A method for optimizing the calculation of internal force and deflection of cable trench cover

Abstract

The present invention relates to the technical field of power cables, and discloses a method for optimizing the calculation of the internal force and deflection of a cable trench cover. The method comprises first obtaining the uniformly distributed load, material properties, span, geometric dimensions and boundary conditions of the cable trench cover. Based on these data, the equilibrium differential equation of the elastic continuous beam is established, and the deflection functions of the simply supported and fixed ends are solved. Next, a finite element model is constructed, and the model is used in combination with two deflection functions to analyze the force changes under different spans to form an internal force balance model. Through the above-mentioned model and function, the relationship between the load and the deflection of the control point and the internal force of the beam is determined to obtain the internal force function. Finally, the standard section moment of inertia is inverted according to the finite element model, and its influence on the internal force and deflection is analyzed to obtain the section optimization parameters. This method solves the problem that the calculation of the cover with unknown section parameters in the actual cable trench engineering is difficult and the calculation results are inaccurate.

Description

Technical Field

[0001] The invention relates to the technical field of power cables, and in particular to a method for optimizing the calculation of internal forces and deflections of a cable trench cover. Background Art

[0002] At present, with the acceleration of urbanization, the construction of power infrastructure has become an indispensable part of modern urban construction. As an important component of the power transmission system, the cable trench is mainly used to protect underground cables from the influence of external environmental factors and provide convenient conditions for maintenance and repair. The cable trench cover not only plays a sealing role, but also needs to bear the load of pedestrians and vehicles and various natural forces that may be encountered. In order to improve the design quality of the cable trench cover, it is necessary to conduct in-depth research on its internal stress distribution and deformation. Internal force refers to the force of interaction between the internal parts of the component, which directly determines whether the component can withstand the external load without damage; and deflection refers to the degree of bending of the component under the action of external force. Excessive deflection will affect the normal use function and reduce user satisfaction. Through accurate calculation of these two aspects, not only can the safety and reliability of the cover be guaranteed within the expected service life, but also unnecessary resource consumption can be effectively reduced to maximize economic and social benefits. Therefore, ensuring the safety and durability of the cable trench cover is crucial to the stable operation of the entire power system.

[0003] In the existing design and analysis of cable trench covers, the calculation method mainly relies on the assumption that the load on the cover is uniformly distributed on its surface. In this process, first, the geometric parameters are defined. The size, shape, thickness and material properties of the cable trench are determined according to the actual engineering requirements. Secondly, a mechanical model is established based on the elastic theory to simplify the cover into a flat plate structure that bears a uniformly distributed load. Then, the geometric characteristic values ​​such as the moment of inertia and area of ​​the cover section are obtained by integration or table lookup to perform cross-sectional characteristic analysis. Next, using the mechanical model established above, the bending moment and shear force at different positions are solved according to the principle of static equilibrium, and the maximum normal stress at each point is calculated in combination with the cross-sectional characteristics. Finally, based on the classical beam theory formula, the maximum deflection of the cover under a uniformly distributed load is calculated to evaluate the deflection.

[0004] However, the existing calculation methods are difficult to calculate for cover plates with unknown cross-sectional parameters in actual cable trench projects, and the calculation results are inaccurate. Summary of the invention

[0005] The invention provides a method for optimizing the calculation of the internal force and deflection of a cable trench cover plate, so as to solve the problem that the calculation of the cover plate with unknown cross-sectional parameters in the actual cable trench project is difficult and the calculation result is inaccurate.

[0006] In the first aspect, in order to solve the above-mentioned technical problems, the present invention provides a method for optimizing the calculation of the internal force and deflection of a cable trench cover, comprising: obtaining the uniformly distributed load, material properties, span, geometric data and boundary conditions of the cable trench cover, wherein the material properties include the elastic modulus, Poisson's ratio, density and thermal expansion coefficient of the cover, the geometric data include the length, width and thickness of the cover, and the boundary conditions include a simply supported support method and a fixed end support method; based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, an equilibrium differential equation of an elastic continuous beam is established, and the equilibrium differential equation is solved to obtain a simply supported perturbation function and a fixed end perturbation function; based on the uniformly distributed load, the material properties, the geometric data and the boundary conditions, a finite element analysis is performed to establish A finite element model is established; according to the finite element model, the simply supported disturbance function and the fixed end disturbance function, the force changes under different spans are analyzed to obtain an internal force balance model; according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function, the functional relationship between the load and the control point deflection and the internal force of the beam is solved to obtain the internal force function; according to the finite element model, the standard section inertia moment is inferred, and the standard internal force and standard disturbance are calculated according to the standard section inertia moment; by adjusting different geometric data, combining the internal force function, the simply supported disturbance function and the fixed end disturbance function, the corresponding internal force and disturbance are recalculated, and the calculation result closest to the standard internal force and the standard disturbance is selected to obtain the section optimization parameters.

[0007] In an optional implementation, the step of establishing a balanced differential equation of the elastic continuous beam based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and solving the balanced differential equation to obtain a simply supported perturbation function and a fixed end perturbation function comprises: calculating the section moment of inertia by the following formula: The equilibrium differential equation is as follows: The simply supported perturbation function is as follows: The fixed-end disturbance function is shown as follows: in, represents the simply supported perturbation function, represents the fixed-end disturbance function, represents the section moment of inertia, Indicates width, Indicates thickness, represents the elastic modulus, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Indicates disturbance.

[0008] In an optional implementation, analyzing the force changes under different spans according to the finite element model, the simply supported perturbation function and the fixed end perturbation function to obtain an internal force balance model includes: the internal force balance model is as follows: in, represents the shear force, represents the bending moment, represents the elastic modulus, represents the section moment of inertia, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Indicates the disturbance, Indicates span.

[0009] In an optional implementation, solving the functional relationship between the load and the control point deflection and the internal force of the beam according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force function includes: the internal force function is as follows: in, represents the shear force, represents the bending moment, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span.

[0010] In an optional embodiment, the method of inverting the standard section moment of inertia according to the finite element model, and analyzing the influence of the section moment of inertia on the internal force and disturbance according to the section moment of inertia, the internal force function, the simply supported disturbance function and the fixed end disturbance function to obtain section optimization parameters includes: taking the midpoint of the beam in the finite element model to apply a unit force, and recording the disturbance change at the midpoint to obtain the maximum disturbance; inverting the standard section moment of inertia according to the maximum disturbance, and calculating the standard internal force and standard disturbance according to the standard section moment of inertia; calculating different internal forces and disturbances according to the geometric data, and analyzing the influence of different section moments of inertia on the internal force and disturbance according to the calculation results to obtain section optimization parameters; inverting the standard section moment of inertia by the following formula: in, represents the maximum disturbance, represents the standard section moment of inertia, Indicates span, represents unit force, Represents the elastic modulus.

[0011] In an optional implementation, the calculating different internal forces and disturbances according to the geometric data includes: calculating the section inertia moment corresponding to the deadweight load of the first layer of concrete and steel bars by the following formula:

[0012] The section moment of inertia of the second layer of mortar is calculated by the following formula: The total area moment of inertia is calculated using the following formula: in, represents the total section moment of inertia, represents the first layer section moment of inertia, represents the moment of inertia of the second layer section, Indicates width, Indicates height, , Respectively represent the preset heights of the first and second mortar layers. represents the preset first threshold, represents a preset second threshold, Indicates the preset third threshold.

[0013] In an optional embodiment, the influence of different cross-sectional moments of inertia on internal forces and disturbances is analyzed based on the calculation results to obtain cross-sectional optimization parameters, including: comparing the calculation results with the standard internal forces and the standard disturbances, selecting the calculation results that are closest to the standard internal forces and the standard disturbances, and finding the corresponding geometric data as cross-sectional optimization parameters.

[0014] In a second aspect, the present invention provides an apparatus for optimizing the calculation of the internal force and deflection of a cable trench cover, comprising: a data acquisition module for acquiring the uniformly distributed load, material properties, span, geometric data and boundary conditions of the cable trench cover, wherein the material properties include the elastic modulus, Poisson's ratio, density and thermal expansion coefficient of the cover, the geometric data include the length, width and thickness of the cover, and the boundary conditions include simply supported and fixed end support methods; an equilibrium equation construction module for establishing an equilibrium differential equation of an elastic continuous beam based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and solving the equilibrium differential equation to obtain a simply supported perturbation function and a fixed end perturbation function; a finite element model construction module for performing finite element analysis based on the uniformly distributed load, the material properties, the geometric data and the boundary conditions to establish a finite element model; the internal force A balance model construction module is used to analyze the force changes under different spans according to the finite element model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force balance model; an internal force function analysis module is used to solve the functional relationship between the load and the control point deflection and the internal force of the beam according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force function; a geometric influence analysis module is used to infer the standard section inertia moment according to the finite element model, and calculate the standard internal force and standard disturbance according to the standard section inertia moment; by adjusting different geometric data, combining the internal force function, the simply supported disturbance function and the fixed end disturbance function, the corresponding internal force and disturbance are recalculated, and the calculation result closest to the standard internal force and the standard disturbance is selected to obtain the section optimization parameters.

[0015] In a third aspect, the present invention also provides an electronic device comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements the method for optimizing the calculation of the internal force and deflection of the cable trench cover as described in any one of the above.

[0016] In a fourth aspect, the present invention further provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute any one of the above-mentioned methods for optimizing the calculation of internal forces and deflections of cable trench covers.

[0017] Compared with the prior art, the present invention has the following beneficial effects: the present invention discloses a method for optimizing the calculation of the internal force and deflection of a cable trench cover, including obtaining the uniformly distributed load, material properties, span, geometric data and boundary conditions of the cable trench cover, wherein the material properties include the elastic modulus, Poisson's ratio, density and thermal expansion coefficient of the cover, the geometric data include the length, width and thickness of the cover, and the boundary conditions include a simply supported support mode and a fixed end support mode; based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, an equilibrium differential equation of an elastic continuous beam is established, and the equilibrium differential equation is solved to obtain a simply supported perturbation function and a fixed end perturbation function; based on the uniformly distributed load, the The material properties, the geometric data and the boundary conditions are subjected to finite element analysis to establish a finite element model; the force changes under different spans are analyzed according to the finite element model, the simply supported perturbation function and the fixed end perturbation function to obtain an internal force balance model; the functional relationship between the load and the control point deflection and the internal force of the beam is solved according to the finite element model, the internal force balance model, the simply supported perturbation function and the fixed end perturbation function to obtain an internal force function; the standard section inertia moment is inferred according to the finite element model, and the section inertia moment, the internal force function, the simply supported perturbation function and the fixed end perturbation function are analyzed to obtain the influence of the section inertia moment on the internal force and perturbation, and to obtain the section optimization parameters. The present invention establishes and solves the equilibrium differential equation of the elastic continuous beam through the collected data, obtains the deflection functions of the simply supported and fixed ends, and performs finite element analysis to construct a model, and analyzes the force changes under different spans in combination with the deflection function to form an internal force balance model. This model and functional relationship are used to determine the relationship between the load and the deflection of the control point and the internal force of the beam, and the internal force function is obtained. Finally, the moment of inertia of the standard section is inverted through the finite element model, and its influence on the internal force and deflection is analyzed to obtain the section optimization parameters to solve the problem of unknown section parameters of the cover plate in the actual cable trench project, which is difficult to calculate and the calculation results are inaccurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic flow chart of a method for optimizing calculation of internal force and deflection of a cable trench cover provided by a first embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the structure of a device for optimizing calculation of internal forces and deflections of a cable trench cover provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0020] 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 only 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.

[0021] Reference Figure 1 The first embodiment of the present invention provides a method for optimizing the calculation of the internal force and deflection of a cable trench cover, comprising the following steps:

[0022] S11, obtaining the uniformly distributed load, material properties, span, geometric data and boundary conditions of the cable trench cover, wherein the material properties include the elastic modulus, Poisson's ratio, density and thermal expansion coefficient of the cover, the geometric data include the length, width and thickness of the cover, and the boundary conditions include a simply supported support mode and a fixed end support mode;

[0023] S12, establishing a balanced differential equation of the elastic continuous beam based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and solving the balanced differential equation to obtain a simply supported perturbation function and a fixed end perturbation function;

[0024] S13, performing finite element analysis based on the uniformly distributed load, the material properties, the geometric data and the boundary conditions to establish a finite element model;

[0025] S14, analyzing force changes under different spans according to the finite element model, the simply supported disturbance function and the fixed end disturbance function to obtain an internal force balance model;

[0026] S15, solving the functional relationship between the load and the control point deflection and the internal force of the beam according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function to obtain an internal force function;

[0027] S16, inversely calculating the standard section inertia moment according to the finite element model, and calculating the standard internal force and standard disturbance according to the standard section inertia moment;

[0028] S17, by adjusting different geometric data, combining the internal force function, the simply supported disturbance function and the fixed end disturbance function, recalculating the corresponding internal force and disturbance, and selecting the calculation result closest to the standard internal force and the standard disturbance to obtain the section optimization parameters.

[0029] In step S11, the uniformly distributed load, material properties, span, geometric data and boundary conditions of the cable trench cover are obtained, wherein the material properties include the elastic modulus, Poisson's ratio, density and thermal expansion coefficient of the cover, the geometric data include the length, width and thickness of the cover, and the boundary conditions include simply supported support mode and fixed end support mode.

[0030] First, to determine the uniformly distributed load, it is necessary to consider the various actual working conditions that the cover plate may encounter, such as the dynamic loads generated by pedestrians and vehicles passing by, and the static loads acting on it for a long time, such as snow loads, wind loads, etc. This depends on engineering design standards, past experience data or on-site measurements.

[0031] Next, in terms of material properties, physical characteristics such as elastic modulus, Poisson's ratio, density and thermal expansion coefficient will directly affect the mechanical properties of the cover. This information can be obtained from the material specification sheet provided by the manufacturer or through laboratory testing.

[0032] As for span and geometric data, they not only determine the overall size of the cover, but also affect its internal stress distribution. Such data are derived from design drawings or field measurements, ensuring that the model can truly reflect the actual shape of the cover.

[0033] Finally, the choice of boundary conditions, whether simply supported or fixed end support, will greatly affect the load pattern of the cover. This information comes from design requirements or engineering practice, and specifies how the ends of the cover are supported.

[0034] In step S12, a balanced differential equation of the elastic continuous beam is established based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and the balanced differential equation is solved to obtain a simply supported perturbation function and a fixed end perturbation function.

[0035] In a specific implementation, the equilibrium differential equation of the elastic continuous beam is established based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and the equilibrium differential equation is solved to obtain the simply supported perturbation function and the fixed end perturbation function, including: calculating the section moment of inertia by the following formula: The equilibrium differential equation is as follows: The simply supported perturbation function is as follows: The fixed-end disturbance function is shown as follows: in, represents the simply supported perturbation function, represents the fixed-end disturbance function, represents the section moment of inertia, Indicates width, Indicates thickness, represents the elastic modulus, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Indicates disturbance.

[0036] First, in order to establish the equilibrium differential equation, it is necessary to calculate the section inertia moment I, which is an important parameter to measure the section's ability to resist bending. According to the given formula ,in, represents the section moment of inertia, Indicates the width of the cover section, represents the thickness of the cover section. This formula obtains the specific moment of inertia value of the cover by substituting the specific width and thickness values.

[0037] Next, using the elastic modulus E and section inertia moment I of the material, combined with the uniformly distributed load q, we can construct a fourth-order linear ordinary differential equation that describes the bending behavior of the beam after being subjected to force, that is, the equilibrium differential equation of the elastic continuous beam: in, Indicates the position along the beam axis The deflection (i.e. vertical displacement) at represents the elastic modulus, represents uniformly distributed load, represents the moment of inertia of the area, and represents the fourth derivative and is used to express the rate of change of curvature of the deflection curve. This equation shows that under a uniformly distributed load, the degree of bending of the beam is proportional to the load and is affected by the stiffness of the material and the shape of the cross section.

[0038] Then, the above differential equations are solved according to different boundary conditions. For a simply supported beam (constrained but not fixed at both ends), its deflection function can be given by the following expression: This shows that at any location The deflection of a simply supported beam can be calculated using the above formula, where is the total span of the beam. The derivation of this formula is based on the classical beam theory, combining the characteristics of a simply supported beam with no rotation at both ends and maximum deflection in the middle.

[0039] For fixed end beams (one or both ends are completely fixed), the deflection function is different and is as follows: This formula reflects the deflection characteristics of a fixed-end beam under the same load. Generally, a fixed-end beam has a smaller deflection than a simply supported beam because its ends are not allowed to rotate.

[0040] In step S13, finite element analysis is performed based on the uniformly distributed load, the material properties, the geometric data and the boundary conditions to establish a finite element model.

[0041] First, before conducting finite element analysis, you need to select a suitable finite element software tool, such as ANSYS, ABAQUS or COMSOL. Then, create a three-dimensional geometric model based on the specific size and shape of the cover, which should accurately reflect the characteristics of the cover in the actual project. Next, mesh this geometric model, that is, divide the entire cover into a large number of small units.

[0042] After the meshing is completed, the material properties at each node need to be defined. The specific parameters involved here include the elastic modulus E, Poisson's ratio ν, density ρ and thermal expansion coefficient α. In addition, the uniformly distributed load q borne by the cover plate and its distribution need to be specified, which can be achieved by directly applying it to the top surface or through pressure boundary conditions. For boundary conditions, the support type should be set according to the actual situation: if it is a simply supported beam, only vertical displacement is restricted at both ends without constraining rotation; if it is a fixed end, all degrees of freedom are completely restricted.

[0043] After completing the above preparations, we start solving the finite element equations. In the finite element method, the structure is regarded as a system composed of multiple interconnected units, each of which can be represented by a set of linear equations to describe its mechanical behavior. These equations are combined to form a large sparse matrix equation, usually written as , where Stiffness matrix, is the displacement vector, and External force vector. Solving this system of equations gives the displacement value at each node.

[0044] Assume that there is a 5-meter-long, 2-meter-wide, and 0.2-meter-thick concrete cable trench cover plate covering a space with a span of 5 meters and bearing a uniformly distributed load of 1kN / m² per square meter. Through finite element analysis, the deflection of the cover plate at different locations, the maximum stress concentration area, and possible crack risk points are predicted.

[0045] In step S14, the force variation under different spans is analyzed according to the finite element model, the simply supported perturbation function and the fixed end perturbation function to obtain an internal force balance model.

[0046] In a specific implementation, the force changes under different spans are analyzed according to the finite element model, the simply supported perturbation function and the fixed end perturbation function to obtain an internal force balance model, including: the internal force balance model is as follows: in, represents the shear force, represents the bending moment, represents the elastic modulus, represents the section moment of inertia, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Indicates the disturbance, Indicates span.

[0047] Firstly, based on the simply supported disturbance function and fixed end disturbance function obtained previously, the expressions describing the shear force and bending moment are further derived.

[0048] In order to solve for the shear force and bending moment, the basic principles of calculus are used, especially the second and third order derivatives related to the deflection curve. Specifically, the shear force can be obtained by the first order derivative of the bending moment, while the bending moment is equal to the elastic modulus E multiplied by the section moment of inertia I multiplied by the second order derivative of the deflection y with respect to the position x. Therefore, the following internal force balance equations can be written: in, represents the shear force, represents the bending moment, represents the elastic modulus, represents the section moment of inertia, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Indicates disturbance.

[0049] Next, substitute the specific deflection function into the above formula for calculation. For a simply supported beam, the shear force and bending moment expressions are:

[0050] For the fixed end beam, the corresponding shear force and bending moment expressions are: These formulas not only reveal the variation of shear force and bending moment with position, but also clarify the intrinsic relationship between them and deflection.

[0051] In step S15, the functional relationship between the load and the control point deflection and the internal force of the beam is solved according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force function.

[0052] In a specific implementation, solving the functional relationship between the load and the control point deflection and the internal force of the beam according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force function includes: the internal force function is as follows: in, represents the shear force, represents the bending moment, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span.

[0053] Next, in a specific implementation, for a simply supported beam or a fixed end beam, based on the aforementioned simply supported perturbation function and the fixed-end disturbance function , the internal force function can be further simplified. Shear force on and bending moment , the formula is as follows: in, represents the shear force, represents the bending moment, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span.

[0054] These formulas reveal how shear force and bending moment vary with position and how they relate directly to the externally applied uniform load and span. or When the shear force reaches its maximum value at the two end points , and in the middle , the shear force drops to zero; at the same time, the bending moment is zero at the two end points, but at the center Reaching the maximum value , which shows that bending deformation is most likely to occur at the center of the beam.

[0055] For example, suppose there is a 5-meter-long, 2-meter-wide, 0.2-meter-thick concrete cable trench cover covering a space with a span of 5 meters and bearing a uniformly distributed load of 1kN / m² per square meter. Using the above formula, the shear force and bending moment of this cover at any position can be accurately calculated, thereby evaluating its overall bearing capacity and local weak points.

[0056] In steps S16 and S17, the standard section inertia moment is inversely deduced from the finite element model, and the standard internal force and standard disturbance are calculated based on the standard section inertia moment. By adjusting different geometric data, combining the internal force function, the simply supported disturbance function and the fixed end disturbance function, the corresponding internal force and disturbance are recalculated, and the calculation result closest to the standard internal force and the standard disturbance is selected to obtain the section optimization parameters.

[0057] In a specific embodiment, the inverse inertia of the standard section according to the finite element model, and the calculation of the standard internal force and the standard disturbance according to the standard section inertia moment, include: taking the midpoint of the beam in the finite element model to apply a unit force, and recording the disturbance change of the midpoint to obtain the maximum disturbance; inversely obtaining the standard section moment of inertia according to the maximum disturbance, and calculating the standard internal force and the standard disturbance according to the standard section moment of inertia in combination with the internal force function, the simply supported disturbance function and the fixed end disturbance function; inversely inferring the standard section moment of inertia by the following formula: in, represents the maximum disturbance, represents the standard section moment of inertia, Indicates span, represents unit force, Represents the elastic modulus.

[0058] In a specific implementation, the adjustment of different geometric data, combined with the internal force function, the simply supported disturbance function and the fixed end disturbance function, recalculating the corresponding internal forces and disturbances, includes: calculating the section inertia moment corresponding to the self-weight load of the first layer of concrete and steel bars by the following formula: The section moment of inertia of the second layer of mortar is calculated by the following formula: The total area moment of inertia is calculated using the following formula: in, represents the total section moment of inertia, represents the first layer section moment of inertia, represents the moment of inertia of the second layer section, Indicates width, Indicates height, , Respectively represent the preset heights of the first and second mortar layers. represents the preset first threshold, represents a preset second threshold, represents a preset third threshold; according to the adjusted geometric data, the total section inertia moment, combined with the internal force function, the simply supported disturbance function and the fixed end disturbance function, the corresponding internal force and disturbance are recalculated.

[0059] In a specific embodiment, the calculation result closest to the standard internal force and the standard disturbance is selected to obtain the section optimization parameters, including: comparing the calculation results with the standard internal force and the standard disturbance, selecting the calculation result closest to the standard internal force and the standard disturbance, and finding the corresponding geometric data as the section optimization parameters.

[0060] It is worth noting that the larger the section moment of inertia, the smaller the bending moment and shear force of the cable trench cover under the same load; the larger the section moment of inertia, the smaller the deflection of the cable trench cover under the same load.

[0061] First, select the midpoint of the beam in the finite element model and apply a unit force , and record the deflection change at the midpoint , recorded as the maximum deflection. This maximum deflection is to determine the moment of inertia of the section The key parameters of The standard section moment of inertia can be inferred ,in is the span, is the elastic modulus of the material. The obtained standard section moment of inertia is used to calculate the internal forces (shear and bending moment) and standard disturbances under standard conditions, which helps to establish a baseline for subsequent comparison of performance differences under different geometric data.

[0062] Next, based on the obtained standard section moments of inertia, we start to explore the specific effects of different geometric configurations on internal forces and disturbances. For example, consider a first-story structure made of concrete and steel and a second-story structure made of mortar. The section moment of inertia corresponding to the self-weight load of the first floor is It can be calculated according to the following rules: For the second layer of mortar, its section moment of inertia is According to the height of the mortar layer and Relative to the preset threshold The total section moment of inertia is determined by the relationship: is the sum of the moments of inertia of the two layers: .

[0063] in, represents the total section moment of inertia, represents the first layer section moment of inertia, represents the moment of inertia of the second layer section, Indicates width, Indicates height, , Respectively represent the preset heights of the first and second mortar layers. represents the preset first threshold, represents a preset second threshold, It represents a preset third threshold value, which is used to distinguish different construction situations.

[0064] Furthermore, by adjusting different geometric data, such as changing thickness or material combination, the corresponding internal forces and disturbances are recalculated. The larger the section inertia moment, the smaller the bending moment and shear force of the cable trench cover under the same load; at the same time, a larger section inertia moment will also lead to smaller deflection. This means that a higher moment of inertia can provide better structural stiffness, reduce deformation, and thus improve the safety and durability of the structure.

[0065] Compare the newly calculated internal forces and disturbances with the previously established standard internal forces and standard disturbances. Select the result that is closest to the standard value, and find the most suitable geometric data as the section optimization parameters. For example, when optimizing a concrete cable trench cover that is 5 meters long, 2 meters wide and 0.2 meters thick, the standard conditions are first established based on the uniformly distributed load of 1kN / m² per square meter. Under this condition, when a unit force is applied to the midpoint of the beam, the maximum deflection recorded is 0.008 meters, and the standard section moment of inertia deduced from this is 0.0033m 4 . Based on this standard section moment of inertia, it is calculated that the shear force reaches a maximum value of 2.5kN at the two ends of the beam, and the shear force drops to zero in the middle; at the same time, the bending moment is zero at the two end points, but reaches a maximum value of 6.25kNm at the center. Next, by adjusting different geometric data configurations, such as changing the thickness or material combination, the corresponding internal forces and disturbances are recalculated. After a series of calculations, it was found that when the optimized thickness of 0.25 meters and a specific strength grade of concrete and steel bar ratio were used, the newly calculated results showed smaller deflections and more reasonable internal force distribution, and were closest to the standard values. Specifically, the optimized configuration reduced the maximum deflection of the cover plate to 0.005 meters, and the corresponding maximum bending moment was reduced to 5kNm.

[0066] Finally, by comparing these calculation results with the previously established standard internal forces and standard disturbances, the optimized geometric data were determined as the cross-sectional optimization parameters. The optimized design scheme meets the safety requirements and ensures the reliable performance of the cable trench cover within the expected service life.

[0067] If the calculation results for a certain thickness and material configuration show small deflections and reasonable internal force distribution, then this configuration becomes the optimized design solution.

[0068] The following describes the working process of the present invention using a relatively common scenario as an example. Figure 1, a method for optimizing the calculation of internal forces and deflections of cable trench covers, including the following steps: For a concrete cable trench cover with a length of 5 meters, a width of 2 meters, and a thickness of 0.2 meters, covering a space with a span of 5 meters, and bearing a uniformly distributed load of 1kN / m² per square meter. Through a series of calculations and analyses, the following results were obtained: For this cable trench cover, under simply supported conditions, when a unit force is applied to the midpoint of the beam, the maximum deflection recorded is 0.008 meters. Based on this maximum deflection value, the inertia moment of the standard section is inferred to be 0.0033m 4 The standard internal force calculated based on this standard section inertia moment shows that the shear force reaches a maximum value of 2.5kN at the two ends of the beam, while the shear force drops to zero in the middle; at the same time, the bending moment is zero at the two end points, but reaches a maximum value of 6.25kNm at the center.

[0069] Further analysis of the effects of different geometric data on internal forces and disturbances shows that as the moment of inertia of the section increases, the bending moment and shear force of the cable trench cover under the same load decrease, and a larger moment of inertia of the section leads to a smaller deflection. Specifically, when the optimized thickness and material combination is adopted, the newly calculated results show smaller deflections and more reasonable internal force distribution. For example, the optimized configuration reduces the maximum deflection of the cover to 0.005 meters, while the corresponding maximum bending moment is reduced to 5kNm, which proves that a higher moment of inertia does provide better structural stiffness and reduces deformation, thereby improving the safety and durability of the structure.

[0070] By comparing the calculation results with the standard internal forces and standard disturbances, a set of optimal geometric data was determined as the cross-sectional optimization parameters. The optimized design not only meets the safety requirements, but is also cost-effective, ensuring the reliable performance of the cable trench cover within its expected service life.

[0071] In summary, this method effectively solves the problem of unknown cross-sectional parameters encountered in actual cable trench engineering projects, significantly reduces the difficulty of calculation, and greatly improves the accuracy of calculation results. Through a systematic analysis process and precise mathematical model, this method can not only accurately evaluate the mechanical properties of cable trench covers under various working conditions, but also provide reliable data support for optimized design, ensuring the safety of the design scheme.

[0072] Reference Figure 2The second embodiment of the present invention provides an optimized calculation device for the internal force and deflection of a cable trench cover, comprising: a data acquisition module, used to obtain the uniformly distributed load, material properties, span, geometric data and boundary conditions of the cable trench cover, wherein the material properties include the elastic modulus, Poisson's ratio, density and thermal expansion coefficient of the cover, the geometric data include the length, width and thickness of the cover, and the boundary conditions include simply supported and fixed end support methods; a balance equation construction module, used to establish a balanced differential equation of an elastic continuous beam based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and solve the balanced differential equation to obtain a simply supported perturbation function and a fixed end perturbation function; a finite element model construction module, used to perform finite element analysis based on the uniformly distributed load, the material properties, the geometric data and the boundary conditions, and establish a finite element model; internal force A balance model construction module is used to analyze the force changes under different spans according to the finite element model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force balance model; an internal force function analysis module is used to solve the functional relationship between the load and the control point deflection and the internal force of the beam according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force function; a geometric influence analysis module is used to infer the standard section inertia moment according to the finite element model, and calculate the standard internal force and standard disturbance according to the standard section inertia moment; by adjusting different geometric data, combining the internal force function, the simply supported disturbance function and the fixed end disturbance function, the corresponding internal force and disturbance are recalculated, and the calculation result closest to the standard internal force and the standard disturbance is selected to obtain the section optimization parameters.

[0073] It should be noted that a cable trench cover internal force and deflection optimization calculation device provided in an embodiment of the present invention is used to execute all process steps of a cable trench cover internal force and deflection optimization calculation method of the above-mentioned embodiment. The working principles and beneficial effects of the two correspond one to one, and thus will not be repeated here.

[0074] The embodiment of the present invention also provides an electronic device. The electronic device includes: a processor, a memory, and a computer program stored in the memory and executable on the processor, such as a cable trench cover internal force and deflection optimization calculation program. When the processor executes the computer program, the steps in the above-mentioned cable trench cover internal force and deflection optimization calculation method embodiments are implemented, such as Figure 1 Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are realized, such as the cable trench cover internal force and deflection optimization calculation module.

[0075] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program in the electronic device.

[0076] The electronic device may be a computing device such as a desktop computer, a notebook, a PDA, and a smart tablet. The electronic device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the above components are merely examples of electronic devices and do not constitute a limitation on the electronic device. The electronic device may include more or fewer components than the above components, or may combine certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0077] The processor may be a central processing unit (CPU), other general-purpose 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, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the electronic device, and uses various interfaces and lines to connect various parts of the entire electronic device.

[0078] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the electronic device by running or executing the computer program and / or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0079] Wherein, if the module / unit integrated in the electronic device 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 such an 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. Wherein, 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, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. 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.

[0080] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0081] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for optimizing the calculation of internal force and deflection of a cable trench cover, characterized in that: include: Obtain the uniformly distributed load, material properties, span, geometric data and boundary conditions of the cable trench cover, wherein the material properties include the elastic modulus, Poisson's ratio, density and thermal expansion coefficient of the cover, the geometric data include the length, width and thickness of the cover, and the boundary conditions include a simply supported support method and a fixed end support method; establish the equilibrium differential equation of the elastic continuous beam based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and solve the equilibrium differential equation to obtain the simply supported perturbation function and the fixed end perturbation function; perform finite element analysis based on the uniformly distributed load, the material properties, the geometric data and the boundary conditions, and establish a finite element model; analyze the force changes under different spans according to the finite element model, the simply supported perturbation function and the fixed end perturbation function, and obtain an internal force balance model; The functional relationship between the load and the control point deflection and the internal force of the beam is solved by using the finite element model, the simply supported perturbation function and the fixed end perturbation function to obtain the internal force function; the standard section inertia moment is inferred according to the finite element model, and the standard internal force and standard perturbation are calculated according to the standard section inertia moment; by adjusting different geometric data, the internal force function, the simply supported perturbation function and the fixed end perturbation function are combined to recalculate the corresponding internal force and perturbation, and the calculation result closest to the standard internal force and the standard perturbation is selected to obtain the section optimization parameters; wherein, the equilibrium differential equation of the elastic continuous beam is established based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and the equilibrium differential equation is solved to obtain the simply supported perturbation function and the fixed end perturbation function, including: calculating the section inertia moment by the following formula: The equilibrium differential equation is as follows: The simply supported perturbation function is as follows: The fixed-end disturbance function is shown as follows: in, represents the simply supported perturbation function, represents the fixed-end disturbance function, represents the section moment of inertia, Indicates width, Indicates thickness, represents the elastic modulus, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Represents disturbance; analyzing the force changes under different spans according to the finite element model, the simply supported disturbance function and the fixed end disturbance function to obtain an internal force balance model, including: the internal force balance model is as follows: in, represents the shear force, represents the bending moment, represents the elastic modulus, represents the section moment of inertia, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Indicates the disturbance, Represents the span; solving the functional relationship between the load and the control point deflection and the internal force of the beam according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force function, including: the internal force function is as follows: in, represents the shear force, represents the bending moment, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span.

2. According to claim 1, the cable trench cover internal force and deflection optimization calculation method is characterized in that: The inverse deduction of the standard section inertia moment according to the finite element model, and the calculation of the standard internal force and the standard disturbance according to the standard section inertia moment, comprises: taking the midpoint of the beam in the finite element model to apply a unit force, and recording the disturbance change of the midpoint to obtain the maximum disturbance; inversely deducing the standard section inertia moment according to the maximum disturbance, and calculating the standard internal force and the standard disturbance according to the standard section inertia moment, in combination with the internal force function, the simply supported disturbance function and the fixed end disturbance function; inversely deducing the standard section inertia moment by the following formula: in, represents the maximum disturbance, represents the standard section moment of inertia, Indicates span, represents unit force, Represents the elastic modulus.

3. The method for optimizing the calculation of internal force and deflection of cable trench cover according to claim 2 is characterized in that: The method comprises adjusting different geometric data, combining the internal force function, the simply supported disturbance function and the fixed end disturbance function, and recalculating the corresponding internal force and disturbance, including: calculating the section inertia moment corresponding to the self-weight load of the first layer of concrete and steel bars by the following formula: The section moment of inertia of the second layer of mortar is calculated by the following formula: The total area moment of inertia is calculated using the following formula: in, represents the total section moment of inertia, represents the first layer section moment of inertia, represents the moment of inertia of the second layer section, Indicates width, Indicates height, , Respectively represent the preset heights of the first and second mortar layers. represents the preset first threshold, represents a preset second threshold, represents a preset third threshold; according to the adjusted geometric data, the total section inertia moment, combined with the internal force function, the simply supported disturbance function and the fixed end disturbance function, the corresponding internal force and disturbance are recalculated.

4. The method for optimizing the calculation of internal force and deflection of cable trench cover according to claim 2 is characterized in that: The method comprises: comparing the calculation result with the standard internal force and the standard disturbance, selecting the calculation result with the closest value to the standard internal force and the standard disturbance, and finding the corresponding geometric data as the section optimization parameter.

5. A device for optimizing the calculation of internal force and deflection of a cable trench cover, characterized in that: include: A data acquisition module is used to obtain the uniformly distributed load, material properties, span, geometric data and boundary conditions of the cable trench cover, wherein the material properties include the elastic modulus, Poisson's ratio, density and thermal expansion coefficient of the cover, the geometric data include the length, width and thickness of the cover, and the boundary conditions include simply supported and fixed end support methods; a balance equation construction module is used to establish a balanced differential equation of the elastic continuous beam based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and solve the balanced differential equation to obtain a simply supported perturbation function and a fixed end perturbation function; a finite element model construction module is used to perform finite element analysis based on the uniformly distributed load, the material properties, the geometric data and the boundary conditions to establish a finite element model; an internal force balance model construction module is used to analyze the force changes under different spans according to the finite element model, the simply supported perturbation function and the fixed end perturbation function to obtain an internal force balance model; an internal force function analysis ... An analysis module is used to solve the functional relationship between the load and the control point deflection and the internal force of the beam according to the finite element model, the internal force balance model, the simply supported perturbation function and the fixed end perturbation function to obtain the internal force function; a geometric influence analysis module is used to infer the standard section inertia moment according to the finite element model, and calculate the standard internal force and standard perturbation according to the standard section inertia moment; by adjusting different geometric data, combining the internal force function, the simply supported perturbation function and the fixed end perturbation function, recalculating the corresponding internal force and perturbation, and selecting the calculation result closest to the standard internal force and the standard perturbation in the calculation result to obtain the section optimization parameter; wherein, the equilibrium differential equation of the elastic continuous beam is established based on the uniformly distributed load, the material properties, the span, the geometric data and the boundary conditions, and the equilibrium differential equation is solved to obtain the simply supported perturbation function and the fixed end perturbation function, including: calculating the section inertia moment by the following formula: The equilibrium differential equation is as follows: The simply supported perturbation function is as follows: The fixed-end disturbance function is shown as follows: in, represents the simply supported perturbation function, represents the fixed-end disturbance function, represents the section moment of inertia, Indicates width, Indicates thickness, represents the elastic modulus, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Represents disturbance; analyzing the force changes under different spans according to the finite element model, the simply supported disturbance function and the fixed end disturbance function to obtain an internal force balance model, including: the internal force balance model is as follows: in, represents the shear force, represents the bending moment, represents the elastic modulus, represents the section moment of inertia, represents uniformly distributed load, Indicates the position of the preset control point relative to the span, Indicates the disturbance, Represents the span; solving the functional relationship between the load and the control point deflection and the internal force of the beam according to the finite element model, the internal force balance model, the simply supported disturbance function and the fixed end disturbance function to obtain the internal force function, including: the internal force function is as follows: in, represents the shear force, represents the bending moment, Indicates span, represents uniformly distributed load, Indicates the position of the preset control point relative to the span.

6. An electronic device, characterized in that: It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, it implements the method for optimizing the calculation of the internal force and deflection of the cable trench cover as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the cable trench cover internal force and deflection optimization calculation method as described in any one of claims 1 to 4.

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