarios such as power systems, electrical equipment manufacturing, and electrical installation engineering. It enables technicians to identify design flaws and evaluate system performance in advance without actually building physical prototypes, thereby reducing R&D costs and engineering risks. One type of cable laying simulation system based on the finite element method (FEM) is a technical system specifically designed to simulate the physical behavior and state of cables during the laying process. It encompasses mechanical analysis during cable laying path planning, stress and strain calculations during cable laying, and deformation simulation of cables under different laying environments. Specifically, it establishes a geometric and material property model of the cable, discretizes the cable into multiple elements based on the principles of finite element analysis, determines the boundary and load conditions during cable laying, and uses finite element solving algorithms to perform mechanical calculations on the discretized cable elements. This yields the stress distribution, strain, and deformation data of the cable during laying, thereby simulating the cable laying process.

[0003] Existing technologies only establish cable geometric and material property models, discretize elements based on the finite element principle, and determine boundary and load conditions for mechanical calculations. They do not consider the influence of structural characteristics such as cable conductor stranding on mechanical properties, nor do they take into account actual environmental loads such as ground traffic above the laying path. This results in deviations between the constructed model and the real cable structure and actual laying stress scenarios, and the simulation results are not accurate enough. For example, in scenarios where the cable is laid in a bending manner or there is traffic load on the ground, it is difficult to accurately reflect the actual stress and strain state of the cable, affecting the reliability of the safety assessment of the laying scheme. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a cable laying simulation system based on the finite element method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a cable laying simulation system based on finite element method, the system comprising a cable parameter acquisition module for acquiring cable conductor strand pitch, number of strands, minimum bending radius and fatigue damage threshold, and simultaneously acquiring the weight of ground vehicles and traffic frequency above the laying path, and integrating them to generate a set of basic cable parameters.

[0006] The geometric material modeling module calculates the conductor stranding helix angle and total cross-sectional area based on the basic parameters, obtains the conductor's equivalent stiffness parameters through coupling calculations, and associates them with the cable's geometric coordinates to construct a cable structural material model.

[0007] The finite element discretization module calculates the actual bending radius of the laying path segment by segment based on the structural material model and compares it with the minimum bending radius. If the actual value is too small, the element discretization density is increased. Then, the mesh is divided according to the adjusted density to generate the cable discrete element model.

[0008] The load boundary determination module calculates the cumulative pressure of a single vehicle type based on vehicle weight and traffic frequency, sums them to obtain the total cumulative pressure on the ground, and then converts it into the equivalent pressure at the cable laying depth through the soil force transmission coefficient, finally generating the cable load boundary parameters.

[0009] The mechanical results calculation module calculates the stress value of the discrete element under equivalent pressure and compares it with the fatigue damage threshold. If the stress value exceeds the threshold, the cumulative fatigue damage value is obtained by multiplying the stress value by the number of cycles, and then recalculated. Finally, the mechanical simulation results of cable laying are output.

[0010] As a further embodiment of the present invention, the cable basic parameter set includes cable conductor strand pitch, number of cable conductor strands, minimum bending radius of the cable, weight of ground vehicles, frequency of ground vehicle traffic, and cable fatigue damage threshold. The cable structural material model includes conductor equivalent stiffness parameters, cable geometric coordinate data, total conductor cross-sectional area, and conductor strand helix angle. The cable discrete element model includes adjusted element discrete density data, segmented laying path element division results, and element data corresponding to the actual bending radius of each segment. The cable load boundary parameters include single vehicle type cumulative pressure, total ground cumulative pressure, equivalent pressure at cable laying depth, and soil force transmission coefficient. The cable laying mechanical simulation results include element stress value, element strain data, cumulative fatigue damage value, and mechanical calculation data corresponding to the number of stress cycles.

[0011] As a further embodiment of the present invention, the cable parameter acquisition module includes a cable parameter acquisition submodule and a parameter set generation submodule; The cable parameter acquisition submodule acquires the cable conductor strand pitch, number of conductor strands, minimum bending radius of the cable, weight of ground vehicles above the laying path, frequency of vehicle traffic, and cable fatigue damage threshold to obtain cable parameter items. The parameter set generation submodule integrates conductor strand pitch, number of conductor strands, minimum bending radius of cable, ground vehicle weight, vehicle traffic frequency, and cable fatigue damage threshold based on cable parameter items to generate a basic set of cable parameters.

[0012] As a further embodiment of the present invention, the geometric material modeling module includes an equivalent stiffness calculation submodule and a structural model generation submodule; The equivalent stiffness calculation submodule calls the cable basic parameter set, extracts the conductor strand pitch to calculate the conductor strand helix angle, extracts the product of the number of conductor strands and the cross-sectional area of ​​a single conductor to obtain the total cross-sectional area of ​​the conductor, and couples the conductor strand helix angle with the total cross-sectional area of ​​the conductor to obtain the conductor equivalent stiffness parameter. The structural model generation submodule, based on the conductor's equivalent stiffness parameters, associates them with the cable's geometric coordinates, and integrates the conductor's equivalent stiffness parameters and the cable's geometric coordinate information to generate a cable structural material model.

[0013] As a further embodiment of the present invention, the finite element discretization module includes a bending radius calculation submodule, an element density adjustment submodule, and a discrete model generation submodule; The bending radius calculation submodule uses the cable structure material model to call the minimum bending radius of the cable, divides the cable laying path into segments, calculates the actual bending radius of each segment, and obtains the bending radius value of each segment. The process involves calling the bending radius values ​​of each segment, comparing the actual bending radius of each segment with the minimum bending radius of the cable, setting the unit discrete density as the base value when the actual bending radius is greater than the minimum bending radius, and increasing the corresponding proportion on the base value when it is less than the minimum bending radius to obtain the adjusted unit density. The discrete model generation submodule divides the cable structure material model into units based on the adjusted unit density, integrates the unit information after division, and generates a discrete unit model of the cable.

[0014] As a further embodiment of the present invention, the load boundary determination module includes a cumulative pressure calculation submodule and an equivalent pressure conversion submodule; The cumulative pressure calculation submodule, for the cable discrete unit model, calls the ground vehicle weight and vehicle traffic frequency, multiplies the vehicle weight and traffic frequency to obtain the cumulative pressure of a single vehicle type, and sums up the cumulative pressure of all single vehicle types to obtain the total ground cumulative pressure. The equivalent pressure conversion submodule converts the total cumulative ground pressure according to the soil force transmission coefficient to obtain the equivalent pressure at the cable laying depth and generates the cable load boundary parameters.

[0015] As a further aspect of the present invention, the mechanical result calculation module includes an element stress calculation submodule and a mechanical result generation submodule; The unit stress calculation submodule calls the cable discrete unit model and cable load boundary parameters to calculate the unit stress value of the discrete unit under equivalent pressure and obtain the unit stress data. The mechanical results generation submodule is based on the unit stress data. It calls the cable fatigue damage threshold. When the unit stress value is less than the threshold, it directly outputs the unit stress-strain data. When it is greater than the threshold, it multiplies the unit stress value with the number of stress cycles to obtain the cumulative fatigue damage value, substitutes it into the mechanical equation, and recalculates to generate the mechanical simulation results of cable laying.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are as follows: This invention collects structural parameters such as the stranding pitch of cable conductors and environmental parameters such as the weight of ground vehicles, calculates the equivalent stiffness parameters of the conductors to construct a realistic structural material model, adjusts the discrete density of the units according to the bending radius of the laying path to generate a suitable discrete unit model, converts ground traffic load into equivalent cable pressure to determine load boundary parameters, and combines fatigue damage threshold calculations with mechanical data to incorporate cable structural characteristics and actual environmental influences into the simulation process, improving the fit between the simulation results and real laying conditions, and providing more accurate data support for the safety assessment of cable laying schemes. Attached Figure Description

[0017] Figure 1 This is a flowchart of the cable laying simulation system of the present invention; Figure 2 This is a flowchart of the cable parameter acquisition module of the present invention; Figure 3 This is a flowchart of the geometric material modeling module of the present invention; Figure 4 This is a flowchart of the finite element unit discretization module of the present invention; Figure 5 This is a flowchart of the load boundary determination module of the present invention; Figure 6 This is a flowchart of the mechanical result calculation module of the present invention. Detailed Implementation

[0018] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0019] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0020] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0021] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0022] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0023] Please see Figure 1 This invention provides a technical solution: a cable laying simulation system based on the finite element method, the system comprising: The cable parameter acquisition module obtains the cable conductor strand pitch, number of conductor strands, minimum bending radius of the cable, weight of ground vehicles above the laying path, frequency of vehicle traffic, cable fatigue damage threshold, and generates a set of basic cable parameters. The geometric material modeling module is based on the cable basic parameter set. It calls the conductor strand pitch to calculate the conductor strand helix angle, calls the number of conductor strands and the cross-sectional area of ​​a single conductor to perform a product operation to obtain the total cross-sectional area of ​​the conductor, couples the conductor strand helix angle and the total cross-sectional area of ​​the conductor to obtain the conductor equivalent stiffness parameter, and associates the conductor equivalent stiffness parameter with the cable geometric coordinates to generate the cable structural material model. The finite element discretization module, based on the cable structure material model, calls the minimum bending radius of the cable, divides the cable laying path into segments, calculates the actual bending radius of each segment, compares the actual bending radius of each segment with the minimum bending radius of the cable, and if the actual bending radius is greater than the minimum bending radius of the cable, sets the element discretization density as the base value; if the actual bending radius is less than the minimum bending radius of the cable, increases the element discretization density, divides the cable structure material model into elements according to the adjusted density, and generates a cable discrete element model. The load boundary determination module, targeting the cable discrete element model, calls upon the weight of ground vehicles and the frequency of vehicle traffic. It multiplies the vehicle weight and traffic frequency to obtain the cumulative pressure for each vehicle type, sums the cumulative pressures of all vehicle types to obtain the total cumulative ground pressure, and converts this total cumulative ground pressure into the equivalent pressure at the cable laying depth according to the soil force transmission coefficient, generating cable load boundary parameters. The mechanical results calculation module calls upon the cable discrete element model, cable load boundary parameters, and cable fatigue damage threshold to calculate the element stress value of the discrete element under equivalent pressure. It compares the element stress value with the cable fatigue damage threshold. If the element stress value is less than the threshold, it directly outputs the element stress-strain data; if the element stress value is greater than the threshold, it multiplies the element stress value by the number of stress cycles to obtain the cumulative fatigue damage value, substitutes it into the mechanical equations, and recalculates to generate the cable laying mechanical simulation results.

[0024] The cable basic parameter set includes cable conductor strand pitch, number of cable conductor strands, minimum bending radius of cable, ground vehicle weight, ground vehicle traffic frequency, and cable fatigue damage threshold. The cable structural material model includes conductor equivalent stiffness parameters, cable geometric coordinate data, total conductor cross-sectional area, and conductor strand helix angle. The cable discrete element model includes adjusted element discrete density data, segmented laying path element division results, and element data corresponding to the actual bending radius of each segment. The cable load boundary parameters include single vehicle type cumulative pressure, total ground cumulative pressure, equivalent pressure at cable laying depth, and soil force transmission coefficient. The cable laying mechanical simulation results include element stress values, element strain data, cumulative fatigue damage values, and mechanical calculation data corresponding to the number of stress cycles.

[0025] Please see Figure 2 The cable parameter acquisition module includes a cable parameter acquisition submodule and a parameter set generation submodule; The cable parameter acquisition submodule acquires the cable conductor strand pitch, number of conductor strands, minimum bending radius of the cable, weight of ground vehicles above the laying path, frequency of vehicle traffic, and cable fatigue damage threshold to obtain cable parameter items. The cable parameter acquisition submodule reads data from the user input interface or a preset database. When reading the conductor strand pitch, it obtains a specific value by measuring the axial length of a complete helix of the stranded conductor. For example, the measured pitch value for a certain type of cable is 0.25 meters. When reading the conductor strand count, it obtains an integer value by counting the number of independent metal wires in the conductor. For example, a certain cable is made of 48 copper wires. When reading the minimum bending radius of the cable, it obtains a fixed value according to the cable specification. For example, the minimum bending radius of a certain cable specification specifies 1.2 meters. When reading the weight of ground vehicles, it obtains typical vehicle axle load data through a traffic monitoring system. For example, it collects data on passing trucks weighing 10 tons, 15 tons, and 20 tons. When reading the frequency of vehicle passage, it counts the number of vehicles passing per unit time using an inductive loop counter. For example, it counts the number of times three types of trucks pass per hour: 5, 3, and 2 times, respectively. When reading the cable fatigue damage threshold, it obtains the critical stress value of the cable insulation material through material testing. For example, the fatigue damage threshold of this type of cable is measured to be 120 MPa through a cyclic bending test. Finally, the six parameters are compiled into a parameter list.

[0026] The parameter set generation submodule integrates conductor strand pitch, number of conductor strands, minimum bending radius of cable, ground vehicle weight, vehicle traffic frequency, and cable fatigue damage threshold based on cable parameter items to generate a basic set of cable parameters.

[0027] The parameter set generation submodule receives conductor strand pitch parameters (e.g., 0.25 meters), conductor strand count parameters (e.g., 48 strands), minimum cable bending radius parameters (e.g., 1.2 meters), ground vehicle weight parameters (e.g., 10,000 kg, 15,000 kg, 20,000 kg), vehicle traffic frequency parameters (e.g., 5 times / hour, 3 times / hour, 2 times / hour), and cable fatigue damage threshold parameters (e.g., 120 MPa). It then performs a positional multiplication operation on the vehicle weight and traffic frequency, calculating 1000... Multiplying 0 kg by 5 cycles / hour yields 50,000 kg·cycle / hour; multiplying 15,000 kg by 3 cycles / hour yields 45,000 kg·cycle / hour; multiplying 20,000 kg by 2 cycles / hour yields 40,000 kg·cycle / hour. Adding these three products together gives a total cumulative pressure value of 135,000 kg·cycle / hour. Arrange all parameters in a pre-defined order into a structured data set. The pitch parameter is placed in the first field, the number of strands in the second field, the minimum bending radius in the third field, the three weight-frequency product values ​​in the fourth to sixth fields, the fatigue damage threshold in the seventh field, and the total cumulative pressure value in the eighth field, generating a cable basic parameter set containing eight fields.

[0028] Please see Figure 3 The geometric material modeling module includes an equivalent stiffness calculation submodule and a structural model generation submodule; The equivalent stiffness calculation submodule calls the cable basic parameter set, extracts the conductor strand pitch to calculate the conductor strand helix angle, extracts the product of the number of conductor strands and the cross-sectional area of ​​a single conductor to obtain the total cross-sectional area of ​​the conductor, and couples the conductor strand helix angle with the total cross-sectional area of ​​the conductor to obtain the conductor equivalent stiffness parameters. The equivalent stiffness calculation submodule reads the conductor strand pitch parameter from a specified field in the cable foundation parameter set, for example, a strand pitch value of 0.25 meters; it also reads the conductor strand number parameter, for example, a strand number of 48; and it reads the single-strand conductor cross-sectional area parameter from the material database, for example, a single-strand copper conductor cross-sectional area of ​​0.8 square millimeters. Then, it calculates the equivalent stiffness using the formula... Calculate the twisted helix angle, where The representative twist pitch is 0.25 meters. The diameter of the conductor is calculated by inversely using the number of strands and the area of ​​each strand. For example, based on 48 strands and a single strand area of ​​0.8 square millimeters, the total area is calculated to be 38.4 square millimeters, which translates to a diameter of approximately 7 millimeters. Substituting these values ​​into the formula yields the helix angle. Approximately 0.15 radians. Multiplying the number of strands (48) by the area of ​​a single strand (0.8 square millimeters) yields a total conductor cross-sectional area of ​​38.4 square millimeters. A coupling relationship between the helix angle and the total cross-sectional area is then established. ,in For equivalent stiffness, The elastic modulus of copper is taken as 110 gigapascals. The total cross-sectional area is 38.4 square millimeters. With a helix angle of 0.15 radians, the equivalent stiffness value is calculated to be 4150 kN, thus completing the generation of the conductor's equivalent stiffness parameters.

[0029] The structural model generation submodule takes the conductor's equivalent stiffness parameters, associates them with the cable's geometric coordinates, and merges the conductor's equivalent stiffness parameters and the cable's geometric coordinate information to generate a cable structural material model.

[0030] The structural model generation submodule receives the conductor equivalent stiffness parameters from the equivalent stiffness calculation submodule. For example, if the received equivalent stiffness value is 4150 kN, it extracts the cable geometric coordinate parameters from the cable geometry database, including the sequence of three-dimensional coordinate points of the cable axis. For example, it obtains continuous coordinate points (0,0,0), (1,0,-0.2), (2,0,-0.5), etc., on the laying path. It establishes a mapping relationship between the equivalent stiffness parameters and each geometric coordinate point. For example, it associates the stiffness value of 4150 kN with the coordinate point (0,0,0) and the same stiffness value with the coordinate point (1,0,-0.2). It binds the stiffness parameters to the geometric mesh nodes through a data structure. For example, it creates a data table containing four fields: coordinates (x,y,z) and stiffness k. It performs a stiffness assignment operation on each mesh node. For example, it writes the stiffness value of 4150 kN to each of the nodes numbered 1 to 100. It generates a structured data set containing the correspondence between geometric coordinates and material stiffness, forming the cable structure material model.

[0031] Please see Figure 4 The finite element discretization module includes a bending radius calculation submodule, an element density adjustment submodule, and a discrete model generation submodule. The bending radius calculation submodule uses the cable structure material model to call the minimum bending radius of the cable, divides the cable laying path into segments, calculates the actual bending radius of each segment, and obtains the bending radius value of each segment. The bending radius calculation submodule reads the geometric coordinate sequence from the cable structure material model, for example, obtaining three consecutive coordinate points: P1(0,0,0), P2(2,1,0), and P3(5,3,0). It divides these three adjacent points into a calculation segment; for example, P1P2P3 can be divided into a bending segment. The bending radius at the intermediate point P2 is calculated using vector operations, specifically the calculation vector V. 12 Given (2,1,0), vector V 23 Given (3,2,0), calculate the cosine of the angle θ between the two vectors, substitute it into the curvature formula to obtain the curvature κ, and take its reciprocal to obtain the actual bending radius R. a =1 / κ, for example, the calculated bending radius of this section is 3.5 meters, and the minimum bending radius R is read from the cable foundation parameter set. min The parameters, such as a reading value of 1.2 meters, are used to repeat the steps of reading the three-point coordinates, calculating the vector, and solving the curvature for each segment. For example, the bending radius is calculated to be 2.8 meters for subsequent points P2P3P4 and 0.9 meters for P3P4P5. Finally, the set of bending radius values ​​for each segment is output as {3.5, 2.8, 0.9} meters.

[0032] Call the bending radius values ​​of each segment, compare the actual bending radius of each segment with the minimum bending radius of the cable. If the actual bending radius is greater than the minimum bending radius, set the discrete density of the unit to the base value. If it is less than the base value, increase the corresponding proportion to obtain the adjusted unit density. The discrete density adjustment module reads the set of segmented bending radii {3.5, 2.8, 0.9} meters, reads the minimum bending radius threshold of 1.2 meters, sets the basic discrete density parameter ρ0 = 10 units / meter, and establishes the discrete density adjustment rule: when R a ≥k·R min When ρ0 is used, when R a <k·R min The formula ρ0·(1+δ) is used, where the proportionality coefficient k is 1.5 and the density enhancement coefficient δ is 1.2. A comparison operation is performed on the first segment with a bending radius of 3.5 meters, and 1.5×1.2=1.8 meters is calculated. Since 3.5>1.8, the discrete density of this segment is determined to be 10 units / meter. A comparison operation is performed on the second segment with a bending radius of 2.8 meters, and 2.8>1.8 is calculated. The discrete density of this segment is determined to be 10 units / meter. A comparison operation is performed on the third segment with a bending radius of 0.9 meters, and 0.9<1.8 is calculated. The adjusted density is 10×(1+1.2)=22 units / meter. A discrete density configuration table {10,10,22} units / meter is generated for each segment.

[0033] The discrete model generation submodule divides the cable structure material model into elements based on the adjusted element density, integrates the element information after division, and generates a discrete element model of the cable.

[0034] The discrete model generation submodule reads the geometric data of the cable structure material model, including the coordinate point sequence and stiffness parameters. It reads the discrete density configuration table {10,10,22} units / meter, calculates the number of units (36) for the first segment (3.6 meters long) at a density of 10 units / meter, and evenly inserts 35 new nodes within the segment, assigning material stiffness values ​​to each node. For the second segment (3.2 meters long), calculates the number of units (32) at a density of 10 units / meter, inserts 31 new nodes and assigns stiffness. For the third segment (1.5 meters long), calculates the number of units (33) at a density of 22 units / meter, inserts 32 new nodes and assigns stiffness. It integrates the node coordinates, unit connection relationships, and material parameters generated from all segments to construct a structured dataset containing 101 nodes and 100 beam elements.

[0035] Please see Figure 5 The load boundary determination module includes a cumulative pressure calculation submodule and an equivalent pressure conversion submodule. The cumulative pressure calculation submodule, for the cable discrete unit model, calls the ground vehicle weight and vehicle traffic frequency, multiplies the vehicle weight and traffic frequency to obtain the cumulative pressure of a single vehicle type, and sums the cumulative pressure of all single vehicle types to obtain the total ground cumulative pressure; The cumulative pressure calculation submodule extracts ground vehicle weight parameters from the cable foundation parameter set. For example, it extracts weight data for three vehicle types: 12,000 kg, 18,000 kg, and 22,000 kg. It also extracts corresponding vehicle traffic frequency parameters, such as the number of times each vehicle passes per hour: 8, 5, and 3 times. For the first vehicle type, it performs a weight-frequency multiplication operation, calculating 12,000 kg multiplied by 8 times / hour to obtain 96,000 kg·times / hour. For the second... For the first vehicle type, the weight and frequency multiplication operation is performed. 18,000 kg is multiplied by 5 times / hour to get 90,000 kg·times / hour. For the third vehicle type, the weight and frequency multiplication operation is performed. 22,000 kg is multiplied by 3 times / hour to get 66,000 kg·times / hour. The three products are then added together to get 96,000 + 90,000 + 66,000, resulting in a total of 252,000 kg·times / hour. This total value is recorded as the total cumulative ground pressure parameter.

[0036] The equivalent pressure conversion submodule converts the total cumulative ground pressure according to the soil force transmission coefficient to obtain the equivalent pressure at the cable laying depth and generates the cable load boundary parameters.

[0037] The equivalent pressure conversion submodule reads the total cumulative ground pressure value of 252,000 kg·h output from the cumulative pressure calculation submodule, obtains the soil force transmission coefficient from the soil parameter database, and determines this coefficient based on the cable laying depth and soil type. For example, for sandy clay at a burial depth of 1.5 meters, the force transmission coefficient γ is taken as 0.15. The equivalent pressure calculation formula is then established. ,in Indicates the equivalent pressure at the cable laying depth. This indicates a total cumulative ground pressure of 252,000 kg·h. This indicates a soil force transfer coefficient of 0.15. The pressure distribution area is taken as 10 square meters. Substituting the values, we get... The calculation result is calculated in kilograms per square meter per hour. This result is then correlated with the node coordinates of the cable discrete element model. For example, an equivalent pressure value of 3780 is assigned to all nodes of a cable segment with a depth of 1.5 meters, generating a load boundary parameter set containing node numbers, spatial coordinates, and equivalent pressure values.

[0038] Please see Figure 6 The mechanical results calculation module includes an element stress calculation submodule and a mechanical results generation submodule; The element stress calculation submodule calls the cable discrete element model and cable load boundary parameters to calculate the element stress value of the discrete element under equivalent pressure and obtain the element stress data. The element stress calculation submodule reads the node coordinates and element connection information of the cable discrete element model. For example, it obtains the element E1 composed of nodes N1(0,0,0) and N2(1,0,0). It reads the equivalent pressure values ​​from the cable load boundary parameters, such as the pressure value P1 = 3780 kg·h / m²·h at node N1 and P2 = 3800 kg·h / m²·h at node N2. Based on the element length L = 1 meter and the section property A = 38.4 mm², it calculates the element stiffness matrix, converts the node pressure values ​​into node load vectors, and solves for the node displacement U using the equilibrium equation K*U = F. K is the stiffness matrix, F is the nodal load vector, and the element strain ε=ΔU / L is calculated based on the displacement result U. For example, the strain value of element E1 is calculated to be 0.0025. The element stress is calculated using the stress-strain relationship σ=E·ε, where E is the elastic modulus of 110 GPa. The stress value of element E1 is calculated to be 275 MPa. The steps of reading nodal coordinates, assembling load vectors, solving displacement, calculating strain, and calculating stress are repeated for all elements. For example, the stress value calculated for element E2 is 182 MPa, and the stress value calculated for element E3 is 415 MPa. An element stress data set containing all element numbers and their corresponding stress values ​​is generated.

[0039] The mechanical results generation submodule is based on the unit stress data. It calls the cable fatigue damage threshold. When the unit stress value is less than the threshold, it directly outputs the unit stress-strain data. When it is greater than the threshold, it multiplies the unit stress value with the number of stress cycles to obtain the cumulative fatigue damage value, substitutes it into the mechanical equation, and recalculates to generate the mechanical simulation results of cable laying.

[0040] The mechanical results generation submodule reads the stress values ​​of each element in the element stress data set. For example, it reads the stress values ​​of elements E1 (275 MPa), E2 (182 MPa), and E3 (415 MPa). It reads the cable fatigue damage threshold parameter S_th = 120 MPa, compares the stress value of element E1 (275 MPa) with the threshold of 120 MPa, determines that 275 > 120, and performs a multiplication operation. It reads the stress cycle count N_cyc = 10000 times for this element and calculates the cumulative fatigue damage value D_1 = 275 × 10000 = 2750000 MPa·cycle. It compares the stress value of element E2 (182 MPa) with the threshold of 120 MPa, determines that 182 > 120, and performs a multiplication operation. It reads the stress cycle count of 8000 times and calculates the damage value D_2 = 182 × 8000 = 1456000 MPa·cycle. It compares the stress value of element E3 (415 MPa) with the threshold of 120 MPa and determines... 415>120, perform multiplication, read the stress cycle count of 12000, calculate the damage value D_3=415×12000=4980000 MPa·cycle, establish the damage correction equation σ_corr=σ_orig+α·log(D), where α is the damage influence coefficient taken as 0.15, calculate the corrected stress for element E1 σ_corr1=275+0.15×log(2750000)≈282 MPa, calculate the corrected stress for element E2 σ_corr2=182+0.15×log(1456000)≈188 MPa, calculate the corrected stress for element E3 σ_corr3=415+0.15×log(4980000)≈423 MPa, integrate the corrected stress values, strain values ​​and cumulative damage values ​​of all elements, and generate the cable laying mechanical simulation results containing complete data of the mechanical state of the elements.

[0041] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A finite element based cable laying simulation system, characterized by, The system comprises: The cable parameter acquisition module acquires the cable conductor stranding pitch, the strand number, the minimum bending radius and the fatigue damage threshold, and simultaneously acquires the ground vehicle weight and the passing frequency on the laying path, and integrates to generate a cable basic parameter set. The geometric material modeling module calculates the conductor stranding spiral angle and the total cross-sectional area based on the basic parameters, obtains the conductor equivalent stiffness parameter through coupling operation, and associates it with the cable geometric coordinates to construct a cable structure material model. The finite element unit discrete module calculates the actual bending radius of the laying path according to the structure material model and compares it with the minimum bending radius, and if the actual value is small, the unit discrete density is increased, then the grid is divided according to the adjusted density, and a cable discrete unit model is generated. The load boundary determination module calculates the single-vehicle cumulative pressure according to the vehicle weight and the passing frequency, sums up the total cumulative pressure on the ground, and then converts it into the equivalent pressure of the cable laying depth through the soil force transmission coefficient to finally generate the cable load boundary parameter. The mechanical result calculation module calculates the stress value of the discrete unit under the equivalent pressure, compares it with the fatigue damage threshold, and if it exceeds the threshold, multiplies the stress value by the cycle number to obtain the fatigue damage cumulative value, and re-substitutes it into the calculation to finally output the cable laying mechanical simulation result.

2. The finite element based cable routing simulation system of claim 1, wherein: The cable basic parameter set includes the cable conductor stranding pitch, the cable conductor strand number, the cable minimum bending radius, the ground vehicle weight, the ground vehicle passing frequency and the cable fatigue damage threshold, the cable structure material model includes the conductor equivalent stiffness parameter, the cable geometric coordinate data, the conductor total cross-sectional area and the conductor stranding spiral angle, the cable discrete unit model includes the adjusted unit discrete density data, the segmented laying path unit division result and the actual bending radius corresponding unit data, and the cable load boundary parameter includes the single-vehicle cumulative pressure, the total cumulative pressure on the ground, the equivalent pressure of the cable laying depth and the soil force transmission coefficient, and the cable laying mechanical simulation result includes the unit stress value, the unit strain data, the fatigue damage cumulative value and the stress cycle number corresponding mechanical calculation data.

3. The finite element based cable routing simulation system of claim 1, wherein: The cable parameter acquisition module includes a cable parameter acquisition submodule and a parameter set generation submodule. The cable parameter acquisition submodule acquires the cable conductor stranding pitch, the conductor strand number and the cable minimum bending radius, acquires the ground vehicle weight and the vehicle passing frequency on the laying path, acquires the cable fatigue damage threshold, and obtains the cable parameter items; The parameter set generation submodule integrates the conductor stranding pitch, the conductor strand number, the cable minimum bending radius, the ground vehicle weight, the vehicle passing frequency and the cable fatigue damage threshold based on the cable parameter items to generate the cable basic parameter set.

4. The finite element based cable routing simulation system of claim 1, wherein: The geometric material modeling module includes an equivalent stiffness calculation submodule and a structure model generation submodule. The equivalent stiffness calculation submodule calls the cable basic parameter set, extracts the conductor stranding pitch to calculate the conductor stranding spiral angle, extracts the conductor strand number and the cross-sectional area of a single conductor to obtain the conductor total cross-sectional area, and couples the conductor stranding spiral angle and the conductor total cross-sectional area to obtain the conductor equivalent stiffness parameter; The structure model generation submodule is configured to correlate conductor equivalent stiffness parameters with cable geometric coordinates, fuse the conductor equivalent stiffness parameters and the cable geometric coordinate information, and generate a cable structure material model.

5. The finite element based cable routing simulation system of claim 1, wherein: The finite element unit discretization module includes a bending radius calculation submodule, a unit density adjustment submodule, and a discrete model generation submodule. The bending radius calculation submodule is configured to call a minimum bending radius of the cable according to the cable structure material model, segment a cable laying path, calculate an actual bending radius of each segment, and obtain a bending radius value of each segment. The calling of the bending radius value of each segment, the comparison of the actual bending radius of each segment with the minimum bending radius of the cable, the setting of the unit discretization density as a basic value when the actual bending radius is greater than the minimum bending radius, and the increase of the unit density by a corresponding proportion on the basis value when the actual bending radius is less than the minimum bending radius are performed to obtain an adjusted unit density. The discrete model generation submodule is configured to divide the cable structure material model into units based on the adjusted unit density, integrate the divided unit information, and generate a cable discrete unit model.

6. The finite element based cable routing simulation system of claim 1, wherein: The load boundary determination module includes a cumulative pressure calculation submodule and an equivalent pressure conversion submodule. The cumulative pressure calculation submodule is configured to call a vehicle weight and a vehicle passing frequency for the cable discrete unit model, multiply the vehicle weight and the passing frequency to obtain a single-vehicle cumulative pressure, sum all single-vehicle cumulative pressures to obtain a total ground cumulative pressure, and convert the total ground cumulative pressure according to a soil force transmission coefficient to obtain a cable laying depth equivalent pressure and generate a cable load boundary parameter. The mechanical result calculation module includes a unit stress calculation submodule and a mechanical result generation submodule.

7. The finite element based cable routing simulation system of claim 1, wherein: The unit stress calculation submodule is configured to call the cable discrete unit model and the cable load boundary parameter, calculate a unit stress value of the discrete unit under the equivalent pressure, and obtain unit stress data. The mechanical result generation submodule is configured to call a cable fatigue damage threshold based on the unit stress data, directly output unit stress and strain data when the unit stress value is less than the threshold, multiply the unit stress value and a stress cycle number to obtain a fatigue damage cumulative value when the unit stress value is greater than the threshold, substitute the fatigue damage cumulative value into a mechanical equation to recalculate, and generate a cable laying mechanical simulation result.

8. The finite element based cable routing simulation system of claim 7, wherein: ​

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