Numerical simulation based method and device for loading of marine structures

Abstract

The present application relates to the technical field of ocean engineering, in particular to a load loading method and device for ocean structure based on numerical simulation. The load loading method for ocean structure based on numerical simulation provided by the present application calculates the ocean environmental load of the ocean structure through the numerical simulation of the numerical model, thereby realizing the fluid simulation calculation of the ocean structure in the real ocean environment, obtaining the load time history suffered by the ocean structure, and considering the grid elements of the numerical model when establishing the finite element model, thereby facilitating the loading of the pressure data corresponding to as many grid elements as possible according to the grid parameters of the two models, so that the change of the load of the model at different nodes in the real ocean environment can be more accurately fitted, and thus the safety performance of the ocean structure can be more accurately evaluated, which is helpful to improve the design safety and reliability of the ocean structure.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and specifically to a method and apparatus for loading loads onto marine structures based on numerical simulation. Background Technology

[0002] As humanity explores marine resources, marine structures are playing an increasingly important role in their development and utilization. In the marine environment, conditions such as wind and waves pose serious threats to the structural strength of marine structures. Therefore, to ensure the safe operation and long-term stability of marine structures, accurately verifying their structural strength in the real marine environment during the design phase is crucial.

[0003] Currently, the main methods for verifying the structural strength of marine structures include experimental methods, theoretical analysis methods, and finite element simulation methods. Experimental methods involve conducting tests under actual marine environmental conditions, collecting and analyzing the stress on the structure. This method can more realistically simulate the impact of the marine environment on the structure, but it suffers from high cost, long time commitment, and high risk. Theoretical analysis methods, based on the principles of structural mechanics, calculate and evaluate the structural strength of marine structures through mathematical models and stress analysis. However, due to the complexity of marine structures, the accuracy of calculations using simplified theoretical formulas is difficult to guarantee. Finite element simulation methods can solve the above two problems, but accurately applying loads to ensure the accuracy of finite element analysis presents a new challenge. Summary of the Invention

[0004] In view of this, the present invention provides a method and apparatus for loading loads on marine structures based on numerical simulation, in order to solve the problem of how to accurately load loads using the finite element method.

[0005] In a first aspect, the present invention provides a method for loading loads onto marine structures based on numerical simulation. The method includes: calculating the marine environmental loads on the marine structure based on a numerical model of the marine structure, obtaining load calculation results, wherein the numerical model includes multiple grid cells, and the load calculation results include the coordinates of the center points of the grid cells and their corresponding pressure data at different times under a preset time series; establishing a finite element model of the marine structure based on the grid cells of the numerical model; and loading the marine environmental loads onto the finite element model based on the grid parameters of the finite element model and the grid parameters of the numerical model.

[0006] The numerical simulation-based load loading method for marine structures provided in this invention calculates the marine environmental load on marine structures by establishing a numerical model and performing numerical simulation. This enables fluid simulation calculation of marine structures in a real marine environment, obtaining the load time history experienced by the marine structure. Furthermore, by considering the mesh elements of the numerical model when establishing the finite element model, it is easier to load as many mesh elements as possible corresponding to the pressure data based on the mesh parameters of both models. This allows for a more accurate representation of the load variations at different nodes in the real marine environment, thereby enabling a more accurate assessment of the safety performance of marine structures and contributing to improving the design safety and reliability of marine structures.

[0007] In one optional implementation, the marine environmental load of the marine structure is calculated based on a numerical model of the marine structure to obtain the load calculation results, including: establishing a numerical model of the marine structure based on 3D modeling software; meshing the numerical model and setting model parameters according to the marine environment; and using a fluid dynamics solver to calculate the marine environmental load of the model after setting the model parameters to obtain the load calculation results.

[0008] In one optional implementation, before meshing the numerical model, the method further includes: selecting multiple different mesh sizes and different time steps as candidate values ​​based on whether the marine environmental load under different mesh sizes and different time steps exhibits monotonic convergence; and selecting from the candidate values ​​a mesh size and time step that meet the preset load calculation accuracy requirements and preset resource consumption requirements.

[0009] In this embodiment, before mesh generation, candidate values ​​for mesh size and time step are determined based on convergence analysis. This ensures that key flow field changes are captured when load calculation is performed based on the candidate values. Then, the final mesh size and time step are determined from the candidate values ​​based on the requirements for computational accuracy and resource consumption. This ensures that the final determined mesh size and time step meet the requirements for computational efficiency and accuracy.

[0010] In one optional implementation, the marine environmental load is loaded onto the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model, including: when the mesh parameters of the finite element model and the mesh parameters of the numerical model are consistent, the pressure data corresponding to each mesh is loaded onto the corresponding mesh of the finite element model; when the mesh parameters of the finite element model and the mesh parameters of the numerical model are inconsistent, the marine environmental load is loaded onto the finite element model based on a preset tolerance.

[0011] In this embodiment, when loading the load, based on the mesh parameters of the two models, when the mesh parameters are inconsistent, the mesh loading is performed by setting a tolerance, so that the load time history corresponding to each mesh point is loaded onto the finite element model for analysis and calculation as much as possible. This can more accurately reflect the load changes at different nodes in the real marine environment.

[0012] In one optional implementation, the preset tolerance includes multiple different preset tolerances, and the load calculation results include the stress time series of the numerical model in each direction. Loading the marine environmental load onto the finite element model based on the preset tolerance includes: loading the marine environmental load onto the finite element model based on different preset tolerances to obtain different loading results; obtaining different stress results based on the different loading results; comparing the different stress results with the stress time series of the numerical model in each direction to determine the preset tolerance that meets the requirements among the multiple different preset tolerances; and loading the marine environmental load onto the finite element model based on the preset tolerance that meets the requirements.

[0013] In this embodiment, when setting tolerances, load checks are performed on multiple tolerances to select the tolerance that meets the requirements for loading, thereby ensuring that as many grid node loads as possible are loaded, thus ensuring the accuracy and comprehensiveness of load loading.

[0014] In one optional implementation, the marine environmental load is loaded onto the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model. This further includes: determining the relationship between the loading time point and the preset time series corresponding to the pressure data; when the loading time point is within the preset time series, but the preset time series does not contain the loading time point, performing linear interpolation on the pressure data according to the time points corresponding to the loading time point to obtain the pressure data corresponding to the loading time point; loading the corresponding pressure data onto the finite element model according to the loading time point based on the mesh parameters of the finite element model and the mesh parameters of the numerical model; and setting the load loaded onto the finite element model to 0 when the loading time point is not within the preset time series.

[0015] In this embodiment, before loading, the pressure data in the load calculation results are linearly interpolated based on the loading time point, thereby ensuring that the load can be loaded and analyzed at any time point in the preset time series.

[0016] In one alternative implementation, the method further includes: obtaining the equivalent stress after loading marine environmental loads onto the finite element model; and verifying the strength of the marine structure based on the relationship between the maximum value of the equivalent stress and the ratio of the allowable stress to the safety factor.

[0017] In this embodiment, the strength verification of marine structures is achieved by determining the relationship between the maximum value of the equivalent stress and the ratio of the allowable stress and the safety factor.

[0018] Secondly, the present invention provides a load loading device for marine structures based on numerical simulation. The device includes: a load calculation module for calculating the marine environmental load of the marine structure based on a numerical model of the marine structure, and obtaining load calculation results. The numerical model includes multiple grid cells, and the load calculation results include the coordinates of the center points of the grid cells and their corresponding pressure data at different times under a preset time series; a model building module for building a finite element model of the marine structure based on the grid cells of the numerical model; and a loading module for loading the marine environmental load onto the finite element model based on the grid parameters of the finite element model and the grid parameters of the numerical model.

[0019] Thirdly, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the numerical simulation-based marine structure load loading method of the first aspect or any corresponding embodiment described above.

[0020] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the numerical simulation-based method for loading loads onto marine structures according to the first aspect or any corresponding embodiment described above.

[0021] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute the numerical simulation-based method for loading loads onto marine structures as described in the first aspect or any corresponding embodiment thereof. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating a numerical simulation-based load loading method for marine structures according to an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the grid and boundary fixation of a simple columnar structure in a marine structure according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the load loading process according to an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram illustrating the stress variation on the surface of a column according to an embodiment of the present invention;

[0027] Figure 5 This is a structural block diagram of a marine structure load loading device based on numerical simulation according to an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] According to an embodiment of the present invention, a method for loading loads on marine structures based on numerical simulation is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0031] This embodiment provides a numerical simulation-based load loading method for marine structures, which can be used in electronic devices such as computers, mobile phones, and tablets. Figure 1 This is a flowchart of a numerical simulation-based load loading method for marine structures according to an embodiment of the present invention, as shown below. Figure 1 As shown, the process includes the following steps:

[0032] Step S101: Calculate the marine environmental load of the marine structure based on the numerical model of the marine structure, and obtain the load calculation results. The numerical model includes multiple grid cells, and the load calculation results include the coordinates of the center point of the grid cell and the pressure data corresponding to different times under the preset time series.

[0033] Specifically, numerical models of marine structures can be created using 3D modeling software, such as AutoCAD, SolidWorks, and Blender. After the model is built, relevant parameters can be set in the model according to the marine environment in which the marine structure is located, thereby enabling the calculation of corresponding marine environmental loads. For example, when the environment in which the marine structure is located includes strong winds, strong waves, and strong currents, wind loads, wave loads, and current loads can be calculated by setting relevant parameters.

[0034] Furthermore, to facilitate numerical simulation of the marine environment and load calculations, the numerical model can be divided into multiple grid cells. This simplifies the complex continuum into discrete grid cells, allowing complex physical problems to be approximated by solving the equations on each small cell, thus reducing processing complexity. Based on multiple grid cells, load calculation results can be output on a per-grid-cell basis. The output includes the coordinates of the grid cell center points and their corresponding pressure data at different times, as well as the force sequence of the entire model in each direction. The output data can be integrated with the coordinates of all grid cell center points and the pressure data at all times for subsequent pressure application to the finite element model. Additionally, by plotting a scatter plot of the grid cell coordinates, it can be checked whether it matches the shape of the original marine structure model to determine if any data is missing.

[0035] Step S102: Establish a finite element model of the marine structure based on the mesh elements of the numerical model. Specifically, the finite element model of the marine structure can be established using finite element software. Furthermore, mesh generation is also required when establishing the finite element model. This embodiment uses the general-purpose finite element analysis software Abaqus as an example. Initially, Hypermesh software can be used to generate the mesh and set the material properties and flow field calculation parameters of the marine structure, including but not limited to elastic modulus, Poisson's ratio, density, and possible nonlinear material characteristics, such as yield strength and plastic deformation parameters. Then, the finite element model is exported to Abaqus for subsequent load loading.

[0036] Meanwhile, the mesh elements generated in the finite element model should be as consistent as possible with those in the numerical model. For example, the shape and size of the mesh elements in both models should be exactly the same, or the difference should be less than a certain value. Furthermore, the mesh elements in the finite element model should fit the geometric model and retain necessary geometric features. In addition, mesh distortion should be avoided at the connections between components in the finite element model, particularly in stress concentration areas. For example, after mesh generation, the mesh quality can be checked using the built-in functions of the finite element software.

[0037] Step S103: Based on the mesh parameters of the finite element model and the numerical model, the marine environmental load is loaded onto the finite element model. Specifically, when loading the marine environmental load, a user subroutine built into the finite element software can be used, such as the Dload program included in Abaqus. Furthermore, when loading the marine environmental load, the mesh elements corresponding to the pressure data in the load calculation results and the mesh elements of the finite element model should be considered. The goal is to load the load time history corresponding to each mesh point onto the finite element model for analysis and calculation as accurately as possible. This allows for a more precise representation of the load variations at different nodes in the real marine environment.

[0038] The numerical simulation-based load loading method for marine structures provided in this invention calculates the marine environmental load on marine structures by establishing a numerical model and performing numerical simulation. This enables fluid simulation calculation of marine structures in a real marine environment, obtaining the load time history experienced by the marine structure. Furthermore, by considering the mesh elements of the numerical model when establishing the finite element model, it is easier to load as many mesh elements as possible corresponding to the pressure data based on the mesh parameters of both models. This allows for a more accurate representation of the load variations at different nodes in the real marine environment, thereby enabling a more accurate assessment of the safety performance of marine structures and contributing to improving the design safety and reliability of marine structures.

[0039] This embodiment provides a method for loading loads onto marine structures based on numerical simulation. The process includes the following steps:

[0040] Step S201 involves calculating the marine environmental load on the marine structure based on a numerical model, obtaining the load calculation results. The numerical model includes multiple grid cells, and the load calculation results include the coordinates of the center points of the grid cells and their corresponding pressure data at different times within a preset time series. The grid division for the three numerical models balances computational accuracy and efficiency, capturing key flow field changes while avoiding unnecessary computational resource consumption. The shape and size of the grid are rationally set according to the specific structural characteristics and operating environment conditions of the marine structure. Therefore, in this embodiment, candidate values ​​that meet the conditions are first screened during grid division, and then parameters are selected from the candidate values ​​based on the actual situation for grid division.

[0041] Specifically, step S201 includes:

[0042] Step S2011: Select multiple different grid sizes and different time steps as candidate values based on whether the ocean environmental loads under different grid sizes and different time steps in the numerical model show monotonic convergence. Specifically, before establishing the numerical model, first determine the candidate values of the grid size and the time step. Among them, the time step is the interval between two consecutive time points during time-dependent numerical simulations, which is used for the advancement of time in the numerical simulation process. The size of the time step is crucial for ensuring the stability and accuracy of the simulation. Therefore, before establishing the numerical model, it is necessary to determine the candidate values of the grid size and the time step respectively.

[0043] In this embodiment, when selecting candidate values, perform convergence analysis on the grid size and the time step, that is, select different grid sizes and time steps, and determine whether the maximum values in the corresponding load calculation results under different grid sizes and time steps show a trend of monotonic convergence. Moreover, to ensure that the candidate values can meet different requirements, the selected candidate values should at least include three grid sizes of large, medium, and small and three time steps. That is, three grid sizes of large, medium, and small and three time steps can be used as a group, and multiple groups of different grid sizes and time steps can be set to determine the candidate values.

[0044] Among them, when determining the candidate values, it can be judged whether the maximum load calculation result of each group meets the requirement of monotonic convergence. For whether each group meets the requirement of monotonic convergence, it can be calculated using the following formula:

[0045]

[0046] where ε 32 = S III - S II , represents the difference in the maximum load between the large grid and the medium grid or the small time step and the medium time step; ε 21 = S II - S I , represents the difference in the maximum load between the medium grid and the small grid or the medium time step and the large time step. When the R calculated using the above formula satisfies 0 < R < 1, it shows monotonic convergence. Thus, when it is judged to satisfy monotonic convergence using the above formula, the three grid sizes of large, medium, and small and the three time steps of the corresponding group can be used as candidate values.

[0047] Step S2012 involves selecting a mesh size and time step from the candidate values ​​that meet the preset load calculation accuracy requirements and preset resource consumption requirements. Specifically, during the actual numerical model construction, it is necessary to select an appropriate mesh size and time step from three mesh sizes (large, medium, and small) and three time steps for subsequent processing, based on the current load calculation accuracy requirements and the resource consumption required by the 3D modeling software used. For example, by balancing numerical calculation accuracy and computational resource consumption, a numerical model with a sufficiently fine mesh and a sufficiently small time step can be selected from the candidate values ​​for calculation. Furthermore, when the difference between the results corresponding to a medium mesh / time step and the smallest mesh / time step is small, a model with a medium mesh size and a medium time step can be selected for formal calculation.

[0048] Step S2013: Establish a numerical model of the marine structure using 3D modeling software. When establishing the numerical model, only the external shape of the marine structure is retained.

[0049] Step S2014 involves meshing the numerical model and setting model parameters according to the marine environment. Specifically, meshing can be performed based on the mesh size determined in step S2012; when setting model parameters, corresponding boundary conditions and flow field parameters need to be set. For example, when calculating wave loads, velocity inlets can be set at both the inlet and outlet of the computational domain, and the corresponding wave levels can be set according to the ITTC (International Towing Tank Conference) two-parameter spectrum.

[0050] Step S2015 involves using a fluid dynamics solver to calculate the marine environmental load on the model after setting the model parameters, and obtaining the load calculation results. Specifically, the load calculation can be performed based on the time step determined in step S2012 above, thereby realizing the calculation of the marine environmental load and obtaining the load calculation results.

[0051] Step S202: Establish a finite element model of the marine structure based on the mesh elements of the numerical model. For details, please refer to [link to relevant documentation]. Figure 1 Step S102 of the illustrated embodiment will not be described again here.

[0052] Step S203: The marine environmental load is loaded into the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model.

[0053] Specifically, step S203 includes:

[0054] Step S2031: When the mesh parameters of the finite element model and the mesh parameters of the numerical model are consistent, the pressure data corresponding to each mesh is loaded onto the corresponding mesh of the finite element model. Specifically, when loading the load, if the mesh parameters of the finite element model and the mesh parameters of the numerical model are consistent, that is, the meshes of the two are completely corresponding, the pressure data of each mesh point can be directly loaded onto the finite element model.

[0055] Step S2032: When the mesh parameters of the finite element model and the numerical model are inconsistent, the marine environmental load is loaded onto the finite element model based on a preset tolerance. Specifically, when the mesh parameters of the finite element model and the numerical model are inconsistent, i.e., their meshes do not completely correspond, a tolerance can be set to load the load of the numerical model mesh node into the finite element model mesh node. That is, if the distance between the finite element model mesh node and its neighboring numerical model mesh node in three-dimensional space is within the tolerance range, the load of that numerical model mesh node is loaded. Furthermore, when the difference between the finite element model mesh element and the numerical model mesh element at different heights is large, different tolerances can be set at different heights to meet the load loading requirements of different parts. Multiple tolerances can be set, and a corresponding loading result can be obtained based on each tolerance. Then, by verifying the loading results, a suitable tolerance is selected.

[0056] In an optional implementation, step S3032 includes:

[0057] Step a1 involves loading marine environmental loads onto the finite element model based on different preset tolerances, resulting in different loading results. Specifically, when different preset tolerances are used, the loading method of the marine environmental load may differ, meaning that the pressure data loaded onto different mesh elements of the finite element model will be different, thus yielding different loading results.

[0058] Step a2 yields different stress results based on different loading outcomes. Specifically, when different grid cells are loaded with different pressure data, the marine structure experiences different forces. The stress results in this embodiment include the Mises equivalent stress σ. v Support reaction force RF, displacement U, etc., and can also be calculated based on the Mises equivalent stress σ of marine structures. v Obtain the Mises equivalent stress σ v Stress-time history. Among them, the Mises equivalent stress σ v The following formula is used for calculation:

[0059]

[0060] In the formula, σ xx σ yy σ zzσ xy σ yz With σ zx These represent stress components in different directions.

[0061] In addition, for a given support reaction force, the support reaction forces at all nodes on the support boundary can be summed and calculated, and the curves of the support reaction force in each direction as a function of time can be plotted.

[0062] Step a3 involves comparing different stress results with the stress time series of the numerical model in each direction to determine the preset tolerance that meets the requirements among multiple different preset tolerances. Specifically, when comparing results, the stress time series of the entire model in each direction can be obtained from the load calculation results, resulting in curves showing the change of stress in each direction over time. These curves are then compared with the curves showing the change of support reaction forces in each direction over time, as plotted in step a2. If the curves show a basically consistent change, then the corresponding preset tolerance is determined to meet the requirements.

[0063] Step a4: Load the marine environmental loads into the finite element model based on the preset tolerance that meets the requirements.

[0064] In an optional implementation, before applying the load, it is necessary to determine whether the time point of load application corresponds one-to-one with the preset time series corresponding to the pressure data obtained through numerical simulation. If they do not correspond, the pressure data needs to be further processed. Therefore, step S203 above also includes:

[0065] Step S2033: Determine the relationship between the loading time point and the preset time series corresponding to the pressure data; wherein, the loading time point can be a predetermined moment when the load needs to be applied. When determining the relationship between the loading time point and the preset time series, it can be determined whether multiple moments in the preset time series correspond to the loading time point. For example, if the loading time point is 10:05, and the preset time series also includes pressure data for that moment, then the two correspond. As another example, if the loading time point is 10:08, but the preset time series does not include pressure data for that moment, then the two do not correspond.

[0066] Step S2034: When the loading time point is in a preset time series and the preset time series does not include the loading time point, the pressure data is linearly interpolated according to the loading time point and the time point corresponding to the pressure data to obtain the pressure data corresponding to the loading time point.

[0067] In this context, "the loading time point is within the preset time series but not included in the preset time series" means that the loading time point falls within the maximum and minimum value range of the preset time series, but the pressure data for that specific loading time point is not included. For example, if the preset time series is from 10:00 to 11:00, and the loading time point is 10:08, then the loading time point is within the preset time series, but the preset time series does not include the pressure data for that moment. In this case, it is necessary to determine the pressure data for the loading time point based on the pressure data corresponding to the two ends of the loading time point included in the preset time series. For example, if the loading time point is 10:08, and the preset time series includes the two ends of the loading time point as 10:05 and 10:10, then linear interpolation is performed based on the pressure data at these two moments to obtain the pressure data for the loading time point, i.e., 10:08.

[0068] Step S2035: Based on the mesh parameters of the finite element model and the numerical model, the corresponding pressure data is loaded into the finite element model according to the loading time point. Specifically, after obtaining the pressure data at the loading time point, the pressure data of all mesh elements corresponding to that time point in the numerical model can be loaded according to the mesh parameters of the finite element model and the numerical model. The specific loading method can be implemented by referring to steps S2031 and S2032 above, and will not be repeated here.

[0069] Step S2036: When the loading time point is not in the preset time series, set the load loaded on the finite element model to 0. Specifically, when the loading time point is not in the preset time series, for example, if the preset time series is 10:00 to 11:00 and the loading time point is 12:00, it means that the loading time point is not in the preset time series. In this case, the load loaded on each mesh element of the finite element model can be directly set to 0.

[0070] Step S204: Obtain the equivalent stress after applying marine environmental loads to the finite element model; perform strength verification of the marine structure based on the relationship between the maximum value of the equivalent stress and the ratio of allowable stress to the safety factor. Specifically, the Mises equivalent stress can be calculated using the formula in step a2 above. After calculating the Mises equivalent stress, the Mises equivalent stress σ can be determined. v The maximum value over the time history is compared with the allowable stress using the following formula:

[0071]

[0072] In the formula, σ v,max Mises equivalent stress σ v The maximum value over time; σ limLet be the allowable stress; n be the safety factor. When this formula holds true, the strength check of the marine structure material is complete.

[0073] The numerical simulation-based load loading method for marine structures provided in this invention obtains the load time history of the marine structure through fluid simulation calculations in a real marine environment. The load time history of each mesh element is then used as input, processed, and loaded onto the finite element model of the marine structure to calculate the maximum stress and maximum strain, thereby determining whether the material safety factor requirements are met. This invention can more realistically simulate the stress conditions of marine structures in complex marine environments, and while effectively reducing costs and risks, it can more accurately assess the safety performance of marine structures, contributing to improving the design safety and reliability of marine structures.

[0074] As a specific application embodiment of the present invention, the numerical simulation-based method for loading loads on marine structures is implemented using the following process:

[0075] 1. Calculate the load.

[0076] For specific marine environments, such as strong winds and waves, a fluid dynamics solver is used to calculate the loads on a marine structure model. Before the calculation, a numerical model needs to be created using 3D modeling software, meshed, and the appropriate boundary conditions and flow field parameters set. For example, when calculating wave loads, velocity inlets can be set at both the inlet and outlet of the computational domain, and the corresponding wave levels can be set according to the ITTC two-parameter spectrum. Only the external shape of the marine structure is retained when creating the 3D model.

[0077] The mesh generation process must balance computational accuracy and efficiency, capturing key flow field changes while avoiding unnecessary computational resource consumption. The shape and size of the mesh should be rationally determined based on the specific structural characteristics of the marine structure and the operating environment conditions.

[0078] To determine the mesh size, a convergence analysis is performed on the mesh size and time step before the formal calculation. In this embodiment, three mesh sizes (large, medium, and small) and three time steps are grouped together, and multiple marine structure load calculation models with different mesh sizes and time steps are set up. Then, the values ​​that satisfy monotonically convergent are used as candidate values ​​for mesh size and time step. Specifically, the monotonically convergent analysis can be performed using the following formula:

[0079]

[0080] Where, ε 32 =S III -S II, representing the difference in the maximum load between the fine grid and the medium grid or between the small time step and the medium time step; ε 21 = S II - S I , representing the difference in the maximum load between the medium grid and the coarse grid or between the medium time step and the large time step. When 0 < R < 1, it converges monotonically.

[0081] During the formal calculation, the accuracy of the numerical calculation and the consumption of computing resources should be taken into account, and a numerical model with a sufficiently fine grid and a sufficiently small time step should be selected from the candidate values of the convergence analysis. Usually, when the difference between the results corresponding to the medium grid / time step and the smallest grid / time step is small, a model corresponding to a medium-sized grid and a medium-sized time step can be selected for the formal calculation.

[0082] 2. Load output and processing.

[0083] The load calculation results of the numerical model are output in units of grid cells. The output content should include the coordinates of the center points of the grid cells and the corresponding pressure data at different times, and the force time series in each direction of the entire model is output. Through data processing, the coordinates of all the center points of the grid cells and the pressure data at all times are integrated together for subsequent application of the pressure to the finite element model. By plotting the scatter plot of the coordinates of the grid cells, check whether it conforms to the shape of the original marine structure model to determine whether there is missing data.

[0084] 3. Establish a finite element model of the marine structure.

[0085] After load processing, the next step is to establish a finite element model of the marine structure, divide the grid, set the material properties of the marine structure according to the actual situation, and select the flow field calculation parameters. The shape and size of the grid of the finite element model should be as consistent as possible with the grid of the hydrodynamics calculation in the previous steps, and the grid model should fit the geometric model and retain the necessary geometric features. At the joints between the components of the platform, grid distortion should be avoided in the stress concentration area. After grid division, the software's built-in function can be used to check the grid quality.

[0086] In this embodiment, the general finite element analysis software Abaqus is taken as an example. Hypermesh software can be used in the early stage to divide the grid and set the material properties of the marine structure, including but not limited to elastic modulus, Poisson's ratio, density, and possible material nonlinear characteristics, such as yield strength and plastic deformation parameters, etc., and then export the finite element model to Abaqus for calculation. Figure 2 Shows the grid and boundary fixation of a simple columnar structure in the marine structure.

[0087] 4. Load application.

[0088] After obtaining the load time history at various points on the structure through the preceding steps, it is loaded onto the finite element model using a user subroutine built into the finite element software, such as the Dload program included in Abaqus. The purpose of loading is to ensure that the load time history corresponding to each grid point output by the numerical model can be loaded onto the finite element model for analysis and calculation. This allows for a more accurate representation of the load variations at different nodes in the real marine environment.

[0089] Among them, such as Figure 3 As shown, before loading, it is necessary to read the coordinates of all grid elements and the pressure time series in the load calculation results, and traverse the time series to determine whether the loading time point is within the time series. If it is within the time series, the load value corresponding to the loading time point, i.e., the pressure at that point, is accurately calculated based on the pressure values ​​of two adjacent time points using a linear interpolation method. If it is not within the time series, the current loop calculation process is automatically stopped. At this time, the load value of all grid points at that time point is uniformly set to 0.

[0090] During loading, it's necessary to determine whether to set a tolerance based on whether the mesh elements of the numerical model and the finite element model correspond. If they correspond, loading can be done directly. If they don't correspond, a tolerance R needs to be set to load the load from the numerical model mesh nodes into the finite element model mesh nodes. Specifically, if the distance between the finite element model mesh and its neighboring numerical model mesh nodes in 3D space is within the tolerance range, the load on that numerical model mesh node is loaded. When there are significant differences between the finite element model elements and the numerical model elements at different heights, different tolerances can be set at different heights to meet the load loading requirements of different locations.

[0091] Furthermore, to ensure that as many numerical model mesh nodes as possible are loaded, multiple tolerances can be set, and the loading results corresponding to each tolerance can be checked. Specifically, a reasonable tolerance setting is crucial for the accurate loading of loads onto the finite element model. Therefore, after selecting the tolerances, load checks are performed. After the load loading settings are completed, the output variables of the finite element model are determined, including the Mises equivalent stress σ. v (Formula 2), support reaction force RF, displacement U, etc., can be used to solve the Mises equivalent stress σ of marine structures through software. v Stress-time history. Figure 4This describes the strain observed on the surface of the column after loading. The support reactions at all nodes on the support boundary are summed and calculated, and curves showing the change of support reactions in each direction over time are plotted. These curves are then compared with the curves showing the change of forces in each direction over time in the marine structure model from the load calculation results. If the two sets of curves are basically consistent, the tolerance setting can be considered reasonable, and the load input in the finite element analysis is consistent with the load calculated by the fluid.

[0092] 5. Material strength verification.

[0093] After determining the required tolerance, a load is applied based on this tolerance, and the equivalent stress output by the finite element model after load application is obtained to determine the equivalent stress σ. v By comparing the maximum value over time with the allowable stress, the strength of marine structure materials can be verified.

[0094] This embodiment also provides a numerical simulation-based load-loading device for marine structures, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0095] This embodiment provides a load loading device for marine structures based on numerical simulation, such as... Figure 5 As shown, it includes:

[0096] The load calculation module 51 is used to calculate the marine environmental load of the marine structure based on the numerical model of the marine structure and obtain the load calculation results. The numerical model includes multiple grid cells, and the load calculation results include the coordinates of the center point of the grid cell and the pressure data corresponding to different times under the preset time series.

[0097] Model building module 52 is used to build finite element models of marine structures based on the mesh elements of the numerical model;

[0098] Loading module 53 is used to load marine environmental loads onto the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model.

[0099] In one optional implementation, the load calculation module is specifically used for: establishing a numerical model of the marine structure based on modeling software; meshing the numerical model and setting model parameters according to the marine environment; and using a fluid dynamics solver to calculate the marine environmental load on the model after setting the model parameters, thereby obtaining the load calculation results.

[0100] In one optional implementation, the load calculation module is further configured to select multiple different grid sizes and different time steps as candidate values ​​based on whether the marine environmental load under different grid sizes and different time steps of the numerical model exhibits monotonic convergence; and select from the candidate values ​​a grid size and time step that meet the preset load calculation accuracy requirements and preset resource consumption requirements.

[0101] In one optional implementation, the loading module includes: a first loading unit, used to load the pressure data corresponding to each grid into the corresponding grid of the finite element model when the grid parameters of the finite element model and the grid parameters of the numerical model are consistent; and a second loading unit, used to load the marine environmental load into the finite element model based on a preset tolerance when the grid parameters of the finite element model and the grid parameters of the numerical model are inconsistent.

[0102] In one optional implementation, the preset tolerance includes multiple different preset tolerances, and the load calculation results include the stress sequence of the numerical model in each direction. The second loading unit is specifically used for: loading the marine environmental load onto the finite element model based on different preset tolerances to obtain different loading results; obtaining different stress results based on the different loading results; comparing the different stress results with the stress sequence of the numerical model in each direction to determine the preset tolerance that meets the requirements among the multiple different preset tolerances; and loading the marine environmental load onto the finite element model based on the preset tolerance that meets the requirements.

[0103] In one optional implementation, the loading module is specifically used to: determine the relationship between the loading time point and the preset time series corresponding to the pressure data; when the loading time point is in the preset time series and the preset time series does not contain the loading time point, perform linear interpolation on the pressure data according to the time point corresponding to the loading time point and the pressure data to obtain the pressure data corresponding to the loading time point; based on the mesh parameters of the finite element model and the mesh parameters of the numerical model, load the corresponding pressure data into the finite element model according to the loading time point; when the loading time point is not in the preset time series, set the load loaded on the finite element model to 0.

[0104] In one optional embodiment, the device further includes: a verification module, specifically used to obtain the equivalent stress after loading marine environmental loads onto the finite element model; and to verify the strength of the marine structure based on the relationship between the maximum value of the equivalent stress and the ratio of the allowable stress and the safety factor.

[0105] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0106] This invention also provides a computer device having the above-described features. Figure 5 The image shows a load-loading device for marine structures based on numerical simulation.

[0107] Please see Figure 6 , Figure 6 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 6 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 6 Take a processor 10 as an example.

[0108] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0109] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0110] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device as shown by a landing page for an app. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, which can be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0111] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0112] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0113] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0114] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0115] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A numerical simulation-based method for load application to a marine structure, characterized by, The method includes: The marine environmental load on the marine structure is calculated based on a numerical model of the marine structure, and the load calculation results are obtained. The numerical model includes multiple grid cells, and the load calculation results include the coordinates of the center point of the grid cell and the pressure data corresponding to different times under a preset time series. A finite element model of the marine structure is established based on the mesh elements of the numerical model. The marine environmental load is loaded onto the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model. The marine environmental load is loaded onto the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model, including: When the mesh parameters of the finite element model and the mesh parameters of the numerical model are consistent, the pressure data corresponding to each mesh is loaded into the mesh corresponding to the finite element model. When the mesh parameters of the finite element model and the mesh parameters of the numerical model are inconsistent, the marine environmental load is applied to the finite element model based on a preset tolerance. The preset tolerances include multiple different preset tolerances. The load calculation results include the force sequence of the numerical model in each direction. Based on the preset tolerances, the marine environmental loads are applied to the finite element model, including: Different loading results were obtained by applying marine environmental loads to the finite element model based on different preset tolerances. Different loading results yield different force results; By comparing different stress results with the stress time series of the numerical model in each direction, the preset tolerance that meets the requirements among multiple different preset tolerances is determined. The marine environmental load is loaded into the finite element model based on the preset tolerance that meets the requirements.

2. The method of claim 1, wherein, The marine environmental loads on marine structures are calculated based on numerical models of the structures, and the load calculation results are obtained, including: Numerical models of marine structures were established using modeling software. The numerical model is meshed, and the model parameters are set according to the marine environment. A fluid dynamics solver was used to calculate the marine environmental load on the model after setting the model parameters, and the load calculation results were obtained.

3. The method of claim 2, wherein, Before meshing the numerical model, the method further includes: Based on whether the marine environmental load under different grid sizes and time steps exhibits monotonic convergence, multiple different grid sizes and time steps are selected as candidate values. Select a grid size and time step from the candidate values ​​that meet the preset load calculation accuracy requirements and preset resource consumption requirements.

4. The method of claim 1, wherein, The marine environmental load is applied to the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model, and the method further includes: Determine the relationship between the loading time point and the preset time series corresponding to the pressure data; When the loading time point is within the preset time series, and the preset time series does not include the loading time point, the pressure data is linearly interpolated based on the loading time point and the time point corresponding to the pressure data to obtain the pressure data corresponding to the loading time point. Based on the mesh parameters of the finite element model and the mesh parameters of the numerical model, the corresponding pressure data is loaded into the finite element model according to the loading time point; When the loading time point is not in the preset time sequence, the load of the finite element model is set to 0.

5. The method of claim 1, wherein, The method further comprises: obtaining the equivalent stress after the marine environmental load is loaded on the finite element model; performing strength checking of the marine structure according to the relationship between the maximum value of the equivalent stress and the ratio of the allowable stress and the safety factor.

6. A numerical simulation based loading device for a marine structure, characterized by The device comprises: a load calculation module configured to calculate marine environmental load of a marine structure based on a numerical model of the marine structure, the numerical model comprising a plurality of grid elements, and obtain load calculation results, the load calculation results comprising coordinates of center points of the grid elements and corresponding pressure data of the center points at different time points in a preset time sequence; a model establishment module configured to establish a finite element model of the marine structure based on the grid elements of the numerical model; a loading module configured to load the marine environmental load to the finite element model based on grid parameters of the finite element model and grid parameters of the numerical model; the loading module comprises a first loading unit configured to load the corresponding pressure data of each grid to the corresponding grid of the finite element model when the grid parameters of the finite element model and the grid parameters of the numerical model are consistent, and a second loading unit configured to load the marine environmental load to the finite element model based on a preset tolerance when the grid parameters of the finite element model and the grid parameters of the numerical model are inconsistent; the preset tolerance comprises a plurality of different preset tolerances, and the load calculation results comprise force time sequences of the numerical model in each direction, the second loading unit is specifically configured to load the marine environmental load to the finite element model based on the different preset tolerances to obtain different loading results, obtain different force results based on the different loading results, compare the different force results with the force time sequences of the numerical model in each direction to determine a preset tolerance meeting the requirements from the plurality of different preset tolerances, and load the marine environmental load to the finite element model based on the preset tolerance meeting the requirements.

7. A computer device, comprising: comprise: a memory and a processor, which are communicatively connected, the memory stores computer instructions, and the processor executes the computer instructions to perform the load loading method of the marine structure based on numerical simulation according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions, and the computer instructions are used to make the computer execute the load loading method of the marine structure based on numerical simulation according to any one of claims 1 to 5.

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