Flexible aircraft motion deformation coupling analysis method, device, equipment and medium

Abstract

The present application discloses a method, device, equipment and medium for analyzing the coupling of motion and deformation of a flexible aircraft, and relates to the field of structural rigid-flexible coupling analysis, including: constructing a finite element model of a flexible aircraft, determining the mass and inertia tensor based on the finite element model grid and the material parameters of the flexible aircraft; calculating the resultant force and resultant moment of the flexible aircraft, and determining the six-degree-of-freedom motion state of the flexible aircraft using the mass, inertia tensor and resultant moment; determining the inertial acceleration field and inertial load of the flexible aircraft, and performing finite element deformation solution in a body coordinate system through the inertial load and the converted external load to obtain the deformation result; updating the inertia tensor, resultant force and resultant moment based on the deformation result, performing motion deformation coupling and time advancement according to the updated inertia tensor, the updated resultant force and the updated resultant moment, and outputting the coupled physical quantity when the time advancement meets the preset conditions to complete the motion deformation coupling analysis. The present application realizes accurate coupling analysis.

Description

Technical Field

[0001] The present invention relates to the field of structural rigid-flexible coupling analysis, and in particular to a method, device, equipment and medium for analyzing the motion deformation coupling of a flexible aircraft. Background Art

[0002] With the widespread application of lightweight flexible materials and corresponding flexible components, the coupling analysis of flexible body spatial motion and flexible deformation has begun to receive special attention. For flexible bodies such as wind turbine blades and flexible wing aircraft that have large-scale spatial motion during actual operation, there is a complex coupling effect between their spatial motion and flexible deformation, which makes their motion laws significantly different from those of rigid bodies, and their deformation laws are significantly different from those of flexible bodies under quasi-static conditions. Using unreasonable analysis methods will give wrong predictions on the results of the coupled response of flexible body motion and deformation, which may lead to accidents in serious cases.

[0003] Existing analysis methods for the coupled motion and deformation of flexible bodies can be divided into two categories: one is the hybrid coordinate method, which uses a body-accompanying coordinate system that accompanies the motion of the flexible body to decompose the motion of each particle of the flexible body into the associated motion (corresponding to spatial motion) synchronized with the body coordinate system and the relative motion with respect to the body coordinate system (corresponding to flexible deformation), and discretizes the deformation motion using finite element node coordinates or modal coordinates to form the corresponding flexible degrees of freedom, which together with the rigid body degrees of freedom constitute the flexible body degrees of freedom of the hybrid coordinates; the other is the absolute coordinate method, which does not distinguish between the components from the overall motion and the components from the deformation in the actual motion of each particle of the flexible body, but directly analyzes it in the inertial system of absolute coordinates.

[0004] The first type of method has fewer generalized coordinates in the dynamic equations and simple constraint equations, which makes it easy to achieve high computational efficiency. However, for the "dynamic stiffening" that exists in high-speed rotating flexible bodies, that is, when other conditions such as external loads are equivalent, its flexible amplitude will decrease as the speed increases, and the traditional mixed coordinate method cannot correctly describe it. In the second type of method, the motion laws followed by each particle of the flexible body are all real physical laws under the inertial system, and the overall dynamic response of the flexible body also conforms to the real physical performance. However, the displacement values ​​corresponding to this method are large, and it is impossible to use various ideas based on small linearization to reduce degrees of freedom and simplify equations, making it difficult to guarantee its actual solution efficiency. At the same time, the solution idea that does not distinguish between motion and deformation makes this type of method more troublesome in the multidisciplinary coupling analysis scenario, and the coupling analysis between physical fields that require separate motion or deformation as input. Therefore, how to achieve accurate analysis of the coupled dynamic response of complex configuration flexible bodies with motion and deformation is a problem that needs to be solved urgently. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method, device, equipment and medium for analyzing the motion deformation coupling of a flexible aircraft, which can realize accurate analysis of the motion deformation coupling dynamic response of a flexible body with a complex configuration, while improving the solution efficiency. The specific scheme is as follows:

[0006] In a first aspect, the present application discloses a flexible aircraft motion deformation coupling analysis method, comprising:

[0007] Constructing a finite element model of a flexible aircraft, and determining the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to a body coordinate system based on a finite element model grid and material parameters of the flexible aircraft; the finite element model is a model constructed based on a three-node shell unit;

[0008] Calculating the resultant force and resultant moment of the flexible aircraft relative to the body coordinate system according to the finite element load, and determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment;

[0009] Determine the inertial acceleration field and the corresponding inertial load of the flexible aircraft relative to the body coordinate system in the current time step based on the six-degree-of-freedom motion state, perform finite element deformation solution of the flexible aircraft in the body coordinate system through the inertial load and the converted external load determined based on the target transformation matrix, and obtain the corresponding deformation result;

[0010] The inertia tensor, the resultant force and the resultant moment are updated based on the deformation result, and motion deformation coupling and time advancement are performed according to the corresponding updated inertia tensor, updated resultant force and updated resultant moment using the target coupling strategy and time advancement mechanism. When the time advancement meets the preset conditions, the corresponding coupling physical quantities are output to complete the motion deformation coupling analysis of the flexible aircraft.

[0011] Optionally, determining the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to a body coordinate system based on a finite element model mesh and material parameters of the flexible aircraft includes:

[0012] Determine the mass of each shell element according to the area, thickness and material density of the shell element of the finite element model, and add up the masses of each shell element to obtain the mass of the flexible aircraft;

[0013] The inertia tensor of the flexible aircraft relative to the body coordinate system is determined based on a preset inertia tensor calculation formula and the rotational inertia of the flexible aircraft relative to the body coordinate system; the preset inertia tensor calculation formula is:

[0014] ;

[0015] in, is the inertia tensor of the flexible aircraft relative to the body coordinate system; , and are the moments of inertia of the flexible aircraft relative to the x-axis, y-axis and z-axis of the body coordinate system respectively; , and The elements other than are non-diagonal elements, and the non-diagonal elements are the inertia products of the flexible aircraft relative to the axes of the body coordinate system;

[0016] The process of determining the moment of inertia of the flexible aircraft relative to the body coordinate system includes:

[0017] The target moments of inertia of each shell element relative to each axis of the body coordinate system are accumulated to determine the moment of inertia of the flexible aircraft relative to the body coordinate system; wherein the expression of the target moment of inertia is:

[0018] ;

[0019] in, is the target moment of inertia; is the area of ​​the shell element; is the shell element thickness; is the area element; is the density of the material; is the position vector of the integral differential element relative to the body coordinate system, For The unit direction vector of the coordinate axis of the body coordinate system corresponding to the value;

[0020] Furthermore, the process of determining the product of inertia of the flexible aircraft relative to each axis of the body coordinate system includes:

[0021] The target inertia products of the shell elements relative to the axes of the body coordinate system are accumulated to determine the inertia products of the flexible aircraft relative to the axes of the body coordinate system; wherein the expression of the target inertia product is:

[0022] ;

[0023] in, is the target product of inertia; is the area of ​​the shell element; is the shell element thickness; is the area element; is the density of the material.

[0024] Optionally, the calculating the resultant force and the resultant moment of the flexible aircraft relative to the body coordinate system according to the finite element load includes:

[0025] The resultant force of the flexible aircraft relative to the body coordinate system is calculated according to a preset resultant force calculation formula and the finite element load; the preset resultant force calculation formula is:

[0026] ;

[0027] in, is the finite element load vector; is the resultant force;

[0028] The resultant moment of the flexible aircraft relative to the body coordinate system is calculated according to a preset resultant moment calculation formula and the finite element load; the preset resultant moment calculation formula is:

[0029] ;

[0030] in, is the finite element load vector; is the resultant moment; is the position vector of the load application point relative to the body coordinate system.

[0031] Optionally, the determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment includes:

[0032] determining the motion displacement of the flexible aircraft according to the product of the mass and the translational acceleration of the flexible aircraft;

[0033] The speed and acceleration of the flexible aircraft are determined according to the preset speed and acceleration calculation formula, the inertia tensor and the resultant moment; the preset speed and acceleration calculation formula is:

[0034] ;

[0035] in, is the speed of the flexible aircraft; is the acceleration of the flexible aircraft; is the resultant moment; is the inertia tensor of the flexible aircraft relative to the body coordinate system.

[0036] Optionally, determining the inertial acceleration field and corresponding inertial load of the flexible aircraft relative to the body coordinate system in the current time step based on the six-degree-of-freedom motion state includes:

[0037] A vector of each inertial acceleration based on the six-degree-of-freedom motion state; the inertial acceleration includes translational acceleration, rotational acceleration, centripetal acceleration and Coriolis acceleration;

[0038] Determine the sum of the vectors of the inertial accelerations as the inertial acceleration field of the flexible aircraft relative to the body coordinate system;

[0039] The inertial load of the corresponding mass point of the flexible aircraft relative to the body coordinate system is determined by the inertial acceleration field and the mass of the mass point infinitesimal element.

[0040] Optionally, performing finite element deformation solution on the flexible aircraft in the body coordinate system by using the inertial load and the converted external load determined based on the target transformation matrix to obtain corresponding deformation results includes:

[0041] Determine the angle between the body coordinate system and the inertial system according to the rotational displacement of the flexible aircraft at the current time step, and determine the target transformation matrix of the inertial system to the body coordinate system using the angle;

[0042] The external load corresponding to the inertial system is transformed by using the target transformation matrix to obtain the transformed external load corresponding to the body coordinate system;

[0043] The converted external load is superimposed on the inertial load, and the finite element deformation of the flexible aircraft in the body coordinate system is solved according to the corresponding superimposed load to obtain the corresponding deformation result.

[0044] Optionally, the target coupling strategy and the time advancement mechanism are used to perform motion deformation coupling and time advancement according to the corresponding updated inertia tensor, the updated resultant force and the updated resultant moment, and when the time advancement meets the preset conditions, the corresponding coupling physical quantity is output to complete the motion deformation coupling analysis of the flexible aircraft, including:

[0045] Determining the current target coupling strategy;

[0046] If the current target coupling strategy is loose coupling, the next time step is directly advanced, and the step of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment is re-executed based on the updated inertia tensor, the updated resultant force and the updated resultant moment, until the time advancement meets the preset condition;

[0047] If the current target coupling strategy is tight coupling, then based on the updated inertia tensor, the updated resultant force and the updated resultant moment, the step of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment is re-executed, and coupling iteration is performed until the difference between the result of the current iteration step and the result of the previous iteration step is less than a preset threshold value, then it is determined that the iteration is completed, and the next time step is advanced until the time advancement meets the preset condition;

[0048] Output corresponding coupling physical quantities to complete the motion deformation coupling analysis of the flexible aircraft; the coupling physical quantities include the six-degree-of-freedom motion state, node displacement, node velocity, node acceleration, internal stress distribution of the flexible aircraft, and the displacement, velocity and acceleration of each node after the motion deformation of the flexible aircraft in the inertial system is superimposed, corresponding to the flexible aircraft at each time step.

[0049] In a second aspect, the present application discloses a flexible aircraft motion deformation coupling analysis device, comprising:

[0050] A mass and inertia tensor determination module, used to construct a finite element model of a flexible aircraft, and determine the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to a body coordinate system based on a finite element model grid and material parameters of the flexible aircraft; the finite element model is a model constructed based on a three-node shell unit;

[0051] a motion state determination module, for calculating the resultant force and resultant moment of the flexible aircraft relative to the body coordinate system according to the finite element load, and determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment;

[0052] A deformation result acquisition module is used to determine the inertial acceleration field and the corresponding inertial load of the flexible aircraft relative to the body coordinate system in the current time step based on the six-degree-of-freedom motion state, and perform finite element deformation solution of the flexible aircraft in the body coordinate system through the inertial load and the converted external load determined based on the target transformation matrix to obtain the corresponding deformation result;

[0053] The motion deformation coupling analysis completion module is used to update the inertia tensor, the resultant force and the resultant moment based on the deformation result, use the target coupling strategy and time advancement mechanism and perform motion deformation coupling and time advancement according to the corresponding updated inertia tensor, updated resultant force and updated resultant moment, and when the time advancement meets the preset conditions, output the corresponding coupling physical quantity to complete the motion deformation coupling analysis of the flexible aircraft.

[0054] In a third aspect, the present application discloses an electronic device, comprising:

[0055] Memory, used to store computer programs;

[0056] A processor is used to execute the computer program to implement the flexible aircraft motion deformation coupling analysis method as described above.

[0057] 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 flexible aircraft motion-deformation coupling analysis method as described above.

[0058] When performing motion-deformation coupling analysis on a flexible aircraft, the present application first constructs a finite element model of the flexible aircraft, and determines the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to a body coordinate system based on the finite element model grid and the material parameters of the flexible aircraft; the finite element model is a model constructed based on a three-node shell unit; then, the resultant force and resultant moment of the flexible aircraft relative to the body coordinate system are calculated based on the finite element load, and the mass, the inertia tensor and the resultant moment are used to determine the six-degree-of-freedom motion state of the flexible aircraft in the current time step; then, based on the six-degree-of-freedom motion state, the flexible aircraft is determined in the current time step. The inertial acceleration field and the corresponding inertial load of the flexible aircraft relative to the body coordinate system are used to solve the finite element deformation of the flexible aircraft in the body coordinate system through the inertial load and the converted external load determined based on the target transformation matrix to obtain the corresponding deformation result; finally, based on the deformation result, the inertia tensor, the resultant force and the resultant moment are updated, and the target coupling strategy and time advancement mechanism are used to perform motion deformation coupling and time advancement according to the corresponding updated inertia tensor, updated resultant force and updated resultant moment, and when the time advancement meets the preset conditions, the corresponding coupling physical quantity is output to complete the motion deformation coupling analysis of the flexible aircraft. It can be seen that the present application realizes the finite element deformation solution of the flexible body in the non-inertial system by applying the inertial load in the finite element solution. At the same time, the spatial motion is solved by using a method similar to the traditional single rigid body space 6-DOF motion. Then, the idea of ​​two-field coupling is adopted, and the corresponding coupling physical quantities are calculated using the solution results of the two parts to complete the motion deformation coupling analysis. In this way, the coupled analysis process based on the coupling relationship between spatial motion and flexible deformation in the actual physical process ensures that the analysis results are accurate and reliable; by using non-inertial finite elements to realize deformation solution in the body coordinate system, the solution scale is effectively controlled and the solution efficiency is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] 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.

[0060] Figure 1 A flow chart of a flexible aircraft motion deformation coupling analysis method disclosed in this application;

[0061] Figure 2 A schematic diagram of the structural appearance of a flying wing aircraft disclosed in this application;

[0062] Figure 3 A schematic diagram of a finite element mesh of a flying wing aircraft disclosed in the present application;

[0063] Figure 4 A schematic diagram of load vector distribution disclosed in this application;

[0064] Figure 5 A schematic diagram of the inertial system motion results of a flying wing aircraft disclosed in this application;

[0065] Figure 6 A schematic diagram of deformation results of a body coordinate system of a flying wing aircraft disclosed in the present application;

[0066] Figure 7 A schematic diagram of the coupled superposition results of the motion deformation of a flying wing aircraft disclosed in the present application;

[0067] Figure 8 A flowchart of a specific flexible aircraft motion deformation coupling analysis method disclosed in this application;

[0068] Fig. 9 This is a schematic structural diagram of a flexible aircraft motion deformation coupling analysis device disclosed in this application;

[0069] Fig.10 This is a structural diagram of an electronic device disclosed in this application.

[0070] Reference numerals:

[0071] 11-mass and inertia tensor determination module; 12-motion state determination module; 13-deformation result acquisition module; 14-motion deformation coupling analysis completion module; 20-electronic equipment; 21-processor; 22-memory; 221-operating system; 222-computer program; 23-power supply; 24-communication interface; 25-input and output interface; 26-communication bus. DETAILED DESCRIPTION

[0072] 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.

[0073] Existing analysis methods for the coupling problem of motion and deformation of flexible bodies can be divided into two categories: the first type of method has fewer generalized coordinates in the dynamic equations and simple constraint equations, which can easily achieve high computational efficiency; however, for the "dynamic stiffening" existing in high-speed rotating flexible bodies, that is, when other conditions such as external loads are equivalent, its flexible amplitude will decrease as the speed increases, and the traditional mixed coordinate method cannot correctly describe it. In the second type of method, the motion laws followed by each particle of the flexible body are all real physical laws under the inertial system, and the overall dynamic response of the flexible body also conforms to the real physical performance; however, the displacement values ​​corresponding to this method are large, and it is impossible to use various ideas based on small linearization to reduce the degree of freedom and simplify the equations, making it difficult to ensure its actual solution efficiency; at the same time, the solution ideas that do not distinguish between motion and deformation make this type of method more troublesome in the multidisciplinary coupling analysis scenario, and the coupling analysis between physical fields that require separate motion or deformation as input. In order to solve the above technical problems, the present application discloses a method, device, equipment and medium for coupling analysis of motion and deformation of flexible aircraft, which can realize accurate analysis of the coupled dynamic response of motion and deformation of complex flexible bodies, and improve the solution efficiency at the same time.

[0074] See also Figure 1 As shown, an embodiment of the present invention discloses a method for analyzing the motion deformation coupling of a flexible aircraft, including:

[0075] Step S11, construct a finite element model of the flexible aircraft, and determine the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to the body coordinate system based on the finite element model mesh and the material parameters of the flexible aircraft; the finite element model is a model constructed based on three-node shell elements.

[0076] In this embodiment, the present application firstly Figure 2 The flexible aircraft model shown in the figure is used to establish its finite element model, as shown in Figure 3As shown in the figure, the model is established by three-node shell elements, with a total of 9012 shell elements and 5198 nodes. To reduce the amount of subsequent calculations, the origin of the model body coordinate system is taken at the center of mass of the flexible body, and the direction of the coordinate axis is the same as its principal axis of inertia. The model mesh is established based on the geometric shape and size of the flexible body to be analyzed. The specific establishment method is roughly the same as that of the conventional finite element. It should be noted that in order to facilitate the calculation and update of the inertia tensor of the flexible body, the origin of the model coordinate system should give priority to the center of mass of the flexible body, and the direction of the coordinate axis should give priority to the principal axis of inertia of the flexible body. The model coordinate system is the body coordinate system in the coupling of motion and deformation of the flexible body. In addition, it is necessary to define the constraints of the finite element model based on the actual constraints of the flexible body. The specific application method refers to the conventional finite element. The constraint state of the flexible body should be unconstrained or underconstrained so that it can move in space. At the same time, for the non-inertial system finite element facing the body coordinate system, due to the existence of inertial loads to balance the actual loads, its spatial motion is not reflected in the finite element, and there is no need to apply additional rigid body constraints. Defining the initial motion state of a flexible body means giving its position, translational / rotational velocity and acceleration at the initial moment, while the initial deformation state is defined by the initial displacement, velocity and acceleration of each node of the finite element mesh.

[0077] Next, the total mass of the aircraft and its inertia tensor relative to the body coordinate system are calculated using the finite element mesh and material parameters. The mass of each shell element is determined according to the area, thickness, and material density of the shell element of the finite element model, and the mass of each shell element is accumulated to obtain the mass of the flexible aircraft. Specifically, the mass of each shell element is: ; is the area of ​​the shell element; is the shell element thickness; is the material density; then add them up to get the total mass of the aircraft model: .

[0078] The inertia tensor of the flexible aircraft relative to the body coordinate system is determined based on the preset inertia tensor calculation formula and the rotational inertia of the flexible aircraft relative to the body coordinate system; the preset inertia tensor calculation formula is:

[0079] ;

[0080] in, is the inertia tensor of the flexible aircraft relative to the body coordinate system; , and are respectively the moments of inertia of the flexible aircraft relative to the x-axis, y-axis and z-axis of the body coordinate system; , and The elements outside are non-diagonal elements, which are the inertia products of the flexible aircraft relative to the axes of the body coordinate system;

[0081] The process of determining the moment of inertia of the flexible aircraft relative to the body coordinate system includes:

[0082] The target moment of inertia of each shell element relative to each axis of the body coordinate system is accumulated to determine the moment of inertia of the flexible aircraft relative to the body coordinate system; the expression of the target moment of inertia is:

[0083] ;

[0084] in, is the target moment of inertia; is the area of ​​the shell element; is the shell element thickness; is the material density; is the area element; is the position vector of the integral differential element relative to the body coordinate system, For The unit direction vector of the coordinate axis of the body coordinate system corresponding to the value (when i=x, =(1, 0, 0), and so on). In addition, the process of determining the inertia product of the flexible aircraft relative to each axis of the body coordinate system includes: accumulating the target inertia product of each shell unit relative to each axis of the body coordinate system to determine the inertia product of the flexible aircraft relative to each axis of the body coordinate system; wherein the expression of the target inertia product is:

[0085] ;

[0086] in, is the target product of inertia; is the area of ​​the shell element; is the shell element thickness; is the area element; is the material density.

[0087] Finally, the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to the body coordinate system are determined.

[0088] Step S12, calculating the resultant force and resultant moment of the flexible aircraft relative to the body coordinate system according to the finite element load, and determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step using the mass, the inertia tensor and the resultant moment.

[0089] In this embodiment, the load on the aircraft is as follows: Figure 4As shown, it is evenly distributed on the outer surface of the aircraft, and the direction of the load vector generally points to the positive direction of the Z axis, but the Z axis component gradually decreases from the right end to the left end of the aircraft, and the negative Y axis component gradually increases; in addition to this load, it is also affected by gravity. Based on this load condition, the resultant force relative to the body coordinate system is calculated:

[0090] ;

[0091] in, is the finite element load vector (including gravity); For the joint force;

[0092] At the same time, the resultant moment of the flexible aircraft relative to the body coordinate system is calculated according to the preset resultant moment calculation formula and the finite element load; the preset resultant moment calculation formula is:

[0093] ;

[0094] in, is the finite element load vector; is the resultant moment; It is the position vector of the load application point relative to the body coordinate system.

[0095] For each time step in the solution (corresponding to a moment t in the motion / deformation process of the flexible body), based on the motion and deformation state of the flexible body in the previous time step (time th, where h is the solution time step), and the load of the current time step, the motion and deformation state of the time step is obtained through the motion-deformation coupling solution, which specifically includes: spatial motion time-marching solution, inertial acceleration field calculation, body coordinate system load update, non-inertial system finite element time-marching solution, inertia tensor update and rigid body load update. The first step is to solve the 6-degree-of-freedom motion displacement, velocity and acceleration of the flexible body in the current time step based on the motion state of the flexible body in the previous time step, and the resultant force and torque of the current time step. The solution process is similar to the analysis of the traditional single rigid body 6-degree-of-freedom motion in space, and the following is obtained: Figure 5 The rigid body motion results are shown. Specifically, the motion displacement of the flexible aircraft is determined according to the product of the mass and the translational acceleration of the flexible aircraft. Translational part: , where m is the mass of the flexible body, is the translational acceleration of the flexible body, and F is the resultant external force on the flexible body; the speed and acceleration of the flexible aircraft are determined according to the preset speed and acceleration calculation formula, the inertia tensor and the resultant moment; the preset speed and acceleration calculation formula is:

[0096] ;

[0097] in, is the speed of the flexible aircraft; is the acceleration of the flexible aircraft; is the resultant moment; is the inertia tensor of the flexible aircraft relative to the body coordinate system.

[0098] Step S13, based on the six-degree-of-freedom motion state, determine the inertial acceleration field and the corresponding inertial load of the flexible aircraft relative to the body coordinate system in the current time step, and perform finite element deformation solution of the flexible aircraft in the body coordinate system through the inertial load and the converted external load determined based on the target transformation matrix to obtain the corresponding deformation result.

[0099] In this embodiment, based on the 6-DOF motion state of the flexible body obtained by motion solution, the inertial acceleration field and the corresponding inertial load in the body coordinate system in the current time step are calculated, specifically including: the vector of each inertial acceleration based on the 6-DOF motion state; the inertial acceleration includes translational acceleration, rotational acceleration, centripetal acceleration and Coriolis acceleration; translational acceleration: ,in, is the translational acceleration of the flexible body. Rotational acceleration: ,in, is the acceleration vector rotating with the body coordinate system, is the particle position vector. Centripetal acceleration: ,in, is the angular velocity vector. Coriolis acceleration: ,in, is the angular velocity vector of the body coordinate system, is the linear velocity vector of the particle relative to the body coordinate system. The vector sum of the above inertial accelerations is the total inertial acceleration vector of each particle. .

[0100] Then, the sum of the vectors of the inertial accelerations is determined as the inertial acceleration field of the flexible aircraft relative to the body coordinate system, and the inertial load of the corresponding mass point of the flexible aircraft relative to the body coordinate system is determined by the inertial acceleration field and the mass of the mass point microelement. Based on the inertial acceleration field, the inertial load of each mass point in the body coordinate system is obtained: , where dm is the mass of the particle element.

[0101] After determining the inertial load, determine the angle between the body coordinate system and the inertial system according to the rotational displacement of the flexible aircraft in the current time step, and use the angle to determine the target transformation matrix for converting the inertial system to the body coordinate system; use the target transformation matrix to transform the external load corresponding to the inertial system to obtain the converted external load corresponding to the body coordinate system; superimpose the converted external load with the inertial load, and solve the finite element deformation of the flexible aircraft in the body coordinate system according to the corresponding superimposed load to obtain the corresponding deformation result. Specifically, for some external loads that are consistent with the overall inertial system, it is also necessary to perform a coordinate transformation based on the angle between the flexible body and the inertial system after movement. When updating the body coordinate system load, the angle between the body coordinate system and the inertial system is obtained based on the flexible body movement result in the current time step, mainly the rotational displacement, and the load defined in the inertial system is converted to the body coordinate system, that is, ;in, is the load vector in the inertial system, is the load vector in the body coordinate system, is the transformation matrix from the inertial system to the body coordinate system. The inertial load and the external load are applied to the aircraft finite element model, and the time-marching solution of the finite element deformation in the non-inertial system is performed to obtain the following: Figure 6 The deformation results in the body coordinate system are shown.

[0102] Step S14, based on the deformation result, the inertia tensor, the resultant force and the resultant moment are updated, and the motion deformation coupling and time advancement are performed according to the corresponding updated inertia tensor, updated resultant force and updated resultant moment by using the target coupling strategy and time advancement mechanism, and when the time advancement meets the preset conditions, the corresponding coupling physical quantity is output to complete the motion deformation coupling analysis of the flexible aircraft.

[0103] In this embodiment, based on the deformation state of the flexible body in the previous time step and the load in the current time step, the inertial load obtained by the aforementioned inertial acceleration field is superimposed, and a finite element time marching solution is performed to obtain the grid node displacement, velocity, and acceleration corresponding to the deformation of the flexible body in the current time step. At the same time, the displacement of the flexible body grid node in the current time step is used to obtain the current position of each node, and the inertia tensor of the flexible body in the deformation state of the current time step is calculated accordingly. The specific calculation method is the same as the above method. The resultant force and resultant torque are updated based on the motion and deformation results of the current time step. The specific calculation method is the same as the above method, but the position vector value should be based on the deformed finite element grid. For the load applied to the finite element grid node, it is necessary to update its torque to the body coordinate system based on the position of the node relative to the body coordinate system after deformation.

[0104] In this embodiment, according to the coupling strategy adopted, if it is loose coupling, time advancement is directly performed and the step of using the mass, the inertia tensor and the resultant torque to determine the six-degree-of-freedom motion state of the flexible aircraft in the current time step is returned; if it is tight coupling, the step of using the mass, the inertia tensor and the resultant torque to determine the six-degree-of-freedom motion state of the flexible aircraft in the current time step to update the resultant force and the resultant torque is repeated until the relevant accuracy requirements are met and then the coupled time advancement is performed. In other words, based on the corresponding coupling strategy, after the step of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant torque to the step of updating the inertia tensor, the resultant force and the resultant torque based on the deformation result is completed, the time advancement of the next time step is directly performed based on the obtained result and the load. The coupling at this time is called loose coupling; the accuracy of loose coupling depends on the value of the time step. When the accuracy requirement is high and the time step cannot be made smaller, after the step of updating the inertia tensor, the resultant force and the resultant torque based on the deformation result is completed, the result is returned to the step of determining the current time by using the mass, the inertia tensor and the resultant torque. The step of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step, re-advancing the time of the current time step, and repeating the step of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant torque to the step of updating the inertia tensor, the resultant force and the resultant torque based on the deformation result, that is, performing coupled iteration of motion and deformation. The coupling at this time is called tight coupling, and its accuracy is much less dependent on the time step than loose coupling. Each repeated process is called a coupling step, and the end criterion of the coupling iteration usually uses the residual, that is, the difference between the current iteration step and the previous iteration step. When the residual is less than the predetermined value, it is determined that the coupling iteration is completed and the time advancement of the next time step can be performed.

[0105] Therefore, the present application first determines the current target coupling strategy; if the current target coupling strategy is loose coupling, the next time step is directly advanced, and based on the updated inertia tensor, the updated resultant force and the updated resultant moment, the steps of using the mass, inertia tensor and resultant moment to determine the six-degree-of-freedom motion state of the flexible aircraft in the current time step are re-executed until the time advancement meets the preset conditions; if the current target coupling strategy is tight coupling, the steps of using the mass, inertia tensor and resultant moment to determine the six-degree-of-freedom motion state of the flexible aircraft in the current time step are re-executed based on the updated inertia tensor, the updated resultant force and the updated resultant moment, and coupling iteration is performed until the difference between the results of the current iteration step and the previous iteration step is less than the preset threshold, then the iteration is determined to be completed, and the next time step is advanced until the time advancement meets the preset conditions. Finally, the corresponding coupling physical quantities are output to complete the motion deformation coupling analysis of the flexible aircraft; the coupling physical quantities include the six-degree-of-freedom motion state, node displacement, node velocity, node acceleration, the internal stress distribution of the flexible aircraft and the displacement, velocity and acceleration of each node after the motion deformation of the flexible aircraft in the inertial system is superimposed. In other words, the judgment time is over, post-processing is performed, and the results are recorded. Among them, the 6-degree-of-freedom spatial motion displacement, velocity, acceleration of the aircraft at the corresponding moment of each time step, its node displacement, velocity, acceleration in the body coordinate system, and the internal stress distribution of the aircraft can be directly obtained and recorded in the aforementioned time advancement solution process; and for the displacement, velocity and acceleration results of each node in the inertial system after the superposition of the aircraft motion and deformation, superposition calculations are required. For each node in the aircraft model, its position vector in the inertial system is: ;in is the displacement vector of the body coordinate system relative to the inertial system. Since the inertial system coincides with the body coordinate system in the initial state, It is also the position vector of the body coordinate system relative to the inertial system after the movement. is the transformation matrix from the inertial system to the body coordinate system, is the position vector of the node relative to the body coordinate system before deformation, is the deformation displacement vector of the node relative to the body coordinate system. The obtained motion deformation superposition result in the aircraft inertial system is as follows: Figure 7 As shown in the figure, the motion-deformation coupling analysis of the flexible aircraft is finally completed. While accurately simulating the motion-deformation coupling dynamic response of a complex flexible body, the solution efficiency is greatly improved compared with the absolute coordinate method.

[0106] It can be seen that the present application realizes the finite element deformation solution of the flexible body in the non-inertial system by applying inertial loads in the finite element solution. At the same time, a method similar to the traditional single rigid body space 6-DOF motion is used to solve its spatial motion. Then, the idea of ​​two-field coupling is adopted, and the corresponding coupling physical quantities are calculated using the solution results of the two parts to complete the motion deformation coupling analysis. In this way, the coupling analysis process based on the coupling relationship between spatial motion and flexible deformation in the actual physical process is used to ensure that the analysis results are accurate and reliable; by using non-inertial system finite elements to realize the deformation solution in the body coordinate system, the scale of the solution is effectively controlled and the efficiency of the solution is guaranteed.

[0107] Based on the above embodiment, the present application discloses a flexible aircraft motion deformation coupling analysis method, which can realize accurate simulation of the motion deformation coupling dynamic response of a complex flexible body. Next, the specific flexible aircraft motion deformation coupling analysis process will be described in detail.

[0108] like Figure 8 As shown, step (1): the present application first establishes a finite element model for a given flexible aircraft model. The model is established by three-node shell elements, with a total number of shell elements of 9012 and a total number of nodes of 5198. In order to reduce the amount of subsequent calculations, the origin of the model body coordinate system is taken at the center of mass of the flexible body, and the direction of the coordinate axis is the same as its principal axis of inertia, thus completing the finite element pre-processing.

[0109] Step (2): Initial calculation of inertial parameters: Calculate the total mass of the aircraft and its inertia tensor relative to the body coordinate system using the finite element mesh and material parameters. The mass of each shell element is determined based on the area, thickness, and material density of the shell element of the finite element model, and the mass of each shell element is accumulated to obtain the mass of the flexible aircraft. Specifically, the mass of each shell element is: ; is the area of ​​the shell element; is the shell element thickness; is the material density; then add them up to get the total mass of the aircraft model: .

[0110] The inertia tensor of the flexible aircraft relative to the body coordinate system is determined based on the preset inertia tensor calculation formula and the rotational inertia of the flexible aircraft relative to the body coordinate system; the preset inertia tensor calculation formula is:

[0111] ;

[0112] in, is the inertia tensor of the flexible aircraft relative to the body coordinate system; , and are respectively the moments of inertia of the flexible aircraft relative to the x-axis, y-axis and z-axis of the body coordinate system; , and The elements outside are non-diagonal elements, which are the inertia products of the flexible aircraft relative to the axes of the body coordinate system;

[0113] The process of determining the moment of inertia of the flexible aircraft relative to the body coordinate system includes:

[0114] The target moment of inertia of each shell element relative to each axis of the body coordinate system is accumulated to determine the moment of inertia of the flexible aircraft relative to the body coordinate system; the expression of the target moment of inertia is:

[0115] ;

[0116] in, is the target moment of inertia; is the area of ​​the shell element; is the shell element thickness; is the area element; is the material density; is the position vector of the integral differential element relative to the body coordinate system, For The unit direction vector of the coordinate axis of the body coordinate system corresponding to the value (when i=x, =(1, 0, 0), and so on). In addition, the process of determining the inertia product of the flexible aircraft relative to each axis of the body coordinate system includes: accumulating the target inertia product of each shell unit relative to each axis of the body coordinate system to determine the inertia product of the flexible aircraft relative to each axis of the body coordinate system; wherein the expression of the target inertia product is:

[0117] ;

[0118] in, is the target product of inertia; is the area of ​​the shell element; is the shell element thickness; is the material density.

[0119] Finally, the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to the body coordinate system are determined.

[0120] Step (3): Initial calculation of the resultant external force / moment. The load on the aircraft is evenly distributed on the outer surface of the aircraft. The direction of the load vector generally points to the positive direction of the Z axis, but the Z axis component gradually decreases from the right end to the left end of the aircraft, and the negative Y axis component gradually increases; in addition to this load, it is also affected by gravity. Based on this load condition, the resultant force relative to the body coordinate system is calculated , resultant moment ;in, is the finite element load vector; is the resultant moment; It is the position vector of the load application point relative to the body coordinate system.

[0121] Step (4): Use the resultant external force calculated in step (3) and the resultant external torque , perform time-marching solution of the flexible body's spatial motion, and solve the 6-DOF motion displacement, velocity and acceleration of the flexible body in the current time step.

[0122] Step (5): Using the spacecraft's horizontal / rotational velocity, acceleration, etc. calculated in step (4), calculate the inertial acceleration field of the flexible body in the non-inertial body coordinate system. , based on the inertial acceleration field, the inertial load of each particle in the body coordinate system is obtained: , where dm is the mass of the particle element.

[0123] Step (6): For some external loads that are consistent with the overall inertial system, coordinate transformation is also required based on the angle between the flexible body and the inertial system after movement. Taking gravity as an example, its vector expression in the body-following coordinate system is: ,in is the transformation matrix from the inertial system to the body coordinate system, is the gravity vector expression in the inertial system.

[0124] Step (7): Apply the inertial load obtained in step (5) together with the external load to the aircraft finite element model, perform a time-marching solution of the finite element deformation in the non-inertial system, and obtain the deformation result in the body coordinate system.

[0125] Step (8): Based on the deformation state of the flexible body in the previous time step and the load in the current time step, the inertial load obtained from the above-mentioned inertial acceleration field is superimposed, and the finite element time marching solution is performed to obtain the mesh node displacement, velocity, and acceleration corresponding to the deformation of the flexible body in the current time step. At the same time, the displacement of the flexible body mesh node in the current time step is used to obtain the current position of each node, and the inertia tensor of the flexible body in the deformation state in the current time step is calculated based on this. The specific calculation method is the same as the above method. Update the resultant force and resultant torque based on the motion and deformation results of the current time step. The specific calculation method is the same as the above method, but the position vector value should be based on the deformed finite element mesh. For the load applied to the finite element mesh node, it is necessary to update its torque on the body coordinate system based on the position of the node relative to the body coordinate system after deformation.

[0126] Step (9): Based on the coupling strategy adopted, if it is loose coupling, directly perform time advancement and return to step (4); if it is tight coupling, repeat steps (4) to (8) until the relevant accuracy requirements are met and then perform coupled time advancement.

[0127] Step (10): Determine the end of time, perform post-processing, and record the results. The 6-DOF spatial motion displacement, velocity, acceleration of the aircraft at each time step, its node displacement, velocity, acceleration in the body coordinate system, and the internal stress distribution of the aircraft can be directly obtained and recorded in the aforementioned time-marching solution process; and for the displacement, velocity, and acceleration results of each node in the inertial system after the superposition of the aircraft motion and deformation, it is necessary to perform superposition calculations. For each node in the aircraft model, its position vector in the inertial system is: ;in is the displacement vector of the body coordinate system relative to the inertial system. Since the inertial system coincides with the body coordinate system in the initial state, It is also the position vector of the body coordinate system relative to the inertial system after the movement. is the transformation matrix from the inertial system to the body coordinate system, is the position vector of the node relative to the body coordinate system before deformation, is the deformation displacement vector of the node relative to the body coordinate system. The obtained motion deformation superposition result in the inertial system of the aircraft is finally completed.

[0128] In this way, the present application achieves accurate simulation of the coupled dynamic response of the motion and deformation of complex-configuration flexible bodies, while significantly improving the solution efficiency compared to absolute coordinate methods.

[0129] See also Fig. 9 As shown, an embodiment of the present invention discloses a flexible aircraft motion deformation coupling analysis device, comprising:

[0130] The mass and inertia tensor determination module 11 is used to construct a finite element model of the flexible aircraft, and determine the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to the body coordinate system based on the finite element model grid and the material parameters of the flexible aircraft; the finite element model is a model constructed based on a three-node shell unit;

[0131] A motion state determination module 12, for calculating the resultant force and resultant moment of the flexible aircraft relative to the body coordinate system according to the finite element load, and determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment;

[0132] The deformation result acquisition module 13 is used to determine the inertial acceleration field and the corresponding inertial load of the flexible aircraft relative to the body coordinate system in the current time step based on the six-degree-of-freedom motion state, and perform finite element deformation solution of the flexible aircraft in the body coordinate system through the inertial load and the converted external load determined based on the target transformation matrix to obtain the corresponding deformation result;

[0133] The motion deformation coupling analysis completion module 14 is used to update the inertia tensor, the resultant force and the resultant moment based on the deformation result, and use the target coupling strategy and time advancement mechanism to perform motion deformation coupling and time advancement according to the corresponding updated inertia tensor, updated resultant force and updated resultant moment, and when the time advancement meets the preset conditions, output the corresponding coupling physical quantity to complete the motion deformation coupling analysis of the flexible aircraft.

[0134] It can be seen that the present application realizes the finite element deformation solution of the flexible body in the non-inertial system by applying inertial loads in the finite element solution. At the same time, a method similar to the traditional single rigid body space 6-DOF motion is used to solve its spatial motion. Then, the idea of ​​two-field coupling is adopted, and the corresponding coupling physical quantities are calculated using the solution results of the two parts to complete the motion deformation coupling analysis. In this way, the coupling analysis process based on the coupling relationship between spatial motion and flexible deformation in the actual physical process is used to ensure that the analysis results are accurate and reliable; by using non-inertial system finite elements to realize the deformation solution in the body coordinate system, the scale of the solution is effectively controlled and the efficiency of the solution is guaranteed.

[0135] In some specific embodiments, the mass and inertia tensor determination module 11 can be specifically used to determine the mass of each shell unit according to the area, thickness and material density of the shell unit of the finite element model, and accumulate the mass of each shell unit to obtain the mass of the flexible aircraft;

[0136] The inertia tensor of the flexible aircraft relative to the body coordinate system is determined based on a preset inertia tensor calculation formula and the rotational inertia of the flexible aircraft relative to the body coordinate system; the preset inertia tensor calculation formula is:

[0137] ;

[0138] in, is the inertia tensor of the flexible aircraft relative to the body coordinate system; , and are the moments of inertia of the flexible aircraft relative to the x-axis, y-axis and z-axis of the body coordinate system respectively; , and The elements other than are non-diagonal elements, and the non-diagonal elements are the inertia products of the flexible aircraft relative to the axes of the body coordinate system;

[0139] The process of determining the moment of inertia of the flexible aircraft relative to the body coordinate system includes:

[0140] The target moments of inertia of each shell element relative to each axis of the body coordinate system are accumulated to determine the moment of inertia of the flexible aircraft relative to the body coordinate system; wherein the expression of the target moment of inertia is:

[0141] ;

[0142] in, is the target moment of inertia; is the area of ​​the shell element; is the shell element thickness; is the area element; is the density of the material; is the position vector of the integral differential element relative to the body coordinate system, For The unit direction vector of the coordinate axis of the body coordinate system corresponding to the value;

[0143] Furthermore, the process of determining the product of inertia of the flexible aircraft relative to each axis of the body coordinate system includes:

[0144] The target inertia products of the shell elements relative to the axes of the body coordinate system are accumulated to determine the inertia products of the flexible aircraft relative to the axes of the body coordinate system; wherein the expression of the target inertia product is:

[0145] ;

[0146] in, is the target product of inertia; is the area of ​​the shell element; is the shell element thickness; is the area element; is the density of the material.

[0147] In some specific embodiments, the motion state determination module 12 can be specifically used to calculate the resultant force of the flexible aircraft relative to the body coordinate system according to a preset resultant force calculation formula and the finite element load; the preset resultant force calculation formula is:

[0148] ;

[0149] in, is the finite element load vector; is the resultant force;

[0150] The resultant moment of the flexible aircraft relative to the body coordinate system is calculated according to a preset resultant moment calculation formula and the finite element load; the preset resultant moment calculation formula is:

[0151] ;

[0152] in, is the finite element load vector; is the resultant moment; is the position vector of the load application point relative to the body coordinate system.

[0153] In some specific embodiments, the motion state determination module 12 can be specifically used to determine the motion displacement of the flexible aircraft according to the product of the mass and the translational acceleration of the flexible aircraft; determine the speed and acceleration of the flexible aircraft according to a preset speed and acceleration calculation formula, the inertia tensor and the resultant moment; the preset speed and acceleration calculation formula is:

[0154] ;

[0155] in, is the speed of the flexible aircraft; is the acceleration of the flexible aircraft; is the resultant moment; is the inertia tensor of the flexible aircraft relative to the body coordinate system.

[0156] In some specific embodiments, the deformation result acquisition module 13 can be specifically used for the vectors of each inertial acceleration based on the six-degree-of-freedom motion state; the inertial acceleration includes translational acceleration, rotational acceleration, centripetal acceleration and Coriolis acceleration; the sum between the vectors of each inertial acceleration is determined as the inertial acceleration field of the flexible aircraft relative to the body coordinate system; the inertial load of the corresponding particle of the flexible aircraft relative to the body coordinate system is determined through the inertial acceleration field and the mass of the particle infinitesimal element.

[0157] In some specific embodiments, the deformation result acquisition module 13 can be specifically used to determine the angle between the body coordinate system and the inertial system according to the rotational displacement of the flexible aircraft at the current time step, and use the angle to determine the target transformation matrix for converting the inertial system into the body coordinate system; use the target transformation matrix to transform the external load corresponding to the inertial system to obtain the converted external load corresponding to the body coordinate system; superimpose the converted external load with the inertial load, and perform finite element deformation solution of the flexible aircraft in the body coordinate system according to the corresponding superimposed load to obtain the corresponding deformation result.

[0158] In some specific embodiments, the motion deformation coupling analysis completion module 14 can be specifically used to determine the current target coupling strategy; if the current target coupling strategy is loose coupling, the next time step is directly advanced, and based on the updated inertia tensor, the updated resultant force and the updated resultant moment, the step of using the mass, the inertia tensor and the resultant moment to determine the six-degree-of-freedom motion state of the flexible aircraft in the current time step is re-executed until the time advancement meets the preset conditions; if the current target coupling strategy is tight coupling, the step of using the mass, the inertia tensor and the resultant moment to determine the six-degree-of-freedom motion state of the flexible aircraft in the current time step is re-executed based on the updated inertia tensor, the updated resultant force and the updated resultant moment. and the step of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by the resultant torque, performing coupling iteration until the difference between the current iteration step and the result of the previous iteration step is less than a preset threshold, then determining that the iteration is completed, and advancing to the next time step until the time advancement meets the preset conditions; outputting corresponding coupling physical quantities to complete the motion deformation coupling analysis of the flexible aircraft; the coupling physical quantities include the six-degree-of-freedom motion state, node displacement, node velocity, node acceleration, internal stress distribution of the flexible aircraft, and displacement, velocity and acceleration of each node after superposition of the motion deformation of the flexible aircraft in the inertial system corresponding to the flexible aircraft at each time step.

[0159] Furthermore, the present application also discloses an electronic device. Fig.10 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.

[0160] Fig.10The 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 flexible aircraft motion deformation coupling analysis method disclosed in any of the aforementioned embodiments. In addition, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0161] 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.

[0162] In addition, the memory 22 as a carrier for storing resources 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.

[0163] The operating system 221 is used to manage and control the hardware devices and computer program 222 on the electronic device 20, and can be Windows Server, Netware, Unix, Linux, etc. In addition to the computer program that can be used to complete the flexible aircraft motion deformation coupling analysis method performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include computer programs that can be used to complete other specific tasks.

[0164] 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 flexible aircraft motion deformation coupling analysis method disclosed above is implemented. For the specific steps of the method, reference may be made to the corresponding contents disclosed in the above embodiments, and no further description will be given here.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] 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 flexible aircraft motion deformation coupling analysis method, characterized in that: include: Constructing a finite element model of a flexible aircraft, and determining the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to a body coordinate system based on a finite element model grid and material parameters of the flexible aircraft; the finite element model is a model constructed based on a three-node shell unit; Calculating the resultant force and resultant moment of the flexible aircraft relative to the body coordinate system according to the finite element load, and determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment; Determine the inertial acceleration field and the corresponding inertial load of the flexible aircraft relative to the body coordinate system in the current time step based on the six-degree-of-freedom motion state, perform finite element deformation solution of the flexible aircraft in the body coordinate system through the inertial load and the converted external load determined based on the target transformation matrix, and obtain the corresponding deformation result; The inertia tensor, the resultant force and the resultant moment are updated based on the deformation result, and motion deformation coupling and time advancement are performed according to the corresponding updated inertia tensor, updated resultant force and updated resultant moment using the target coupling strategy and time advancement mechanism. When the time advancement meets the preset conditions, the corresponding coupling physical quantities are output to complete the motion deformation coupling analysis of the flexible aircraft.

2. The flexible aircraft motion deformation coupling analysis method according to claim 1 is characterized in that: The method of determining the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to a body coordinate system based on a finite element model grid and material parameters of the flexible aircraft comprises: Determine the mass of each shell element according to the area, thickness and material density of the shell element of the finite element model, and add up the masses of each shell element to obtain the mass of the flexible aircraft; The inertia tensor of the flexible aircraft relative to the body coordinate system is determined based on a preset inertia tensor calculation formula and the rotational inertia of the flexible aircraft relative to the body coordinate system; the preset inertia tensor calculation formula is: ； in, is the inertia tensor of the flexible aircraft relative to the body coordinate system; , and are respectively the moments of inertia of the flexible aircraft relative to the x-axis, y-axis and z-axis of the body coordinate system; , and The elements other than are non-diagonal elements, and the non-diagonal elements are the inertia products of the flexible aircraft relative to the axes of the body coordinate system; The process of determining the moment of inertia of the flexible aircraft relative to the body coordinate system includes: The target moments of inertia of each shell element relative to each axis of the body coordinate system are accumulated to determine the moment of inertia of the flexible aircraft relative to the body coordinate system; wherein the expression of the target moment of inertia is: ； in, is the target moment of inertia; is the area of ​​the shell element; is the shell element thickness; is the area element; is the density of the material; is the position vector of the integral differential element relative to the body coordinate system, For The unit direction vector of the coordinate axis of the body coordinate system corresponding to the value; Furthermore, the process of determining the product of inertia of the flexible aircraft relative to each axis of the body coordinate system includes: The target inertia products of the shell elements relative to the axes of the body coordinate system are accumulated to determine the inertia products of the flexible aircraft relative to the axes of the body coordinate system; wherein the expression of the target inertia product is: ； in, is the target product of inertia; is the area of ​​the shell element; is the shell element thickness; is the area element; is the density of the material.

3. The flexible aircraft motion deformation coupling analysis method according to claim 1, characterized in that: The calculating the resultant force and the resultant moment of the flexible aircraft relative to the body coordinate system according to the finite element load comprises: The resultant force of the flexible aircraft relative to the body coordinate system is calculated according to a preset resultant force calculation formula and the finite element load; the preset resultant force calculation formula is: ； in, is the finite element load vector; is the resultant force; The resultant moment of the flexible aircraft relative to the body coordinate system is calculated according to a preset resultant moment calculation formula and the finite element load; the preset resultant moment calculation formula is: ； in, is the finite element load vector; is the resultant moment; is the position vector of the load application point relative to the body coordinate system.

4. The flexible aircraft motion deformation coupling analysis method according to claim 1, characterized in that: The method of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment includes: determining the motion displacement of the flexible aircraft according to the product of the mass and the translational acceleration of the flexible aircraft; The speed and acceleration of the flexible aircraft are determined according to the preset speed and acceleration calculation formula, the inertia tensor and the resultant moment; the preset speed and acceleration calculation formula is: ； in, is the speed of the flexible aircraft; is the acceleration of the flexible aircraft; is the resultant moment; is the inertia tensor of the flexible aircraft relative to the body coordinate system.

5. The flexible aircraft motion deformation coupling analysis method according to claim 1, characterized in that: The step of determining the inertial acceleration field and the corresponding inertial load of the flexible aircraft relative to the body coordinate system in the current time step based on the six-degree-of-freedom motion state includes: A vector of each inertial acceleration based on the six-degree-of-freedom motion state; the inertial acceleration includes translational acceleration, rotational acceleration, centripetal acceleration and Coriolis acceleration; Determine the sum of the vectors of the inertial accelerations as the inertial acceleration field of the flexible aircraft relative to the body coordinate system; The inertial load of the corresponding mass point of the flexible aircraft relative to the body coordinate system is determined by the inertial acceleration field and the mass of the mass point infinitesimal element.

6. The flexible aircraft motion deformation coupling analysis method according to claim 1, characterized in that: The step of performing finite element deformation solution on the flexible aircraft in the body coordinate system by using the inertial load and the converted external load determined based on the target transformation matrix to obtain corresponding deformation results includes: Determine the angle between the body coordinate system and the inertial system according to the rotational displacement of the flexible aircraft at the current time step, and determine the target transformation matrix of the inertial system to the body coordinate system using the angle; The external load corresponding to the inertial system is transformed by using the target transformation matrix to obtain the transformed external load corresponding to the body coordinate system; The converted external load is superimposed on the inertial load, and the finite element deformation of the flexible aircraft in the body coordinate system is solved according to the corresponding superimposed load to obtain the corresponding deformation result.

7. The flexible aircraft motion deformation coupling analysis method according to any one of claims 1 to 6, characterized in that: The method utilizes the target coupling strategy and the time advancement mechanism and performs motion deformation coupling and time advancement according to the corresponding updated inertia tensor, the updated resultant force and the updated resultant moment, and outputs the corresponding coupling physical quantity when the time advancement meets the preset conditions to complete the motion deformation coupling analysis of the flexible aircraft, including: Determining the current target coupling strategy; If the current target coupling strategy is loose coupling, the next time step is directly advanced, and the step of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment is re-executed based on the updated inertia tensor, the updated resultant force and the updated resultant moment, until the time advancement meets the preset condition; If the current target coupling strategy is tight coupling, then based on the updated inertia tensor, the updated resultant force and the updated resultant moment, the step of determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment is re-executed, and coupling iteration is performed until the difference between the result of the current iteration step and the result of the previous iteration step is less than a preset threshold value, then it is determined that the iteration is completed, and the next time step is advanced until the time advancement meets the preset condition; Output corresponding coupling physical quantities to complete the motion deformation coupling analysis of the flexible aircraft; the coupling physical quantities include the six-degree-of-freedom motion state, node displacement, node velocity, node acceleration, internal stress distribution of the flexible aircraft, and the displacement, velocity and acceleration of each node after the motion deformation of the flexible aircraft in the inertial system is superimposed, corresponding to the flexible aircraft at each time step.

8. A flexible aircraft motion deformation coupling analysis device, characterized in that: include: A mass and inertia tensor determination module, used to construct a finite element model of a flexible aircraft, and determine the mass of the flexible aircraft and the inertia tensor of the flexible aircraft relative to a body coordinate system based on a finite element model grid and material parameters of the flexible aircraft; the finite element model is a model constructed based on a three-node shell unit; a motion state determination module, for calculating the resultant force and resultant moment of the flexible aircraft relative to the body coordinate system according to the finite element load, and determining the six-degree-of-freedom motion state of the flexible aircraft in the current time step by using the mass, the inertia tensor and the resultant moment; A deformation result acquisition module is used to determine the inertial acceleration field and the corresponding inertial load of the flexible aircraft relative to the body coordinate system in the current time step based on the six-degree-of-freedom motion state, and perform finite element deformation solution of the flexible aircraft in the body coordinate system through the inertial load and the converted external load determined based on the target transformation matrix to obtain the corresponding deformation result; The motion deformation coupling analysis completion module is used to update the inertia tensor, the resultant force and the resultant moment based on the deformation result, use the target coupling strategy and time advancement mechanism and perform motion deformation coupling and time advancement according to the corresponding updated inertia tensor, updated resultant force and updated resultant moment, and when the time advancement meets the preset conditions, output the corresponding coupling physical quantity to complete the motion deformation coupling analysis of the flexible aircraft.

9. 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 flexible aircraft motion deformation coupling analysis method as described in any one of claims 1 to 7.

10. 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 flexible aircraft motion deformation coupling analysis method according to any one of claims 1 to 7 is implemented.

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