Cross-sectional load analysis method and its application for offshore floating structures

Abstract

The present invention belongs to the field of marine engineering technology and specifically discloses a cross-sectional load analysis method and application for offshore floating structures, wherein the method comprises the following steps: Step S1: determining the cross-sectional location of the structural load of the floating structure, and dividing the floating structure into multiple blocks according to the cross-sectional location; Step S2: solving the hydrodynamic coefficients of each block based on potential flow theory and the frequency domain boundary element method; Step S3: establishing a multi-block floating structure model in the time domain and determining the performance parameters of each unit in the model; Step S4: constructing a virtual beam unit between each unit and the cross-section, and calculating the load difference at the nodes at both ends of the virtual beam unit to obtain the cross-sectional load of the floating structure. The present invention converts the problem of solving the cross-sectional load of the floating structure into the problem of solving the difference in the external load of multiple blocks of the floating structure, thereby achieving an integrated solution to the motion and cross-sectional load of the floating structure.

Description

Technical Field

[0001] The present invention relates to the field of marine engineering technology, and in particular to a cross-sectional load analysis method and application of an offshore floating structure. Background Art

[0002] Currently, in the fields of marine engineering and offshore renewable energy, indirect time-domain methods are widely used to analyze the wave loads, motion responses, and mooring tensions experienced by floating structures under various marine environmental conditions. However, because indirect time-domain methods treat floating structures as point masses without volume, they are unable to resolve cross-sectional loads at specific locations on the floating structure. This results in most current methods for solving cross-sectional loads on floating structures being indirect decoupling methods, which are unable to simultaneously resolve the motion response and structural loads of floating structures. This reduces the accuracy of structural load calculations, increases computational costs, and reduces engineering design efficiency.

[0003] In summary, there is a need to design a cross-sectional load analysis method and its application for offshore floating structures to solve the above problems in the existing technology. Summary of the Invention

[0004] The present invention provides a cross-sectional load analysis method for offshore floating structures and its application, which solves the technical problem that the indirect time domain method cannot simultaneously solve the motion response and cross-sectional load of the floating structure.

[0005] In order to achieve the purpose of solving the above technical problems, the present invention adopts the following technical solutions:

[0006] The cross-sectional load analysis method for an offshore floating structure includes the following steps:

[0007] Step S1: determining a cross-sectional location of a structural load of a floating structure, and dividing the floating structure into a plurality of blocks according to the cross-sectional location;

[0008] Step S2, solving the hydrodynamic coefficients of each block based on potential flow theory and frequency domain boundary element method;

[0009] Step S3: establishing a multi-block floating structure model in the time domain, wherein the floating structure model includes a plurality of volume units, the number of which is the same as the number of the blocks; and determining performance parameters of each volume unit;

[0010] Step S4: construct a virtual beam unit between each section and its adjacent body unit, and obtain the corresponding section load by calculating the load difference between the nodes at both ends of the virtual beam unit.

[0011] In some embodiments of the present invention, step S3 includes the following steps:

[0012] S31. Establishing volume units based on indirect time domain method;

[0013] S32. Determine performance parameters of each body element, wherein the performance parameters include buoyancy, hydrostatic restoring force stiffness, and mass;

[0014] S33. Calculate the hydrodynamic parameters of each unit in the time domain.

[0015] In some embodiments of the present invention, the process of constructing the virtual beam unit in step S4 includes:

[0016] S41, constructing a first virtual beam element between a certain section p and an adjacent solid element B1, and constructing a second virtual beam element between a certain section p and an adjacent solid element B2; wherein the first virtual beam element has a first node and a second node at both ends; and the second virtual beam element has a third node and a fourth node at both ends;

[0017] S42. Construct a third virtual beam unit between the second node and the third node, where the second node and the third node are symmetrical about the section p and both the second node and the third node are nodes infinitely close to the section P.

[0018] In some embodiments of the present invention, the first node is equivalent to the body element B1; the first virtual beam unit is used to transfer the external force exerted on the body element B1 to the second node; the fourth node is equivalent to the body element B2; the second virtual beam unit is used to transfer the external force exerted on the body element B2 to the third node.

[0019] In some embodiments of the present invention, the calculation process of the cross-sectional load is:

[0020] S43, calculating the load of the second node using the performance parameters and hydrodynamic parameters of the body element B1; calculating the load of the third node using the performance parameters and hydrodynamic parameters of the body element B2;

[0021] S44. Calculate the load difference between the second node and the third node, where the load difference is the section load of section p;

[0022] S45. Solve the loads of each section according to steps S41 to S44.

[0023] In some embodiments of the present invention, the masses of the first virtual beam unit, the second virtual beam unit and the third virtual unit are all close to 0, and the axial stiffness, bending stiffness and torsional stiffness of the cross section are all taken as larger values, such as 1E15N, 1E15, and 1E15.

[0024] In some embodiments of the present invention, step S32 includes:

[0025] S321. Calculate the buoyancy suffered by each body element according to the displacement volume of each body element, and add it to the body element in the form of additional external force;

[0026] S322. Calculate the hydrostatic restoring force stiffness of each body element according to the following formula and input it into the hydrostatic restoring force stiffness matrix of each body element:

[0027] ;

[0028] Among them, g is the acceleration of gravity, ρ refers to the fluid density, m is the weight of the body unit, n3 is the vertical component of the surface normal vector of the object, S b Represents the wet surface of the object; x, y, z represent the coordinates of the body element on the x-axis, y-axis, and z-axis respectively; x b 、y b 、z b Respectively represent the coordinates of the center of buoyancy on the x-axis, y-axis, and z-axis; g 、y g 、z g Respectively represent the coordinates of the center of gravity of the body unit on the x-axis, y-axis, and z-axis;

[0029] S323. The mass, center of gravity and moment of inertia of each body unit are given according to the mass and mass distribution of each body unit.

[0030] In some embodiments of the present invention, an application of a cross-sectional load analysis method for an offshore floating structure is provided, including:

[0031] Establishing a time domain model of the floating structure according to the cross-sectional load analysis method;

[0032] Establish a numerical model of the mooring system based on the location of the fairlead, anchorage points, and cross-sectional properties of the mooring line;

[0033] Input wave condition parameters into the above model;

[0034] Perform time domain simulation to output the motion response time history of the floating structure and the structural loads at the cross-section of the floating structure.

[0035] In some embodiments of the present invention, an electronic device is provided, comprising:

[0036] a processor, and a memory and a transceiver communicatively connected to the processor;

[0037] The memory stores computer-executable instructions; the transceiver is used to transmit and receive data;

[0038] The processor executes the computer-executable instructions stored in the memory to implement the above-mentioned section load analysis method.

[0039] In some embodiments of the present invention, a computer-readable storage medium is provided, characterized in that:

[0040] The computer-readable storage medium stores computer-executable instructions, which are used to implement the above-mentioned section load analysis method when executed by a processor.

[0041] The technical solution of the present invention has the following technical effects compared with the prior art:

[0042] The present invention proposes a modeling method for multi-block floating structures, which converts the problem of solving the cross-sectional load of the floating structure into the problem of solving the difference of the external load of the multi-block floating structure. This solves the problem of being unable to calculate the cross-sectional load of the floating structure during the time-domain coupling analysis of the floating structure; and realizes the integrated solution of the movement and cross-sectional load of the floating structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 Schematic diagram of the cross-section of a floating structure.

[0045] Figure 2 Schematic diagram of the axial force of sections 1 and 2.

[0046] Figure 3 Schematic diagram of horizontal shear force in sections 1 and 2.

[0047] Figure 4 Schematic diagram of vertical shear force in sections 1 and 2.

[0048] Figure 5 Schematic diagram of horizontal bending moment of sections 1 and 2.

[0049] Figure 6 Schematic diagram of the vertical bending moment of sections 1 and 2.

[0050] Figure 7 Schematic diagram of the torque of sections 1 and 2.

[0051] Figure 8 Schematic diagram of the structure of the electronic device.

[0052] Reference numerals: 100 , floating structure; 110 , side column; 120 , central column; 200 , electronic device; 210 , processor; 220 , memory; 230 , transceiver. DETAILED DESCRIPTION

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0054] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections. A person of ordinary skill in the art will understand the specific meanings of the above terms in the present invention in specific circumstances. In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any appropriate manner in any one or more embodiments or examples.

[0055] Example 1: This example provides a cross-sectional load analysis method for an offshore floating structure, comprising the following steps:

[0056] Step S1: determining a cross-sectional location of a structural load of a floating structure, and dividing the floating structure into a plurality of blocks according to the cross-sectional location;

[0057] Reference Figure 1 As shown, the cross-sectional positions of the structural load of the floating structure are located at the middle sections of three horizontal buoys, three side columns and one central column, for a total of seven cross-sectional positions;

[0058] The entire floating structure is divided into blocks based on the cross-sectional locations. Since the entire floating structure consists of seven parts: a central column, three side columns, and three horizontal buoys, and each part is divided into two parts by the cross-sectional location of interest, the entire floating structure is divided into 14 blocks.

[0059] Step S2, solving the hydrodynamic coefficients of each block based on potential flow theory and frequency domain boundary element method;

[0060] The hydrodynamic coefficients include a wave excitation force transfer function and a wave radiation force transfer function.

[0061] S21. Calculate the wave excitation force transfer function. The wave excitation force includes the incident wave force generated by the incident velocity potential and the diffraction wave force generated by the diffraction velocity potential:

[0062] The expression of the incident velocity potential φ0 is:

[0063] ;

[0064] Where d is the water depth and k is the wave number. As long as the incident wave frequency ω0 and the water depth d are determined, the corresponding unique wave number k can be determined by the dispersion relation equation: k tanh kd =ω0 2 / g.

[0065] Diffraction velocity potential φ D It can be obtained by solving the following governing equations and boundary conditions:

[0066]

[0067] After obtaining the incident potential φ0 and diffraction velocity potential φ D After that, the dynamic pressure on the surface of the floating structure can be obtained by the Bernoulli equation: p=-iω0ρφ;

[0068] Here, ρ refers to the fluid density.

[0069] The transfer function of the wave excitation force acting on the surface of an object can be obtained by integrating the incident and diffracted pressures on the wet surface of the object:

[0070] .

[0071] S22. Solve the wave radiation force transfer function, radiation potential φ j It can be obtained by solving the following governing equations and boundary conditions:

[0072]

[0073] In obtaining the radiation potential φ j Finally, the dynamic pressure on the surface of the floating structure can be obtained by the Bernoulli equation: p=-iω0ρφ; where ρ is the fluid density.

[0074] The wave radiation force transfer function acting on the surface of an object can be obtained by integrating the radiation pressure on the wet surface of the object:

[0075]

[0076] Among them, A jk is the additional mass, B jk is radiation damping.

[0077] Step S3: establishing a multi-block floating structure model in the time domain, wherein the floating structure model includes a plurality of volume units, the number of which is the same as the number of the blocks; and determining performance parameters of each volume unit;

[0078] S31. Establishing volume units based on indirect time domain method;

[0079] Based on the block division of the floating structure, a multi-block floating structure model is established in the time domain. This step can be performed in any software based on the indirect time domain method, such as SIMA, Orcaflex, OpenFast, etc. The specific steps are as follows (taking SIMA as an example):

[0080] Based on the SIMO module, the number of body units is the same as the number of blocks. Since the phase of the wave load suffered by the body unit is related to its reference coordinates, in order to ensure that the phase of the wave force suffered by each body unit of the multi-block floating structure model is consistent with the phase of the wave force suffered by the rigid floating structure model at the same time, the reference coordinates of each body unit are set to (0, 0, 0).

[0081] S32. Determine performance parameters of each body element, wherein the performance parameters include buoyancy, hydrostatic restoring force stiffness, and mass;

[0082] S321. Calculate the buoyancy suffered by each unit based on the displacement volume of the unit and add it to the unit in the form of additional external force.

[0083] S322. Calculate the hydrostatic restoring force stiffness of each body element according to the following formula and input it into the hydrostatic restoring force stiffness matrix of each body element:

[0084]

[0085] Among them, g is the acceleration of gravity, ρ refers to the fluid density, m is the weight of the body unit, n3 is the vertical component of the surface normal vector of the object, S b Represents the wet surface of the object; x, y, z represent the coordinates of the body element on the x-axis, y-axis, and z-axis respectively; x b 、y b 、z b Respectively represent the coordinates of the center of buoyancy on the x-axis, y-axis, and z-axis; g 、y g 、z g They represent the coordinates of the center of gravity of the body element on the x-axis, y-axis, and z-axis respectively.

[0086] S323. The mass, center of gravity and moment of inertia of each body unit are given according to the mass and mass distribution of each body unit.

[0087] S33. Calculate the hydrodynamic coefficients of each unit cell in the time domain.

[0088] S331. Based on the frequency-time domain conversion technology of the indirect time domain method, calculate the wave excitation force experienced by the floating structure unit i in the time domain:

[0089]

[0090]

[0091] where f wj (1) (ω) The wave excitation force transfer function calculated in the frequency domain; η(t) represents the wave time history.

[0092] S332. Based on the frequency-time domain conversion technology of the indirect time domain method, calculate the wave radiation force on the floating structure (block i) in the time domain:

[0093]

[0094] Where A(∞) is the additional mass matrix when the wave frequency is infinite:

[0095]

[0096]

[0097] Where K(t) is the delay function and B(ω) is the additional damping coefficient matrix of the floating structure.

[0098] Step S4: construct a virtual beam unit between each section and its adjacent body unit, and obtain the corresponding section load by calculating the load difference between the nodes at both ends of the virtual beam unit.

[0099] S41, constructing a first virtual beam element between a certain section p and an adjacent solid element B1, and constructing a second virtual beam element between a certain section p and an adjacent solid element B2; wherein the first virtual beam element has a first node and a second node at both ends; and the second virtual beam element has a third node and a fourth node at both ends;

[0100] The first node N1 is located at the reference coordinate (0,0,0), which is used to associate the solid element B1. The second node N2 is located on the center axis of the section P, and its coordinates in the global coordinate system are (x PN2 , y PN2 , z PN2 ); The function of the first virtual beam unit is to connect the first node N1 and the second node N2.

[0101] The coordinates of the fourth node N4 in the global coordinate system are (x PN4 , y PN4, z PN4 ) is used to associate the solid element B2. The third node N3 is located on the center axis of the section P. Its coordinates in the global coordinate system are (x PN3 , y PN3 , z PN3 ); The function of the second virtual beam unit is to connect the fourth node N4 and the third node N3.

[0102] In some embodiments, both the body element B1 and the body element B2 can be considered as a mass point, and the first node N1 and the fourth node N4 can be used to replace the corresponding mass points. The mass of the cross section of the first virtual beam element and the second virtual beam element is close to 0, and the axial stiffness, bending stiffness, and torsional stiffness of the cross section are all set to large values, such as 1E15N, 1E15, and 1E15, which can effectively avoid the influence of the mass and structural deformation of the virtual beam element on the solution of the cross section load.

[0103] The resultant external force acting on the body element B1 can be transferred to the second node N2 through the first virtual beam element; similarly, the resultant external force acting on the body element B2 can be transferred to the third node N3 through the second virtual beam element.

[0104] S42. Construct a third virtual beam unit between the second node and the third node, where the second node and the third node are symmetrical about the section p and both the second node and the third node are nodes infinitely close to the section P.

[0105] The function of the third virtual beam unit is to connect the second node N2 and the third node N3. Similarly, the mass of the cross section of the third virtual beam unit is close to 0, and the axial stiffness, bending stiffness, and torsional stiffness of the cross section are all taken as larger values, such as 1E15N, 1E15, and 1E15, which can effectively avoid the influence of the mass of this virtual beam unit and the structural deformation on the solution of the cross-sectional load.

[0106] S43, calculating the load of the second node using the performance parameters and hydrodynamic parameters of the body element B1; calculating the load of the third node using the performance parameters and hydrodynamic parameters of the body element B2;

[0107] S44. Calculate the load difference between the second node and the third node, where the load difference is the section load of section p;

[0108] S45. Solve the loads of each section according to steps S41 to S44.

[0109] Continue to refer to Figure 1 As shown, Section 1 and Section 2 are both sections of the side columns of the floating structure along the Z-axis direction.

[0110] Reference Figure 2-Figure 7 , which is a schematic diagram comparing multiple loads on Sections 1 and 2 obtained using the calculation method of this embodiment. It can be seen from the figure that both Sections 1 and 2 are loaded in terms of axial force, vertical shear force, and vertical bending moment, but the load intensities are different. Specifically, Section 1 is loaded more heavily. In terms of horizontal shear force, horizontal bending moment, and torque, Section 2 is loaded more heavily, while Section 1 is loaded almost to zero.

[0111] This method, based on the indirect time-domain method widely used in the field of marine engineering, innovatively proposes a multi-block floating structure modeling approach. This method transforms the problem of solving the cross-sectional load of the floating structure into solving the problem of solving the difference in the external load of the multi-block float. This solves the problem of being unable to calculate the cross-sectional load of the floating structure during the time-domain coupled analysis of floating structures. Compared with the finite element method, it has the advantage of computational efficiency because it does not require meshing the entire floating structure at each calculation time step.

[0112] Example 2: Provided is an application of a cross-sectional load analysis method for an offshore floating structure, including:

[0113] Step 1: Establishing a time domain model of the floating structure according to the cross-sectional load analysis method;

[0114] Step 2: Establish a numerical model of the mooring system based on the location of the fairlead, anchor point, and cross-sectional properties of the mooring line;

[0115] Step 3: Input wave condition parameters into the model of step 2; specifically, wave spectrum type, significant wave height, spectrum peak period, spectrum peak rise factor and other parameters;

[0116] Step 4: Perform time-domain simulation to output the motion response time history of the floating structure and the structural loads at the cross-section of the floating structure, including axial force, shear force, bending moment, torque, etc.

[0117] In existing calculations of floating structure cross-sectional loads, the finite element method (FEM) separates the calculation of the structure's motion from the calculation of cross-sectional loads due to the need for other methods to input the external environmental loads during the structure's motion. This method, however, integrates the calculations of both the structure's motion and cross-sectional loads. This overcomes the technical challenge of indirect time-domain methods, which cannot simultaneously calculate the structure's motion response and cross-sectional loads. This improves the accuracy of structural load calculations, reduces computational costs, and enhances engineering design efficiency.

[0118] Example 3: Reference Figure 8 As shown, an electronic device 200 is provided, including:

[0119] A processor 210, and a memory 220 and a transceiver 230 communicatively connected to the processor;

[0120] The memory 220 stores computer-executable instructions; the transceiver 230 is used to send and receive data;

[0121] The processor 210 executes the computer-executable instructions stored in the memory 220 to implement the cross-sectional load analysis method in Example 1.

[0122] It should be understood that the electronic device 200 can be used to execute the corresponding steps and / or processes in the above-mentioned method embodiments. Optionally, the memory 220 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory 220 may also include a non-volatile random access memory. For example, the memory 220 may also store device type information. The processor 210 can be used to execute the instructions stored in the memory 220, and when the processor 210 executes the instructions, the processor 210 may perform the corresponding steps and / or processes in the above-mentioned method embodiments.

[0123] It should be understood that in the embodiment of the present application, the processor 210 may be a central processing unit (CPU), or may be other general-purpose processors, DSP digital signal processors, ASIC application-specific integrated circuits, field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0124] During implementation, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor 210 or by instructions in the form of software. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor 210. The software module can be located in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor executes the instructions in the memory, and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

[0125] Example 4: In this example, a computer-readable storage medium is provided, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the cross-sectional load analysis method in Example 1.

[0126] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0127] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0128] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0129] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0130] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0131] The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A cross-sectional load analysis method for offshore floating structures, characterized in that: The following steps are involved: Step S1: determining a cross-sectional location of a structural load of a floating structure, and dividing the floating structure into a plurality of blocks according to the cross-sectional location; Step S2, solving the hydrodynamic coefficients of each block based on potential flow theory and frequency domain boundary element method; Step S3: establishing a multi-block floating structure model in the time domain, wherein the floating structure model includes a plurality of volume units, the number of which is the same as the number of the blocks; and determining performance parameters of each volume unit; The step S3 comprises the following steps: S31. Establishing volume units based on indirect time domain method; S32. Determine performance parameters of each body element, wherein the performance parameters include buoyancy, hydrostatic restoring force stiffness, and mass; S321. Calculate the buoyancy suffered by each body element according to the displacement volume of each body element, and add it to the body element in the form of additional external force; S322. Calculate the hydrostatic restoring force stiffness of each body element according to the following formula and input it into the hydrostatic restoring force stiffness matrix of each body element: ； Among them, g is the acceleration of gravity, ρ refers to the fluid density, m is the weight of the body unit, n3 is the vertical component of the surface normal vector of the object, S b Represents the wet surface of the object; x, y, z represent the coordinates of the body element on the x-axis, y-axis, and z-axis respectively; x b 、y b 、z b Respectively represent the coordinates of the center of buoyancy on the x-axis, y-axis, and z-axis; g 、y g 、z g Respectively represent the coordinates of the center of gravity of the body unit on the x-axis, y-axis, and z-axis; S323. Determine the mass, center of gravity, and moment of inertia of each body element according to the mass and mass distribution of each body element; S33, calculating the hydrodynamic parameters of each unit in the time domain; Step S4: construct a virtual beam element between each section and its adjacent body element, and obtain the corresponding section load by calculating the load difference between the nodes at both ends of the virtual beam element; The construction process of the virtual beam element includes: S41, constructing a first virtual beam element between a certain section p and an adjacent solid element B1, and constructing a second virtual beam element between a certain section p and an adjacent solid element B2; wherein the first virtual beam element has a first node and a second node at both ends; and the second virtual beam element has a third node and a fourth node at both ends; S42: construct a third virtual beam element between the second node and the third node, where the second node and the third node are symmetrical about the cross section p and both the second node and the third node are nodes infinitely close to the cross section P; The calculation process of the cross-sectional load is as follows: S43, calculating the load of the second node using the performance parameters and hydrodynamic parameters of the body element B1; calculating the load of the third node using the performance parameters and hydrodynamic parameters of the body element B2; S44. Calculate the load difference between the second node and the third node, where the load difference is the section load of section p; S45. Solve the loads of each section according to steps S41 to S44.

2. The cross-sectional load analysis method for an offshore floating structure according to claim 1, characterized in that: The first node is equivalent to the body element B1; the first virtual beam element is used to transfer the external force exerted on the body element B1 to the second node; the fourth node is equivalent to the body element B2; the second virtual beam element is used to transfer the external force exerted on the body element B2 to the third node.

3. The cross-sectional load analysis method for an offshore floating structure according to claim 1, characterized in that: The masses of the first virtual beam unit, the second virtual beam unit, and the third virtual unit are all close to zero.

4. Application of cross-sectional load analysis method for offshore floating structures, characterized in that: include: Establishing a time domain model of the floating structure according to the cross-sectional load analysis method according to any one of claims 1 to 3; Establish a numerical model of the mooring system based on the location of the fairlead, anchorage points, and cross-sectional properties of the mooring line; Input wave condition parameters into the above model; Perform time domain simulation to output the motion response time history of the floating structure and the structural loads at the cross-section of the floating structure.

5. An electronic device, characterized in that: include: a processor, and a memory and a transceiver communicatively connected to the processor; The memory stores computer-executable instructions; the transceiver is used to transmit and receive data; The processor executes the computer-executable instructions stored in the memory to implement the cross-sectional load analysis method according to any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the cross-sectional load analysis method according to any one of claims 1 to 3.

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