Aircraft structure finite element calculation unit connection method, device, equipment and medium

Abstract

The present application discloses a method, device, equipment and medium for connecting finite element calculation units of aircraft structures, and relates to the field of structural finite element analysis, including: determining slave nodes and master nodes based on the interfaces of different calculation units of a finite element model, and determining the node degrees of freedom of the master nodes and slave nodes; determining the coordinate difference between each master node and the slave node, and determining the first transformation relationship matrices of the force and torque of each master node transmitted to the slave node according to each coordinate difference; determining the intermediate variable matrix based on the node degrees of freedom and the first transformation relationship matrix, and determining the second transformation relationship matrices of the force and torque of the slave node transmitted to each master node through the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix; determining the displacement relationship between the master node and the slave node according to the second transformation relationship matrix, and determining the connection mode of the calculation units using the displacement relationship. It is possible to realize the connection between different calculation units.

Description

Technical Field

[0001] The present invention relates to the field of structural finite element analysis, and in particular to a method, device, equipment and medium for connecting finite element calculation units of aircraft structures. Background Art

[0002] Finite Element Analysis (FEA) is a numerical analysis method widely used in engineering. It divides complex physical domain problems into a limited number of simple sub-regions, uses mathematical methods to discretely solve each sub-region, and then assembles to obtain the distribution of physical quantities in real scenarios. It is widely used in the analysis of engineering problems in disciplines such as structure, electromagnetics, and acoustics. Among them, structural finite element is mainly used to carry out structural characteristic analysis, obtain the deformation, vibration, stress and other responses of the structure under different loads (force, heat, sound, etc.), and provide methods and tools to support structural design and safety platforms. In recent decades, with the rapid improvement of computer hardware capabilities and the great progress of numerical calculation methods, finite elements have been able to simulate and predict the mechanical behavior of real complex structures under various loads and environmental conditions. It has been widely used in the fields of fault prediction, performance evaluation and structural optimization of aviation and aerospace vehicles, and has become an important tool to promote the development and innovation of aircraft. In the finite element analysis of aircraft structures, scenes spanning multiple spatial scales are often encountered, and multiple calculation units (solids, beams, shells) need to be used in combination to simulate the mechanical responses of different structural components of the aircraft under load. For example, the main solid structural components (fuselage) of an aircraft are discretized using tetrahedral or hexahedral solid units; slender structures such as the main beams and support rods of the aircraft wings are mainly discretized using beam units; thin-walled structures such as the aircraft skin are mainly discretized using shell units. There are differences in the structural degrees of freedom of different units. Solid units have 3 degrees of freedom, spatial beam units that do not consider cross-sectional warping have 6 degrees of freedom, and shell units have 5 degrees of freedom. In structural analysis, if the differences in the degrees of freedom of the calculation units are not considered, and the nodes between different units are directly rigidly connected in the form of common nodes, the degrees of freedom of some units will be lost, which will cause large analysis errors and even cause analysis failure due to the singularity of the stiffness matrix.

[0003] When using different types of calculation units to conduct structural finite element analysis, in order to obtain accurate analysis results, it is necessary to ensure that the common nodes of different calculation units can accurately transmit forces and displacements. At present, the mainstream method used in finite element analysis is the "displacement method", which regards "displacement" as an unknown variable to be calculated, and calculates the values ​​of other unknown physical quantities based on the obtained displacement values. Therefore, establishing the displacement motion constraint relationship at the connection nodes of different finite element calculation units is the core key to constructing the connection relationship of calculation units and improving the simulation analysis accuracy of hybrid calculation units. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a method, device, equipment and medium for connecting aircraft structure finite element calculation units, which can introduce displacement relationship into structural finite element analysis, realize connection between different calculation units, and improve the accuracy of aircraft structure finite element analysis. The specific scheme is as follows:

[0005] In a first aspect, the present application discloses a method for connecting aircraft structure finite element calculation units, comprising:

[0006] Constructing a finite element model of the target aircraft, determining a slave node and a plurality of master nodes based on interfaces of different computing units of the finite element model, and determining the node degrees of freedom of the master node and the slave nodes; the finite element model is a model composed of solid units, beam units and shell units;

[0007] Determine the coordinate difference between each of the master nodes and the slave nodes, and determine first transformation relationship matrices of the force and torque of each of the master nodes transmitted to the force and torque of the slave nodes according to each of the coordinate differences;

[0008] Determine the intermediate variable matrix corresponding to each of the master nodes based on the node degrees of freedom corresponding to each of the master nodes and the first transformation relationship matrix, and determine the second transformation relationship matrices of the forces and torques transmitted from the slave nodes to the forces and torques of each of the master nodes through the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix;

[0009] The displacement relationship between the master node and the slave node is determined according to the second transformation relationship matrix, and the connection mode of the calculation units of the finite element of the target aircraft structure is determined using the displacement relationship.

[0010] Optionally, determining a slave node and a plurality of master nodes based on interfaces of different computing units of the finite element model includes:

[0011] Determine the nodes on the beam element as the slave nodes and the nodes on the shell element as the master nodes at the interface between the beam element and the shell element in the finite element model;

[0012] At the interface between the beam unit or the shell unit and the solid unit, a node on the beam unit or the shell unit is determined as the slave node, and a node on the solid unit is determined as the master node.

[0013] Optionally, the determining the node degrees of freedom of the master node and the slave node includes:

[0014] The node degrees of freedom of the master node and the slave node are determined based on the unit type composed of each node; the unit type includes the solid unit, the shell unit and the beam unit; wherein the degree of freedom corresponding to the solid unit is 3; the degree of freedom corresponding to the beam unit is 6; and the degree of freedom corresponding to the shell unit is 5.

[0015] Optionally, the coordinate differences respectively determine first transformation relationship matrices of the forces and torques of the master nodes transmitted to the slave nodes, including:

[0016] The first transformation relationship matrices of the forces and torques of the master nodes transmitted to the slave nodes are determined by using the coordinate differences according to the translation theorem of force.

[0017] Optionally, determining the intermediate variable matrix corresponding to each of the main nodes based on the node degrees of freedom corresponding to each of the main nodes and the first transformation relationship matrix includes:

[0018] A diagonal matrix is ​​determined based on the node degrees of freedom corresponding to each of the master nodes; wherein, if the node degrees of freedom do not exist, the elements on the diagonal line of the diagonal matrix are 0; if the node degrees of freedom are a first preset value, the elements on the diagonal line of the diagonal matrix are 1; if the node degrees of freedom are a second preset value, the elements on the diagonal line of the diagonal matrix are target values; the target value is the average distance from the slave node to all the master nodes;

[0019] The intermediate variable matrix is ​​determined based on the first transformation relationship matrix and the diagonal matrix according to a preset intermediate variable matrix calculation formula; the preset intermediate variable matrix calculation formula is:

[0020] ;

[0021] in, is the intermediate variable matrix; is the first transformation relationship matrix; is the diagonal matrix; is the transposed matrix of the first transformation relationship matrix.

[0022] Optionally, the determining of each second transformation relationship matrix of the force and torque of the slave node transmitted to each of the master nodes by using the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix, and the intermediate variable matrix includes:

[0023] Performing a matrix summation operation on the intermediate variable matrix to obtain a summed matrix;

[0024] Performing a matrix inversion operation on the summed matrix to obtain a target intermediate variable matrix;

[0025] The second transformation relationship matrix is ​​determined based on the diagonal matrix determined by the node degrees of freedom, the first transformation relationship matrix, the target intermediate variable matrix and the intermediate variable matrix according to the second transformation relationship matrix calculation formula; the second transformation relationship matrix calculation formula is:

[0026] ;

[0027] in, is the second transformation relationship matrix; is the diagonal matrix; is the transposed matrix of the first transformation relationship matrix; is the target intermediate variable matrix.

[0028] Optionally, determining the displacement relationship between the master node and the slave node according to the second transformation relationship matrix includes:

[0029] The displacement relationship between the master node and the slave node is determined based on the second transformation relationship matrix, the displacement vector of the slave node and the displacement vector of the master node through a preset displacement relationship formula; the preset displacement relationship formula is:

[0030] ;

[0031] in, is the displacement vector of the slave node; is the transposed matrix of the second transformation relationship matrix; is the displacement vector of the master node.

[0032] In a second aspect, the present application discloses an aircraft structure finite element calculation unit connection device, comprising:

[0033] A node and degree of freedom determination module, used to construct a finite element model of the target aircraft, determine a slave node and a plurality of master nodes based on the interface of different calculation units of the finite element model, and determine the node degrees of freedom of the master node and the slave nodes; the finite element model is a model composed of solid units, beam units and shell units;

[0034] A first matrix determination module, used to determine the coordinate difference between each of the master nodes and the slave nodes, and to determine first transformation relationship matrices of the force and torque of each of the master nodes transmitted to the force and torque of the slave nodes according to each of the coordinate differences;

[0035] A second matrix determination module is used to determine the intermediate variable matrix corresponding to each of the master nodes based on the node degrees of freedom corresponding to each of the master nodes and the first transformation relationship matrix, and determine the second transformation relationship matrices of the forces and torques of the slave nodes transmitted to the forces and torques of each of the master nodes through the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix;

[0036] A connection mode determination module is used to determine the displacement relationship between the master node and the slave node according to the second transformation relationship matrix, and determine the connection mode of the calculation unit of the finite element of the target aircraft structure using the displacement relationship.

[0037] In a third aspect, the present application discloses an electronic device, comprising:

[0038] Memory, used to store computer programs;

[0039] A processor is used to execute the computer program to implement the aforementioned aircraft structure finite element calculation unit connection method.

[0040] In a fourth aspect, the present application discloses a computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the aforementioned aircraft structure finite element calculation unit connection method.

[0041] When connecting the finite element calculation units of the aircraft structure, the present application first constructs a finite element model of the target aircraft, determines a slave node and several master nodes based on the interface of different calculation units of the finite element model, and determines the node degrees of freedom of the master node and the slave node; the finite element model is a model composed of solid units, beam units and shell units; then the coordinate difference between each of the master nodes and the slave nodes is determined, and the first transformation relationship matrices of the forces and torques of each of the master nodes transmitted to the slave nodes are determined according to each of the coordinate differences; then the intermediate variable matrix corresponding to each of the master nodes is determined based on the node degrees of freedom corresponding to each of the master nodes and the first transformation relationship matrix, and the second transformation relationship matrices of the forces and torques of the slave nodes transmitted to the forces and torques of each of the master nodes are determined by the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix; finally, the displacement relationship between the master node and the slave node is determined according to the second transformation relationship matrix, and the connection mode of the calculation units of the finite element of the target aircraft structure is determined by using the displacement relationship. It can be seen that the present application selects the grid nodes at the interfaces of different calculation units as slave nodes and master nodes respectively, and establishes the displacement relationship between the master node and the slave node through the relationship between the force and torque between the master node and the slave node; then, the displacement relationship is introduced into the structural finite element analysis, which realizes the connection between different calculation units and improves the accuracy of the finite element analysis of the aircraft structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0043] Figure 1 A flow chart of a method for connecting aircraft structure finite element calculation units disclosed in this application;

[0044] Figure 2 A schematic diagram of a finite element model of an aircraft disclosed in this application;

[0045] Figure 3 A schematic diagram of a finite element model node disclosed in this application;

[0046] Figure 4 A schematic diagram of a beam unit and a shell unit disclosed in this application;

[0047] Figure 5 A schematic diagram of a shell unit and a hexahedral unit disclosed in this application;

[0048] Figure 6 A schematic diagram of a beam unit and a hexahedron unit disclosed in this application;

[0049] Figure 7 A flowchart of a specific aircraft structure finite element calculation unit connection method disclosed in this application;

[0050] Figure 8 This is a schematic diagram of the structure of a connection device for a finite element calculation unit of an aircraft structure disclosed in this application;

[0051] Fig. 9 This is a structural diagram of an electronic device disclosed in this application.

[0052] Reference numerals:

[0053] 1-beam element; 2-shell element; 3-hexahedron element; 4-node of beam element; 5-node of shell element; 6-node of shell element; 7-node of shell element; 8-node of shell element; 9-node of hexahedron element; 10-node of hexahedron element; 11-node of hexahedron element; 12-node of hexahedron element. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0055] In the finite element analysis of aircraft structures, scenes spanning multiple spatial scales are often encountered, and multiple computational units (solids, beams, and shells) need to be used in combination to simulate the mechanical responses of different structural components of the aircraft under load. For example, the main solid structural components (fuselage) of the aircraft are discretized using tetrahedral or hexahedral solid units; slender structures such as the main beams and support rods of the aircraft wings are mainly discretized using beam units; thin-walled structures such as the aircraft skin are mainly discretized using shell units. There are differences in the structural degrees of freedom of different units. The solid unit has 3 degrees of freedom, the spatial beam unit without considering the cross-sectional warping has 6 degrees of freedom, and the shell unit has 5 degrees of freedom. In structural analysis, if the differences between the degrees of freedom of the computational units are not considered, and the nodes between different units are rigidly connected directly in the form of common nodes, the degrees of freedom of some units will be lost, which will cause large analysis errors and even cause analysis failure due to the singularity of the stiffness matrix. In order to solve the above technical problems, the present application discloses a method for connecting aircraft structure finite element calculation units, which can introduce displacement relationship into structural finite element analysis, realize connection between different calculation units, and improve the accuracy of aircraft structure finite element analysis.

[0056] See also Figure 1 As shown, an embodiment of the present invention discloses a method for connecting finite element calculation units of an aircraft structure, comprising:

[0057] Step S11, constructing a finite element model of the target aircraft, determining a slave node and several master nodes based on the interfaces of different computing units of the finite element model, and determining the node degrees of freedom of the master node and the slave nodes; the finite element model is a model composed of solid units, beam units and shell units.

[0058] In this embodiment, it is first necessary to construct a finite element model of the target aircraft. Figure 2 The finite element model shown in the figure is composed of hexahedral elements, beam elements and shell elements. The nodes at the interface are as follows: Figure 3 It should be noted that the structural finite element analysis in this application includes but is not limited to aircraft, and is applicable to other related structures in the fields of wind turbines, ship design, automobile aerodynamics, etc.

[0059] After constructing the finite element model of the target aircraft, determine the master node and slave node, as well as the corresponding node degrees of freedom, at the interface between the hexahedron unit and the beam unit. Figure 4 As shown in the figure, at the interface between beam elements and shell elements, the nodes on the beam elements are determined as slave nodes, and the nodes on the shell elements are determined as master nodes; at the interface between beam elements or shell elements and solid elements, the nodes on the beam elements or shell elements are determined as slave nodes, and the nodes on the solid elements are determined as master nodes. Among them, the shell elements and solid elements (which can be hexahedral elements) are as follows Figure 5 As shown, beam elements and solid elements (hexahedral elements) are Figure 6 As shown. The number of degrees of freedom of the master node and the slave node is determined by the unit type composed of each node. The solid element has three degrees of freedom, the spatial beam element without considering the cross-section warping has six degrees of freedom, and the shell element usually has five degrees of freedom. In a specific embodiment, the node on the shell element is selected as the slave node and numbered as 25; the 24 nodes on the hexahedral element are selected as the master nodes, and the nodes are numbered 1 to 24. The slave node 25 has 6 degrees of freedom, and the master nodes 1 to 24 have 3 degrees of freedom. The coordinates of the slave node 25 are , the coordinates of master nodes 1~24 are , ,……, .

[0060] Step S12, determining the coordinate difference between each of the master nodes and the slave nodes, and determining first transformation relationship matrices of the force and torque of each master node transmitted to the force and torque of the slave node according to each of the coordinate differences.

[0061] In this embodiment, for each master node, the difference between its coordinates and the coordinates of the slave node is calculated. The coordinates of the slave node s are set to , the coordinates of the master node m are set to . Set the coordinates of the main node m , minus the coordinates of node s , get the coordinate difference between the master node m and the slave node s ,Right now:

[0062] ;

[0063] Specifically, the coordinates of master node 1 are , minus the coordinates of node 25 , the coordinate difference between the master node 1 and the slave node 25 is Using the same method, we can get the coordinate difference between master nodes 2~24 and slave node 25 , ,……, .

[0064] For each master node m, calculate the transformation relationship matrix of the force / torque of the master node transmitted to the force / torque on the slave node .use Represents the force vector on the main node m, and uses Represents the force vector on the slave node s. The force vector has six components, namely the forces in the three directions of x, y, and z and the torques in the three directions. According to the translation theorem of force, the first transformation relationship matrices of the forces and torques of each master node transmitted to the forces and torques of the slave node are determined by the coordinate differences. In this way, the first transformation relationship matrix can be used to represent and The transformation between them. The force / torque on a main node m Force / torque transmitted to slave node s ,Right now ,in, is the force vector on the slave node s; is the force vector on the main node m; is the first transformation relationship matrix. Therefore, using the coordinate difference obtained in the above process , transformation relationship matrix It can be expressed as:

[0065] ;

[0066] By using the above method, the first transformation relationship matrices of the master nodes 1 to 24 and the slave node 25 can be obtained.

[0067] Step S13, determine the intermediate variable matrix corresponding to each master node based on the node degrees of freedom corresponding to each master node and the first transformation relationship matrix, and determine the second transformation relationship matrices of the force and torque transmitted from the slave node to each master node through the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix.

[0068] In this embodiment, the diagonal matrix is ​​first determined based on the node degrees of freedom corresponding to each main node; wherein, if the node degrees of freedom do not exist, the elements on the diagonal line in the diagonal matrix are 0; if the node degrees of freedom are the first preset value, the elements on the diagonal line in the diagonal matrix are 1; if the node degrees of freedom are the second preset value, the elements on the diagonal line in the diagonal matrix are the target values; the target value is the average distance from the node to all main nodes. Then, the intermediate variable matrix is ​​determined based on the first transformation relationship matrix and the diagonal matrix according to the preset intermediate variable matrix calculation formula; the preset intermediate variable matrix calculation formula is:

[0069] ;

[0070] in, is the intermediate variable matrix; is the first transformation relationship matrix; is a diagonal matrix; is the transposed matrix of the first transformation matrix.

[0071] Then for each master node m, the matrix Perform matrix summation, and then perform matrix inversion on the summed matrix to obtain the target intermediate variable matrix. In this way, the second transformation relationship matrix, that is, the force / torque transformation relationship matrix from node s to main node m, can be determined based on the diagonal matrix determined by the node degrees of freedom, the first transformation relationship matrix, the target intermediate variable matrix, and the intermediate variable matrix according to the second transformation relationship matrix calculation formula; the second transformation relationship matrix calculation formula is:

[0072] ;

[0073] in, is the second transformation relationship matrix; is a diagonal matrix; is the transposed matrix of the first transformation relationship matrix; is the target intermediate variable matrix.

[0074] Step S14: determining the displacement relationship between the master node and the slave node according to the second transformation relationship matrix, and determining the connection mode of the calculation units of the finite element structure of the target aircraft using the displacement relationship.

[0075] In this embodiment, after determining the force / torque transformation relationship matrix from the slave node s to the master node m, the displacement relationship between the master node m and the slave node s can be established. In this process, the displacement vector of the slave node s is equal to the displacement transformation matrix of all the master nodes m. The transpose of is multiplied by the displacement vector of the master node and the displacement vector of the slave node s is defined as , the displacement vector of the master node m is defined as , then the displacement relationship between the slave node s and all the master nodes m is:

[0076] ;

[0077] in, is the displacement vector from the node; is the transposed matrix of the second transformation relationship matrix; is the displacement vector of the master node. In the above formula, the displacement vector has 6 components, representing the translation in three directions and the rotation in three directions. Specifically, the displacement of slave node 25 is , the displacements of master nodes 1 to 24 are , then the displacement relationship between the slave node and the master node is:

[0078] ;

[0079] It should be noted that node 25 has 6 degrees of freedom, while nodes 1 to 24 have only 3 degrees of freedom, and the rotational components in the displacement vector are all 0. Finally, the displacement relationship between the slave node and the master node can be used to determine the connection mode of the calculation unit of the target aircraft structure finite element. The displacement relationship expression between the slave node and the master node can be applied to the structural finite element analysis in the form of a "constraint equation" to finally determine the connection mode of the calculation unit of the target aircraft structure finite element.

[0080] In summary, when connecting the finite element calculation units of the aircraft structure, the present application first constructs a finite element model of the target aircraft, determines a slave node and several master nodes based on the interface of different calculation units of the finite element model, and determines the node degrees of freedom of the master node and the slave node; the finite element model is a model composed of solid units, beam units and shell units; then the coordinate difference between each of the master nodes and the slave nodes is determined, and the first transformation relationship matrices of the forces and torques of each of the master nodes transmitted to the slave nodes are determined according to each of the coordinate differences; then the intermediate variable matrix corresponding to each of the master nodes is determined based on the node degrees of freedom corresponding to each of the master nodes and the first transformation relationship matrix, and the second transformation relationship matrices of the forces and torques of the slave nodes transmitted to the master nodes are determined by the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix; finally, the displacement relationship between the master node and the slave node is determined according to the second transformation relationship matrix, and the connection mode of the calculation units of the finite element of the target aircraft structure is determined by using the displacement relationship. It can be seen that the present application selects the grid nodes at the interfaces of different calculation units as slave nodes and master nodes respectively, and establishes the displacement relationship between the master node and the slave node through the relationship between the force and torque between the master node and the slave node; then, the displacement relationship is introduced into the structural finite element analysis, which realizes the connection between different calculation units and improves the accuracy of the finite element analysis of the aircraft structure.

[0081] Based on the previous embodiment, it can be known that the present application can establish the displacement relationship between the master node and the slave node according to the force / torque transformation relationship matrix from the slave node to the master node, and then determine the calculation unit connection mode of the finite element of the target aircraft structure. Next, how to determine the force / torque transformation relationship matrix from the slave node to the master node will be described in detail.

[0082] See also Figure 7 As shown, the embodiment of the present invention discloses a specific method for connecting aircraft structure finite element calculation units, including:

[0083] Step S21, determining a diagonal matrix based on the node degrees of freedom corresponding to each master node.

[0084] In this embodiment, the diagonal matrix is ​​determined according to the node degrees of freedom of each node. If the node degrees of freedom do not exist, the elements on the diagonal line of the diagonal matrix are 0; if the node degrees of freedom are the first preset value, the elements on the diagonal line of the diagonal matrix are 1; if the node degrees of freedom are the second preset value, the elements on the diagonal line of the diagonal matrix are the target values; the target value is the average distance from the node to all the main nodes. Specifically, the diagonal matrix The expression is:

[0085] ;

[0086] If the degree of freedom i does not exist, then the corresponding = 0. If the degree of freedom exists, when i = 1, 2, 3, =1; when i=4, 5, 6, , L represents the average distance from node s to all main nodes m. Taking the finite element model composed of hexahedral elements on the left and shell elements on the right as an example, for main nodes 1 to 24, a diagonal matrix composed of weight factors is obtained according to the node degrees of freedom , ,……, Since master nodes 1 to 24 have only three degrees of freedom in translation, the diagonal matrix of all master nodes m is Both are:

[0087] .

[0088] Step S22: determining an intermediate variable matrix based on the first transformation relationship matrix and the diagonal matrix according to a preset intermediate variable matrix calculation formula.

[0089] In this embodiment, when determining the intermediate variable matrix, it can be determined based on the first transformation relationship matrix and the diagonal matrix by using a preset intermediate variable matrix calculation formula. The preset intermediate variable matrix calculation formula is:

[0090] ;

[0091] in, is the intermediate variable matrix; is the first transformation relationship matrix; is a diagonal matrix; is the transposed matrix of the first transformation matrix.

[0092] In general, the first transformation relationship matrix First multiply it by the diagonal matrix composed of weight factors , then multiply it by the transformation relationship matrix The transposed matrix of , thus obtaining the matrix of each master node Through matrix operations, we can get the matrix The expression is:

[0093] .

[0094] Step S23, performing a matrix summation operation on the intermediate variable matrix to obtain a summed matrix, and performing a matrix inversion operation on the summed matrix to obtain a target intermediate variable matrix.

[0095] In this embodiment, the matrix of each master node m is Perform matrix summation operation, and then perform matrix inversion operation on the summed matrix to obtain the target intermediate variable matrix R. The mathematical expression of the target intermediate variable matrix R is:

[0096] .

[0097] Step S24, determining a second transformation relationship matrix according to a second transformation relationship matrix calculation formula based on the diagonal matrix determined by the node degrees of freedom, the first transformation relationship matrix, the target intermediate variable matrix and the intermediate variable matrix.

[0098] In this embodiment, for each main node m, the force / torque transformation relationship matrix from node s to main node m is calculated respectively: . First, the diagonal matrix Multiply by the first transformation matrix The transposed matrix is ​​then multiplied by the target intermediate variable matrix R, and finally the force / torque transformation relationship matrix from node s to the main node m is obtained , its mathematical expression is:

[0099] ;

[0100] in, is the second transformation relationship matrix; is a diagonal matrix; is the transposed matrix of the first transformation relationship matrix; is the target intermediate variable matrix.

[0101] Afterwards, the displacement relationship between the master node m and the slave node s can be established according to the force / torque transformation relationship matrix from the slave node s to the master node m, and finally the calculation unit connection method of the finite element of the target aircraft structure can be determined according to the displacement relationship.

[0102] It can be seen that the present application can establish the displacement relationship between the master node and the slave node according to the force / torque transformation relationship matrix from the slave node to the master node by calculating the force / torque transformation relationship matrix from the slave node to the master node. In this way, the displacement relationship is introduced into the structural finite element analysis, the connection between different calculation units is realized, and the accuracy of the finite element analysis of the aircraft structure is improved.

[0103] See also Figure 8 As shown, an embodiment of the present invention discloses a finite element calculation unit connection device for an aircraft structure, comprising:

[0104] The node and degree of freedom determination module 111 is used to construct a finite element model of the target aircraft, determine a slave node and a plurality of master nodes based on the interface of different calculation units of the finite element model, and determine the node degrees of freedom of the master node and the slave nodes; the finite element model is a model composed of solid units, beam units and shell units;

[0105] A first matrix determination module 112 is used to determine the coordinate difference between each of the master nodes and the slave nodes, and determine first transformation relationship matrices of the force and torque of each of the master nodes transmitted to the force and torque of the slave nodes according to each of the coordinate differences;

[0106] A second matrix determination module 113 is used to determine the intermediate variable matrix corresponding to each of the master nodes based on the node degrees of freedom corresponding to each of the master nodes and the first transformation relationship matrix, and determine the second transformation relationship matrices of the forces and torques transmitted from the slave nodes to the forces and torques of each of the master nodes through the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix;

[0107] The connection mode determination module 114 is used to determine the displacement relationship between the master node and the slave node according to the second transformation relationship matrix, and determine the connection mode of the calculation unit of the finite element of the target aircraft structure using the displacement relationship.

[0108] It can be seen that the present application selects the grid nodes at the interfaces of different calculation units as slave nodes and master nodes respectively, and establishes the displacement relationship between the master node and the slave node through the relationship between the force and torque between the master node and the slave node; then, the displacement relationship is introduced into the structural finite element analysis, which realizes the connection between different calculation units and improves the accuracy of the finite element analysis of the aircraft structure.

[0109] In some specific embodiments, the node and degree of freedom determination module 111 may specifically include:

[0110] A first node determination unit, used for determining a node on the beam unit as the slave node and a node on the shell unit as the master node at an interface between the beam unit and the shell unit in the finite element model;

[0111] The second node determination unit is used to determine the nodes on the beam unit or the shell unit as the slave nodes and determine the nodes on the solid unit as the master nodes at the interface between the beam unit or the shell unit and the solid unit.

[0112] In some specific embodiments, the node and degree of freedom determination module 111 may specifically include:

[0113] A node degree of freedom determination unit is used to determine the node degrees of freedom of the master node and the slave node based on the unit type composed of each node; the unit type includes the solid unit, the shell unit and the beam unit; wherein the degree of freedom corresponding to the solid unit is 3; the degree of freedom corresponding to the beam unit is 6; and the degree of freedom corresponding to the shell unit is 5.

[0114] In some specific embodiments, the first matrix determination module 112 may specifically include:

[0115] The first transformation relationship matrix determination unit is used to determine the first transformation relationship matrices of the force and torque of each master node transmitted to the force and torque of the slave node through each coordinate difference according to the translation theorem of force.

[0116] In some specific embodiments, the second matrix determination module 113 may specifically include:

[0117] A diagonal matrix determination unit, used to determine a diagonal matrix based on the node degrees of freedom corresponding to each of the master nodes; wherein, if the node degrees of freedom do not exist, the elements on the diagonal line of the diagonal matrix are 0; if the node degrees of freedom are a first preset value, the elements on the diagonal line of the diagonal matrix are 1; if the node degrees of freedom are a second preset value, the elements on the diagonal line of the diagonal matrix are target values; the target value is the average distance from the slave node to all the master nodes;

[0118] An intermediate variable matrix determining unit is used to determine the intermediate variable matrix based on the first transformation relationship matrix and the diagonal matrix according to a preset intermediate variable matrix calculation formula; the preset intermediate variable matrix calculation formula is:

[0119] ;

[0120] in, is the intermediate variable matrix; is the first transformation relationship matrix; is the diagonal matrix; is the transposed matrix of the first transformation relationship matrix.

[0121] In some specific embodiments, the second matrix determination module 113 may specifically include:

[0122] A matrix summing unit, used for performing a matrix summing operation on the intermediate variable matrix to obtain a summed matrix;

[0123] A matrix inverse operation unit, used for performing a matrix inverse operation on the summed matrix to obtain a target intermediate variable matrix;

[0124] The second transformation relationship matrix determination unit is used to determine the second transformation relationship matrix according to the second transformation relationship matrix calculation formula based on the diagonal matrix determined by the node degrees of freedom, the first transformation relationship matrix, the target intermediate variable matrix and the intermediate variable matrix; the second transformation relationship matrix calculation formula is:

[0125] ;

[0126] in, is the second transformation relationship matrix; is the diagonal matrix; is the transposed matrix of the first transformation relationship matrix; is the target intermediate variable matrix.

[0127] In some specific embodiments, the connection mode determination module 114 may specifically include:

[0128] A displacement relationship determining unit, configured to determine the displacement relationship between the master node and the slave node based on the second transformation relationship matrix, the displacement vector of the slave node, and the displacement vector of the master node by using a preset displacement relationship formula; the preset displacement relationship formula is:

[0129] ;

[0130] in, is the displacement vector of the slave node; is the transposed matrix of the second transformation relationship matrix; is the displacement vector of the master node.

[0131] Furthermore, the present application also discloses an electronic device. Fig. 9 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content in the diagram cannot be regarded as any limitation on the scope of use of the present application.

[0132] Fig. 9 The present invention provides a schematic diagram of the structure of an electronic device 20 provided in an embodiment of the present application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the aircraft structure finite element calculation unit connection method disclosed in any of the aforementioned embodiments. In addition, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0133] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0134] In addition, the memory 22 as a carrier for resource storage may be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon may include an operating system 221, a computer program 222, etc., and the storage method may be temporary storage or permanent storage.

[0135] The operating system 221 is used to manage and control the hardware devices and computer programs 222 on the electronic device 20, and may be Windows Server, Netware, Unix, Linux, etc. In addition to the computer program that can be used to complete the aircraft structure finite element calculation unit connection method performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 may further include computer programs that can be used to complete other specific tasks.

[0136] Furthermore, the present application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the aforementioned disclosed aircraft structure finite element calculation unit connection method is implemented. For the specific steps of the method, reference may be made to the corresponding contents disclosed in the aforementioned embodiments, and no further description will be given here.

[0137] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0138] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0139] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0140] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0141] The technical solution provided by the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for general technicians in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for connecting finite element calculation units of an aircraft structure, characterized in that: include: Constructing a finite element model of the target aircraft, determining a slave node and a plurality of master nodes based on interfaces of different computing units of the finite element model, and determining the node degrees of freedom of the master node and the slave nodes; the finite element model is a model composed of solid units, beam units and shell units; Determine the coordinate difference between each of the master nodes and the slave nodes, and determine first transformation relationship matrices of the force and torque of each of the master nodes transmitted to the force and torque of the slave nodes according to each of the coordinate differences; Determine the intermediate variable matrix corresponding to each of the master nodes based on the node degrees of freedom corresponding to each of the master nodes and the first transformation relationship matrix, and determine the second transformation relationship matrices of the forces and torques transmitted from the slave nodes to the forces and torques of each of the master nodes through the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix; Determine the displacement relationship between the master node and the slave node according to the second transformation relationship matrix, and determine the connection mode of the calculation units of the finite element of the target aircraft structure by using the displacement relationship; Determining a slave node and a plurality of master nodes based on interfaces of different computing units of the finite element model includes: Determine the nodes on the beam element as the slave nodes and the nodes on the shell element as the master nodes at the interface between the beam element and the shell element in the finite element model; At the interface between the beam unit or the shell unit and the solid unit, a node on the beam unit or the shell unit is determined as the slave node, and a node on the solid unit is determined as the master node.

2. The method for connecting aircraft structure finite element calculation units according to claim 1, characterized in that: The determining of the node degrees of freedom of the master node and the slave node comprises: The node degrees of freedom of the master node and the slave node are determined based on the unit type composed of each node; the unit type includes the solid unit, the shell unit and the beam unit; wherein the degree of freedom corresponding to the solid unit is 3; the degree of freedom corresponding to the beam unit is 6; and the degree of freedom corresponding to the shell unit is 5.

3. The aircraft structure finite element calculation unit connection method according to claim 1, characterized in that: The first transformation relationship matrices of the force and torque of each master node transmitted to the force and torque of the slave node are determined according to each coordinate difference, including: The first transformation relationship matrices of the forces and torques of the master nodes transmitted to the slave nodes are determined by using the coordinate differences according to the translation theorem of force.

4. The aircraft structure finite element calculation unit connection method according to claim 1, characterized in that: The determining the intermediate variable matrix corresponding to each of the main nodes based on the node degrees of freedom corresponding to each of the main nodes and the first transformation relationship matrix includes: A diagonal matrix is ​​determined based on the node degrees of freedom corresponding to each of the master nodes; wherein, if the node degrees of freedom do not exist, the elements on the diagonal line of the diagonal matrix are 0; if the node degrees of freedom are a first preset value, the elements on the diagonal line of the diagonal matrix are 1; if the node degrees of freedom are a second preset value, the elements on the diagonal line of the diagonal matrix are target values; the target value is the average distance from the slave node to all the master nodes; The intermediate variable matrix is ​​determined based on the first transformation relationship matrix and the diagonal matrix according to a preset intermediate variable matrix calculation formula; the preset intermediate variable matrix calculation formula is: ； in, The intermediate variable matrix; is the first transformation relationship matrix; is the diagonal matrix; is the transposed matrix of the first transformation relationship matrix.

5. The aircraft structure finite element calculation unit connection method according to claim 1, characterized in that: The second transformation relationship matrices for transmitting the force and torque of the slave node to the force and torque of each master node by determining the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix, and the intermediate variable matrix include: Performing a matrix summation operation on the intermediate variable matrix to obtain a summed matrix; Performing a matrix inversion operation on the summed matrix to obtain a target intermediate variable matrix; The second transformation relationship matrix is ​​determined based on the diagonal matrix determined by the node degrees of freedom, the first transformation relationship matrix, the target intermediate variable matrix and the intermediate variable matrix according to the second transformation relationship matrix calculation formula; the second transformation relationship matrix calculation formula is: ； in, is the second transformation relationship matrix; is the diagonal matrix; is the transposed matrix of the first transformation relationship matrix; is the target intermediate variable matrix.

6. The method for connecting aircraft structure finite element calculation units according to any one of claims 1 to 5, characterized in that: The determining the displacement relationship between the master node and the slave node according to the second transformation relationship matrix includes: The displacement relationship between the master node and the slave node is determined based on the second transformation relationship matrix, the displacement vector of the slave node and the displacement vector of the master node through a preset displacement relationship formula; the preset displacement relationship formula is: ； in, is the displacement vector of the slave node; is the transposed matrix of the second transformation relationship matrix; is the displacement vector of the master node.

7. An aircraft structure finite element calculation unit connection device, characterized in that: include: A node and degree of freedom determination module, used to construct a finite element model of the target aircraft, determine a slave node and a plurality of master nodes based on the interface of different calculation units of the finite element model, and determine the node degrees of freedom of the master node and the slave nodes; the finite element model is a model composed of solid units, beam units and shell units; A first matrix determination module, used to determine the coordinate difference between each of the master nodes and the slave nodes, and to determine first transformation relationship matrices of the force and torque of each of the master nodes transmitted to the force and torque of the slave nodes according to each of the coordinate differences; A second matrix determination module is used to determine the intermediate variable matrix corresponding to each of the master nodes based on the node degrees of freedom corresponding to each of the master nodes and the first transformation relationship matrix, and determine the second transformation relationship matrices of the forces and torques of the slave nodes transmitted to the forces and torques of each of the master nodes through the diagonal matrix determined according to the node degrees of freedom, the first transformation relationship matrix and the intermediate variable matrix; A connection mode determination module, used to determine the displacement relationship between the master node and the slave node according to the second transformation relationship matrix, and determine the connection mode of the calculation unit of the finite element of the target aircraft structure by using the displacement relationship; The node and degree of freedom determination module comprises: A first node determination unit, used for determining a node on the beam unit as the slave node and a node on the shell unit as the master node at an interface between the beam unit and the shell unit in the finite element model; The second node determination unit is used to determine the nodes on the beam unit or the shell unit as the slave nodes and determine the nodes on the solid unit as the master nodes at the interface between the beam unit or the shell unit and the solid unit.

8. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor is used to execute the computer program to implement the aircraft structure finite element calculation unit connection method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: Used to store a computer program, wherein when the computer program is executed by a processor, the aircraft structure finite element calculation unit connection method according to any one of claims 1 to 6 is implemented.

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