Method, device and equipment for determining creep damage of high-temperature part coupled with fatigue damage, medium and product

Abstract

The invention discloses a method and a device for determining creep damage of a high-temperature part coupled with fatigue damage, a medium and a product, and relates to the field of high-temperature part safety assessment, the method comprises the following steps: constructing a cyclic elastic-plastic constitutive model; building a high-temperature part finite element model; the cyclic stress-strain and fatigue process of the high-temperature part under the service cyclic load is simulated; calculating the fatigue damage of the high-temperature part under the cyclic load spectrum; through fatigue damage and creep damage, the initial ratchet deformation serves as initial deformation of the creep damage stage of the high-temperature component, a service temperature field and a service load of the creep damage stage are applied to the high-temperature component, and elasticoplastic deformation and creep deformation of the component in the creep damage stage are obtained; and constructing a failure criterion and judging whether a failure occurs or not. According to the method, the creep-related structural integrity of the high-temperature part subjected to fatigue damage can be analyzed, and creep failure of the high-temperature part is prevented.

Description

Technical Field

[0001] The present application relates to the field of safety assessment of high-temperature components, and in particular to a method, device, equipment, medium and product for determining creep damage of high-temperature components coupled with fatigue damage. Background Art

[0002] With the rapid development of industrial technology, the creep failure assessment of high-temperature components of high-end equipment has attracted more and more attention from academia and industry. In particular, the safety assessment method for high-temperature components that first experience fatigue damage and then experience continuous creep damage is still a technical problem that plagues related fields. Taking nuclear power equipment as an example, once an accident occurs in a nuclear facility, causing the leakage of radioactive materials, the harm is huge. In order to prevent and prevent the occurrence of nuclear accidents, the second and third generation nuclear power equipment currently used adopts the In-Vessel Retention (IVR) technology as an important strategy for severe accident management of large advanced pressurized water reactors. The reactor takes IVR mitigation measures under severe accident conditions, generally through the cooling of the melt in the lower head and the cooling of the outer surface of the lower head. In the presence of external cooling water, the temperature difference between the inner and outer walls of the head is very large, often exceeding 1000℃, which causes large thermal stress in the entire head. Therefore, the lower head material is very prone to severe creep damage. Therefore, considering the early fatigue damage of the pressure vessel, preventing the creep failure of the pressure vessel over time is a necessary condition to ensure the integrity of the pressure vessel.

[0003] Currently, there is no documented method for safety assessment of high temperature components that first experience fatigue damage and then experience continuous creep damage in the prior art.

[0004] Therefore, how to conduct creep-related structural integrity analysis on high-temperature components that have experienced fatigue damage to prevent creep failure has become an urgent problem to be solved in this field. Summary of the invention

[0005] The purpose of this application is to provide a method, device, equipment, medium and product for determining creep damage of high-temperature components coupled with fatigue damage, which can analyze the creep-related structural integrity of high-temperature components that have experienced fatigue damage to prevent creep failure.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a method for determining creep damage of a high temperature component coupled with fatigue damage, comprising:

[0008] Determine the parameters of the cyclic elastoplastic constitutive model;

[0009] constructing a cyclic elastoplastic constitutive model based on the parameters;

[0010] Construct finite element models of high temperature components;

[0011] Based on the cyclic elastic-plastic constitutive model and the finite element model of the high-temperature component, preset boundary conditions and service load spectrum are applied to simulate the cyclic stress-strain and fatigue process of the high-temperature component under the service cyclic load;

[0012] Calculating fatigue damage of the high temperature component under a cyclic load spectrum based on the cyclic stress-strain and fatigue process of the high temperature component under the service cyclic load;

[0013] Based on the fatigue damage, a creep damage constitutive model coupled with fatigue damage is constructed;

[0014] Determining creep damage based on the creep damage constitutive model of coupled fatigue damage;

[0015] Through the fatigue damage and creep damage, the initial ratchet deformation is used as the initial deformation of the high-temperature component in the creep damage stage, and the service temperature field and service load of the creep damage stage are applied to the high-temperature component to obtain the elastic-plastic deformation and creep deformation of the component in the creep damage stage;

[0016] constructing a failure criterion based on the elastic-plastic deformation and creep deformation;

[0017] It is determined whether the high temperature component has failed based on the failure criterion.

[0018] Optionally, the expression of the cyclic elastoplastic constitutive model is as follows:

[0019] ε=ε e +ε p

[0020] ε e =D -1 :σ

[0021]

[0022]

[0023] Where ε is the total strain tensor, ε e is the elastic strain tensor, ε p is the plastic strain tensor, D is the elastic matrix, σ is the stress tension, F y is the yield criterion, s is the deviatoric stress tensor, α is the back stress tensor, R is the isotropic deformation resistance, is the plastic strain rate, is the equivalent plastic strain rate, J is the second invariant of the effect stress deviator, is the tensor under the ij component, z is the number of superpositions of back stress, k is the cyclic parameter, Ck is the initial kinematic hardening modulus, γ k As the plastic deformation increases, the kinematic hardening modulus C k The rate of decrease, ij is each component, α ij is the component of back stress, R 0 is the initial yield stress, is the equivalent plastic strain, R ∞ is the maximum change in the size of the yield surface, and b is the rate of change of the size of the yield surface with the increase of plastic strain.

[0024] Optionally, determining the parameters of the cyclic elastoplastic constitutive model specifically comprises the following steps:

[0025] Obtain stress-plastic strain curves of high-temperature component materials;

[0026] The stress-plastic strain curve is divided into three stages according to the curvature of each stage;

[0027] The kinematic hardening modulus C is determined based on the slopes of the three stages. k The initial value of; wherein k = 1, 2 or 3;

[0028] C-based k The initial value of γ is determined k The initial value of; where k = 1, 2 or 3; C k / γ k =σ maxi -R 0 , where σ maxi Represents the maximum stress value at each stage, R 0 represents the initial yield stress of the material, γ k As the plastic deformation increases, the kinematic hardening modulus C k The rate of decrease;

[0029] For the C k The initial value and γ k The initial value of C is optimized to obtain the final k and γ k .

[0030] Optionally, the calculation of fatigue damage of the high temperature component under the cyclic load spectrum specifically adopts the following formula:

[0031]

[0032] Among them, τ max and σ h,max They represent the maximum shear stress and maximum normal stress in a cycle, Δγ / 2 and Δε / 2 represent the shear strain amplitude and normal strain amplitude, τ' f , γ'f They represent shear fatigue strength and shear ductility strength, σ' f is the fatigue strength constant, ε' f is the fatigue ductility coefficient, G represents the shear modulus, b and c represent two indices related to fatigue strength and ductility, N f Parameters describing fatigue loss, E represents elastic modulus, and v′ represents Poisson's ratio.

[0033] Optionally, the expression of the creep damage constitutive model of coupled fatigue damage is as follows:

[0034]

[0035] in, is the component of creep strain rate, A, n, m are all material parameters, ω f is the initial fatigue damage of the material, f(ω f ) is the creep rate magnification factor, σ eq is the equivalent stress, S ij is the deviatoric stress, t is the time, ω c It is creep damage.

[0036] Optionally, the failure criterion constructed based on the elastic-plastic deformation and creep deformation specifically adopts the following formula:

[0037]

[0038] in, is the equivalent plastic strain, is the equivalent creep strain, is the plastic fracture strain, is the creep rupture strain, D is the total damage, and failure occurs when D exceeds 1.

[0039] In a second aspect, the present application provides a device for determining creep damage of a high-temperature component coupled with fatigue damage, the device for determining creep damage of a high-temperature component coupled with fatigue damage comprising:

[0040] A parameter determination module, used to determine the parameters of the cyclic elastic-plastic constitutive model;

[0041] A cyclic elastic-plastic constitutive model construction module, used for constructing a cyclic elastic-plastic constitutive model based on the parameters;

[0042] Finite element model building module, used to build finite element models of high-temperature components;

[0043] A cyclic stress-strain and fatigue process simulation module is used to apply preset boundary conditions and service load spectrum based on the cyclic elastic-plastic constitutive model and the high-temperature component finite element model to simulate the cyclic stress-strain and fatigue process of the high-temperature component under the service cyclic load;

[0044] A fatigue damage calculation module, used for calculating the fatigue damage of the high temperature component under the cyclic load spectrum based on the cyclic stress-strain and fatigue process of the high temperature component under the service cyclic load;

[0045] A creep damage constitutive model construction module coupled with fatigue damage, used to construct a creep damage constitutive model coupled with fatigue damage based on the fatigue damage;

[0046] A creep damage determination module, used for determining creep damage based on the creep damage constitutive model of coupled fatigue damage;

[0047] An elastic-plastic deformation and creep deformation determination module is used to use the fatigue damage and creep damage to take the initial ratchet deformation as the initial deformation of the high-temperature component in the creep damage stage, apply the service temperature field and service load of the creep damage stage to the high-temperature component, and obtain the elastic-plastic deformation and creep deformation of the component in the creep damage stage;

[0048] A failure criterion determination module constructs a failure criterion based on the elastic-plastic deformation and creep deformation;

[0049] The failure judgment module is used to judge whether the high-temperature component has failed based on the failure judgment criterion.

[0050] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for determining creep damage of a high-temperature component with coupled fatigue damage as described in any one of the above.

[0051] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-mentioned methods for determining creep damage of a high-temperature component with coupled fatigue damage.

[0052] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of any of the above-mentioned methods for determining creep damage of high-temperature components with coupled fatigue damage.

[0053] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0054] The present application provides a method, device, equipment, medium and product for determining creep damage of high-temperature components with coupled fatigue damage. A creep damage constitutive model of high-temperature components with coupled fatigue damage is established and numerically realized. At the same time, in conjunction with relevant cyclic constitutive models and fatigue damage calculation methods, secondary development of user subroutines and APDL language is carried out to achieve the continuity and data transmission of the entire numerical simulation process, and a complete creep damage analysis process for high-temperature components with coupled fatigue damage is established. The creep-related structural integrity of high-temperature components that have undergone fatigue damage can be analyzed to prevent creep failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 This is an application environment diagram of a method for determining creep damage of a high-temperature component coupled with fatigue damage in one embodiment of the present application;

[0057] Figure 2 A schematic flow chart of a method for determining creep damage of a high-temperature component coupled with fatigue damage provided in one embodiment of the present application;

[0058] Figure 3 A schematic diagram of strain cyclic deformation behavior at 1100 degrees and 1% strain amplitude simulated by a cyclic elastic-plastic constitutive model after determining parameters in an embodiment of the present application;

[0059] Figure 4 A schematic diagram of a fatigue load spectrum applied in an embodiment of the present application;

[0060] Figure 5 This is a fatigue simulation of three cycles in one embodiment of the present application, part (a) is the peak value of the first cycle, and part (b) is the peak value of the third cycle;

[0061] Figure 6 A schematic diagram of a stress-strain curve of a dangerous point under cyclic load in an embodiment of the present application;

[0062] Figure 7 The initial stress diagram obtained by the cyclic elastic-plastic model of the Chaboche nonlinear kinematic hardening evolution equation and the Voce nonlinear isotropic equation in one embodiment of the present application;

[0063] Figure 8The initial strain diagram obtained by the cyclic elastic-plastic model of the Chaboche nonlinear kinematic hardening evolution equation and the Voce nonlinear isotropic equation in one embodiment of the present application;

[0064] Fig. 9 This is a distribution diagram of the creep rate magnification factor of the lower head in one embodiment of the present application;

[0065] Fig.10 This is the final creep deformation cloud map of the lower head after 72 hours in one embodiment of the present application. Part (a) is the creep distribution cloud map without considering fatigue damage, and part (b) is the creep distribution cloud map with coupled fatigue damage.

[0066] Fig.11 This is the final plastic deformation cloud map of the lower head after 72 hours in one embodiment of the present application. Part (a) is the plastic deformation distribution cloud map without considering fatigue damage, and part (b) is the plastic deformation distribution cloud map coupled with fatigue damage;

[0067] Fig.12 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0069] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0070] The method for determining creep damage of a high temperature component coupled with fatigue damage provided in the embodiment of the present application can be applied to Figure 1In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, or it can be integrated on the server 104, or it can be placed on the cloud or other servers. The terminal 102 can send the high-temperature component data to be processed to the server 104. After the server 104 receives the high-temperature component data to be processed, for the high-temperature component data to be processed, the server 104 first determines the parameters of the cyclic elastic-plastic constitutive model; constructs a cyclic elastic-plastic constitutive model based on the parameters; constructs a finite element model of the high-temperature component; based on the cyclic elastic-plastic constitutive model and the high-temperature component finite element model, applies preset boundary conditions and service load spectra to simulate the cyclic stress-strain and fatigue process of the high-temperature component under service cyclic loads; based on the cyclic stress of the high-temperature component under service cyclic loads The fatigue damage of the high-temperature component under the cyclic load spectrum is calculated by force-strain and fatigue process; a creep damage constitutive model coupled with fatigue damage is constructed based on fatigue damage; creep damage is determined based on the creep damage constitutive model coupled with fatigue damage; through fatigue damage and creep damage, the initial ratchet deformation is used as the initial deformation of the creep damage stage of the high-temperature component, and the service temperature field and service load of the creep damage stage are applied to the high-temperature component to obtain the elastic-plastic deformation and creep deformation of the component in the creep damage stage; a failure criterion is constructed based on the elastic-plastic deformation and creep deformation; and whether the high-temperature component fails is determined based on the failure criterion. The server 104 can feed back the obtained result of whether the high-temperature component fails to the terminal 102. In addition, in some embodiments, the method for determining the creep damage of the high-temperature component coupled with fatigue damage can also be implemented by the server 104 or the terminal 102 alone, such as the terminal 102 can directly process the high-temperature component data to be processed to obtain the result of whether it fails, or the server 104 can obtain the high-temperature component data to be processed from the data storage system for processing to obtain the result of whether it fails.

[0071] The terminal 102 may be, but is not limited to, various desktop computers, laptop computers, smart phones, tablet computers, IoT devices, and portable wearable devices. The IoT devices may be smart speakers, smart TVs, smart air conditioners, smart vehicle-mounted devices, etc. The portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers, or may be a cloud server.

[0072] In an exemplary embodiment, Figure 2 As shown, a method for determining creep damage of a high temperature component coupled with fatigue damage is provided. The method is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1The server 104 in the example is used as an example to illustrate, including the following steps 201 to 210. Among them:

[0073] Step 201: Determine the parameters of the cyclic elastoplastic constitutive model.

[0074] Specifically, the stress-plastic strain curve of the material is obtained by processing the experimental single tension curve, and the stress-plastic strain curve is divided into three stages according to the curvature of each stage, and C is determined according to the slopes of the three stages. k (k = 1, 2 or 3), and then calculate γ according to formula (1) k (k=1, 2 or 3) initial value.

[0075] C k / γ k =σ maxi -R 0 (1)

[0076] where σ maxi Represents the maximum stress value at each stage, R 0 represents the initial yield stress of the material. Finally, the initial value is optimized through error iteration to obtain the final C k and γ k .

[0077] Step 202: constructing a cyclic elastic-plastic constitutive model based on the parameters.

[0078] Among them, the cyclic elastoplastic constitutive model is based on the superposition of Chaboche nonlinear kinematic hardening evolution equation and Voce nonlinear isotropic hardening evolution equation.

[0079] The specific formula is as follows:

[0080] ε=ε e +ε p (2)

[0081] ε e =D -1 :σ(3)

[0082]

[0083] Among them, Formula 6 and Formula 7 are nonlinear kinematic hardening evolution equations, Formula 8 is the nonlinear isotropic hardening evolution equation, ε is the total strain tensor, ε e is the elastic strain tensor, ε p is the plastic strain tensor, D is the elastic matrix, σ is the stress tension, F y is the yield criterion, s is the deviatoric stress tensor, α is the back stress tensor, R is the isotropic deformation resistance, is the plastic strain rate, is the equivalent plastic strain rate, J is the second invariant of the effect stress deviator, is the tensor under the ij component, z is the number of superpositions of back stress, k is the cyclic parameter, C k is the initial kinematic hardening modulus, γ k As the plastic deformation increases, the kinematic hardening modulus C k The rate of decrease, ij is each component, α ij is the component of back stress, R 0 is the initial yield stress, is the equivalent plastic strain, R ∞ and b are material constants, R ∞ is the maximum change value of the yield surface size, and b is the rate of change of the yield surface size with the increase of plastic strain, which can be obtained through the evolution curve of the material's response stress amplitude with the number of cycles and the trial and error method respectively.

[0084] In this embodiment, taking the steel 16MND5 for the lower head of the pressure vessel as an example, a cyclic elastic-plastic constitutive model based on the superposition of the Chaboche nonlinear kinematic hardening evolution equation and the Voce nonlinear isotropic hardening evolution equation is used to describe the cyclic deformation of the steel 16MND5 for the lower head of the pressure vessel under cyclic loads. The corresponding C k and γ k See Table 1. Figure 3 The model is given to simulate the strain cyclic deformation behavior of 16MND5 material at 1100 degrees and 1% strain amplitude. It can be seen that the model can describe the cyclic softening behavior of 16MND5 material.

[0085] Step 203: Construct a finite element model of a high temperature component.

[0086] Step 204: Based on the cyclic elastic-plastic constitutive model and the high-temperature component finite element model, preset boundary conditions and service load spectrum are applied to simulate the cyclic stress-strain and fatigue process of the high-temperature component under the service cyclic load.

[0087] Based on the secondary development of large-scale finite element software, the service process of the lower head structure under cyclic load is simulated to obtain the ratchet deformation value and the corresponding equivalent stress amplitude. At the same time, a fatigue damage model based on the critical plane method is introduced to calculate the fatigue damage of the lower head under the cyclic load spectrum in real time. This embodiment adopts a load spectrum of Pmax = 50MPa, Pmin = -10MPa (see Figure 4 ), three cycles of fatigue simulation were performed. Figure 5 As shown, Figure 5 Part (a) is the peak value of the first week. Figure 5Part (b) in the figure is the peak value of the third cycle. It can be seen that under the cyclic load of Pmax = 50MPa, Pmin = -10MPa, the peak stress gradually decreases with the number of cycles, showing a cyclic softening characteristic. At the same time, Figure 6 The stress-strain curve of the dangerous point shows that the reverse yield effect is generated when the valley value is loaded, and a hysteresis loop curve that gradually moves forward is generated, that is, ratchet deformation is generated. In the process of cycling, two aspects of fatigue damage will be caused: on the one hand, the superposition of ratchet deformation, and on the other hand, the fatigue damage that causes crack initiation.

[0088] Step 205: Calculate fatigue damage of the high temperature component under the cyclic load spectrum based on the cyclic stress-strain and fatigue process of the high temperature component under the service cyclic load.

[0089] This application adopts the critical plane (SWT) method, considering the contribution of shear strain and normal strain to total strain damage, to realize the MGSA fatigue damage model. This method combines the MC equation to establish a fatigue damage model based on the critical plane method, and calculates the fatigue damage of high-temperature components under cyclic load spectrum in real time.

[0090] The specific calculation formula is as follows:

[0091]

[0092] Among them, τ max and σ h,max They represent the maximum shear stress and maximum normal stress in a cycle, Δγ / 2 and Δε / 2 represent the shear strain amplitude and normal strain amplitude, τ' f , γ' f They represent shear fatigue strength and shear ductility strength, σ' f is the fatigue strength constant, ε' f is the fatigue ductility coefficient, G represents the shear modulus, b and c represent two indices related to fatigue strength and ductility, which can be obtained through fatigue tests on materials, and N f Parameters describing fatigue loss, E represents elastic modulus, and v′ represents Poisson's ratio.

[0093] In terms of fatigue prediction of high-temperature components, the model shows good prediction ability. In the numerical simulation process of fatigue first and creep later, the state variables of the ANSYS creep subroutine are used to calculate and record the initial fatigue damage, thereby providing fatigue damage values ​​for the creep analysis process.

[0094] Step 206: constructing a creep damage constitutive model coupled with fatigue damage based on the fatigue damage.

[0095] Based on the full-life creep test of component materials, this application establishes the following creep damage constitutive model coupled with fatigue damage, and numerically implements it through the Usercreep user subroutine.

[0096] The specific formula is as follows:

[0097]

[0098] in, is the component of creep strain rate, A, n, and m are all material parameters, which can be obtained by performing creep tests on materials with initial fatigue damage and correlating creep strain evolution with fatigue damage, ω f is the initial fatigue damage of the material, f(ω f ) is the creep rate magnification factor, σ eq is the equivalent stress, S ij is the deviatoric stress, t is the time, ω c It is creep damage.

[0099] Among them, ω c The evolution equation of creep damage is:

[0100]

[0101] and are the creep damage rate and creep strain rate, respectively. Represents the multiaxial creep rupture strain, that is, the multiaxial creep ductility. Due to the complexity of the stress state in the crack tip area, its value is usually different from the uniaxial creep ductility ε f Different from the uniaxial creep ductility is the multi-axial ductility factor. This application selects the MCDF model redefined in exponential form by Wen-Tu et al. as the multi-axial ductility factor, and its expression is as shown in formula (13):

[0102]

[0103] In order to facilitate engineering applications, this model takes ε f is a constant, σ m is the hydrostatic pressure.

[0104] Step 207: Determine creep damage based on the creep damage constitutive model of coupled fatigue damage.

[0105] Based on the full-life creep test of component materials, a creep damage constitutive model of coupled fatigue damage is established, and numerically implemented through the Usercreep user subroutine, and reasonable state variables are set to establish a data and result transfer module between the fatigue service process and the creep service process of the lower head. After completing the fatigue unloading, the temperature field is assigned to the lower head, considering the influence of the high-temperature melt, killing the melting unit, and at the same time giving the initial stress and strain field of the creep analysis of the lower head, and the ratchet deformation is used as the initial deformation of the creep analysis of the lower head under the IVR condition. Transfer to the creep analysis stage, at the same time, the fatigue damage formula in the cycle process is transferred and coupled to the creep damage constitutive model through the state variables, that is, the deterioration of the material's creep resistance caused by fatigue damage is taken into account in the creep analysis of the lower head.

[0106] Step 208: Using the fatigue damage and creep damage, the initial ratchet deformation is used as the initial deformation of the high-temperature component in the creep damage stage, and the service temperature field and service load of the creep damage stage are applied to the high-temperature component to obtain the elastic-plastic deformation and creep deformation of the component in the creep damage stage.

[0107] Through the data and result transfer module, the initial ratchet deformation is taken as the initial deformation of the lower head creep damage stage, and the initial stress distribution and strain distribution are obtained as follows: Figure 7 and Figure 8 The service temperature field and service load of the creep damage stage are applied to the lower head. The elastic-plastic deformation and creep deformation of the component in this service stage are obtained through finite element analysis. The creep parameters involved in this stage are listed in Table 1.

[0108] Table 1 Parameters of cyclic constitutive model and creep damage constitutive model at different temperatures

[0109]

[0110]

[0111] Based on the above steps, this embodiment conducts creep analysis on the lower head of the pressure vessel, simulating the elastic-plastic deformation and creep deformation within 72 hours after the lower head accident. f =1500; b = -0.25, calculate the creep rate magnification factor after material degradation. The obtained creep rate magnification factor cloud diagram is as follows: Fig. 9 As shown, Fig.10 This is the final creep deformation cloud diagram of the lower head after 72 hours. Fig.10 Part (a) is the 72-hour creep distribution cloud diagram of the lower head without considering fatigue damage. Fig.10Part (b) is the 72-hour creep distribution cloud diagram of the lower head with coupled fatigue damage. It can be seen from the figure that when fatigue damage is not considered, the maximum creep deformation of the lower head after 72 hours is about 0.72%, while after coupled fatigue damage, the maximum creep deformation of the lower head is about 1.62%. It can be seen that under the influence of fatigue damage, the creep deformation of the lower head has been significantly improved. Fig.11 This is the final plastic deformation cloud diagram of the lower head after 72 hours, where: Fig.11 Part (a) is the 72-hour plastic deformation distribution cloud diagram of the lower head without considering fatigue damage. Fig.11 Part (b) is the 72-hour plastic deformation distribution cloud diagram of the lower head with coupled fatigue damage. It can also be seen that under the influence of fatigue damage, the plastic deformation of the lower head has been improved.

[0112] Step 209: constructing a failure criterion based on the elastic-plastic deformation and creep deformation.

[0113] The specific formula is as follows:

[0114]

[0115] in, is the equivalent plastic strain, is the equivalent creep strain, is the plastic fracture strain, is the creep rupture strain, D is the total damage, and failure occurs when D exceeds 1.

[0116] Step 210: Determine whether the high-temperature component has failed based on the failure criterion.

[0117] In this embodiment, the overall damage and failure of the lower head are evaluated and safety assessed based on the established failure criterion of combined elastic-plastic damage and creep deformation damage. In this embodiment, a finite element simulation is performed on the lower head, and the maximum creep strain point A (see Fig.10 ) were analyzed and calculated, and the results are shown in Table 2. It can be seen that under the influence of fatigue damage, the creep strain, plastic strain and total damage parameter D of the lower head have increased significantly.

[0118] Table 2 Final strain and total damage parameter D at point A of lower head at 72 hours

[0119]

[0120] In summary, the creep analysis method of high-temperature components considering fatigue damage in this application provides a set of calculation methods considering fatigue damage of high-temperature components in service. A creep damage constitutive model of high-temperature components considering fatigue damage is established and numerically implemented. At the same time, in conjunction with the relevant cyclic constitutive model and fatigue damage calculation method, secondary development of user subroutines and APDL language is carried out to achieve the continuity and data transfer of the entire numerical simulation process, and establish a complete creep analysis process considering fatigue damage of high-temperature components.

[0121] Based on the same inventive concept, the embodiment of the present application also provides a device for determining creep damage of high-temperature components with coupled fatigue damage as mentioned above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations of one or more embodiments of the device for determining creep damage of high-temperature components with coupled fatigue damage provided below can refer to the limitations of the method for determining creep damage of high-temperature components with coupled fatigue damage above, and will not be repeated here.

[0122] In an exemplary embodiment, a device for determining creep damage of a high temperature component coupled with fatigue damage is provided, comprising:

[0123] A parameter determination module, used to determine the parameters of the cyclic elastic-plastic constitutive model;

[0124] A cyclic elastic-plastic constitutive model construction module, used for constructing a cyclic elastic-plastic constitutive model based on the parameters;

[0125] Finite element model building module, used to build finite element models of high-temperature components;

[0126] A cyclic stress-strain and fatigue process simulation module is used to apply preset boundary conditions and service load spectrum based on the cyclic elastic-plastic constitutive model and the high-temperature component finite element model to simulate the cyclic stress-strain and fatigue process of the high-temperature component under the service cyclic load;

[0127] A fatigue damage calculation module, used for calculating the fatigue damage of the high temperature component under the cyclic load spectrum based on the cyclic stress-strain and fatigue process of the high temperature component under the service cyclic load;

[0128] A creep damage constitutive model construction module coupled with fatigue damage, used to construct a creep damage constitutive model coupled with fatigue damage based on the fatigue damage;

[0129] A creep damage determination module, used for determining creep damage based on the creep damage constitutive model of coupled fatigue damage;

[0130] An elastic-plastic deformation and creep deformation determination module is used to use the fatigue damage and creep damage to take the initial ratchet deformation as the initial deformation of the high-temperature component in the creep damage stage, apply the service temperature field and service load of the creep damage stage to the high-temperature component, and obtain the elastic-plastic deformation and creep deformation of the component in the creep damage stage;

[0131] A failure criterion determination module constructs a failure criterion based on the elastic-plastic deformation and creep deformation;

[0132] The failure judgment module is used to judge whether the high-temperature component has failed based on the failure judgment criterion.

[0133] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig.12 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is 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, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store high-temperature component safety assessment data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for determining creep damage of a high-temperature component coupled with fatigue damage is implemented.

[0134] Those skilled in the art will understand that Fig.12 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0135] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0136] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0137] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0138] 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 used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0139] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and 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-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. 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), magnetic 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 may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0140] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0141] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0142] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for determining creep damage of a high temperature component coupled with fatigue damage, characterized in that: The method for determining creep damage of a high temperature component coupled with fatigue damage comprises: Determine the parameters of the cyclic elastoplastic constitutive model; constructing a cyclic elastoplastic constitutive model based on the parameters; Construct finite element models of high temperature components; Based on the cyclic elastic-plastic constitutive model and the finite element model of the high-temperature component, preset boundary conditions and service load spectrum are applied to simulate the cyclic stress-strain and fatigue process of the high-temperature component under the service cyclic load; Calculating fatigue damage of the high temperature component under a cyclic load spectrum based on the cyclic stress-strain and fatigue process of the high temperature component under the service cyclic load; Based on the fatigue damage, a creep damage constitutive model coupled with fatigue damage is constructed; Determining creep damage based on the creep damage constitutive model of coupled fatigue damage; Through the fatigue damage and creep damage, the initial ratchet deformation is used as the initial deformation of the high-temperature component in the creep damage stage, and the service temperature field and service load of the creep damage stage are applied to the high-temperature component to obtain the elastic-plastic deformation and creep deformation of the component in the creep damage stage; constructing a failure criterion based on the elastic-plastic deformation and creep deformation; It is determined whether the high temperature component has failed based on the failure criterion.

2. The method for determining creep damage of high temperature components coupled with fatigue damage according to claim 1, characterized in that: The expression of the cyclic elastoplastic constitutive model is as follows: e=e e +e p e e =D -1 :s Where ε is the total strain tensor, ε e is the elastic strain tensor, ε p is the plastic strain tensor, D is the elastic matrix, σ is the stress tension, F y is the yield criterion, s is the deviatoric stress tensor, α is the back stress tensor, R is the isotropic deformation resistance, is the plastic strain rate, is the equivalent plastic strain rate, J is the second invariant of the effect stress deviator, is the tensor under the ij component, z is the number of superpositions of back stress, k is the cyclic parameter, C k is the initial kinematic hardening modulus, γ k As the plastic deformation increases, the kinematic hardening modulus C k The rate of decrease, ij is each component, α ij is the component of back stress, R0 is the initial yield stress, is the equivalent plastic strain, R ∞ is the maximum change in the size of the yield surface, and b is the rate of change of the size of the yield surface with the increase of plastic strain.

3. The method for determining creep damage of high temperature components coupled with fatigue damage according to claim 1, characterized in that: The step of determining the parameters of the cyclic elastoplastic constitutive model specifically comprises the following steps: Obtain stress-plastic strain curves of high-temperature component materials; The stress-plastic strain curve is divided into three stages according to the curvature of each stage; The kinematic hardening modulus C is determined based on the slopes of the three stages. k The initial value of; wherein k = 1, 2 or 3; C-based k The initial value of γ is determined k The initial value of; where k = 1, 2 or 3; C k / γ k =σ maxi -R0, where σ maxi represents the maximum stress value in each stage, R0 represents the initial yield stress of the material, γ k As the plastic deformation increases, the kinematic hardening modulus C k The rate of decrease; For the C k The initial value and γ k The initial value of C is optimized to obtain the final k and γ k .

4. The method for determining creep damage of high temperature components coupled with fatigue damage according to claim 1, characterized in that: The calculation of fatigue damage of high temperature components under cyclic load spectrum specifically adopts the following formula: Among them, τ max and σ h,max They represent the maximum shear stress and maximum normal stress in a cycle, Δγ / 2 and Δε / 2 represent the shear strain amplitude and normal strain amplitude, τ' f , γ' f They represent shear fatigue strength and shear ductility strength, σ' f is the fatigue strength constant, ε' f is the fatigue ductility coefficient, G represents the shear modulus, b and c represent two indices related to fatigue strength and ductility, N f Parameters describing fatigue loss, E represents elastic modulus, and v′ represents Poisson's ratio.

5. The method for determining creep damage of high temperature components coupled with fatigue damage according to claim 1, characterized in that: The expression of the creep damage constitutive model of coupled fatigue damage is as follows: in, is the component of creep strain rate, A, n, m are all material parameters, ω f is the initial fatigue damage of the material, f(ω f ) is the creep rate magnification factor, σ eq is the equivalent stress, S ij is the deviatoric stress, t is the time, ω c It is creep damage.

6. The method for determining creep damage of high temperature components coupled with fatigue damage according to claim 1, characterized in that: The failure criterion constructed based on the elastic-plastic deformation and creep deformation specifically adopts the following formula: in, is the equivalent plastic strain, is the equivalent creep strain, is the plastic fracture strain, is the creep rupture strain, D is the total damage, and failure occurs when D exceeds 1.

7. A device for determining creep damage of high temperature components coupled with fatigue damage, characterized in that: The device for determining creep damage of a high temperature component coupled with fatigue damage comprises: A parameter determination module, used to determine the parameters of the cyclic elastic-plastic constitutive model; A cyclic elastic-plastic constitutive model construction module, used for constructing a cyclic elastic-plastic constitutive model based on the parameters; Finite element model building module, used to build finite element models of high-temperature components; A cyclic stress-strain and fatigue process simulation module is used to apply preset boundary conditions and service load spectrum based on the cyclic elastic-plastic constitutive model and the high-temperature component finite element model to simulate the cyclic stress-strain and fatigue process of the high-temperature component under the service cyclic load; A fatigue damage calculation module, used for calculating the fatigue damage of the high temperature component under the cyclic load spectrum based on the cyclic stress-strain and fatigue process of the high temperature component under the service cyclic load; A creep damage constitutive model construction module coupled with fatigue damage, used to construct a creep damage constitutive model coupled with fatigue damage based on the fatigue damage; A creep damage determination module, used for determining creep damage based on the creep damage constitutive model of coupled fatigue damage; An elastic-plastic deformation and creep deformation determination module is used to use the fatigue damage and creep damage to take the initial ratchet deformation as the initial deformation of the high-temperature component in the creep damage stage, apply the service temperature field and service load of the creep damage stage to the high-temperature component, and obtain the elastic-plastic deformation and creep deformation of the component in the creep damage stage; A failure criterion determination module constructs a failure criterion based on the elastic-plastic deformation and creep deformation; The failure judgment module is used to judge whether the high-temperature component has failed based on the failure judgment criterion.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for determining creep damage of a high temperature component coupled with fatigue damage according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for determining creep damage of a high-temperature component coupled with fatigue damage according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method for determining creep damage of a high-temperature component coupled with fatigue damage according to any one of claims 1 to 6 are implemented.

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