Ocean structure load loading method and device based on numerical simulation

Abstract

The invention relates to the technical field of ocean engineering, in particular to an ocean structure load loading method and device based on numerical simulation. According to the ocean structure load loading method based on numerical simulation provided by the embodiment of the invention, the ocean environment load of the ocean structure is calculated by establishing the numerical model for numerical simulation, so that fluid simulation calculation of the ocean structure in a real ocean environment is realized; meanwhile, the grid units of the numerical model are considered when the finite element model is established, so that loading of pressure data corresponding to the grid units as many as possible is conveniently realized according to grid parameters of the two models; therefore, the change condition of the load of the model at different nodes in a real marine environment can be more accurately fitted, the safety performance of the marine structure can be more accurately evaluated, and the design safety and reliability of the marine structure can be improved.

Description

Technical Field

[0001] The present invention relates to the field of marine engineering technology, and in particular to a method and device for loading a marine structure based on numerical simulation. Background Art

[0002] With the exploration of marine resources by human beings, marine structures have played an increasingly important role in the development and utilization of marine resources. In the marine environment, conditions such as wind and waves will pose a serious threat to the structural strength of marine structures. Therefore, in order to ensure the safe operation and long-term stability of marine structures, it is particularly important to accurately verify the structural strength of marine structures in the real marine environment during the design stage.

[0003] At present, the structural strength verification methods of marine structures mainly include experimental method, theoretical analysis method and finite element simulation method. The experimental method collects and analyzes the stress conditions of the structure by conducting tests under actual marine environmental conditions. This method can more realistically simulate the impact of the marine environment on the structure of marine structures, but it has problems such as high cost, long time and high risk. The theoretical analysis method is based on the principles of structural mechanics. It calculates and evaluates the structural strength of marine structures by establishing mathematical models and stress analysis methods. However, due to the complexity of the structure of marine structures, the accuracy of the results cannot be guaranteed by simply using simplified theoretical formulas for calculation. The use of finite element simulation method can solve the above two problems, but how to accurately load the load and ensure the accuracy of finite element analysis has become a new problem. Summary of the invention

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

[0005] In a first aspect, the present invention provides a method for loading a marine structure based on numerical simulation, the method comprising: calculating the marine environmental load of the marine structure based on a numerical model of the marine structure to obtain a load calculation result, the numerical model comprising a plurality of grid units, the load calculation result comprising the coordinates of a center point of the grid unit and its corresponding pressure data at different times in a preset time series; establishing a finite element model of the marine structure based on the grid units of the numerical model; and loading the marine environmental load to the finite element model based on the grid parameters of the finite element model and the grid parameters of the numerical model.

[0006] The marine structure load loading method based on numerical simulation provided by the embodiment of the present invention calculates the marine environmental load of the marine structure by means of numerical simulation through establishing a numerical model, thereby realizing fluid simulation calculation of the marine structure in a real marine environment, and obtaining the load time history suffered by the marine structure. At the same time, the grid units of the numerical model are considered when establishing the finite element model, so as to facilitate the loading of pressure data corresponding to as many grid units as possible according to the grid parameters of the two models, so as to more accurately fit the load changes at different nodes of the model in the real marine environment, thereby being able to more accurately evaluate the safety performance of the marine structure, which is helpful to improve the design safety and reliability of the marine structure.

[0007] In an optional embodiment, the marine environment load of the marine structure is calculated based on the numerical model of the marine structure to obtain the load calculation result, including: establishing the numerical model of the marine structure based on three-dimensional modeling software; gridding the numerical model and setting the model parameters according to the marine environment; using a fluid mechanics solver to calculate the marine environment load of the model after setting the model parameters to obtain the load calculation result.

[0008] In an optional embodiment, before gridding the numerical model, the method also includes: selecting multiple different grid sizes and different time steps as candidate values ​​based on whether the ocean environmental load of the numerical model shows monotonic convergence under different grid sizes and different time steps; and selecting a grid size and time step that meets preset load calculation accuracy requirements and preset resource consumption requirements from the candidate values.

[0009] In this embodiment, before meshing is performed, candidate values ​​for the grid size and time step are first determined based on a convergence analysis, so that when load calculation is performed based on the candidate values, key flow field changes can be captured. Then, the final grid size and time step to be used are determined from the candidate values ​​based on the calculation accuracy requirements and resource consumption requirements, so that the final determined grid size and time step meet the calculation efficiency and calculation accuracy.

[0010] In an optional embodiment, the marine environment load is loaded into the finite element model based on the grid parameters of the finite element model and the grid parameters of the numerical model, including: when the grid parameters of the finite element model and the grid parameters of the numerical model are consistent, the pressure data corresponding to each grid is loaded into the grid corresponding to the finite element model; when the grid parameters of the finite element model and the grid parameters of the numerical model are inconsistent, the marine environment load is loaded into the finite element model based on a preset tolerance.

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

[0012] In an optional embodiment, the preset tolerance includes multiple different preset tolerances, the load calculation result includes the force sequence of the numerical model in various directions, and the marine environment load is loaded into the finite element model based on the preset tolerance, including: loading the marine environment load into the finite element model based on different preset tolerances to obtain different loading results; obtaining different force results based on different loading results; comparing the different force results with the force sequence of the numerical model in various directions to determine the preset tolerance that meets the requirements among multiple different preset tolerances; loading the marine environment load into the finite element model based on the preset tolerance that meets the requirements.

[0013] In this embodiment, when setting tolerances, load verification is performed on multiple tolerances that are set, so that a tolerance that meets the requirements is selected for loading, so that as many grid node loads as possible are loaded, ensuring the accuracy and comprehensiveness of load loading.

[0014] In an optional embodiment, loading the marine environmental load into the finite element model based on the grid parameters of the finite element model and the grid parameters of the numerical model also includes: judging 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 include the loading time point, performing linear interpolation processing on the pressure data according to the time points corresponding to the loading time point and the pressure data to obtain the pressure data corresponding to the loading time point; based on the grid parameters of the finite element model and the grid parameters of the numerical model, loading 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, setting the load loaded by the finite element model to 0.

[0015] In this embodiment, before loading, linear interpolation processing is first performed on the pressure data in the load calculation result based on the loading time point, thereby ensuring that the loading and analysis of the load at any time point in the preset time series can be achieved.

[0016] In an optional embodiment, the method further includes: obtaining the equivalent stress after loading the marine environmental load on the finite element model; and performing strength verification 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.

[0017] In this embodiment, the strength check of the marine structure 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] In a second aspect, the present invention provides a load loading device for a marine structure based on numerical simulation, the device comprising: a load calculation module, used to calculate the marine environment load of the marine structure based on the numerical model of the marine structure to obtain a load calculation result, the numerical model comprising a plurality of grid units, the load calculation result comprising the coordinates of the center point of the grid unit and its corresponding pressure data at different times under a preset time series; a model building module, used to establish a finite element model of the marine structure based on the grid units of the numerical model; a loading module, used to load the marine environment load to the finite element model based on the grid parameters of the finite element model and the grid parameters of the numerical model.

[0019] In a third aspect, 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 numerical simulation-based marine structure load loading method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0020] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for loading marine structures based on numerical simulation according to the first aspect or any corresponding embodiment thereof.

[0021] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the method for loading marine structures based on numerical simulation according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 is a flow chart of a method for loading a marine structure based on numerical simulation according to an embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of the grid and boundary fixing of a simple column structure in an ocean structure according to an embodiment of the present invention;

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

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

[0027] Figure 5 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 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

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

[0031] In this embodiment, a method for loading a marine structure based on numerical simulation is provided, which can be used for electronic devices such as computers, mobile phones, tablet computers, etc. Figure 1 is a flow chart of a method for loading a marine structure based on numerical simulation according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0032] Step S101, calculating the marine environmental load of the marine structure based on the numerical model of the marine structure to obtain the load calculation result, the numerical model includes a plurality of grid units, and the load calculation result includes the coordinates of the center point of the grid unit and the corresponding pressure data at different times in a preset time series.

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

[0034] In addition, in order to facilitate the numerical simulation of the marine environment and the calculation of loads, the numerical model can be divided into multiple grid units, so that the complex continuum can be simplified into discrete grid units, so that complex physical problems can be approximately solved by solving the equations on each small unit, reducing the processing complexity. Based on multiple grid units, the load calculation results can be output in units of grid units, and the output content includes the coordinates of the center point of the grid unit and its corresponding pressure data at different times, and outputs the force time series of the entire model in all directions. For the output data, the coordinates of the center points of all grid units and the pressure data at all times can be integrated together so that the pressure can be applied to the finite element model later. And it is also possible to check whether it matches the shape of the original marine structure model by drawing a scatter plot of the coordinates of the grid unit to determine whether there is data missing.

[0035] Step S102, a finite element model of the marine structure is established based on the grid unit of the numerical model. Specifically, the finite element model of the marine structure can be established using finite element software. In addition, the grid unit needs to be divided when establishing the finite element model. This embodiment takes the general finite element analysis software Abaqus as an example. In the early stage, Hypermesh software can be used to divide the grid and set the material properties of the marine structure and the flow field calculation parameters, including but not limited to elastic modulus, Poisson's ratio, density and possible material nonlinear characteristics, such as yield strength and plastic deformation parameters, and then the finite element model is exported to Abaqus for subsequent load loading.

[0036] At the same time, the mesh units divided in the finite element model and the mesh units in the numerical model need to be as consistent as possible, for example, the shapes and sizes of the two mesh units are exactly the same or the difference is less than a certain value. And the mesh units of the finite element model must fit the geometric model and retain the necessary geometric features. In addition, the connections between the components of the finite element model should avoid mesh distortion in stress concentration areas. For example, after the mesh division is completed, the mesh quality can be checked using the built-in function of the finite element software.

[0037] Step S103, based on the mesh parameters of the finite element model and the mesh parameters of the numerical model, the marine environment load is loaded into the finite element model. Specifically, when loading the marine environment load, the user subroutine built into the finite element software can be used for loading, for example, the Dload program included in Abaqus is used to implement the marine environment load loading. In addition, when loading the marine environment load, the grid units corresponding to the pressure data in the load calculation results and the grid units of the finite element model should be considered, and the load time history corresponding to each grid point can be loaded onto the finite element model for analysis and calculation as much as possible, so that the load changes at different nodes of the model in the real marine environment can be more accurately fitted.

[0038] The marine structure load loading method based on numerical simulation provided by the embodiment of the present invention calculates the marine environmental load of the marine structure by means of numerical simulation through establishing a numerical model, thereby realizing fluid simulation calculation of the marine structure in a real marine environment, and obtaining the load time history suffered by the marine structure. At the same time, the grid units of the numerical model are considered when establishing the finite element model, so as to facilitate the loading of pressure data corresponding to as many grid units as possible according to the grid parameters of the two models, so as to more accurately fit the load changes at different nodes of the model in the real marine environment, thereby being able to more accurately evaluate the safety performance of the marine structure, which is helpful to improve the design safety and reliability of the marine structure.

[0039] In this embodiment, a method for loading a marine structure based on numerical simulation is provided, and the process includes the following steps:

[0040] Step S201, calculate the marine environmental load of the marine structure based on the numerical model of the marine structure to obtain the load calculation result, the numerical model includes a plurality of grid units, and the load calculation result includes the coordinates of the center point of the grid unit and its corresponding pressure data at different times under a preset time series. Among them, the division of the grids of the three numerical models takes into account both calculation accuracy and efficiency, and it is necessary to capture the key flow field changes and avoid unnecessary consumption of computing resources. According to the specific structural characteristics and working environment conditions of the marine structure, the shape and size of the grid are reasonably set. Therefore, when dividing the grid, this embodiment first screens the candidate values ​​that meet the conditions, and then selects parameters from the candidate values ​​for grid division according to the actual situation.

[0041] Specifically, the above step S201 includes:

[0042] Step S2011, select multiple different grid sizes and different time steps as candidate values according to 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-related numerical simulation, 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. And, in order to ensure that the candidate values can meet different requirements, the selected candidate values include at least 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 are 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 R calculated using the above formula satisfies 0 < R < 1, it is monotonically convergent. Thus, when it is judged to be monotonically convergent 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, select the grid size and time step that meet the preset load calculation accuracy requirements and the preset resource consumption requirements from the candidate values. Specifically, when actually constructing the numerical model, it is necessary to select the appropriate grid size and time step from the three grid sizes of large, medium and small and the three time steps for subsequent processing according to the requirements of the current load calculation accuracy and the resource consumption required by the adopted three-dimensional modeling software. For example, by taking into account the accuracy of numerical calculations and the consumption of computing resources, a numerical model with a sufficiently fine grid and a sufficiently small time step is selected from the candidate values ​​for calculation. In addition, when the results corresponding to the medium grid / time step are slightly different from those corresponding to the smallest grid / time step, a model corresponding to a medium-sized grid and a medium-sized time step can be selected for formal calculation.

[0048] Step S2013: Building a numerical model of the marine structure based on 3D modeling software, wherein only the outer shape of the marine structure is retained when building the numerical model.

[0049] Step S2014, meshing the numerical model and setting model parameters according to the marine environment. Specifically, when meshing, 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 grade can be set according to the ITTC (International Towing Tank Conference) dual parameter spectrum.

[0050] Step S2015, using a fluid mechanics solver to calculate the ocean environment load on the model after setting the model parameters, and obtain the load calculation result. Specifically, when performing the load calculation, a numerical simulation process can be performed based on the time step determined in the above step S2012 to realize the ocean environment load calculation and obtain the load calculation result.

[0051] Step S202: Establish a finite element model of the marine structure based on the grid cells of the numerical model. Figure 1 Step S102 of the illustrated embodiment will not be described in detail here.

[0052] Step S203 , loading the marine environment load 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, the above step S203 includes:

[0054] Step S2031, when the mesh parameters of the finite element model are consistent with the mesh parameters of the numerical model, the pressure data corresponding to each mesh is loaded into the mesh corresponding to the finite element model; specifically, when performing load loading, if the mesh parameters of the finite element model are consistent with the mesh parameters of the numerical model, that is, the meshes of the two completely correspond, then the pressure data of each mesh point can be directly loaded into the finite element model.

[0055] Step S2032, when the grid parameters of the finite element model and the grid parameters of the numerical model are inconsistent, the marine environment load is loaded into the finite element model based on the preset tolerance. Specifically, when the grid parameters of the finite element model and the grid parameters of the numerical model are inconsistent, that is, the grids of the two do not completely correspond, the tolerance can be set to load the load of the numerical model grid node into the finite element model grid node, that is, the distance between the numerical model grid node in the finite element model grid and its neighboring numerical model grid nodes in the three-dimensional space is within the tolerance range, and the load of the numerical model grid node is loaded. And, when the difference between the finite element model grid unit and the numerical model grid unit at different heights is large, different tolerances can be set at different heights to meet the load loading requirements of different parts. Among them, when setting the tolerance, multiple tolerances can be set, and the corresponding loading result is obtained based on each tolerance, and then the appropriate tolerance is selected by checking the loading result.

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

[0057] Step a1, loading the marine environment load to the finite element model based on different preset tolerances to obtain different loading results. Specifically, when different preset tolerances are used, the loading method of the marine environment load may be different, that is, the pressure data loaded on different grid units of the finite element model are different, thereby obtaining different loading results.

[0058] Step a2, different stress results are obtained based on different loading results. Specifically, when the pressure data loaded by different grid units are different, the stress of the marine structure is different. The stress results in this embodiment include Mises equivalent stress σ v , support reaction RF, displacement U, etc., and the Mises equivalent stress σ of the marine structure can also be used. v Get the Mises equivalent stress σ v Stress-time history. Among them, Mises equivalent stress σ v The calculation is done using the following formula:

[0059]

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

[0061] In addition, for the determined support reaction, the support reaction of all nodes on the support boundary can be summed and calculated, and a curve showing the change of support reaction in each direction over time can be drawn.

[0062] Step a3, compare different force results with the force sequence of the numerical model in each direction, and determine the preset tolerance that meets the requirements among multiple different preset tolerances. Specifically, when comparing the results, the force sequence of the entire model in each direction in the load calculation result can be obtained, and the curve of the force of the numerical model in each direction changing with time can be obtained. The curve is compared with the curve of the support reaction force in each direction drawn in step a2 and changing with time. If the curve changes are basically consistent, it is determined that the corresponding preset tolerance meets the requirements.

[0063] Step a4, loading the marine environment load into the finite element model based on a preset tolerance that meets the requirements.

[0064] In an optional implementation, before performing load loading, it is also necessary to determine whether the time point of load loading corresponds to the preset time series corresponding to the pressure data obtained by numerical simulation. If not, the pressure data needs to be further processed. Therefore, the above step S203 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 time point at which the load needs to be loaded. When determining the relationship between the loading time point and the preset time series, it can be determined whether multiple moments of the preset time series can correspond to the loading time point. For example, when the loading time point is 10:05, and the preset time series also contains the pressure data at 10:05, it means that the two correspond. For another example, when the loading time point is 10:08, and the preset time series does not contain the pressure data at 10:08, it means that the two do not correspond.

[0066] Step S2034, when the loading time point is in the preset time sequence and the preset time sequence 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] Among them, the loading time point is in the preset time sequence but the preset time sequence does not include the loading time point means that the loading time point is within the maximum and minimum value range of the preset time sequence, but does not include the pressure data of the loading time point. For example, the preset time sequence is 10:00 to 11:00, and the loading time point is 10:08, which means that the loading time point is in the preset time sequence, but the preset time sequence does not include the pressure data at the moment of 10:08. At this time, it is necessary to determine the pressure data of the loading time point based on the pressure data corresponding to the moment points at both ends of the loading time point in the moment points included in the preset time sequence. For example, the loading time point is 10:08, and the moment points at both ends of the loading time point included in the preset time sequence are 10:05 and 10:10, then linear interpolation processing is performed based on the pressure data of these two moment points to obtain the pressure data of the loading time point, i.e., the moment point of 10:08.

[0068] Step S2035, 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; specifically, after obtaining the pressure data at the loading time point, the pressure data of all mesh units of the numerical model corresponding to the time point can be loaded according to the mesh parameters of the finite element model and the mesh parameters of the numerical model. The specific loading method can be implemented with reference to the above steps S2031 and S2032, which will not be repeated here.

[0069] Step S2036, when the loading time point is not in the preset time sequence, the load loaded on the finite element model is set to 0. Specifically, when the loading time point is not in the preset time sequence, for example, the preset time sequence 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 sequence, and at this time, the load loaded on each grid unit of the finite element model can be directly set to 0.

[0070] Step S204, obtain the equivalent stress after loading the marine environment load on 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 the allowable stress and 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 found v The maximum value in the time history is compared with the allowable stress in the following manner:

[0071]

[0072] In the formula, σ v,max is the Mises equivalent stress σ v The maximum value in the time history; σ limis the allowable stress; n is the safety factor. When this formula is established, the verification of the material strength of the marine structure is completed.

[0073] The method for loading marine structures based on numerical simulation provided by the embodiment of the present invention obtains the load time history suffered by the marine structure by simulating the fluid of the marine structure in the real marine environment, and then takes the load time history of each grid unit as input, and loads it onto the finite element model of the marine structure after processing, and calculates the maximum stress and maximum strain suffered by it, so as to judge whether the material meets the safety factor requirements. The present invention can more realistically simulate the stress conditions of marine structures in complex marine environments, and at the same time, under the premise of effectively reducing costs and risks, it can more accurately evaluate the safety performance of marine structures, which helps to improve the design safety and reliability of marine structures.

[0074] As a specific application example of the embodiment of the present invention, the marine structure load loading method based on numerical simulation is implemented by the following process:

[0075] 1. Calculate the load.

[0076] For certain marine environments, such as strong winds and strong waves, the loads on the marine structure model are calculated using a fluid mechanics solver. Before calculation, it is necessary to first establish a numerical model based on 3D modeling software, perform meshing, and set the corresponding boundary conditions and flow field parameters. For example, when calculating wave loads, you can set velocity inlets at both the inlet and outlet of the calculation domain, and set the corresponding wave level according to the ITTC dual-parameter spectrum. When establishing a 3D model, only the external structure of the marine structure is retained.

[0077] The division of the grid must take into account both computational accuracy and efficiency, capturing key flow field changes while avoiding unnecessary consumption of computing resources. The shape and size of the grid should be reasonably set according to the specific structural characteristics and working environment conditions of the marine structure.

[0078] In order to determine the size of the grid division, before the formal calculation, the convergence analysis of the grid size and time step is performed. In this embodiment, three grid sizes of large, medium and small and three time steps are used as a group, and multiple groups of marine structure load calculation models with different grid sizes and time steps are set, and then the ones that meet monotonic convergence are used as candidate values ​​of the grid and time step. Specifically, the monotonic convergence analysis can be analyzed using the following formula:

[0079]

[0080] Among them, 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 for calculation. 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 the medium-sized grid and the 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 of the entire model in each direction 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 judge whether there is data loss.

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

[0085] After the 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 hydrodynamic calculation in the previous steps, and the grid model should fit the geometric model and retain the necessary geometric features. At the connection points between the components of the platform, grid distortion should be avoided in the stress concentration areas. After the grid division is completed, the software's built-in function can be used to check the grid quality.

[0086] In this embodiment, taking the general finite element analysis software Abaqus as an example, the grid can be divided and the material properties of the marine structure can be set using Hypermesh software in the early stage, 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 the finite element model is exported 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 series at each location of the structure through the previous steps, it is loaded onto the finite element model through the built-in user subroutine of 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, so that the load changes at different nodes of the model in the real marine environment can be more accurately fitted.

[0089] Among them, Figure 3 As shown in the figure, before loading, it is necessary to read all grid unit coordinates and 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, that is, the pressure at the point, is accurately calculated based on the pressure values ​​of the two adjacent time points of the loading time point according to the linear interpolation method. If it is not within the time series, the current cycle calculation process is automatically stopped. At this time, for all grid points at this time point, their load values ​​are uniformly set to 0.

[0090] When loading, it is necessary to determine whether to set a tolerance based on whether the mesh units of the numerical model and the finite element model correspond. When they correspond, they can be loaded directly. When they do not correspond, it is necessary to set the tolerance R to load the load of the numerical model mesh node into the finite element model mesh node, that is, if the distance between the numerical model mesh node in the finite element model mesh and its neighboring numerical model mesh nodes in three-dimensional space is within the tolerance range, the load of the numerical model mesh node is loaded. When the difference between the finite element model unit and the numerical model unit at different heights is large, different tolerances can be set at different heights to meet the load loading requirements of different parts.

[0091] In addition, in order to ensure that as many numerical model grid node loads as possible are loaded, multiple tolerances can be set, and the load results corresponding to each tolerance can be checked. Specifically, reasonable tolerance setting is the key to accurately loading the load on the finite element model. Therefore, after selecting the tolerance, the load is checked. After the load loading setting is completed, the output variables of the finite element model are determined, including the Mises equivalent stress σ v (Formula 2), support reaction RF, displacement U, etc., the Mises equivalent stress σ of the marine structure can be solved through the software v Stress-time history. Figure 4It is the strain on the surface of the column after the load is applied. The support reaction forces of all nodes on the support boundary are summed and calculated, and the curves of the support reaction forces in various directions changing with time are plotted, and then compared with the curves of the forces in various directions of the marine structure model in the load calculation results changing with time. If the two sets of curves are basically consistent, it can be considered that the tolerance setting is 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 tolerance that meets the requirements, load is applied based on the tolerance, and the equivalent stress output by the finite element model after load application is obtained to determine the equivalent stress σ v The maximum value in the time history is compared with the allowable stress to verify the strength of the marine structure material.

[0094] In this embodiment, a marine structure load loading device based on numerical simulation is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made are not repeated. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0095] This embodiment provides a marine structure load loading device based on numerical simulation, such as Figure 5 As shown, including:

[0096] A load calculation module 51 is used to calculate the marine environment load of the marine structure based on the numerical model of the marine structure to obtain the load calculation result, the numerical model includes a plurality of grid units, and the load calculation result includes the coordinates of the center point of the grid unit and the corresponding pressure data at different times in a preset time series;

[0097] A model building module 52, for building a finite element model of the marine structure based on the grid cells of the numerical model;

[0098] The loading module 53 is used to load the marine environment load to the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model.

[0099] In an optional embodiment, the load calculation module is specifically used to: establish a numerical model of the marine structure based on the modeling software; grid the numerical model and set the model parameters according to the marine environment; use a fluid mechanics solver to calculate the marine environment load on the model after setting the model parameters, and obtain the load calculation result.

[0100] In an optional embodiment, the load calculation module is also used to select multiple different grid sizes and different time steps as candidate values ​​based on whether the marine environmental load of the numerical model shows monotonic convergence under different grid sizes and different time steps; and select a grid size and time step that meets preset load calculation accuracy requirements and preset resource consumption requirements from the candidate values.

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

[0102] In an optional embodiment, the preset tolerance includes multiple different preset tolerances, the load calculation result includes the force sequence of the numerical model in various directions, and the second loading unit is specifically used to: load the marine environment load to the finite element model based on different preset tolerances to obtain different loading results; obtain different force results based on different loading results; compare the different force results with the force sequence of the numerical model in various directions to determine the preset tolerance that meets the requirements among multiple different preset tolerances; load the marine environment load to the finite element model based on the preset tolerance that meets the requirements.

[0103] In an optional embodiment, 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 include the loading time point, linearly interpolate 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 by the finite element model to 0.

[0104] In an optional embodiment, the device also includes: a verification module, which is specifically used to obtain the equivalent stress after loading the marine environmental load on the finite element model; and perform strength verification 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] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0106] The embodiment of the present invention also provides a computer device having the above Figure 5 The load loading device for marine structures based on numerical simulation is shown.

[0107] See also Figure 6 , Figure 6 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 6 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 6 A processor 10 is taken as an example.

[0108] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0109] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0110] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created by the use of a computer device based on the presentation of a small program landing page, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

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

[0112] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0113] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0114] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

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

Claims

1. A method for loading marine structures based on numerical simulation, characterized in that: The method comprises: Calculate the marine environmental load of the marine structure based on the numerical model of the marine structure to obtain the load calculation result, wherein the numerical model includes a plurality of grid units, and the load calculation result includes the coordinates of the center point of the grid unit and the corresponding pressure data at different times in a preset time series; Establishing a finite element model of the marine structure based on the grid cells of the numerical model; The marine environment 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.

2. The method according to claim 1, characterized in that The marine environmental loads of marine structures are calculated based on the numerical model of marine structures, and the load calculation results are obtained, including: Establish numerical models of marine structures based on modeling software; Meshing the numerical model and setting model parameters according to the marine environment; The fluid mechanics solver is used to calculate the marine environmental load of the model after setting the model parameters, and the load calculation results are obtained.

3. The method according to claim 2, characterized in that Before meshing the numerical model, the method further includes: According to whether the marine environmental load of the numerical model shows monotonic convergence under different grid sizes and different time steps, multiple different grid sizes and different time steps are selected as candidate values; A grid size and a time step that meet preset load calculation accuracy requirements and preset resource consumption requirements are selected from the candidate values.

4. The method according to claim 1, characterized in that Loading the marine environment load to the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model includes: 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 environment load is loaded to the finite element model based on a preset tolerance.

5. The method according to claim 4, characterized in that The preset tolerance includes a plurality of different preset tolerances, the load calculation result includes a force time sequence of the numerical model in each direction, and the marine environment load is loaded to the finite element model based on the preset tolerance, including: Loading the marine environment load to the finite element model based on different preset tolerances to obtain different loading results; Different force results are obtained based on different loading results; Compare different force results with the force time series of the numerical model in various directions, and determine a preset tolerance that meets the requirements among a plurality of different preset tolerances; The marine environment loads are applied to the finite element model based on preset tolerances that meet requirements.

6. The method according to claim 1, characterized in that Loading the marine environment load to the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model, further comprising: 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 sequence and the preset time sequence 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; Based on the mesh parameters of the finite element model and the mesh parameters of the numerical model, loading 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 sequence, the load loaded on the finite element model is set to 0.

7. The method according to claim 1, characterized in that The method further comprises: Obtain the equivalent stress after loading the marine environment load on the finite element model; The strength of the marine structure is checked based on the relationship between the maximum value of the equivalent stress and the ratio of the allowable stress and the safety factor.

8. A load loading device for marine structures based on numerical simulation, characterized in that: The device comprises: A load calculation module, used to calculate the marine environment load of the marine structure based on the numerical model of the marine structure to obtain the load calculation result, wherein the numerical model includes a plurality of grid units, and the load calculation result includes the coordinates of the center point of the grid unit and the corresponding pressure data at different times in a preset time series; A model building module, used for building a finite element model of the marine structure based on the grid cells of the numerical model; The loading module is used to load the marine environment load to the finite element model based on the mesh parameters of the finite element model and the mesh parameters of the numerical model.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the marine structure load loading method based on numerical simulation according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the marine structure load loading method based on numerical simulation according to any one of claims 1 to 7.

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