Method and system for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment for ships and storage medium

Abstract

The application discloses a kind of ship high-pressure hydrogen environment material hydrogen embrittlement damage prediction method, system and storage medium, method includes: the hydrogen-pressure component of ship involved hydrogen is collected Hydrogen-force coupling constitutive parameter and ship service dynamic boundary load, constructs multi-source physical input dataset.Rely on dataset to build dynamic stress-hydrogen diffusion coupling model driven by stress gradient and dislocation transport, solve the concentration field of transient lattice hydrogen and trap hydrogen inside component.Hydrogen concentration field is substituted into hydrogen-induced material performance degradation criterion, establishes hydrogen embrittlement damage evolution model relying on cohesive force attenuation.Combined with the convergence characteristics of multi-physical field model and damage critical fracture standard, adaptive time step is used to complete double-model coupling iteration solution, finally output the hydrogen embrittlement damage spatial distribution result of pressure-bearing component, realize the quantitative prediction of component residual fatigue life.Provide reliable technical support for the stable development of hydrogen energy ship.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen embrittlement detection technology, and more specifically, relates to a method, system and storage medium for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications. Background Technology

[0002] As the shipbuilding industry continues its green and low-carbon transformation, high-pressure hydrogen energy storage and transportation equipment is gradually being installed on large-scale ocean-going and inland waterway vessels. Various hydrogen-related pressure-bearing components have become key components of the power systems of hydrogen-powered ships. Under high-pressure hydrogen operating conditions, metallic materials are highly susceptible to hydrogen embrittlement damage. During long-term service, microcracks develop in components and gradually propagate, which can lead to hydrogen leakage or even equipment explosion, directly threatening the safety of ship navigation. Therefore, predicting hydrogen embrittlement damage in marine pressure-bearing components has become a crucial aspect of the operation and maintenance management of hydrogen-powered ships.

[0003] Currently, most commonly used hydrogen embrittlement assessment methods in the industry rely on static high-pressure hydrogen environment tests in land-based laboratories. These tests have relatively simple load conditions, only allowing for material performance testing under constant pressure and fixed loads, making it difficult to replicate the complex stress conditions experienced by ships during maritime service. Ships continuously endure alternating bending loads caused by waves, high-frequency vibration loads from power equipment operation, and instantaneous impact loads from floating objects. The coupling effect of these multiple load types alters the internal stress distribution and hydrogen atom migration patterns of the material. Therefore, hydrogen embrittlement prediction data obtained from static tests has a low degree of consistency with actual ship operating conditions, limiting its reference value.

[0004] Traditional numerical prediction methods generally suffer from a lack of understanding of the underlying mechanisms in hydrogen concentration calculations. Most rely solely on concentration differences as the driving force for hydrogen diffusion, neglecting two crucial hydrogen migration pathways: stress gradient-driven diffusion and dislocation-driven transport. This leads to inaccurate calculations of local hydrogen enrichment levels within the material. Furthermore, most damage evolution models assume constant material mechanical parameters, failing to update yield strength and interfacial bonding strength in real-time to reflect changes in local hydrogen content. They also cannot quantify the accelerating effect of hydrogen-induced material degradation on crack propagation. Fixed-step solution methods are also prone to computational divergence near component failure, resulting in excessively long simulation times for long-cycle fatigue life.

[0005] Relying on manual disassembly and flaw detection to identify hydrogen embrittlement risks requires ships to be shut down for maintenance, which significantly increases shipping operating costs and hinders the commercialization of hydrogen-powered ships. The rapid development of the shipping industry is forcing the industry to improve hydrogen embrittlement prediction technology, and there is an urgent need to develop an integrated prediction solution adapted to the multi-load service characteristics of ships to reduce the safety risks caused by hydrogen embrittlement failure from the source and contribute to the stable development of the green shipbuilding industry. Summary of the Invention

[0006] This invention aims to overcome the shortcomings of existing hydrogen embrittlement detection methods, which rely on static tests, cannot match the complex alternating service loads of ships, and have insufficient accuracy in calculating hydrogen diffusion and damage evolution. It constructs a multi-physics field coupled hydrogen embrittlement damage prediction system to calculate the hydrogen embrittlement distribution and remaining fatigue life of hydrogen-related pressure-bearing components, improve the safety assessment level of marine high-pressure hydrogen equipment, and reduce the risk of operational failure of marine hydrogen energy equipment.

[0007] To address the aforementioned deficiencies or improvement needs of existing technologies, as a first aspect of this invention, the present invention provides a method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environments in marine applications, comprising: S1. Obtain the material hydrogen-force coupling constitutive parameters of the target marine hydrogen-related pressure-bearing components and the dynamic boundary conditions of the ship's service, and construct a multi-source physical input dataset; S2. Based on the multi-source physical input dataset, a dynamic stress-hydrogen diffusion multi-physics coupling model considering dislocation transport and stress gradient driving is constructed to calculate the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field inside the material. S3. Input the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field into a preset hydrogen-induced material mechanical property degradation mechanism, and construct a hydrogen embrittlement damage evolution model based on cohesive traction force degradation; S4. Based on the time step convergence characteristics of the dynamic stress-hydrogen diffusion multiphysics coupling model and the critical fracture criterion of the hydrogen embrittlement damage evolution model, the transient lattice hydrogen concentration and trap hydrogen concentration distribution field and the hydrogen embrittlement damage evolution model are adaptively fused and iteratively solved to obtain the spatial distribution of hydrogen embrittlement damage and the prediction results of the remaining fatigue life of the target marine hydrogen-related pressure-bearing component.

[0008] Furthermore, the hydrogen-force coupling constitutive parameters of the material in S1 include the lattice hydrogen diffusion coefficient, hydrogen trap binding energy, hydrogen-induced volume expansion coefficient, and elastoplastic mechanical parameters in a hydrogen-free environment. The dynamic boundary conditions for ship service include alternating bending moments of mid-arch and mid-sag caused by wave excitation, broadband vibration loads caused by the ship's main engine and propulsion system, and transient impact loads caused by collisions with floating objects on the water surface.

[0009] Furthermore, the multiphysics coupling model in S2 transforms the dynamic boundary conditions of the ship's service into a dynamic stress-strain field that evolves within the material over time, and extracts the hydrostatic stress gradient and plastic strain rate. Based on the hydrostatic stress gradient to correct the lattice hydrogen diffusion flux, and based on the plastic strain rate to calculate the transport flux of dislocation-carrying hydrogen atoms, the transient lattice hydrogen concentration and trap hydrogen concentration distribution field fluctuating with the dynamic load period is obtained by solving the mass conservation partial differential equation.

[0010] Furthermore, the transformation of the ship's service dynamic boundary conditions into a dynamic stress-strain field that evolves within the material over time specifically includes: The spectral characteristics of the ship's service dynamic boundary conditions are decoupled to separate low-frequency wave alternating loads, high-frequency equipment vibration loads, and transient broadband impact loads. A global hull beam dynamic model and a local refined solid mechanics sub-model are constructed for the target marine hydrogen-related pressure-bearing component. For the low-frequency wave alternating load and the high-frequency equipment vibration load, frequency domain harmonic response analysis is performed in the global hull beam dynamic model using the modal superposition method to extract the dynamic displacement frequency response function at the installation node of the target marine hydrogen-related pressure-bearing component. For the transient broadband impact load, time-domain transient dynamic integration is performed using the explicit central difference method to extract the transient acceleration time history at the installation node. Perform a global-to-local dynamic boundary downscaling mapping, reconstruct the dynamic displacement frequency response function into a time-domain displacement boundary through inverse Fourier transform, and apply the time-domain displacement boundary and the transient acceleration time history as driving conditions to the truncated boundary of the local refined solid mechanics sub-model. In the locally refined solid mechanics sub-model, a high-pressure hydrogen internal pressure boundary is superimposed, using an implicit-Newmark model. The time-integration algorithm solves the local dynamic equilibrium equations and outputs the dynamic stress-strain field inside the material that evolves over time, including the hydrostatic stress gradient and the equivalent plastic strain rate.

[0011] Furthermore, the hydrogen-induced degradation mechanism of material mechanical properties preset in S3 specifically includes: Based on the theory of hydrogen-induced local plasticity enhancement, a first decay function of local hydrogen concentration and material yield stress is constructed. The local total hydrogen concentration in the transient lattice hydrogen concentration and the trapped hydrogen concentration distribution field is extracted and substituted into the first decay function to calculate the transient yield stress that decreases with increasing hydrogen concentration. Based on the theory that hydrogen reduces atomic bonding force, a second decay function of local hydrogen concentration and material cohesive strength is constructed. The local total hydrogen concentration is substituted into the second decay function to calculate the transient cohesive strength that decreases with increasing hydrogen concentration. The transient yield stress and the transient cohesive strength are used to replace the initial yield stress and initial cohesive strength in the hydrogen-force coupled constitutive parameters of the material in the hydrogen-free state, thereby completing the update of the degradation of the mechanical properties of the hydrogen-induced material.

[0012] Furthermore, the hydrogen embrittlement damage evolution model in S3 specifically includes: A damage initiation criterion considering hydrogen embrittlement is constructed. The hydrostatic stress triaxiality and equivalent plastic strain in the dynamic stress-strain field are used as input variables, and an initiation strain reduction factor determined by the local total hydrogen concentration is introduced to calculate the critical initiation strain for micro-damage to occur in the material. When the accumulated equivalent plastic strain reaches the critical initiation strain, damage evolution is triggered. A damage evolution rate equation based on hydrogen force coupling is constructed. In the damage softening evolution law based on fracture energy, a hydrogen-induced damage acceleration factor driven by the local total hydrogen concentration and dynamic equivalent plastic strain rate is introduced to calculate the transient damage evolution rate of the material under high pressure hydrogen environment. The transient damage evolution rate is integrated over time to obtain the cumulative damage variable. When the cumulative damage variable reaches a preset failure threshold, it is determined that hydrogen-induced cracking failure has occurred locally in the material, and the spatial distribution and evolution time of hydrogen embrittlement damage are output.

[0013] Furthermore, the adaptive time step fusion in S4 specifically includes: In the joint iterative solution process of each computational increment step, the nonlinear iterative residual norm of the multiphysics coupling equation system is extracted as the time step convergence feature, and the ratio of the current accumulated damage variable to the preset failure threshold is calculated as the fracture approximation degree. A dual-control adaptive step size adjustment strategy is constructed based on the time step convergence characteristics and the fracture approximation degree: when the nonlinear iterative residual norm exceeds a preset convergence tolerance, or the fracture approximation degree exceeds a preset critical approximation threshold, a step size back-off and reduction mechanism is triggered, the current computation time step is multiplied by a preset decay factor for encryption, and the iterative solution of the current incremental step is reset to suppress the stiffness matrix singularity and numerical divergence caused by rapid damage evolution; when the nonlinear iterative residual norm is lower than a preset convergence tolerance, and the fracture approximation degree is lower than a preset stable evolution threshold, a step size amplification mechanism is triggered, the current computation time step is multiplied by a preset amplification factor for relaxation; Using an adjusted computation time step, the transient lattice hydrogen concentration and trap hydrogen concentration distribution field and the hydrogen embrittlement damage evolution model are synchronously updated and iteratively solved until the cumulative damage variable reaches the preset failure threshold to trigger the critical fracture criterion. The spatial distribution of hydrogen embrittlement damage and the prediction results of the remaining fatigue life of the target marine hydrogen-related pressure-bearing component are then output.

[0014] Furthermore, the confirmation process for the spatial distribution of hydrogen embrittlement damage and the predicted results of remaining fatigue life in S4 specifically includes: Traverse all integration points of the local refined solid mechanics sub-model, extract the cumulative damage variable at the end of the current calculation time step, and construct the full-field cumulative damage distribution matrix; mark the set of integration points where the cumulative damage variable reaches the preset failure threshold as hydrogen-induced cracking region, and extract the geometric boundary and spatial coordinates of the hydrogen-induced cracking region to generate the spatial distribution of hydrogen embrittlement damage of the target marine hydrogen-related pressure-bearing component. For alternating stress cycles caused by low-frequency wave alternating loads and high-frequency equipment vibration loads, the transient damage evolution rate time history within a single complete load cycle is extracted, and the time history is integrated over a single cycle to calculate the cyclic damage increment within a single cycle. Based on the cyclic damage increment and the spatial gradient of the maximum cumulative damage variable in the full-field cumulative damage distribution matrix, the cyclic jump factor is dynamically calculated; the cyclic damage increment is multiplied by the cyclic jump factor to obtain the jump damage increment, and the jump damage increment is superimposed on the full-field cumulative damage distribution matrix to accelerate the update of the full-field damage state after multiple cycles of accumulation. After each execution of the loop jump superposition, it is determined whether the updated hydrogen-induced cracking region has expanded through the component wall thickness, or whether the maximum cumulative damage variable has reached the complete failure threshold. If either of the above conditions is met, the loop jump iteration is terminated, the current cumulative total number of loops is extracted, and the total number of loops or the total service time converted from it is output as the remaining fatigue life prediction result.

[0015] As a second aspect of the present invention, a material hydrogen embrittlement damage prediction system under high-pressure hydrogen environment for marine applications is also provided, comprising: A multi-source data construction unit is used to obtain the material hydrogen-force coupling constitutive parameters of the target marine hydrogen-related pressure-bearing components and the dynamic boundary conditions of the ship in service, and to construct a multi-source physical input dataset. The hydrogen concentration field calculation unit is used to construct a dynamic stress-hydrogen diffusion multiphysics coupling model based on the multi-source physical input dataset, considering dislocation transport and stress gradient driving, and calculate the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field inside the material. The damage model construction unit is used to input the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field into a preset hydrogen-induced material mechanical property degradation mechanism, and to construct a hydrogen embrittlement damage evolution model based on cohesive traction force degradation. The iterative solution prediction unit is used to adaptively fuse and iteratively solve the transient lattice hydrogen concentration and trap hydrogen concentration distribution field and the hydrogen embrittlement damage evolution model based on the time step convergence characteristics of the dynamic stress-hydrogen diffusion multiphysics coupling model and the critical fracture criterion of the hydrogen embrittlement damage evolution model, so as to obtain the spatial distribution of hydrogen embrittlement damage and the prediction results of the remaining fatigue life of the target marine hydrogen-related pressure-bearing component.

[0016] As a third aspect of the invention, a computer-readable storage medium is also provided, on which a computer program is stored, which is executed by a processor as described in any one of the claims, a method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen conditions in marine applications.

[0017] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. The method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications of the present invention integrates the hydrogen-force coupling constitutive parameters of the target hydrogen-bearing pressure components with the dynamic boundary conditions of the ship's service to form a standardized multi-source physical input dataset. The included parameters cover the material's own hydrogen diffusion, hydrogen trap-related physical properties, and composite service loads composed of wave loads, equipment vibrations, and foreign object impacts, fully preserving the load variation characteristics in actual ship operation. This processing method no longer simplifies the complex service conditions of ships, unifies the input benchmark for subsequent simulation calculations, avoids the distortion of basic data caused by one-sided parameter selection and idealized load conditions, reduces data errors from the source of calculation, and ensures that the preconditions for subsequent multiphysics modeling closely match the actual ship working environment. This ensures that hydrogen concentration-related calculations can be carried out based on real operating conditions, steadily improves the data foundation reliability of the entire prediction work, and makes up for the inherent defects of traditional schemes that use static single load parameters.

[0018] 2. The method for predicting hydrogen embrittlement damage of marine materials under high-pressure hydrogen environments of this invention establishes a stress-hydrogen diffusion coupling model jointly regulated by stress gradient and dislocation transport based on a pre-constructed multi-source dataset. It sequentially completes load decoupling, mapping of coarse and fine model boundaries, and dynamic stress field solution. Hydrogen transport flux is calculated based on two hydrogen migration mechanisms, and the transient lattice hydrogen and trapped hydrogen concentration distribution within the component is solved using the mass conservation equation. Traditional calculations mostly rely solely on concentration differences to determine the hydrogen diffusion rate. This scheme simultaneously incorporates stress-driven diffusion and dislocation-draft hydrogen-carrying processes, updating the hydrogen enrichment state in real-time with changes in plastic strain and hydrostatic stress. The calculated hydrogen concentration distribution reflects the local accumulation changes of hydrogen elements caused by the cyclic fluctuations of alternating loads, effectively improving the accuracy of the calculated hydrogen concentration values ​​across the entire region and providing field data for subsequent material performance degradation and damage prediction.

[0019] 3. The method for predicting hydrogen embrittlement damage of marine materials under high-pressure hydrogen environments of this invention establishes a hydrogen embrittlement damage evolution model based on hydrogen concentration field data, which integrates hydrogen-induced mechanical degradation mechanisms and cohesive degradation forms. It then uses an adaptive time step to complete coupled iterative calculations, combining model convergence indices and critical fracture criteria. The material's yield stress and cohesive strength are adjusted in real-time according to local hydrogen content. A hydrogen correlation coefficient is introduced to adjust the damage initiation strain and damage evolution rate. Dynamic time step control avoids numerical solution divergence problems, and the remaining life is calculated based on cyclic damage increments. This approach establishes a quantitative correlation between hydrogen enrichment, material degradation, and structural damage. It can both mark the spatial location of hydrogen embrittlement failure in components and quantitatively calculate the remaining fatigue life of pressure-bearing components, overcoming the shortcomings of existing technologies with poor stability and large deviations in life prediction results due to fixed-step-size algorithms. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications, according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the system units in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention 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 merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] Example 1 Please refer to Figure 1 This embodiment 1 provides a method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications, including: S1. Obtain the material hydrogen-force coupling constitutive parameters of the target marine hydrogen-related pressure-bearing components and the dynamic boundary conditions of the ship's service, and construct a multi-source physical input dataset; S2. Based on the multi-source physical input dataset, a dynamic stress-hydrogen diffusion multi-physics coupling model considering dislocation transport and stress gradient driving is constructed to calculate the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field inside the material. S3. Input the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field into a preset hydrogen-induced material mechanical property degradation mechanism, and construct a hydrogen embrittlement damage evolution model based on cohesive traction force degradation; S4. Based on the time step convergence characteristics of the dynamic stress-hydrogen diffusion multiphysics coupling model and the critical fracture criterion of the hydrogen embrittlement damage evolution model, the transient lattice hydrogen concentration and trap hydrogen concentration distribution field and the hydrogen embrittlement damage evolution model are adaptively fused and iteratively solved to obtain the spatial distribution of hydrogen embrittlement damage and the prediction results of the remaining fatigue life of the target marine hydrogen-related pressure-bearing component.

[0023] This embodiment 1 further elaborates on the above steps.

[0024] (1) Construction of multi-source data First, the hydrogen-force coupling constitutive parameters of the target marine hydrogen-bearing pressure components are obtained. This parameter set forms the basis for constructing the predictive model. It is determined through material testing or obtained from existing material databases, and specifically includes: the lattice hydrogen diffusion coefficient, used to characterize the diffusion ability of hydrogen atoms in the material's lattice interstices; the hydrogen trapping binding energy, used to describe the ability of internal defects, grain boundaries, or second-phase particles to trap hydrogen atoms; the hydrogen-induced volume expansion coefficient, used to quantify the microscopic volume change caused by the dissolution of hydrogen atoms into the material; and the elastoplastic mechanical parameters of the material in a hydrogen-free environment, including elastic modulus, Poisson's ratio, yield strength, and plastic hardening curve, used to define the basic response characteristics of the material under mechanical loads. These parameters collectively constitute the basis of the constitutive relationship of the material under hydrogen-force coupling conditions.

[0025] Simultaneously, dynamic boundary conditions for ship service are collected and defined. These boundary conditions include three main types of loads: the first type is the alternating bending moment of the camber and sag caused by wave excitation, which reflects the periodic bending moment effect on components caused by the overall bending deformation of the hull under wave action; the second type is the broadband vibration load caused by the operation of the ship's main engine and propulsion system, which includes high-frequency vibration excitation generated by mechanical operation; and the third type is the transient impact load caused by the collision of floating objects on the water surface, used to simulate the instantaneous stress response of components caused by sudden external impacts. These three types of loads together constitute the dynamic mechanical environment experienced by the components during service.

[0026] Finally, a multi-source physical input dataset was constructed. The acquired hydrogen-force coupled constitutive parameters of the materials were integrated with the dynamic boundary conditions of the ship during service to construct the multi-source physical input dataset. This dataset not only includes the physical property parameters of the materials themselves, but also incorporates multi-dimensional dynamic load information experienced by the ship during operation in the actual marine environment.

[0027] (2) Calculation of hydrogen concentration field After completing the construction of the multi-source data, a dynamic stress-hydrogen diffusion multiphysics coupling model considering dislocation transport and stress gradient driving is constructed based on the multi-source physical input dataset. This model calculates the transient lattice hydrogen concentration and trapped hydrogen concentration distribution fields within the material. First, the spectral characteristics of the ship's service dynamic boundary conditions need to be decoupled. The total time-domain load vector borne by the target ship's hydrogen-related pressure-bearing components is then obtained. The vector is transformed to the frequency domain using Fourier transform to obtain the total frequency domain load vector. ,in It is the angular frequency. The imaginary unit, The time variable is used. The low-frequency bandpass filter function is defined. High-frequency bandpass filter function and wideband pass filter function The total frequency domain load vector is multiplied by the aforementioned filter function to obtain the frequency domain representation of various load types, such as the frequency domain vector of a low-frequency wave alternating load. Subsequently, through inverse Fourier transform... Obtaining the time history of low-frequency wave alternating load Similarly, the time history of vibration loads on high-frequency equipment can be calculated and obtained. and the time history of transient broadband impact loads .

[0028] Secondly, a global hull beam dynamic model and a locally refined solid mechanics sub-model are constructed for the target marine hydrogen-related pressure-bearing components. For the time histories of low-frequency wave alternating loads and high-frequency equipment vibration loads, frequency domain harmonic response analysis is performed using the modal superposition method in the global hull beam dynamic model. A global modal matrix is ​​introduced. , global physical displacement vector Represented as modal coordinate vector A linear combination, i.e. Substitute this relationship into the frequency domain dynamic equilibrium equation and multiply by the left side. Obtain the decoupled modal frequency domain equations .in, The global modal mass matrix, This is the global modal damping matrix. This is the global modal stiffness matrix. This represents the frequency domain vector of the steady-state load. Solving the modal equation yields... Then, the global frequency domain displacement response vector is calculated, and the dynamic displacement frequency response function at the installation node of the target marine hydrogen-related pressure-bearing component is extracted. Simultaneously, for the time history of transient broadband impact loads, an explicit central difference method is used to perform global time-domain transient dynamic integration. Given the known... Displacement at each time step ,speed and acceleration Under the premise of calculating the first Displacement at each time step ,in The time step is then used. The new acceleration is then obtained by solving the dynamic equations. and update speed The transient acceleration time history at the installation node is extracted by iteratively extracting the time step by time. .

[0029] Next, a global-to-local dynamic boundary downscaling mapping is performed. This involves mapping the dynamic displacement frequency response function... The time-domain displacement boundary is reconstructed using inverse Fourier transform. The time-domain shift boundary With transient acceleration time history As a driving condition, it is applied to the truncated boundary of the locally refined solid mechanics submodel. A high-pressure hydrogen internal pressure boundary is superimposed on the locally refined solid mechanics submodel. Using implicit-Newmark The time integration algorithm solves the local dynamic equilibrium equations. Approximate expressions for displacement and velocity are defined. and ,in and For the integration parameters. Substituting the above approximate expression into the local dynamic equilibrium equation, eliminating velocity and acceleration variables, we construct a system containing only unknown displacement increments. Equivalent stiffness equation .in, The equivalent stiffness matrix, This represents the equivalent load vector. Solving this equation yields the displacement increment and updates the state variables, outputting the dynamic stress-strain field that evolves within the material over time. The Cauchy stress tensor is then used to calculate this dynamic stress-strain field. Calculate hydrostatic stress The hydrostatic stress gradient was calculated using the local differential form of the Gaussian divergence theorem. Based on plastic strain tensor Calculate the equivalent plastic strain And obtain the equivalent plastic strain rate by taking its time partial derivative. .

[0030] Subsequently, the hydrogen atom transport flux was calculated based on the extracted mechanical characteristics. The lattice hydrogen diffusion flux was then corrected based on the hydrostatic stress gradient. Its calculation formula is .in, The lattice hydrogen diffusion coefficient is For local lattice hydrogen concentration, The partial molar volume induced by hydrogen. Let be the ideal gas constant. The absolute temperature is used. Simultaneously, a Taylor hardening model is introduced to establish the dislocation density. Correlation with equivalent plastic strain, calculation ,in The initial dislocation density, Taylor factor, For material constants, Shear modulus Burgers vector, Given the current yield stress, This represents the lattice friction stress. Based on this, the transport flux of hydrogen atoms carried by dislocations is calculated. ,in is the dislocation-hydrogen interaction coefficient.

[0031] Finally, the transient hydrogen concentration distribution field is obtained by solving the mass conservation partial differential equation. A mass conservation partial differential equation incorporating lattice hydrogen and trapped hydrogen is constructed. .in, This represents the localized hydrogen concentration trapped within the trap. (Trap hydrogen concentration) With lattice hydrogen concentration The binding energy between them is based on hydrogen trapping. Local equilibrium relationship ,in For trap density, Let be the density of interstitial sites in the lattice. Take the time partial derivative of this relationship to obtain... Substituting it into the partial differential equation for mass conservation and combining the time derivative terms, we obtain... Introducing test functions In the solution domain By performing integration within the inner quadratic space and applying the divergence theorem, a weakly formal integral equation can be constructed. ,in To solve for the domain boundary, Let be the boundary outward normal vector. The weakly form integral equations described above are spatially discretized using the finite element method, and a system of algebraic equations is constructed and solved by time integration. Finally, the transient lattice hydrogen concentration distribution field and the transient trap hydrogen concentration distribution field, which fluctuate with the dynamic load period, are obtained.

[0032] (3) Damage model construction After calculating the transient lattice hydrogen concentration distribution field and the transient trap hydrogen concentration distribution field, the transient lattice hydrogen concentration and trap hydrogen concentration distribution fields are input into a preset hydrogen-induced material mechanical property degradation mechanism to update the degradation of the hydrogen-induced material mechanical properties.

[0033] In this embodiment, the hydrogen-induced degradation mechanism of the mechanical properties of materials is specifically as follows: First, extract the local lattice hydrogen concentration from the transient lattice hydrogen concentration distribution field. Local trap hydrogen concentration in transient trap hydrogen concentration distribution field The local total hydrogen concentration was calculated by linear superposition. Subsequently, based on the theory of hydrogen-induced local plasticity enhancement, a first decay function of local hydrogen concentration and material yield stress was constructed. ,in For transient yield stress, The initial yield stress is the stress in the hydrogen-free state. This is the maximum reduction ratio of yield stress. The yield stress decay half-saturation concentration constant is given. Next, based on the theory that hydrogen reduces atomic bonding forces, a second decay function of local hydrogen concentration and material cohesive strength is constructed. ,in Transient cohesive strength, The initial cohesive strength in the hydrogen-free state. This is the maximum reduction factor for cohesive strength. This represents the half-saturation concentration constant for cohesive strength decay. Finally, the calculated transient yield stress is... With transient cohesive strength The initial yield stress in the hydrogen-force coupling constitutive parameters of the corresponding replacement material With initial cohesive strength This completes the degradation and renewal of the mechanical properties of hydrogen-induced materials.

[0034] After updating the hydrogen-induced degradation of the mechanical properties of materials, a hydrogen embrittlement damage evolution model based on the degradation of cohesive traction force is constructed. The specific process of constructing the hydrogen embrittlement damage evolution model is as follows: First, a damage initiation criterion considering hydrogen embrittlement is constructed. The Cauchy stress tensor is extracted from the dynamic stress-strain field. Equivalent force of Mises ,in Let be the deviatoric stress tensor, whose calculation satisfies , Using the Kronecker function. Calculate the triaxiality of hydrostatic stress. ,in For hydrostatic stress, an initial strain reduction factor determined by the local total hydrogen concentration is introduced. ,in This represents the hydrogen-induced initial strain attenuation coefficient. Using the Rice-Tracey void nucleation theory, the critical initial strain for microscopic damage in the material is calculated. ,in This is the baseline nucleation strain under hydrogen-free and zero-stress triaxial conditions. Within each computational increment step, the current cumulative equivalent plastic strain is... With critical initial strain Compare them, when the conditions are met At that time, damage evolution is triggered.

[0035] Next, the damage evolution rate equation of hydrogen-force coupling is constructed. The effective cohesive traction force is defined. ,in For normal traction force, and These are the tangential traction forces in two orthogonal directions. The Macaulay bracket operator indicates that it participates in the calculation only when the normal traction force is tensile stress. Based on the damage softening evolution law of fracture energy, the base damage evolution rate is calculated. ,in Based on the rate of damage evolution, For dynamic equivalent plastic strain rate, The critical fracture energy in a hydrogen-free environment. The current cumulative damage variable is defined. A hydrogen-induced damage acceleration factor, driven by both the local total hydrogen concentration and the dynamic equivalent plastic strain rate, is introduced. ,in The concentration-sensitive acceleration coefficient, The strain rate-sensitive acceleration factor, The reference strain rate is used. The transient damage evolution rate of the material under high-pressure hydrogen environment is calculated by multiplying the basic damage evolution rate by the hydrogen-induced damage acceleration factor. .

[0036] Finally, time integration of the damage variables and failure determination are performed. A backward Euler implicit integral scheme is used to integrate the transient damage evolution rate over time, constructing the first... The cumulative damage variable update equation at each time step ,in The cumulative damage variable at the current time step. The cumulative damage variable from the previous time step. This is the current computation time step. This represents the transient damage evolution rate at the current time step. The accumulated damage variable will be calculated accordingly. Compared with the preset failure threshold Compare, when satisfied When hydrogen-induced cracking failure occurs locally in the material, the cohesive traction force of the corresponding unit is forcibly reduced to zero, and the cumulative damage variable state of all spatial nodes is extracted, outputting the spatial distribution and evolution time history of hydrogen embrittlement damage.

[0037] (4) Iterative solution for prediction Based on the above computational steps, and using the time-step convergence characteristics of the dynamic stress-hydrogen diffusion multiphysics coupling model and the critical fracture criterion of the hydrogen embrittlement damage evolution model, an adaptive time-step fusion and iterative solution is adopted for the transient lattice hydrogen concentration and trapped hydrogen concentration distribution fields and the hydrogen embrittlement damage evolution model. Specifically, in the joint iterative solution process of each computational increment step, the nonlinear iterative residual norm is first extracted from the solver of the multiphysics coupling equations. This is used as the core indicator to characterize the convergence feature at the current time step. Simultaneously, the current cumulative damage variable at the current integration point is read. and compare it with a preset failure threshold. The ratio is calculated to obtain the fracture approximation degree. Its calculation formula is Based on this, a dual-control adaptive step size adjustment strategy based on time step convergence characteristics and fracture approximation degree is constructed to dynamically optimize the solution process.

[0038] During the execution of the dual-control adaptive step size adjustment strategy, the extracted nonlinear iterative residual norm is... Compared with the preset convergence tolerance Compare and determine the fracture approximation degree With the preset critical approximation threshold Compare them. When the nonlinear iterative residual norm is satisfied... Exceeding the preset convergence tolerance Or the degree of fracture approximation Exceeding the preset critical approximation threshold If any of the conditions in the above conditions are met, it is determined that the current solution state has a risk of divergence, and a step back and reduction mechanism is triggered. This mechanism will reduce the current computation time step. Multiply by the preset attenuation factor Encryption is performed to obtain the adjusted computation time step. It resets the iterative solution of the current increment step, thereby effectively suppressing the singularity and numerical divergence of the stiffness matrix caused by the rapid evolution of damage.

[0039] Conversely, in the dual-control adaptive step size adjustment strategy, when determining the nonlinear iterative residual norm... Strictly below the preset convergence tolerance And the degree of fracture approximation Strictly below the preset steady-state evolution threshold If the current solution state is deemed stable and convergent, a step-size amplification mechanism is triggered. This mechanism increases the current computation time step. Multiply by the preset magnification factor The time step is relaxed to generate a new, adjusted computation time step. Subsequently, the adjusted computation time step was adopted. The transient lattice hydrogen concentration and trapped hydrogen concentration distribution fields, as well as the hydrogen embrittlement damage evolution model, are synchronously updated and iteratively solved. The above judgment and adjustment process is continuously repeated until the current cumulative damage variable is reached. Reaching the preset failure threshold It triggers the critical fracture criterion and then outputs the preliminary prediction results of the target marine hydrogen-related pressure-bearing components.

[0040] After confirming the spatial distribution of hydrogen embrittlement damage and the predicted results of remaining fatigue life, the process first iterates through all integration points of the locally refined solid mechanics sub-model and extracts the current cumulative damage variable at the end of the current calculation time step. Then, they are assembled according to spatial topological relationships to construct a full-field cumulative damage distribution matrix. Next, the total cumulative damage distribution matrix is... Current cumulative damage variable Reaching the preset failure threshold The set of all integration points is labeled as the hydrogen-induced cracking region. And extract the hydrogen-induced cracked region. The geometric boundaries and spatial coordinates are used to generate a spatial distribution map of hydrogen embrittlement damage in the target marine hydrogen-related pressure-bearing components.

[0041] For alternating stress cycles caused by low-frequency wave alternating loads and high-frequency equipment vibration loads, extract a single complete load cycle period. Transient damage evolution rate time history The time history of the transient damage evolution rate. In a single complete load cycle By performing a single-cycle time integration, the incremental cyclic damage within a single cycle is calculated. Subsequently, based on the calculated cyclic damage increment... and the total cumulative damage distribution matrix Maximum cumulative damage variable Spatial gradient Dynamically calculate the cycle jump factor Increment of cyclic damage Multiply by the loop jump factor Obtain the jump damage increment and the jump damage increment Superimposed on the total damage distribution matrix This accelerates the updating of the overall damage status after multiple cycles of accumulation.

[0042] After each cyclic jump stacking operation, the process proceeds to the failure termination condition determination stage. This involves assessing the updated hydrogen-induced cracking region. Whether the damage extends through the component wall thickness, or the total cumulative damage distribution matrix across the entire field. Maximum cumulative damage variable in Has the critical value for complete failure been reached? If any of the above conditions are met, the loop skipping iteration process is terminated immediately, and the total number of loops executed so far is extracted. and the total number of cycles Or the total service time calculated from it. The output is the predicted final remaining fatigue life of the target marine hydrogen-bearing pressure components.

[0043] Example 2 Please refer to Figure 2 This embodiment 2 provides a material hydrogen embrittlement damage prediction system under high-pressure hydrogen environment for marine applications, including: A multi-source data construction unit is used to obtain the material hydrogen-force coupling constitutive parameters of the target marine hydrogen-related pressure-bearing components and the dynamic boundary conditions of the ship in service, and to construct a multi-source physical input dataset. The hydrogen concentration field calculation unit is used to construct a dynamic stress-hydrogen diffusion multiphysics coupling model based on the multi-source physical input dataset, considering dislocation transport and stress gradient driving, and calculate the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field inside the material. The damage model construction unit is used to input the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field into a preset hydrogen-induced material mechanical property degradation mechanism, and to construct a hydrogen embrittlement damage evolution model based on cohesive traction force degradation. The iterative solution prediction unit is used to adaptively fuse and iteratively solve the transient lattice hydrogen concentration and trap hydrogen concentration distribution field and the hydrogen embrittlement damage evolution model based on the time step convergence characteristics of the dynamic stress-hydrogen diffusion multiphysics coupling model and the critical fracture criterion of the hydrogen embrittlement damage evolution model, so as to obtain the spatial distribution of hydrogen embrittlement damage and the prediction results of the remaining fatigue life of the target marine hydrogen-related pressure-bearing component.

[0044] Example 3 This embodiment 3 also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement any step of a method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications.

[0045] The computer-readable storage medium may include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0046] For a description of the computer-readable storage medium provided in this application, please refer to the above method embodiments; further details will not be repeated here.

[0047] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications, characterized in that, include: S1. Obtain the material hydrogen-force coupling constitutive parameters of the target marine hydrogen-related pressure-bearing components and the dynamic boundary conditions of the ship's service, and construct a multi-source physical input dataset; S2. Based on the multi-source physical input dataset, a dynamic stress-hydrogen diffusion multi-physics coupling model considering dislocation transport and stress gradient driving is constructed to calculate the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field inside the material. S3. Input the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field into a preset hydrogen-induced material mechanical property degradation mechanism, and construct a hydrogen embrittlement damage evolution model based on cohesive traction force degradation; S4. Based on the time step convergence characteristics of the dynamic stress-hydrogen diffusion multiphysics coupling model and the critical fracture criterion of the hydrogen embrittlement damage evolution model, the transient lattice hydrogen concentration and trap hydrogen concentration distribution field and the hydrogen embrittlement damage evolution model are adaptively fused and iteratively solved to obtain the spatial distribution of hydrogen embrittlement damage and the prediction results of the remaining fatigue life of the target marine hydrogen-related pressure-bearing component.

2. The method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications according to claim 1, characterized in that, The hydrogen-force coupling constitutive parameters of the material in S1 include the lattice hydrogen diffusion coefficient, hydrogen trap binding energy, hydrogen-induced volume expansion coefficient, and elastoplastic mechanical parameters in a hydrogen-free environment. The dynamic boundary conditions for ship service include alternating bending moments of mid-arch and mid-sag caused by wave excitation, broadband vibration loads caused by the ship's main engine and propulsion system, and transient impact loads caused by collisions with floating objects on the water surface.

3. The method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications according to claim 1, characterized in that, The multiphysics coupling model in S2 transforms the dynamic boundary conditions of the ship's service into a dynamic stress-strain field that evolves within the material over time, and extracts the hydrostatic stress gradient and plastic strain rate. Based on the hydrostatic stress gradient to correct the lattice hydrogen diffusion flux, and based on the plastic strain rate to calculate the transport flux of dislocation-carrying hydrogen atoms, the transient lattice hydrogen concentration and trap hydrogen concentration distribution field fluctuating with the dynamic load period is obtained by solving the mass conservation partial differential equation.

4. The method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications according to claim 3, characterized in that, The process of transforming the ship's service dynamic boundary conditions into a dynamic stress-strain field that evolves within the material over time specifically includes: The spectral characteristics of the ship's service dynamic boundary conditions are decoupled to separate low-frequency wave alternating loads, high-frequency equipment vibration loads, and transient broadband impact loads. A global hull beam dynamic model and a local refined solid mechanics sub-model are constructed for the target marine hydrogen-related pressure-bearing component. For the low-frequency wave alternating load and the high-frequency equipment vibration load, frequency domain harmonic response analysis is performed in the global hull beam dynamic model using the modal superposition method to extract the dynamic displacement frequency response function at the installation node of the target marine hydrogen-related pressure-bearing component. For the transient broadband impact load, time-domain transient dynamic integration is performed using the explicit central difference method to extract the transient acceleration time history at the installation node. Perform a global-to-local dynamic boundary downscaling mapping, reconstruct the dynamic displacement frequency response function into a time-domain displacement boundary through inverse Fourier transform, and apply the time-domain displacement boundary and the transient acceleration time history as driving conditions to the truncated boundary of the local refined solid mechanics sub-model. In the locally refined solid mechanics sub-model, a high-pressure hydrogen internal pressure boundary is superimposed, using an implicit-Newmark model. The time-integration algorithm solves the local dynamic equilibrium equations and outputs the dynamic stress-strain field inside the material that evolves over time, including the hydrostatic stress gradient and the equivalent plastic strain rate.

5. The method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications according to claim 1, characterized in that, The hydrogen-induced degradation mechanism of material mechanical properties preset in S3 specifically includes: Based on the theory of hydrogen-induced local plasticity enhancement, a first decay function of local hydrogen concentration and material yield stress is constructed. The local total hydrogen concentration in the transient lattice hydrogen concentration and the trapped hydrogen concentration distribution field is extracted and substituted into the first decay function to calculate the transient yield stress that decreases with increasing hydrogen concentration. Based on the theory that hydrogen reduces atomic bonding force, a second decay function of local hydrogen concentration and material cohesive strength is constructed. The local total hydrogen concentration is substituted into the second decay function to calculate the transient cohesive strength that decreases with increasing hydrogen concentration. The transient yield stress and the transient cohesive strength are used to replace the initial yield stress and initial cohesive strength in the hydrogen-force coupled constitutive parameters of the material in the hydrogen-free state, thereby completing the hydrogen-induced degradation and update of the mechanical properties of the material.

6. The method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications according to claim 3, characterized in that, The hydrogen embrittlement damage evolution model in S3 specifically includes: A damage initiation criterion considering hydrogen embrittlement is constructed. The hydrostatic stress triaxiality and equivalent plastic strain in the dynamic stress-strain field are used as input variables, and an initiation strain reduction factor determined by the local total hydrogen concentration is introduced to calculate the critical initiation strain for micro-damage to occur in the material. When the accumulated equivalent plastic strain reaches the critical initiation strain, damage evolution is triggered. A damage evolution rate equation based on hydrogen force coupling is constructed. In the damage softening evolution law based on fracture energy, a hydrogen-induced damage acceleration factor driven by the local total hydrogen concentration and dynamic equivalent plastic strain rate is introduced to calculate the transient damage evolution rate of the material under high pressure hydrogen environment. The transient damage evolution rate is integrated over time to obtain the cumulative damage variable. When the cumulative damage variable reaches a preset failure threshold, it is determined that hydrogen-induced cracking failure has occurred locally in the material, and the spatial distribution and evolution time of hydrogen embrittlement damage are output.

7. The method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications according to claim 1, characterized in that, The adaptive time step fusion in S4 specifically includes: In the joint iterative solution process of each computational increment step, the nonlinear iterative residual norm of the multiphysics coupling equation system is extracted as the time step convergence feature, and the ratio of the current accumulated damage variable to the preset failure threshold is calculated as the fracture approximation degree. A dual-control adaptive step size adjustment strategy is constructed based on the time step convergence characteristics and the fracture approximation degree: when the nonlinear iterative residual norm exceeds a preset convergence tolerance, or the fracture approximation degree exceeds a preset critical approximation threshold, a step size back-off and reduction mechanism is triggered, the current computation time step is multiplied by a preset decay factor for encryption, and the iterative solution of the current incremental step is reset to suppress the stiffness matrix singularity and numerical divergence caused by rapid damage evolution; when the nonlinear iterative residual norm is lower than a preset convergence tolerance, and the fracture approximation degree is lower than a preset stable evolution threshold, a step size amplification mechanism is triggered, the current computation time step is multiplied by a preset amplification factor for relaxation; Using an adjusted computation time step, the transient lattice hydrogen concentration and trap hydrogen concentration distribution field and the hydrogen embrittlement damage evolution model are synchronously updated and iteratively solved until the cumulative damage variable reaches the preset failure threshold to trigger the critical fracture criterion. The spatial distribution of hydrogen embrittlement damage and the prediction results of the remaining fatigue life of the target marine hydrogen-related pressure-bearing component are then output.

8. The method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications according to claim 7, characterized in that, The confirmation process for the spatial distribution of hydrogen embrittlement damage and the predicted results of remaining fatigue life in S4 specifically includes: Traverse all integration points of the local refined solid mechanics sub-model, extract the cumulative damage variable at the end of the current calculation time step, and construct the full-field cumulative damage distribution matrix; mark the set of integration points where the cumulative damage variable reaches the preset failure threshold as hydrogen-induced cracking region, and extract the geometric boundary and spatial coordinates of the hydrogen-induced cracking region to generate the spatial distribution of hydrogen embrittlement damage of the target marine hydrogen-related pressure-bearing component. For alternating stress cycles caused by low-frequency wave alternating loads and high-frequency equipment vibration loads, the transient damage evolution rate time history within a single complete load cycle is extracted, and the time history is integrated over a single cycle to calculate the cyclic damage increment within a single cycle. Based on the cyclic damage increment and the spatial gradient of the maximum cumulative damage variable in the full-field cumulative damage distribution matrix, the cyclic jump factor is dynamically calculated; the cyclic damage increment is multiplied by the cyclic jump factor to obtain the jump damage increment, and the jump damage increment is superimposed on the full-field cumulative damage distribution matrix to accelerate the update of the full-field damage state after multiple cycles of accumulation. After each execution of the loop jump superposition, it is determined whether the updated hydrogen-induced cracking region has expanded through the component wall thickness, or whether the maximum cumulative damage variable has reached the complete failure threshold. If either of the above conditions is met, the loop jump iteration is terminated, the current cumulative total number of loops is extracted, and the total number of loops or the total service time converted from it is output as the remaining fatigue life prediction result.

9. A system for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen environment in marine applications, characterized in that, include: A multi-source data construction unit is used to obtain the material hydrogen-force coupling constitutive parameters of the target marine hydrogen-related pressure-bearing components and the dynamic boundary conditions of the ship in service, and to construct a multi-source physical input dataset. The hydrogen concentration field calculation unit is used to construct a dynamic stress-hydrogen diffusion multiphysics coupling model based on the multi-source physical input dataset, considering dislocation transport and stress gradient driving, and calculate the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field inside the material. The damage model construction unit is used to input the transient lattice hydrogen concentration and trapped hydrogen concentration distribution field into a preset hydrogen-induced material mechanical property degradation mechanism, and to construct a hydrogen embrittlement damage evolution model based on cohesive traction force degradation. The iterative solution prediction unit is used to adaptively fuse and iteratively solve the transient lattice hydrogen concentration and trap hydrogen concentration distribution field and the hydrogen embrittlement damage evolution model based on the time step convergence characteristics of the dynamic stress-hydrogen diffusion multiphysics coupling model and the critical fracture criterion of the hydrogen embrittlement damage evolution model, so as to obtain the spatial distribution of hydrogen embrittlement damage and the prediction results of the remaining fatigue life of the target marine hydrogen-related pressure-bearing component.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is executed by a processor as described in any one of claims 1-8: a method for predicting hydrogen embrittlement damage of materials under high-pressure hydrogen conditions in marine applications.

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