A method for structural deformation and load analysis

Abstract

This application provides a method for structural deformation and load analysis, wherein the load includes resultant force and resultant moment of cross sections. The method includes: performing modal analysis on a finite element model constructed based on a target structure to extract strain modes, displacement modes, nodal force modes, and nodal moment modes; determining the structural deformation of the target structure based on the displacement modes and modal coordinate vectors by superimposing multiple displacement modes; determining the resultant force of the target structure based on the resultant force modes and modal coordinate vectors, wherein the resultant force modes are obtained by summing the nodal force modes corresponding to all nodes on the target cross section; and determining the resultant moment of the target structure based on the resultant moment modes and modal coordinate vectors, wherein the resultant moment modes are obtained based on the moment reference points, nodal coordinates, cross section normal vector directions, nodal moment modes, and nodal force modes corresponding to all nodes on the target cross section.

Description

Technical Field

[0001] This application relates to the field of structural health monitoring, specifically to a method for analyzing structural deformation and load. Background Technology

[0002] Engineering structures may undergo complex three-dimensional deformations during service, and accurate monitoring of these deformations is crucial for ensuring their safe operation. While traditional non-contact measurement methods (such as photogrammetry and laser measurement) can acquire information about the external morphology of structures, they are typically sensitive to environmental conditions and susceptible to factors such as changes in lighting, shading, and vibration. Furthermore, their equipment installation and calibration processes are complex, making stable application in confined spaces or harsh environments difficult.

[0003] In recent years, strain measurement technology based on fiber Bragg gratings (FBGs) has attracted widespread attention in the field of structural health monitoring due to its advantages such as strong resistance to electromagnetic interference, light weight, small size, and high measurement accuracy. However, in practical applications, how to efficiently and accurately reconstruct the three-dimensional large deformation field of a structure using a limited number of discrete strain measurement data, and further recover the load borne by the structure based on this, remains one of the key issues in current research. Summary of the Invention

[0004] The purpose of this application is to provide a method for structural deformation and load analysis, and the specific technical solution adopted is as follows: In a first aspect, a method for structural deformation and load analysis is provided, wherein the load includes resultant force and resultant moment of cross sections, and the method includes: Modal analysis was performed on the finite element model constructed based on the target structure to extract strain modes, displacement modes, nodal force modes, and nodal moment modes. The structural deformation of the target structure is determined by superimposing multiple displacement modes and the modal coordinate vectors. The modal coordinate vectors are determined based on the local strain information of the target structure and the strain modes. The local strain information is obtained by strain sensors installed on the target structure. The resultant force of the target structure is determined based on the resultant force modes of the cross section and the coordinate vector of the modes, wherein the resultant force modes of the cross section are obtained by summing the nodal force modes corresponding to all nodes on the target cross section; the expression of the resultant force modes of the cross section is: ; in, Let i be the nodal force mode of node i; The resultant moment of the cross section of the target structure is determined based on the resultant moment mode of the cross section and the coordinate vector of the mode, wherein the resultant moment mode of the cross section is obtained based on the moment reference point, node coordinates, cross section normal vector direction, nodal moment mode and nodal force mode of all nodes on the target cross section; Using the aforementioned moment reference point as the calculation basis, the resultant moment mode of the cross section is obtained based on the following expression: ; in, The torque reference point is... Let i be the coordinates of node i. for transpose, The direction of the normal vector of the cross section is... for transpose, Let i be the nodal force mode. Let i be the nodal moment mode. Let be the set of all nodes on the target cross section.

[0005] Secondly, a structural deformation and load analysis device is provided, the device comprising: The extraction module is used to perform modal analysis on the finite element model constructed based on the target structure, and to extract strain modes, displacement modes, nodal force modes and nodal moment modes; The first determining module is used to determine the structural deformation of the target structure by superimposing multiple displacement modes and based on the displacement modes and modal coordinate vectors, wherein the modal coordinate vectors are determined based on the local strain information of the target structure and the strain modes, and the local strain information is obtained by strain sensors installed on the target structure; The second determining module is used to determine the resultant force of the cross section of the target structure based on the resultant force mode of the cross section and the mode coordinate vector, wherein the resultant force mode of the cross section is obtained by summing the nodal force modes corresponding to all nodes on the target cross section; the expression of the resultant force mode of the cross section is: ; in, Let i be the nodal force mode of node i; The third determining module is used to determine the resultant moment of the cross section of the target structure based on the resultant moment mode of the cross section and the mode coordinate vector, wherein the resultant moment mode of the cross section is obtained based on the moment reference point, node coordinates, cross section normal vector direction, nodal moment mode and nodal force mode of all nodes on the target cross section; Using the aforementioned moment reference point as the calculation basis, the resultant moment mode of the cross section is obtained based on the following expression: ; in, The torque reference point is... Let i be the coordinates of node i. for transpose, The direction of the normal vector of the cross section is... for transpose, Let i be the nodal force mode. Let i be the nodal moment mode. Let be the set of all nodes on the target cross section.

[0006] Thirdly, an electronic device is provided, comprising: a memory and at least one processor, wherein the memory stores instructions; the at least one processor invokes the instructions in the memory to cause the electronic device to perform the above-described method for structural deformation and load analysis.

[0007] Fourthly, a computer program product is provided, comprising: computer program code, which, when run on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof.

[0008] Fifthly, a computer-readable storage medium is provided that stores computer program code, which, when executed on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof.

[0009] This application offers the following advantages: First, by extracting multiple modal information through modal analysis, it provides a rich data foundation for subsequent analysis. Utilizing local strain information and strain modes to determine modal coordinate vectors, and combining this with displacement modes to determine structural deformation, allows for a direct understanding of the structure's deformation during vibration, aiding in the assessment of its stiffness and stability. Determining the resultant force on the cross-section based on nodal force modes, and determining the resultant moment on the cross-section based on multiple parameters, enables precise analysis of the stress state of the structural cross-section, including the magnitude, direction, and rotational effects of the forces. Based on the principle of structural modal superposition, strain data obtained from a limited number of measuring points is used to identify and reconstruct the structural modal response, thereby achieving high-precision recovery of the structure's large deformation across the entire field, and further calculating the load distribution within the structure. This information is of great significance for structural health monitoring, fault diagnosis, and dynamic design optimization, helping engineers better understand the structure's behavior under dynamic loads, identify potential problems early, and take appropriate measures to ensure the structure's safety and reliability. Attached Figure Description

[0010] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 A schematic diagram illustrating the implementation process of a structural deformation and load analysis method provided in this application embodiment; Figure 2 This is a structural schematic diagram of a structural deformation and load analysis device provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0012] To further illustrate the technical means and effects adopted by this application to achieve the intended inventive purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a structural deformation and load analysis method proposed according to this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined from any suitable form.

[0013] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0014] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0016] This application provides a method for analyzing structural deformation and cross-sectional internal forces, whereby the cross-sectional internal forces include resultant forces and resultant moments. Figure 1 As shown, this can be achieved through the following steps: Step S110: Perform modal analysis on the finite element model constructed based on the target structure to extract strain modes, displacement modes, nodal force modes and nodal moment modes; Here, the target structure is the structural component to be analyzed. For example, the target structure could be a wind turbine blade. Constructing a finite element model for the target structure is a mathematical model that discretizes a continuous real structure into a finite number of elements, interconnected by nodes, to approximate the mechanical properties of the actual structure.

[0017] During implementation, modal analysis was performed on the finite element model. Modal analysis is a method for studying the dynamic characteristics of structures, calculating the vibration patterns of the structure at different frequencies. Strain modes, displacement modes, nodal force modes, and nodal moment modes were extracted from the modal analysis results. Specifically, strain modes describe the strain changes at each point of the structure during vibration; displacement modes describe the displacement changes at each point of the structure during vibration; nodal force modes describe the force changes at each node of the structure during vibration; and nodal moment modes describe the torque changes at each node of the structure during vibration.

[0018] Step S120: Using the superposition of multiple displacement modes, determine the structural deformation of the target structure based on the displacement modes and modal coordinate vectors, wherein the modal coordinate vectors are determined based on the local strain information of the target structure and the strain modes, and the local strain information is obtained by strain sensors installed on the target structure; Here, in modal analysis, the modal coordinate vector is used to describe the degree of vibration of the structure in each mode, reflecting the magnitude of the vibration contribution of the structure in different modes.

[0019] Local strain information refers to strain data at specific locations on the target structure obtained through strain sensors. These data reflect the degree of local deformation of the structure.

[0020] In the implementation process, local strain information of the target structure is first acquired using strain sensors installed on the target structure. Based on this local strain information and the previously extracted strain modes, modal coordinate vectors are determined. The modal coordinate vectors reflect the degree of vibration participation of the structure in each mode. Then, by combining the displacement modes and modal coordinate vectors and using the superposition of multiple displacement modes, specific mathematical operations are performed to determine the structural deformation of the target structure, i.e., the actual deformation of the structure during vibration.

[0021] Step S130: Determine the resultant force of the target structure based on the resultant force mode of the cross section and the mode coordinate vector, wherein the resultant force mode of the cross section is obtained by summing the nodal force modes corresponding to all nodes on the target cross section; the expression (11) of the resultant force mode of the cross section is: (11); in, Let i be the nodal force mode of node i; Here, the resultant force mode of a cross section is a parameter used to describe the change of the resultant force on a certain cross section of the target structure during vibration. It can be obtained by summing the nodal force modes on that cross section.

[0022] The resultant force of a section is the actual resultant force on a certain section of the target structure during vibration. It is an important parameter in structural mechanics analysis and is used to evaluate the stress condition of the section.

[0023] During implementation, for a target section on the target structure, the nodal force modes of all corresponding nodes on that section can be summed to obtain the resultant force mode of the section. The target section can be any section of the target structure. Then, combined with the previously determined modal coordinate vector, the resultant force of the target structure section is determined through corresponding mathematical operations, that is, the magnitude and direction of the resultant force on that section during structural vibration.

[0024] Step S140: Determine the resultant moment of the cross section of the target structure based on the resultant moment mode of the cross section and the mode coordinate vector, wherein the resultant moment mode of the cross section is obtained based on the moment reference point, node coordinates, cross section normal vector direction, nodal moment mode and nodal force mode of all nodes on the target cross section; Using the aforementioned moment reference point as the calculation basis, the resultant moment mode of the cross section is obtained based on the following expression (16): (16); in, The torque reference point is... Let i be the coordinates of node i. for transpose, The direction of the normal vector of the cross section is... for transpose, Let i be the nodal force mode. Let i be the nodal moment mode. Let be the set of all nodes on the target cross section.

[0025] Here, the resultant moment mode of the cross section is a parameter used to describe the change of the resultant moment on a certain cross section of the target structure during vibration. It is calculated by comprehensively considering the moment reference point, nodal coordinates, cross section normal vector direction, nodal moment mode, and nodal force mode.

[0026] The resultant moment of a cross section is the actual resultant moment experienced by a certain cross section of the target structure during vibration. It is used to evaluate the rotational effect and force balance of the cross section.

[0027] During implementation, for the target cross-section of the target structure, the resultant moment modes of the cross-section are calculated using specific mathematical formulas based on the moment reference points (reference positions selected when calculating moments), node coordinates (positions of nodes in the global coordinate system), cross-section normal vector direction (vector direction perpendicular to the cross-section), nodal moment modes, and nodal force modes corresponding to all nodes on that cross-section. Then, combined with the modal coordinate vectors, the resultant moment of the target structure's cross-section is determined through mathematical operations, i.e., the magnitude and direction of the resultant moment experienced by that cross-section during structural vibration.

[0028] In this embodiment, firstly, modal analysis extracts multiple modal information, providing a rich data foundation for subsequent analysis. By utilizing local strain information and strain modes to determine modal coordinate vectors, and combining this with displacement modes to determine structural deformation, the deformation of the structure during vibration can be intuitively understood, aiding in the assessment of structural stiffness and stability. Determining the resultant force of the cross-section based on nodal force modes, and determining the resultant moment of the cross-section based on multiple parameters, allows for precise analysis of the stress state of the structural cross-section, including the magnitude, direction, and rotational effects of the forces. Based on the principle of structural modal superposition, strain data obtained from a limited number of measuring points is used to identify and reconstruct the structural modal response, thereby achieving high-precision recovery of the large deformation across the entire structural field, and further calculating the load distribution within the structure. This information is of great significance for structural health monitoring, fault diagnosis, and dynamic design optimization, helping engineers better understand the behavior of the structure under dynamic loads, identify potential problems in advance, and take corresponding measures to ensure the safety and reliability of the structure.

[0029] Currently, structural deformation reconstruction methods based on strain measurement mainly include the Ko displacement theory method and the inverse finite element method. Among them, the Ko displacement theory method establishes the relationship between strain and displacement based on linear beam theory, which is suitable for simple beam structures, but it is difficult to achieve full-field three-dimensional deformation reconstruction of complex structures. The inverse finite element method (iFEM) establishes the inverse relationship between strain and displacement through finite element discretization, which can achieve high-precision deformation reconstruction, but its calculation process is relatively complex and depends on accurate structural physical parameters, making it difficult to meet the needs of real-time calculation.

[0030] In terms of load recovery, existing methods mostly employ load calibration, which involves pre-establishing a calibration relationship between strain and load to invert the load on the structure. However, this method typically only provides load information at the calibration location and struggles to obtain the complete load distribution along the spanwise or spatially distributed structure.

[0031] Therefore, current technologies still lack a unified method that can simultaneously achieve three-dimensional deformation reconstruction and full-field load recovery of structures under limited strain measurement data. To this end, it is necessary to propose a structural response recovery method that balances computational efficiency and reconstruction accuracy, in order to achieve efficient reconstruction of the structure's full-field response.

[0032] This application provides a method for recovering three-dimensional structural deformation and internal loads based on strain measurement. This method is based on the principle of structural modal superposition. Using strain data obtained from a limited number of measuring points, it identifies and reconstructs the structural modal response, thereby achieving high-precision recovery of the large deformation across the entire structural field, and further calculates the internal load distribution of the structure. The modal method, based on the principle of structural modal superposition, can describe the overall deformation characteristics of the structure with only a limited number of modes, offering advantages such as high computational efficiency and ease of full-field deformation reconstruction.

[0033] This application embodiment is based on the modal superposition method. Based on the strain data of a limited number of measuring points, the modal coordinate vector is solved. By combining the displacement mode and the internal force mode, a high-precision reconstruction of the large deformation of the entire structure and the distribution of its internal loads is achieved.

[0034] The technical solution adopted by the embodiments of this application to solve its technical problem includes the following steps: Step 1: Calculate initialization.

[0035] A finite element model of the structure is established, the model is meshed, element properties and material characteristics are assigned to each element of the finite element mesh, and the boundary conditions required for the calculation are set. In finite element analysis (FEA), boundary conditions (BCs) are constraints or loads applied to the model to define the interaction between the structure and the external environment, ensuring the physical meaning and mathematical convergence of the computational problem. They are crucial for simulating real-world working conditions and directly affect the accuracy and reliability of the analysis results.

[0036] Step 2: Modal analysis.

[0037] Modal analysis of the structure was performed using the SOL103 solver on the MSC.Nastran platform to extract various modal information, including strain modes, displacement modes, nodal force modes, and nodal moment modes.

[0038] Among them, strain modes are used to describe the strain distribution characteristics of the structure under each mode, displacement modes are used to describe the displacement distribution characteristics of the structure under each mode, and nodal force modes and nodal moment modes are used to describe the equivalent internal forces and moments generated at the nodes of the structure under load excitation.

[0039] Step 3: Calculate structural displacements The strain and displacement modes of the structure are extracted using the modal analysis module of the finite element method software. Based on the principle of modal superposition, the strain column vectors within the element are then analyzed. It can be expressed as the following formula (1): (1); in, For the nth strain mode, This is the modal coordinate vector.

[0040] Local strain measurement information is obtained by strain sensors arranged on the structure. The least squares method is used to solve the above formula (1), and the following formula (2) is obtained, which is used to calculate the modal coordinate vector: (2); in, Represents the strain mode matrix, for transpose, This represents the strain column vector within the element.

[0041] Based on the principle of modal superposition, the following formula (3) is obtained by superimposing displacement modes, which is used to calculate structural displacement: (3); in, For structural displacement, This is the nth displacement mode.

[0042] Step 4: Calculate the resultant force of the cross section.

[0043] For any element e, its nodal displacements can be expressed as the following formula (4): (4); in, Let be the nodal displacement of element e. It is the extraction matrix of the degrees of freedom of each node in the unit.

[0044] Based on the element stiffness matrix, the following formula (5) can be used to calculate the nodal internal forces: (5); in, Let be the equivalent nodal force of element e at the node, representing the element's contribution to the internal forces at the node. Let be the stiffness matrix of element e.

[0045] Structural displacement in equation (3) Substituting into equation (5) above, we obtain the equivalent nodal force on node e used to calculate the element e. The following formula (6): (6); in, q The modal coordinate vector can be calculated using the above formula (2).

[0046] To calculate the resultant force and resultant moment of the cross section, let the set of all elements intersecting the cross section and located on the same side of it be . The set of all nodes corresponding to these elements on the cross section is Then the force at node i can be calculated using the following formula (7). : (7); in, Let i be the set of elements that contribute internal forces to node i.

[0047] The nodal force modes can be represented using the following formula (8). : (8); These can be referred to as nodal force modes, which can be obtained through the modal analysis module of finite element software.

[0048] The resultant force on the cross section can be expressed by the following formula (9), which is the sum of the internal forces at each node. : (9); in, This represents the set of all nodes i corresponding to the element on the cross section. Let be the force at node i.

[0049] Based on the above formulas (7), (8) and (9), the following can be obtained for calculating the resultant force of the cross section. Formula (10): (10); in, This can be referred to as the nodal force mode.

[0050] Let the combined matrix within the parentheses be expressed as the following formula (11): (11); in, This can be referred to as the nodal force mode.

[0051] The resultant force of the cross section can then be expressed using the following formula (12). : (12); in, For the resultant force mode of the cross section, qThe modal coordinate vector can be calculated using the above formula (2).

[0052] Step 5: Calculate the resultant moment of the cross section.

[0053] According to the principle of modal superposition, the following formula (13) can be obtained to represent the torque at node i: (13); in, These can be referred to as nodal moment modes, which can be obtained through the modal analysis module of finite element software.

[0054] Let the torque reference point be taken The coordinates of node i are The resultant moment of the cross section is expressed by the following formula (14): (14); in, The resultant moment of the cross section, The direction of the cross section normal vector.

[0055] By further utilizing the above formulas (7), (8) and (13), the following formula for calculating the resultant moment of the cross section (15) can be obtained: (15); in, The torque reference point is... Let i be the coordinates of node i. for transpose, The direction of the normal vector of the cross section is... for transpose, Let i be the nodal force mode. Let i be the nodal moment mode. The set of all nodes on the target cross section. q This is the modal coordinate vector.

[0056] Let the following formula (16) represent the resultant moment mode of the cross section.

[0057] (16); The following expression can be obtained to represent the resultant moment of the cross section. Formula (17): (17); in, For the resultant moment mode of the cross section, q The modal coordinate vector can be calculated using the above formula (2).

[0058] Compared with the prior art, the method provided in this application is based on the principle of modal superposition. It can reconstruct the three-dimensional deformation field of the structure and invert its internal load by relying only on finite strain measurement data. It has the advantages of high computational efficiency, strong robustness and high engineering application value.

[0059] In some embodiments, the strain modes and displacement modes of the structure are extracted using the modal analysis module of finite element software. Based on the principle of modal superposition, the strain column vectors within the element are... It can be expressed as the following formula (1): (1); in, For the nth strain mode, This is the modal coordinate vector.

[0060] Local strain measurement information is obtained by strain sensors arranged on the structure. The least squares method is used to solve the above formula (1), and the following formula (2) is obtained, which is used to calculate the modal coordinate vector: (2); in, Represents the strain mode matrix, This represents the strain column vector within the element.

[0061] In some embodiments, based on the principle of modal superposition, the following formula (3) is obtained by displacement modal superposition and used to calculate structural displacement: (3); in, For structural displacement, This is the nth displacement mode.

[0062] In some embodiments, the resultant force of the cross section can be expressed using the following formula (12). : (12); in, For the resultant force mode of the cross section, q The modal coordinate vector can be calculated using the above formula (2).

[0063] The resultant force mode of the cross section can be represented by the following formula (11): (11); in, This can be referred to as the nodal force mode, and the parameter can be obtained through the analysis of the finite element model in step S110.

[0064] In some embodiments, using the moment reference point as the calculation basis, the resultant moment mode of the cross section is obtained based on the following expression: (16); in, The torque reference point is... Let i be the coordinates of node i. The direction of the normal vector of the cross section is... Let i be the nodal force mode. Let i be the nodal moment mode. Let be the set of all nodes on the target cross section.

[0065] The expression for determining the resultant moment of the cross section of the target structure based on the resultant moment mode of the cross section and the coordinate vector of the mode is as follows: (17); in, M For the cross section and the moment; For the resultant moment mode of the cross section, q Let be the modal coordinate vector.

[0066] In some embodiments, the load further includes nodal forces, which can be obtained by superimposing the nodal force modes using the modal coordinate vector to obtain the nodal forces at each node on the target cross section, expressed as: (18); in, The nodal force corresponding to node i; Let i be the nodal force mode corresponding to node i; q Let be the modal coordinate vector.

[0067] In some embodiments, the nodal forces at all corresponding nodes on the target cross section are summed to obtain the resultant force of the cross section, expressed as: (9); in, The resultant force of the cross section, The nodal force corresponding to node i; Let be the set of all nodes on the target cross section.

[0068] In some embodiments, the load further includes nodal torque, and the method further includes: By superimposing the nodal moment modes using the modal coordinate vectors, the nodal moments of each node on the target cross section are obtained, expressed as follows: (13); in, mi Let be the nodal torque at node i; Let i be the nodal moment mode of node i; q Let be the modal coordinate vector.

[0069] In some embodiments, a finite element model can be obtained through the following steps: Step A: Mesh the target structure to obtain multiple finite element mesh elements; Step B: Determine the element properties and material characteristics of each finite element mesh element, and set boundary conditions; Step C: Obtain the finite element model based on the finite element mesh elements, the element properties, the material properties, and the boundary conditions.

[0070] In this embodiment, by using reasonable mesh generation, accurate element attribute and material property settings, and realistic boundary condition definitions, the mechanical behavior of the target structure can be simulated more accurately, thereby improving the accuracy of finite element analysis and providing a reliable basis for structural design, optimization, and evaluation. The finite element model can be modified and adjusted according to different analysis needs. Boundary conditions can be changed to simulate different working conditions, material properties can be modified to study the impact of material properties on the structure, and mesh size can be adjusted to balance computational accuracy and efficiency.

[0071] This application provides a detailed description of the proposed method for restoring structural displacement and cross-sectional load based on strain measurement. For ease of explanation, a wind turbine blade with a fixed root is used as the research object, with a total spanwise length of 97.7m and a root diameter of 2.9m.

[0072] The specific implementation method of this invention includes: Step 1: Calculate initialization.

[0073] A finite element model of the wind turbine blade was established using finite element software, and the structure was meshed. Corresponding material and element properties were assigned to each finite element. The blade root was set to a six-degree-of-freedom fixed boundary condition. The finite element model information is shown in Table 1. The finite element model has 183,279 GRID nodes and 177,173 CQUAD4 shell elements. A schematic diagram of the finite element model is shown below. Figure 1 As shown.

[0074] Table 1 Finite element model information

[0075] Strain sensors are placed on the blade surface to extract the strain response of the structure at the corresponding location.

[0076] Step 2: Modal analysis.

[0077] Modal analysis of the structure was performed using the SOL103 solver on the MSC.Nastran platform to extract various modal information, including strain modes, displacement modes, nodal force modes, and nodal moment modes. Extracting this modal information provides a foundation for subsequent structural response identification and load recovery.

[0078] Step 3: Calculate the structural displacement.

[0079] In actual blade operation, strain sensors deployed on the blade surface are used to measure the strain response of the structure at the sensor locations, and a strain measurement vector is constructed. The modal coordinate vector is calculated using the least squares method to determine the degree of structural participation in each mode.

[0080] Calculate the modal coordinate vector using the above formula (2): (2); After obtaining the modal coordinates, the displacement modes are linearly superimposed, and the displacement response of each node of the structure can be calculated using the above formula (3), thereby obtaining the overall displacement distribution of the structure under external load and realizing the reconstruction of structural deformation.

[0081] (3); in, For structural displacement, This is the nth displacement mode.

[0082] Step 4: Calculate the resultant force of the cross section.

[0083] For any cross section of the structure, select all elements that intersect the cross section and are located on the same side of the cross section, and extract the set of nodes of these elements on the cross section.

[0084] By superimposing the above nodal force modes, the formula (18) for the nodal force at each node can be obtained using the above formulas (7) and (8) as follows: (18); in, These can be referred to as nodal force modes, which can be obtained through the modal analysis module of finite element software.

[0085] Based on this, the resultant force on the cross section can be obtained by summing all the nodal forces in the set of nodal nodes using the above formula (9). : (9); If no node force information is not required, the resultant force on the cross section can be calculated directly using the following formula (12). : (12); in, For the resultant force mode of the cross section, q The modal coordinate vector can be calculated using the above formula (2).

[0086] Step 5: Calculate the resultant moment of the cross section.

[0087] By superimposing the above nodal moment modes, the nodal moments at each node can be obtained using the following formula (13): (13); in, These can be referred to as nodal moment modes, which can be obtained through the modal analysis module of finite element software.

[0088] Based on the obtained nodal forces at the cross-section, a reference point is selected as the basis for moment calculation. According to the definition of moment, the moment generated by the nodal forces on this reference point is calculated.

[0089] Further superposition yields the resultant moment on this cross section. Let's assume a reference point for the moment. The coordinates of node i are The resultant moment of the cross section is expressed by the following formula (14): (14); in, The resultant moment of the cross section, The direction of the cross section normal vector.

[0090] If it is not necessary to obtain the nodal moment information at the node level, the resultant moment on the cross section can be calculated directly using the following formula (17): (17); in, For the resultant moment mode of the cross section, q The modal coordinate vector can be calculated using the above formula (2).

[0091] By repeating the above calculation process along the span of the structure, the resultant moment distribution of each section of the structure can be obtained.

[0092] This application provides a structural deformation and load analysis device. Please refer to [link / reference]. Figure 2 The device 200 includes: Extraction module 210 is used to perform modal analysis on the finite element model constructed based on the target structure, and extract strain modes, displacement modes, nodal force modes and nodal moment modes; The first determining module 220 is used to determine the structural deformation of the target structure by superimposing multiple displacement modes and based on the displacement modes and modal coordinate vectors, wherein the modal coordinate vectors are determined based on the local strain information of the target structure and the strain modes, and the local strain information is obtained by strain sensors installed on the target structure; The second determining module 230 is used to determine the resultant force of the cross section of the target structure based on the resultant force mode of the cross section and the mode coordinate vector, wherein the resultant force mode of the cross section is obtained by summing the nodal force modes corresponding to all nodes on the target cross section; the expression of the resultant force mode of the cross section is: ; in, Let i be the nodal force mode of node i; The third determining module 240 is used to determine the resultant moment of the cross section of the target structure based on the resultant moment mode of the cross section and the mode coordinate vector, wherein the resultant moment mode of the cross section is obtained based on the moment reference point, node coordinates, cross section normal vector direction, nodal moment mode and nodal force mode of all nodes on the target cross section; Using the aforementioned moment reference point as the calculation basis, the resultant moment mode of the cross section is obtained based on the following expression: ; in, The torque reference point is... Let i be the coordinates of node i. for transpose, The direction of the normal vector of the cross section is... for transpose, Let i be the nodal force mode. Let i be the nodal moment mode. Let be the set of all nodes on the target cross section.

[0093] Figure 3 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. For example, as shown... Figure 3 As shown, the computer device 300 includes: a memory 301, a processor 302, and a computer program 303 stored in the memory 301 and running on the processor 302, wherein when the processor 302 executes the computer program 303, the computer device can perform any of the structural deformation and load analysis methods described above.

[0094] Furthermore, this application also protects a control device, which may include a memory and a processor. The memory stores executable program code, and the processor is used to call and execute the executable program code to perform a structural deformation and load analysis method provided in this application. This application can divide the control device into functional modules based on the above method examples. For example, each module may correspond to a specific function, or two or more functions may be integrated into a single processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this application is illustrative and only represents a logical functional division; other division methods may exist in actual implementation. It should also be noted that all relevant content of each step involved in the above method embodiments can be referenced to the functional description of the corresponding functional module, and will not be repeated here. It should be understood that the control device provided in this application is used to execute the above-described structural deformation and load analysis method, and therefore can achieve the same effect as the above-described implementation method. When using integrated units, the control device may include a processing module and a storage module. When the control device is applied to a block device, the processing module can be used to control and manage the actions of the block device. The storage module can be used to support block devices in executing mutual program code, etc. The processing module can be a processor or controller, which can implement or execute various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor can also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and microprocessors, etc., and the storage module can be a memory.

[0095] Furthermore, the control device provided in the embodiments of this application may specifically be a chip, component, or module. The chip may include a connected processor and a memory. The memory stores instructions, and when the processor calls and executes the instructions, the chip can perform a structural deformation and load analysis method provided in the above embodiments. The embodiments of this application also provide a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the aforementioned method steps to implement the structural deformation and load analysis method provided in the above embodiments.

[0096] This application also provides a computer program product. When the computer program product is run on a computer, it causes the computer to perform the aforementioned related steps to implement the structural deformation and load analysis method provided in the above embodiments. The control device, computer-readable storage medium, computer program product, or chip provided in this application are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here. Through the description of the above embodiments, those skilled in the art can understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the control device can be divided into different functional modules to complete all or part of the functions described above. In the embodiments provided in this application, it should be understood that the disclosed control device and method can be implemented in other ways. For example, the control device embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another control device, 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 an indirect coupling or communication connection through some interface, control device or unit, and can be electrical, mechanical or other forms.

[0097] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some embodiments, multiple task processing and parallel processing are possible or may be advantageous. The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The above content is only a specific implementation of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. A method of structural deformation and load analysis, characterized by, The load includes the resultant force and the resultant moment of the cross section, characterized in that the method includes: Modal analysis was performed on the finite element model constructed based on the target structure to extract strain modes, displacement modes, nodal force modes, and nodal moment modes; The structural deformation of the target structure is determined by superimposing multiple displacement modes and based on the displacement modes and modal coordinate vectors. The modal coordinate vectors are determined based on the local strain information of the target structure and the strain modes. The expression for the modal coordinate vectors is as follows: ； in, q The modal coordinate vector; Represents the strain mode matrix, for Transpose of; This represents the local strain information of the target structure; The local strain information is obtained by strain sensors installed on the target structure; The resultant force of the target structure is determined based on the resultant force modes of the cross section and the coordinate vector of the modes, wherein the resultant force modes of the cross section are obtained by summing the nodal force modes corresponding to all nodes on the target cross section; the expression of the resultant force modes of the cross section is: ； wherein, is the nodal force mode of node i; the expression of which is: ； in, Let e ​​be the stiffness matrix of element e. This is the extraction matrix for the degrees of freedom of each node in the element. Φ For displacement modes, The set of elements that contribute internal forces to node i; The resultant moment of the cross section of the target structure is determined based on the resultant moment mode of the cross section and the coordinate vector of the mode, wherein the resultant moment mode of the cross section is obtained based on the moment reference point, node coordinates, cross section normal vector direction, nodal moment mode and nodal force mode of all nodes on the target cross section; Using the aforementioned moment reference point as the calculation basis, the resultant moment mode of the cross section is obtained based on the following expression: ； in, The torque reference point is... Let be the coordinates of node i. for transpose, The direction of the normal vector of the cross section is... for transpose, Let i be the nodal force mode of node i. Let i be the nodal moment mode. Let be the set of all nodes on the target cross section.

2. The method of claim 1, wherein, The structural deformation of the target structure is determined by superimposing multiple displacement modes and based on the displacement modes and modal coordinate vectors, expressed as follows: u = Φq ； in, u For the deformation of the structure; Φ The displacement mode; q Let be the modal coordinate vector.

3. The method of claim 1, wherein, The expression for determining the resultant force of the cross section of the target structure based on the resultant force mode of the cross section and the mode coordinate vector is as follows: ； wherein, F is the section resultant force; is the section resultant force mode; q is the modal coordinate vector.

4. The method of claim 1, wherein, The expression for determining the resultant moment of the cross section of the target structure based on the resultant moment mode of the cross section and the mode coordinate vector is as follows: ； in, M For the cross section and the moment; For the resultant moment mode of the cross section, q Let be the modal coordinate vector.

5. The method of claim 1, wherein, The load also includes nodal forces, and the method further includes: By superimposing the nodal force modes using the modal coordinate vectors, the nodal forces at each node on the target cross-section are obtained, expressed as follows: ； in, The nodal force corresponding to node i; Let i be the nodal force mode corresponding to node i; q Let be the modal coordinate vector.

6. The method of claim 5, wherein, The method further includes: The resultant force of the cross section is obtained by summing the nodal forces at all corresponding nodes on the target cross section, and the expression is: ； wherein, is the resultant force of the cross-section, is the nodal force corresponding to node i; is the set of all nodes on the target cross-section.

7. The method of claim 5, wherein, The load also includes nodal moments, and the method further includes: By superimposing the nodal moment modes using the modal coordinate vectors, the nodal moments of each node on the target cross section are obtained, expressed as follows: ； wherein, is the nodal moment of node i; is the nodal moment modal of node i; q is the modal coordinate vector.

8. The method according to any one of claims 1 to 7, characterized in that, Before performing modal analysis on the finite element model constructed based on the target structure, the method further includes: The target structure is meshed to obtain multiple finite element mesh elements; Determine the element properties and material characteristics of each finite element mesh element, and set boundary conditions; The finite element model is obtained based on the finite element mesh elements, the element properties, the material properties, and the boundary conditions.

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