Calculation Method, Device and Computer Equipment for Creep Deformation of Finite-Length Cladding Tube

Abstract

The present application relates to a method, apparatus, and computer device for calculating creep deformation of a finite-length cladding tube. The method includes: obtaining the structural parameters of the finite-length cladding tube; performing discretization processing on the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube; calculating stiffness information and load information according to the model parameters of the finite element mesh model and the structural parameters; and calculating the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship. Using this method can improve the accuracy of calculating the creep deformation of the finite-length cladding tube.

Description

Technical Field

[0001] The present application relates to the technical field of cladding creep analysis, and particularly to a method, device, computer device, storage medium, and computer program product for calculating creep deformation of a finite-length cladding tube. Background Art

[0002] Cladding creep collapse failure of fuel rods is one of the main reasons for fuel rod failure. During the operation of a pressurized water reactor, under the severe high-temperature - irradiation - external pressure in the reactor, the finite-length cladding tube will gradually deform inward due to creep, causing the finite-length cladding tube to be flattened, and ultimately leading to creep collapse of the finite-length cladding tube, losing its load-bearing capacity and affecting the safe operation of the reactor. In order to ensure the reliability of fuel rod engineering design and analysis and improve the safety of nuclear power plants, it is necessary to calculate the creep deformation of the finite-length cladding tube. The traditional method is to model an infinitely long cladding tube under plane strain assumption and establish a correction method for the deformation of the finite-length cladding tube to obtain the creep deformation of the finite-length cladding tube.

[0003] However, using the plane assumption of an infinitely long cladding tube to correct the deformation result of the finite-length cladding tube will cause certain errors; and the correction coefficient in the traditional method is affected by structural parameters, making it difficult to obtain accurate creep deformation results of the finite-length cladding tube. Therefore, how to improve the accuracy of calculating the creep deformation of the finite-length cladding tube has become a technical problem to be solved currently. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a method, device, computer device, computer-readable storage medium, and computer program product for calculating creep deformation of a finite-length cladding tube that can improve the accuracy of calculating the creep deformation of the finite-length cladding tube.

[0005] In a first aspect, the present application provides a method for calculating creep deformation of a finite-length cladding tube. The method includes:

[0006] Obtain the structural parameters of the finite-length cladding tube;

[0007] Discretize the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube;

[0008] Calculate stiffness information and load information according to the model parameters of the finite element mesh model and the structural parameters;

[0009] Calculate the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship.

[0010] In one embodiment, calculating the stiffness information and the load information according to the model parameters of the finite element mesh model and the structural parameters includes:

[0011] Obtain a preset matrix;

[0012] Calculate the global stiffness matrix according to the model parameters of the finite element mesh model and the preset matrix to obtain the stiffness information;

[0013] Obtain a first preset function and a second preset function;

[0014] Calculate the load information according to the model parameters of the finite element mesh model, the first preset function, the structural parameters, the preset matrix and the second preset function.

[0015] In one embodiment, calculating the global stiffness matrix according to the model parameters of the finite element mesh model and the preset matrix includes:

[0016] Calculate the element stiffness matrix of each element in the finite element mesh model according to the model parameters of the finite element mesh model and the preset matrix;

[0017] Assemble the element stiffness matrices of each element to obtain the global stiffness matrix.

[0018] In one embodiment, calculating the load information according to the model parameters of the finite element mesh model, the first preset function, the structural parameters, the preset matrix and the second preset function includes:

[0019] Calculate the load vector according to the model parameters of the finite element mesh model, the first preset function and the internal and external pressure difference in the structural parameters;

[0020] Calculate the additional load vector increment generated by creep according to the model parameters, the preset matrix, the structural parameters and the second preset function;

[0021] Obtain the load information according to the load vector and the additional load vector increment generated by creep.

[0022] In one embodiment, calculating the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, the preset additional load vector and the preset creep deformation calculation relationship includes:

[0023] Calculate the nodal displacements of the major axis and the minor axis of the middle cross-section of the finite-length cladding tube according to the stiffness information, the load information, the preset additional load vector and the preset creep deformation relationship;

[0024] Calculate the ovality change result of the finite-length cladding tube according to the nodal displacements of the major axis and minor axis of the middle cross-section.

[0025] Obtain the creep deformation result based on the nodal displacements of the major axis and minor axis of the middle cross-section and the ovality change result.

[0026] In one embodiment, the creep deformation result includes a creep displacement curve and an ovality change curve; the method further includes:

[0027] Obtain the structural parameters of the finite-length cladding tube at the current moment.

[0028] Perform discretization processing on the structural parameters at the current moment to obtain the finite element mesh model corresponding to the finite-length cladding tube at the current moment.

[0029] Calculate the current stiffness information and current load information according to the model parameters of the finite element mesh model corresponding to the current moment and the structural parameters at the current moment.

[0030] Calculate the creep deformation result of the finite-length cladding tube at the current moment according to the current stiffness information, the current load information, a preset additional load vector, and a preset creep deformation calculation relationship.

[0031] Return to the step of obtaining the structural parameters of the finite-length cladding tube at the current moment, update the current moment to the next moment, calculate the creep deformation result of the finite-length cladding tube at the next moment, and stop the calculation until the creep deformation result of the finite-length cladding tube at the end of its service life is obtained, thereby obtaining the creep displacement curve and ovality change curve of the finite-length cladding tube.

[0032] In a second aspect, the present application also provides a device for calculating the creep deformation of a finite-length cladding tube. The device includes:

[0033] A parameter acquisition module for acquiring the structural parameters of the finite-length cladding tube.

[0034] A discretization processing module for performing discretization processing on the structural parameters to obtain the finite element mesh model corresponding to the finite-length cladding tube.

[0035] An information calculation module for calculating the stiffness information and load information according to the model parameters of the finite element mesh model and the structural parameters.

[0036] A deformation calculation module for calculating the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship.

[0037] In a third aspect, the present application also provides a computer device. The computer device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0038] Obtain the structural parameters of the finite-length cladding tube;

[0039] Perform discretization processing on the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube;

[0040] Calculate stiffness information and load information according to the model parameters of the finite element mesh model and the structural parameters;

[0041] Calculate the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship.

[0042] In a fourth aspect, the present application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0043] Obtain the structural parameters of the finite-length cladding tube;

[0044] Perform discretization processing on the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube;

[0045] Calculate stiffness information and load information according to the model parameters of the finite element mesh model and the structural parameters;

[0046] Calculate the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship.

[0047] In a fifth aspect, the present application also provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0048] Obtain the structural parameters of the finite-length cladding tube;

[0049] Perform discretization processing on the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube;

[0050] Calculate stiffness information and load information according to the model parameters of the finite element mesh model and the structural parameters;

[0051] Calculate the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship.

[0052] The above-mentioned creep deformation calculation method, device, computer equipment, storage medium and computer program product for a finite-length cladding tube discretize the structural parameters of the finite-length cladding tube to obtain a finite element mesh model corresponding to the finite-length cladding tube, and then calculate the stiffness information and load information according to the model parameters and structural parameters of the finite element mesh model. Furthermore, according to the stiffness information, load information, preset additional load vector and preset creep deformation calculation relationship, the creep deformation result of the finite-length cladding tube is calculated. By establishing a creep deformation model of the finite-length cladding tube, that is, a finite element mesh model, accurate creep deformation of the finite-length cladding tube can be obtained, solving the problem of large conservatism in the process of correcting the deformation from an infinite-length cladding tube to a finite-length cladding tube. At the same time, the reliability and rationality of the creep deformation and stress analysis of the finite-length fuel rod cladding tube are improved, ensuring the reliability of the cladding creep collapse analysis in the fuel rod design verification and enhancing the safety of the nuclear power plant. Description of the Drawings

[0053] Figure 1 It is a schematic flow chart of a creep deformation calculation method for a finite-length cladding tube in an embodiment;

[0054] Figure 2 It is a schematic flow chart of the step of calculating the stiffness information and load information according to the model parameters and structural parameters of the finite element mesh model in an embodiment;

[0055] Figure 3 It is a schematic flow chart of a creep deformation calculation method for a finite-length cladding tube in another embodiment;

[0056] Figure 4 It is a curve of the change of the internal and external pressure difference of a finite-length cladding tube with the irradiation time in an embodiment;

[0057] Figure 5 It is a curve of the change of the temperature of a finite-length cladding tube with the irradiation time in an embodiment;

[0058] Figure 6 It is a curve of the change of the neutron fluence rate of a finite-length cladding tube with the irradiation time in an embodiment;

[0059] Figure 7 It is a schematic diagram of an 8-node finite element mesh model in an embodiment;

[0060] Figure 8(a) is a curve of the displacement of the minor axis along the axial position of the middle section of a finite-length cladding tube with the irradiation time when the initial ovality e0 is 0.1 in an embodiment;

[0061] Figure 8(b) is a curve of the displacement of the major axis along the axial position of the middle section of a finite-length cladding tube with the irradiation time when the initial ovality e0 is 0.1 in an embodiment;

[0062] Figure 9 The variation curve of the ellipticity of the middle cross-section of a finite-length cladding tube with irradiation time under different initial ellipticities in an embodiment;

[0063] Figure 10 The variation curve of the displacement of the maximum node on the middle cross-section of a finite-length cladding tube with irradiation time in an embodiment;

[0064] Figure 11 The structural block diagram of a creep deformation calculation device for a finite-length cladding tube in an embodiment;

[0065] Figure 12 The internal structure diagram of a computer device in an embodiment. Specific embodiments

[0066] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0067] In one embodiment, as Figure 1 shown, a creep deformation calculation method for a finite-length cladding tube is provided. In this embodiment, an example is given where this method is applied to a terminal. It can be understood that this method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0068] Step 102, obtain the structural parameters of the finite-length cladding tube.

[0069] A finite-length cladding tube refers to the cladding tube of a finite-length fuel rod in a reactor, which is used to support the fissile fuel in the fuel assembly. A finite-length cladding tube is a tubular structure. For example, a finite-length cladding tube can be a zirconium alloy thick-walled circular tube with an initial ellipticity (caused by manufacturing errors).

[0070] When calculating the creep deformation of a finite-length cladding tube, it is necessary to obtain the structural parameters of the finite-length cladding tube. Among them, the structural parameters can be pre-input into the terminal. Specifically, the structural parameters can include geometric parameters, material parameters, irradiation parameters, etc. of the finite-length cladding tube. Geometric parameters include the axial height, cross-section thickness, inner and outer diameters, ellipticity, etc. of the finite-length cladding tube, material parameters include elastic modulus, Poisson's ratio, creep parameters, etc., and irradiation parameters include the inner and outer pressure differences, temperature, neutron fluence rate, etc.

[0071] Step 104, perform discretization processing on the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube.

[0072] The terminal performs discrete processing on the structural parameters, and the discrete processing belongs to the operation process of preprocessing. Specifically, the terminal processes the finite-length cladding tube into a discrete geometric model by performing discrete processing on the structural parameters. The discrete geometric model can also be called a finite element mesh model. For example, the finite element mesh model is an 8-node finite element mesh.

[0073] Step 106, calculate the stiffness information and load information according to the model parameters and structural parameters of the finite element mesh model.

[0074] The model parameters of the finite element mesh model can include the number of meshes, number of nodes, number of elements, total number of nodes, and degrees of freedom of the three-dimensional finite-length cladding tube in the axial, circumferential, and radial directions. Among them, a node is a calculation point that defines each finite element shape function. The number of elements = number of axial meshes * number of circumferential meshes * number of radial meshes, the total number of nodes = number of axial nodes * number of circumferential nodes * number of radial nodes, and the degrees of freedom = total number of nodes * number of radial meshes.

[0075] Specifically, the terminal calculates the element list and node list according to the model parameters of the finite element mesh model, and then calculates the stiffness information and load information according to the element list, node list, and structural parameters. Calculating the element list and node list is to define the calculation domain, map the geometry of the finite-length cladding tube into individual elements of the finite element method, the arrangement of the elements exists in the element list, and the information of each node of the element exists in the node list.

[0076] Among them, the element list can be expressed as:

[0077] {{Element 1, contained node 1, contained node 2, contained node 3,..., contained node 8},

[0078] {Element 2, contained node 1, contained node 2, contained node 3,..., contained node 8},

[0079] ...

[0080] {Element m, contained node 1, contained node 2, contained node 3,..., contained node 8}}.

[0081] The node list can be expressed as:

[0082] {{Node 1, x coordinate of node 1, y coordinate of node 1, z coordinate of node 1},

[0083] {Node 2, x coordinate of node 2, y coordinate of node 2, z coordinate of node 2},

[0084] ...

[0085] {Node n, x coordinate of node n, y coordinate of node n, z coordinate of node n}}.

[0086] The stiffness information may include an overall stiffness matrix, which refers to a matrix obtained by assembling the stiffnesses of all elements. The load information may include a load vector, an additional load vector caused by creep, and an increment of the additional load vector.

[0087] Step 108: Calculate the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship.

[0088] The terminal obtains a preset creep deformation calculation relationship. The preset creep deformation calculation relationship refers to a calculation formula for calculating the creep deformation of a finite-length cladding tube. For example, the preset creep deformation calculation relationship is a system of linear equations. The terminal substitutes the calculated stiffness information, load information, and preset additional load vector into the preset creep deformation calculation relationship to calculate the nodal displacements of the finite-length cladding tube, calculates the change result of the ovality according to the nodal displacements, and further determines the nodal displacements and the change result of the ovality as the creep deformation result of the finite-length cladding tube. Among them, the nodal displacements include the nodal displacements of the major axis and the minor axis of the middle cross-section of the finite-length cladding tube.

[0089] Furthermore, the creep deformation result calculated by the terminal can be the creep deformation result of the finite-length cladding tube at each moment, including the creep deformation result of the finite-length cladding tube at the end of its service life. The terminal draws curves according to the creep deformation results of the finite-length cladding tube from the initial moment to the end of its service life, and can obtain a curve of the nodal displacements of the finite-length cladding tube changing with time and a curve of the ovality changing with time.

[0090] In the above method for calculating the creep deformation of a finite-length cladding tube, the structural parameters of the finite-length cladding tube are discretized to obtain a finite element mesh model corresponding to the finite-length cladding tube, so as to calculate the stiffness information and the load information according to the model parameters and the structural parameters of the finite element mesh model, and further calculate the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship. By establishing a creep deformation model of the finite-length cladding tube, that is, a finite element mesh model, an accurate creep deformation of the finite-length cladding tube can be obtained, solving the problem of large conservatism in the process of correcting the deformation from an infinite-length cladding tube to a finite-length cladding tube. At the same time, the reliability and rationality of the creep deformation and stress analysis of the finite-length fuel rod cladding tube are improved, ensuring the reliability of the cladding creep collapse analysis in the fuel rod design verification and improving the safety of the nuclear power plant.

[0091] In one embodiment, as Figure 2 shown, step 106 includes:

[0092] Step 202: Obtain a preset matrix.

[0093] Step 204: Calculate the global stiffness matrix based on the model parameters of the finite element mesh model and a preset matrix to obtain stiffness information.

[0094] Step 206: Obtain a first preset function and a second preset function.

[0095] Step 208: Calculate load information based on the model parameters of the finite element mesh model, the first preset function, the structural parameters, the preset matrix, and the second preset function.

[0096] The global stiffness matrix refers to the matrix obtained by assembling the stiffnesses of all elements. The load information may include a load vector and an incremental additional load vector caused by creep.

[0097] The terminal obtains a preset matrix, which may include a strain matrix and an elasticity matrix. Both the strain matrix and the elasticity matrix are known matrices. The model parameters of the finite element mesh model may include the number of elements and the total number of nodes. The terminal can calculate an element list and a node list based on the model parameters of the finite element mesh model, and thus calculate the stiffness information and the load information based on the element list, the node list, and the structural parameters. The arrangement of elements exists in the element list, and the information of each node of an element exists in the node list.

[0098] Specifically, the terminal calculates the element stiffness matrix of each element in the element list according to the preset matrix, and then assembles the element stiffness matrices of all elements to obtain the global stiffness matrix. The global stiffness matrix is used as the stiffness information. In addition, the terminal also needs to calculate the load information. In this embodiment, in order to calculate the load information, the terminal obtains a first preset function and a second preset function. The first preset function is used to calculate the load vector, and the second preset function is used to calculate the incremental additional load vector caused by creep. The structural parameters of the finite-length cladding tube include the internal and external pressure difference. The terminal calculates the load vector according to the model parameters of the finite element mesh model, the first preset function, and the internal and external pressure difference, calculates the incremental additional load vector caused by creep according to the preset matrix, the structural parameters, and the second preset function, and further obtains the load information based on the load vector and the incremental additional load vector caused by creep.

[0099] It should be noted that there is no limitation on the calculation order of the stiffness information and the load information. They can be calculated simultaneously, or the stiffness information can be calculated first, or the load information can be calculated first.

[0100] In this embodiment, by establishing a finite element mesh model, it is possible to calculate the global stiffness matrix based on the model parameters of the finite element mesh model and the preset matrix to obtain accurate stiffness information, and it is also possible to calculate accurate load information based on the model parameters of the finite element mesh model, the first preset function, the structural parameters, the preset matrix, and the second preset function.

[0101] In an alternative embodiment of this example, step 204 includes: calculating the global stiffness matrix according to the model parameters of the finite element mesh model and a preset matrix, including: calculating the element stiffness matrix of each element in the finite element mesh model according to the model parameters of the finite element mesh model and the preset matrix; assembling the element stiffness matrices of each element to obtain the global stiffness matrix.

[0102] The terminal calculates an element list according to the model parameters of the finite element mesh model. The element list includes the arrangement information of multiple elements. The preset matrix may include a strain matrix and an elasticity matrix. Both the strain matrix and the elasticity matrix are known matrices.

[0103] The terminal obtains the calculation relationship of the element stiffness matrix, and calculates the element stiffness matrix of each element in the element list according to the model parameters of the finite element mesh model, the strain matrix, the elasticity matrix, and the calculation relationship of the element stiffness matrix. Among them, the calculation relationship of the element stiffness matrix is the calculation formula of the element stiffness matrix, which can be expressed as:

[0104]

[0105] Among them, [K] e represents the element stiffness matrix, B represents the strain matrix, and [B] T represents the transpose matrix of the strain matrix, and D represents the elasticity matrix.

[0106] The model parameters of the finite element mesh model include degrees of freedom. The terminal assembles the element stiffness matrices of each element according to the degrees of freedom to obtain a global stiffness matrix with the number of rows and columns equal to the number of degrees of freedom. Among them, the global stiffness matrix can be expressed as:

[0107] [K] t = ∑[K] e (2)

[0108] Among them, [K] t represents the global stiffness matrix at time t.

[0109] In this example, by calculating the element stiffness matrix of each element in the finite element mesh model according to the model parameters of the finite element mesh model and the preset matrix, and assembling the element stiffness matrices of each element, a more accurate global stiffness matrix can be obtained.

[0110] In an alternative embodiment of this example, step 208 includes: calculating a load vector according to the model parameters of the finite element mesh model, a first preset function, and the internal and external pressure difference in the structural parameters; calculating the additional load vector increment generated by creep according to the model parameters, the preset matrix, the structural parameters, and a second preset function; obtaining load information according to the load vector and the additional load vector increment generated by creep.

[0111] The first preset function is used to calculate the load vector. Specifically, the first preset function is a shape function. The second preset function is used to calculate the incremental additional load vector caused by creep. Specifically, the second preset function is a creep increment calculation function.

[0112] The terminal can obtain the load vector calculation relationship. Determine the loading surface according to the model parameters of the finite element mesh model, and then calculate the initial vector of each loading surface in the finite element mesh model according to the node list corresponding to the finite element mesh model, the first preset function, the internal and external pressure difference in the structural parameters, and the load vector calculation relationship, and assemble the initial vectors of all loading surfaces to obtain the load vector. The load vector calculation relationship can be expressed as:

[0113]

[0114] Among them, {f l} represents the load vector, N represents the shape function, N = 1 / 8(1+ / -x)(1+ / -y)(1+ / -z), and x, y, and z respectively represent the x coordinate, y coordinate, and z coordinate of each node in the node list. [N] T represents the transpose matrix of the shape function, and p represents the internal and external pressure difference (generally, external pressure > internal pressure).

[0115] The terminal calculates each loading surface in the finite element mesh model according to formula (3), and finally assembles to obtain the load vector.

[0116] The preset matrix includes a strain matrix and an elastic matrix. The terminal determines the stress according to the strain matrix and the elastic matrix, calculates the creep increment according to the stress, the structural parameters, and the second preset function, and then calculates the incremental additional load vector caused by creep according to the strain matrix and the creep increment. Furthermore, the load vector and the incremental additional load vector caused by creep are used as load information.

[0117] Furthermore, the stress can be expressed as {σ} = [D]{ε} = [D][B]{u 0}, where D represents the elastic matrix, {ε} represents the strain, B represents the strain matrix, and {u 0} represents the node displacement, which is an unknown number.

[0118] The creep constitutive relationship is a function of stress, temperature, neutron fluence, etc., that is, the creep rate Without loss of generality, the creep constitutive model of the Limback-Andersson model can be adopted, and the creep rate is divided into the thermal creep rate and the irradiation creep rate into two parts. From this, the following second preset function, that is, the creep increment calculation function, can be obtained:

[0119]

[0120] Among them, Δε c represents the creep increment, represents the creep rate, Δt represents the time increment, represents the thermal creep rate, represents the irradiation creep rate, A represents the thermal creep coefficient, E represents the elastic modulus, T represents the temperature, sinh represents the hyperbolic sine function, σ eff represents the equivalent stress, that is, the stress {σ} obtained from the above calculation, φ is the fast neutron fluence rate, Q, R, and C0 are all coefficients, and A, E, Q, R, C0, a i , c1, c2, and f(T) are all structural parameters of the finite-length cladding tube and are known parameters.

[0121] The terminal can determine the loading surface according to the model parameters of the finite element mesh model, calculate the initial additional load vector increment generated by creep for each loading surface in the finite element mesh model according to the strain matrix and the creep increment, and assemble all the initial additional load vector increments of the loading surfaces to obtain the additional load vector increment.

[0122] The calculation formula for the initial additional load vector increment can be expressed as:

[0123]

[0124] Among them, {Δf c} represents the initial additional load vector increment generated by creep, B represents the strain matrix, and [B] T represents the transposed matrix of the strain matrix, and Δε c represents the creep increment.

[0125] In this embodiment, since the finite element mesh model has been established, the load vector calculated according to the model parameters of the finite element mesh model, the first preset function, and the internal and external pressure difference in the structural parameters, and the additional load vector increment generated by creep calculated according to the model parameters, the preset matrix, the structural parameters, and the second preset function are more accurate.

[0126] In one embodiment, step 108 includes: calculating the nodal displacements of the major axis and the minor axis of the middle cross-section of the finite-length cladding tube according to the stiffness information, the load information, the preset additional load vector, and the preset creep deformation relationship; calculating the result of the change in the ovality of the finite-length cladding tube according to the nodal displacements of the major axis and the minor axis of the middle cross-section; obtaining the creep deformation result according to the nodal displacements of the major axis and the minor axis of the middle cross-section and the result of the change in the ovality.

[0127] The preset additional load vector refers to the initial additional load vector. The preset creep deformation relationship refers to the calculation formula for creep deformation.

[0128] The terminal substitutes the calculated stiffness information, load information, and the obtained preset additional load vector into the preset creep deformation relationship to calculate the displacements of all nodes in the finite element mesh model, and determines the displacements of the nodes on the major axis and minor axis of the middle cross-section of the finite-length cladding tube from the calculated node displacements. Among them, the preset creep deformation relationship can be shown as follows:

[0129] [K] t {u 0} t =f l} t +{f c +△f c} t (6)

[0130] Among them, [K] t represents the global stiffness matrix, {u 0} t represents the node displacements, that is, the displacements of the nodes on the major axis and minor axis of the middle cross-section of the finite-length cladding tube, which are unknowns, {f l} t represents the load vector, f c represents the preset additional load vector, {f c +Δf c} t represents the sum of the preset additional load vector and the additional load vector increment.

[0131] The terminal can solve formula (6) by the Gaussian elimination method or the SOR (Successive Over Relaxation) iterative method to obtain the node displacements of the finite-length cladding tube.

[0132] The terminal obtains the initial ovality, and the initial ovality is the difference between the outer diameter of the major axis and the outer diameter of the minor axis of the elliptical cross-section. The ovality change result of the finite-length cladding tube is calculated based on the initial ovality, the node displacements of the major axis and minor axis of the middle cross-section. The ovality change result can be expressed as 2*(d l -d s )+e0, where d l represents the node displacement of the major axis of the middle cross-section, d s represents the node displacement of the minor axis of the middle cross-section, and e0 represents the initial ovality. Furthermore, the terminal determines the node displacements of the major axis and minor axis of the middle cross-section and the ovality change result as the creep deformation result.

[0133] In this embodiment, since the stiffness information and load information calculated from the finite element mesh model are accurate, the calculated nodal displacements of the major axis of the middle section, the nodal displacements of the minor axis, and the results of the ellipticity change are also accurate.

[0134] In one embodiment, the creep deformation results include a creep displacement curve and an ellipticity change curve; the method further includes: obtaining the structural parameters of the finite-length cladding tube at the current moment; discretizing the structural parameters at the current moment to obtain a finite element mesh model corresponding to the finite-length cladding tube at the current moment; calculating the current stiffness information and current load information according to the model parameters of the finite element mesh model corresponding to the current moment and the structural parameters at the current moment; calculating the creep deformation results of the finite-length cladding tube at the current moment according to the current stiffness information, the current load information, and a preset creep deformation calculation relationship; returning to the step of obtaining the structural parameters of the finite-length cladding tube at the current moment, updating the current moment to the next moment, and calculating the creep deformation results of the finite-length cladding tube at the next moment until the creep deformation results of the finite-length cladding tube at the end of its service life are calculated, and then stopping the calculation to obtain the creep displacement curve and the ellipticity change curve of the finite-length cladding tube.

[0135] During the operation of a pressurized water reactor, it is necessary to calculate the creep deformation of the finite-length cladding tube in real time. Therefore, in this embodiment, the terminal needs to calculate the creep deformation results of the finite-length cladding tube at each moment. At the current moment, after the terminal calculates the creep deformation results, it will return to the step of obtaining the structural parameters of the finite-length cladding tube at the current moment, update the time increment, and update the current moment to the next moment. The next moment can be represented by the current moment t + time increment Δt (t + Δt). Calculate the creep deformation calculation results at the next moment in this way until the creep deformation results of the finite-length cladding tube at the end of its service life are calculated, and thus the creep deformation results changing with time can be obtained. Among them, the creep deformation results changing with time include the curve of the nodal displacement of the major axis of the middle section of the finite-length cladding tube changing with time, the curve of the nodal displacement of the minor axis changing with time, and the curve of the ellipticity changing with time.

[0136] In this embodiment, by establishing a finite-length cladding model, accurate creep deformation of the fuel rod cladding can be obtained. Therefore, an accurate curve of the creep deformation results changing with time can be obtained, and at the same time, it can also provide data support for subsequent nuclear power operations and improve the safety of nuclear power plants.

[0137] In another embodiment, as Figure 3 shown, a method for calculating the creep deformation of a finite-length cladding tube is provided, and the method includes the following steps:

[0138] Step 302, obtain the structural parameters of the finite-length cladding tube at the current moment.

[0139] Step 304, discrete processing.

[0140] Perform discrete processing on the structural parameters at the current moment to obtain the finite element mesh model corresponding to the finite-length cladding tube at the current moment.

[0141] Step 306, calculate the element stiffness matrix.

[0142] Calculate the element stiffness matrix of each element in the finite element mesh model according to the model parameters of the finite element mesh model and the preset matrix.

[0143] Step 308, calculate the global stiffness matrix to obtain the current stiffness information.

[0144] Assemble the element stiffness matrices of each element to obtain the global stiffness matrix as the current stiffness information.

[0145] Step 310, calculate the current load vector.

[0146] Calculate the current load vector according to the model parameters, the first preset function, and the internal and external pressure difference in the structural parameters.

[0147] Step 312, calculate the current additional load vector increment generated by creep.

[0148] Calculate the current additional load vector increment generated by creep according to the model parameters, the preset matrix, the structural parameters, and the second preset function.

[0149] Step 314, calculate the current load information.

[0150] Obtain the current load information based on the current load vector and the current additional load vector increment generated by creep.

[0151] Step 316, calculate the nodal displacements of the major axis and the minor axis of the middle cross-section at the current moment.

[0152] Calculate the nodal displacements of the major axis and the minor axis of the middle cross-section of the finite-length cladding tube at the current moment according to the current stiffness information, the current load information, the preset additional load vector, and the preset creep deformation relationship.

[0153] Step 318, calculate the ovality change result at the current moment.

[0154] Calculate the ovality change result of the finite-length cladding tube at the current moment according to the nodal displacements of the major axis and the minor axis of the middle cross-section at the current moment.

[0155] Step 320, calculate the creep deformation result at the current moment.

[0156] According to the nodal displacements of the major axis and minor axis of the central cross-section at the current moment, and the ellipticity change result at the current moment, the creep deformation result at the current moment is obtained.

[0157] Step 322, repeat the calculation steps of the creep deformation result until the calculation ends.

[0158] Return to the step of obtaining the structural parameters of the finite-length cladding tube at the current moment, update the current moment to the next moment, calculate the creep deformation result of the finite-length cladding tube at the next moment, until the creep deformation result of the finite-length cladding tube at the end of its service life is calculated, stop the calculation, and obtain the creep displacement curve and ellipticity change curve of the finite-length cladding tube.

[0159] In this embodiment, the process of the terminal calculating the creep displacement curve and ellipticity change curve is the same as the calculation process in the above embodiment, and will not be elaborated here.

[0160] Next, taking a certain finite-length fuel rod cladding tube as an example, the creep deformation calculation process in the above embodiment will be described.

[0161] 1. Obtain the structural parameters of the finite-length cladding tube at the current moment.

[0162] The structural parameters include the geometric parameters, material parameters, irradiation parameters, etc. of the finite-length cladding tube.

[0163] Geometric parameters: the axial height, cross-sectional thickness, inner and outer diameters, ellipticity, etc. of the finite-length fuel rod cladding tube. For example, the axial height is 10 mm, the cross-sectional thickness is 0.57 mm, the outer diameter is 9.75 mm, and the ellipticity is 0.1 mm.

[0164] Material parameters: elastic modulus, Poisson's ratio, creep parameters, etc. Determine the material type. For example, for Zr-4 alloy, its elastic modulus is taken as 78960 MPa, Poisson's ratio is taken as 0.346, and the creep parameters, that is, the material parameters in the creep constitutive model of the finite-length cladding tube, are shown in the attached table.

[0165] Attached Table Creep Parameters

[0166]

[0167] Irradiation parameters: the internal and external pressure difference, temperature, and neutron fluence rate corresponding to the finite-length cladding tube with irradiation time.

[0168] As Figure 4 , is the curve of the internal and external pressure difference of the finite-length cladding tube changing with irradiation time. As Figure 5 , is the curve of the temperature of the finite-length cladding tube changing with irradiation time, as Figure 6 , is the curve of the neutron fluence rate of the finite-length cladding tube changing with irradiation time.

[0169] 2. Discrete processing.

[0170] The finite-length cladding tube is discretized into a discrete geometric model. The discrete geometric model is an 8-node finite element mesh model, as Figure 7 shown.

[0171] The model parameters of the 8-node finite element mesh model include the number of meshes and nodes, the number of elements, the total number of nodes, and the number of degrees of freedom of the three-dimensional finite-length cladding tube in the axial, circumferential, and radial directions. The number of axial meshes is 7, the number of nodes is 8, the number of circumferential meshes and nodes are both 40, the number of radial meshes is 3, the number of nodes is 4, the number of elements is 840 (=7*40*3), the total number of nodes is 1280 (=8*40*4), and the number of degrees of freedom is 3840 (=1280*3).

[0172] The element list calculated according to the model parameters of the 8-node finite element mesh model is as follows:

[0173] {{Element 1, contained node 1, contained node 2, contained node 3,..., contained node 8},

[0174] {Element 2, contained node 1, contained node 2, contained node 3,..., contained node 8},

[0175] ...

[0176] {Element 840, contained node 1, contained node 2, contained node 3,..., contained node 8}}.

[0177] The node list calculated according to the model parameters of the 8-node finite element mesh model is as follows:

[0178] {{Node 1, x coordinate of node 1, y coordinate of node 1, z coordinate of node 1},

[0179] {Node 2, x coordinate of node 2, y coordinate of node 2, z coordinate of node 2},

[0180] ...

[0181] {Node 1280, x coordinate of node 1280, y coordinate of node 1280, z coordinate of node 1280}}.

[0182] 3. Calculate the element stiffness matrix.

[0183] The element stiffness matrix is calculated according to formula (1). The element stiffness matrix is a 24*24 square matrix, and the integration in formula (1) is calculated using Gauss quadrature.

[0184] 4. Calculate the global stiffness matrix to obtain the current stiffness information.

[0185] According to Equation (2), the stiffness matrices of each unit are assembled to obtain the global stiffness matrix, which is a 3840×3840 square matrix.

[0186] 5. Calculate the current load vector.

[0187] Calculate the initial vector of each loading surface in the 8-node finite element mesh model according to Equation (3), and finally assemble the initial vectors of all loading surfaces to obtain the load vector.

[0188] 6. Calculate the current additional load vector increment generated by creep.

[0189] Calculate the initial additional load vector increment generated by creep of each loading surface in the 8-node finite element mesh model according to Equation (4) and Equation (5), and assemble the initial additional load vector increments of all loading surfaces to obtain the additional load vector increment.

[0190] 7. Calculate the current load information.

[0191] Determine the current load information based on the current load vector and the current additional load vector increment generated by creep.

[0192] 8. Calculate the nodal displacements of the major axis and minor axis of the middle cross-section at the current moment.

[0193] Obtain the preset creep deformation relationship represented by Equation (6), where the unknown is the nodal displacement. Substitute the calculated current stiffness information, current load information, and the obtained preset additional load vector into the preset creep deformation relationship, and solve it by the Gaussian elimination method or the SOR iteration method to obtain the nodal displacements of the finite-length cladding tube at the current moment, and determine the nodal displacements of the major axis and minor axis of the middle cross-section of the finite-length cladding tube from them. The nodal displacements also include the displacement of the largest node on the middle cross-section of the finite-length cladding tube.

[0194] 9. Calculate the ovality change result at the current moment.

[0195] The ovality change result can be expressed as 2×(d l −d s ) + e0, where d l represents the nodal displacement of the major axis of the middle cross-section at the current moment, d s represents the nodal displacement of the minor axis of the middle cross-section at the current moment, and e0 represents the initial ovality.

[0196] 10. Calculate the creep deformation result at the current moment.

[0197] Determine the nodal displacements of the major axis and minor axis of the middle cross-section at the current moment and the ovality change result at the current moment as the creep deformation result at the current moment.

[0198] 11. Repeat the calculation steps of the repeated creep deformation until the calculation ends.

[0199] Repeat the above steps 1 - 10, output the creep deformation results at each moment until the creep deformation results of the finite - length cladding tube at the end of its service life are calculated, then stop the calculation and output the creep displacement curve and the ovality change curve of the finite - length cladding tube. The creep displacement curve includes the curves of the nodal displacements of the long and short axes of the middle cross - section of the finite - length cladding tube varying with the irradiation time. As shown in Fig. 8(a), it is the curve of the displacement of the short axis of the middle cross - section of the finite - length cladding tube along the axial position varying with the irradiation time when the initial ovality e0 is 0.1. As shown in Fig. 8(b), it is the curve of the displacement of the long axis of the middle cross - section of the finite - length cladding tube along the axial position varying with the irradiation time when the initial ovality e0 is 0.1. The position along the axial position is the nodal displacement. As Figure 9 shown, it is the curve of the ovality of the middle cross - section of the finite - length cladding tube varying with the irradiation time under different initial ovalities. In addition, the nodal displacements in the terminal calculation also include the displacement of the largest node on the middle cross - section of the finite - length cladding tube. According to the above creep deformation calculation process, the curve of the displacement of the largest node on the middle cross - section of the finite - length cladding tube varying with the irradiation time can also be output, as Figure 10 shown.

[0200] It should be understood that although each step in the flowcharts involved in the above - mentioned embodiments is shown in sequence according to the indication of the arrows, these steps do not necessarily execute in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above - mentioned embodiments may include multiple steps or multiple stages. These steps or stages do not necessarily execute at the same moment, but can execute at different moments, and the execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0201] Based on the same inventive concept, the embodiments of the present application also provide a finite - length cladding tube creep deformation calculation device for implementing the above - mentioned finite - length cladding tube creep deformation calculation method. The solution provided by this device to solve the problem is similar to the solution recorded in the above - mentioned method. Therefore, the specific limitations in one or more embodiments of the finite - length cladding tube creep deformation calculation device provided below can refer to the limitations on the finite - length cladding tube creep deformation calculation method in the above text, and will not be repeated here.

[0202] In one embodiment, as Figure 11As shown, a creep deformation calculation device for a finite-length cladding tube is provided, including: a parameter acquisition module 1102, a discretization processing module 1104, an information calculation module 1106, and a deformation calculation module 1108, where:

[0203] The parameter acquisition module 1102 is used to acquire the structural parameters of the finite-length cladding tube.

[0204] The discretization processing module 1104 is used to discretize the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube.

[0205] The information calculation module 1106 is used to calculate the stiffness information and load information according to the model parameters of the finite element mesh model and the structural parameters.

[0206] The deformation calculation module 1108 is used to calculate the creep deformation result of the finite-length cladding tube according to the stiffness information, load information, preset additional load vector, and preset creep deformation calculation relationship.

[0207] In one embodiment, the information calculation module 1106 is used to obtain a preset matrix; calculate the global stiffness matrix according to the model parameters of the finite element mesh model and the preset matrix to obtain the stiffness information; obtain a first preset function and a second preset function; calculate the load information according to the model parameters of the finite element mesh model, the first preset function, the structural parameters, the preset matrix, and the second preset function.

[0208] In one embodiment, the information calculation module 1106 is used to calculate the element stiffness matrix of each element in the finite element mesh model according to the model parameters of the finite element mesh model and the preset matrix; assemble the element stiffness matrices of each element to obtain the global stiffness matrix.

[0209] In one embodiment, the information calculation module 1106 is used to calculate the load vector according to the model parameters of the finite element mesh model, the first preset function, and the internal and external pressure difference in the structural parameters; calculate the additional load vector increment generated by creep according to the model parameters, the preset matrix, the structural parameters, and the second preset function; obtain the load information according to the load vector and the additional load vector increment generated by creep.

[0210] In one embodiment, the deformation calculation module 1108 is used to calculate the nodal displacements of the major axis and minor axis of the middle cross-section of the finite-length cladding tube according to the stiffness information, load information, preset additional load vector, and preset creep deformation relationship; calculate the ellipticity change result of the finite-length cladding tube according to the nodal displacements of the major axis and minor axis of the middle cross-section; obtain the creep deformation result according to the nodal displacements of the major axis and minor axis of the middle cross-section and the ellipticity change result.

[0211] In one embodiment, the creep deformation results include a creep displacement curve and an ovality change curve; the above device further includes:

[0212] A parameter acquisition module 1102, configured to acquire the structural parameters of the finite-length cladding tube at the current moment.

[0213] A discrete processing module 1104, configured to perform discrete processing on the structural parameters at the current moment to obtain a finite element mesh model corresponding to the finite-length cladding tube at the current moment.

[0214] An information calculation module 1106, configured to calculate the current stiffness information and the current load information according to the model parameters of the finite element mesh model corresponding to the current moment and the structural parameters at the current moment.

[0215] A deformation calculation module 1108, configured to calculate the creep deformation results of the finite-length cladding tube at the current moment according to the current stiffness information, the current load information, a preset additional load vector, and a preset creep deformation calculation relationship.

[0216] A curve output module, configured to return the steps of acquiring the structural parameters of the finite-length cladding tube at the current moment, update the current moment to the next moment, calculate the creep deformation results of the finite-length cladding tube at the next moment, until the creep deformation results of the finite-length cladding tube at the end of its service life are calculated, stop the calculation, and obtain the creep displacement curve and the ovality change curve of the finite-length cladding tube.

[0217] Each module in the above finite-length cladding tube creep deformation calculation device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in or independent of the processor in the computer device in the form of hardware, or stored in the memory of the computer device in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the above respective modules.

[0218] In one embodiment, a computer device is provided. The computer device can be a terminal, and its internal structure diagram can be as Figure 12As shown in the figure. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a method for calculating the creep deformation of a finite-length cladding tube. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the computer device housing, or an external keyboard, touchpad, or mouse, etc.

[0219] Those skilled in the art can understand that Figure 12 the structure shown in the figure is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0220] In one embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0221] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0222] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0223] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data that have been authorized by the user or fully authorized by all parties. Moreover, the collection, use, and processing of relevant data need to comply with the relevant laws, regulations, and standards of the relevant countries and regions.

[0224] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., and are not limited thereto. The processors involved in the embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., and are not limited thereto.

[0225] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0226] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A calculation method for creep deformation of a finite-length cladding tube, characterized in that, The method includes: Obtaining the structural parameters of a finite-length cladding tube; Performing discretization processing on the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube; Calculating stiffness information and load information according to the model parameters of the finite element mesh model and the structural parameters, including: obtaining a preset matrix; calculating an overall stiffness matrix according to the model parameters of the finite element mesh model and the preset matrix to obtain stiffness information; obtaining a first preset function and a second preset function; calculating a load vector according to the model parameters of the finite element mesh model, the first preset function, and the internal and external pressure difference in the structural parameters; calculating an additional load vector increment generated by creep according to the model parameters, the preset matrix, the structural parameters, and the second preset function; obtaining load information according to the load vector and the additional load vector increment generated by creep; the first preset function is a shape function, and the second preset function is a creep increment calculation function; Calculating the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship, including: calculating the nodal displacements of the major axis and the minor axis of the middle cross-section of the finite-length cladding tube according to the stiffness information, the load information, the preset additional load vector, and the preset creep deformation relationship; calculating the ellipticity change result of the finite-length cladding tube according to the nodal displacements of the major axis and the minor axis of the middle cross-section; obtaining the creep deformation result according to the nodal displacements of the major axis and the minor axis of the middle cross-section and the ellipticity change result.

2. The method according to claim 1, wherein The calculating the overall stiffness matrix according to the model parameters of the finite element mesh model and the preset matrix includes: Calculating the element stiffness matrix of each element in the finite element mesh model according to the model parameters of the finite element mesh model and the preset matrix; Assembling the element stiffness matrices of each element to obtain an overall stiffness matrix.

3. The method according to claim 1, characterized in that The creep deformation result includes a creep displacement curve and an ellipticity change curve; the method further includes: Obtaining the structural parameters of the finite-length cladding tube at the current moment; Performing discretization processing on the structural parameters at the current moment to obtain a finite element mesh model corresponding to the finite-length cladding tube at the current moment; Calculating the current stiffness information and the current load information according to the model parameters of the finite element mesh model corresponding to the current moment and the structural parameters at the current moment; Calculating the creep deformation result of the finite-length cladding tube at the current moment according to the current stiffness information, the current load information, the preset additional load vector, and the preset creep deformation calculation relationship; Returning to the step of obtaining the structural parameters of the finite-length cladding tube at the current moment, updating the current moment to the next moment, calculating the creep deformation result of the finite-length cladding tube at the next moment, and stopping the calculation until the creep deformation result of the finite-length cladding tube at the end of its service life is calculated, to obtain the creep displacement curve and the ellipticity change curve of the finite-length cladding tube.

4. The method according to claim 1, wherein The model parameters of the finite element mesh model include the number of meshes, the number of nodes, the number of elements, the total number of nodes, and the degrees of freedom of the finite-length cladding tube in the axial, circumferential, and radial directions.

5. A creep deformation calculation device for a finite-length cladding tube, characterized in that, The device includes: a parameter acquisition module for acquiring the structural parameters of the finite-length cladding tube; a discretization processing module for discretizing the structural parameters to obtain a finite element mesh model corresponding to the finite-length cladding tube; an information calculation module for calculating the stiffness information and the load information according to the model parameters of the finite element mesh model and the structural parameters, including: obtaining a preset matrix; calculating the global stiffness matrix according to the model parameters of the finite element mesh model and the preset matrix to obtain the stiffness information; obtaining a first preset function and a second preset function; calculating the load vector according to the model parameters of the finite element mesh model, the first preset function, and the internal and external pressure difference in the structural parameters; calculating the additional load vector increment generated by creep according to the model parameters, the preset matrix, the structural parameters, and the second preset function; obtaining the load information according to the load vector and the additional load vector increment generated by creep; the first preset function is a shape function, and the second preset function is a creep increment calculation function; a deformation calculation module for calculating the creep deformation result of the finite-length cladding tube according to the stiffness information, the load information, a preset additional load vector, and a preset creep deformation calculation relationship, including: calculating the node displacements of the major axis and the minor axis of the middle cross-section of the finite-length cladding tube according to the stiffness information, the load information, the preset additional load vector, and the preset creep deformation relationship; calculating the ellipticity change result of the finite-length cladding tube according to the node displacements of the major axis and the minor axis of the middle cross-section; obtaining the creep deformation result according to the node displacements of the major axis and the minor axis of the middle cross-section and the ellipticity change result.

6. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 4 are implemented.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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