Disclosure of Invention
The method aims to provide a whole structure design method and a whole structure design system for the hypersonic aircraft, and the method can determine the structural layout and the size parameters by taking the ballistic data and the pneumatic database as input through a structure optimization technology, solve the problem that the structural layout and the size parameters are difficult to determine in the initial design stage of the hypersonic aircraft, and achieve the aims of initial design of an aircraft structure system and realization of structure lightweight.
In order to achieve the above object, the present invention provides the following technical solutions.
A design method for the whole structure of a hypersonic aircraft comprises the following steps:
taking typical ballistic and aerodynamic data of the hypersonic aircraft as input, analyzing the bearing characteristics of the aircraft reference structure, and determining the design state of each part of the aircraft structure;
determining the optimal layout and size parameters of the structural components by using a hybrid optimization method according to the design state of each structural component of the aircraft;
and establishing a finite element model of the whole structure of the hypersonic aircraft according to the optimal layout and the size parameters, carrying out finite element analysis under the design load to carry out detailed structure design, and evaluating the optimization result.
As a further improvement of the invention, the specific steps of determining the design state of each component of the aircraft structure are as follows:
extracting characteristic points according to the ballistic characteristics of the aircraft so as to analyze aerodynamic load at the characteristic points of the aircraft;
designing a reference structure scheme of the aircraft, establishing a finite element model of the aircraft reference structure, and converting the pneumatic load at the characteristic point into structural node force to act on the finite element model in an interpolation mode;
and calculating the structural stress of each structural component of the aircraft at different characteristic points by using a finite element analysis method, and determining the design state of each component of the aircraft structure by taking the maximum structural stress as a selection principle.
As a further improvement of the invention, the concrete steps of determining the optimal layout and dimension parameters of the structural components by using the hybrid optimization method are as follows:
introducing a dimension variable into a traditional basic structure layout optimization problem, and constructing a structure layout and dimension parameter hybrid optimization model; a genetic algorithm is used as a basic searching method, a gene coding structure supporting unified description of 0-1 type layout variables and continuous type size variables is designed, and a structure layout and size mixed optimization solving process is established.
As a further improvement of the invention, the hybrid optimization solution flow comprises the following steps: genetic operation, fitness function calculation and convergence judgment;
in the genetic operation part, dividing chromosomes into layout variables and size variables according to the characteristics of a structural layout and size mixed optimization problem, and respectively performing intersection and variation to generate new individuals;
in the fitness function calculating part, an optimization frame needs to update the layout of a structure and corresponding structure size parameters according to the value ranges of layout variables and size variables;
in the convergence judging section, the genetic algorithm completes convergence according to a corresponding convergence criterion.
As a further improvement of the present invention, the fitness function calculation specifically includes the following steps:
(a) Updating the finite element model: updating the structure finite element model is mainly completed by a script program of finite element software, and by writing the finite element model of the base structure, the structure layout and the structure size parameters are changed according to the value ranges of the topological variable and the size variable, and a new structure finite element model and a new structure quality file are automatically generated; the structure quality file comprises structure quality information, and the structure quality is obtained in a program reading mode and is used as a target function;
(b) Finite element analysis: the optimization frame recalculates the strength and the rigidity of the newly generated finite element model, and obtains the maximum stress value of the structural component according to the calculation result;
(c) And (3) fitness function calculation: substituting the mass and maximum stress value of the structure into the equation
To be provided with
Obtaining a series of updated finite element models as the fitness function of the population individual
As a further improvement of the present invention, in the step of evaluating the optimization result, if the optimization result is good, the aircraft structural system is designed in detail, otherwise, the basic structural model of the aircraft structural component is changed, and the layout and size mixed optimization design of the component is performed again.
A hypersonic aircraft complete machine structure design system comprises:
the design state determining unit is used for analyzing the bearing characteristics of the aircraft reference structure by taking the typical ballistic and aerodynamic data of the hypersonic aircraft as input, and determining the design state of each part of the aircraft structure;
an optimal parameter determination unit for determining optimal layout and dimensional parameters of the structural components by means of a hybrid optimization method according to the design state of the individual structural components of the aircraft;
and the evaluation optimization unit is used for establishing a finite element model of the whole structure of the hypersonic aircraft according to the optimal layout and the size parameters, carrying out finite element analysis under the design load to carry out detailed structure design and evaluating the optimization result.
An electronic device comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the computer program to realize the steps of the hypersonic flight vehicle overall structure design method.
A computer-readable storage medium, which stores a computer program that, when being executed by a processor, implements the steps of the hypersonic aircraft overall structure design method.
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a whole structure design method of a hypersonic aircraft, and provides a structural layout and size mixed optimization method of subsystem components aiming at the initial structure design of the hypersonic aircraft. The difference between the invention and the prior art is as follows: 1) In the aspect of determining the optimized design state, the method can simultaneously realize the simplified calculation of the strength/rigidity and the quick determination of the initial design state by respectively establishing the finite element models of the base structures of the parts of the aircraft and inputting the characteristic point data of the typical trajectory for analysis; 2) In the aspect of structural component optimization design, most of the existing optimization design processes adopt a structural layout and size sequence optimization method, by introducing a size variable in the traditional basic structural layout optimization process, a gene coding structure supporting unified description of 0-1 type layout variables and continuous type size variables is designed, a structural layout and size mixed optimization solving process is constructed, the optimal structural layout and size parameters of structural components can be obtained at the same time, and the rapid design of an aircraft initial structural system is realized; 3) In the aspect of bearing efficiency, the bearing efficiency of the part structure obtained by the prior art is lower, and the optimal subsystem part structure layout and size parameters are obtained through structure optimization design, so that the structure quality can be reduced, and the bearing efficiency can be improved. The method can determine the initial structural layout and corresponding size parameters of the aircraft at the initial design stage of the hypersonic aircraft, reduces the design time of an aircraft structural system, and can provide relatively reliable structural quality data for the ballistic design of the aircraft.
Detailed Description
In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.
It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a single embodiment.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The invention provides a design method of a whole hypersonic aircraft structure. The structural design process mainly comprises three stages of design state determination, structural layout and size optimization and detailed structural design.
S100, the main purpose of determining the structural design state is to analyze the load bearing characteristics of the aircraft reference structure by taking the typical ballistic and aerodynamic data of the hypersonic aircraft as input, and provide a basis for the subsequent structural optimization design. In the stage, characteristic points such as a maximum dynamic pressure point, a maximum transverse/longitudinal overload point, a maximum lifting force and resistance point and the like are extracted according to the ballistic characteristics of the aircraft, so that the aerodynamic load at the characteristic points of the aircraft is analyzed. Designing a reference structure scheme of the aircraft, establishing a finite element model of the aircraft reference structure, and converting the aerodynamic load at the characteristic point into structural node force to act on the finite element model in an interpolation mode. And calculating the structural stress of each structural component of the aircraft at different characteristic points by using a finite element analysis method, and determining the design state of each component of the aircraft structure by taking the maximum structural stress as a selection principle.
S200, the purpose of the mixed optimization of the structural layout and the size is to determine the optimal layout and size parameters of the structural components by using a structural optimization technology according to the design state of each structural component of the aircraft. Therefore, the invention provides a hybrid optimization method capable of simultaneously realizing the optimization of the structural layout and the dimensional parameters of the aircraft, which comprises the following steps: introducing a dimension variable into a traditional base structure layout optimization problem, and constructing a structure layout and dimension parameter hybrid optimization model; a genetic algorithm is used as a basic searching method, a gene coding structure supporting unified description of 0-1 type layout variables and continuous type size variables is designed, and a structure layout and size mixed optimization solving process is established.
The solving process can be divided into three parts, namely genetic operation, fitness function calculation and convergence judgment.
S201, in the genetic operation part, the chromosome is divided into a layout variable and a size variable according to the characteristics of the structural layout and size mixed optimization problem, and the layout variable and the size variable are respectively crossed and mutated to generate a new individual.
S202, in the fitness function calculating part, the optimization framework needs to update the layout of the structure and corresponding structure size parameters according to the value ranges of the layout variables and the size variables. The invention adopts a mode of secondary software development to realize the functions, and the part mainly comprises the following three steps.
(a) Updating the finite element model: the updating of the structural finite element model is mainly completed by a script program of finite element software. The module automatically generates a new structure finite element model and a new structure quality file by writing in a finite element model of a base structure and changing structure layout and structure size parameters according to the value ranges of the topological variable and the size variable. The structure quality file comprises structure quality information, and the structure quality is obtained in a program reading mode and is used as a target function;
(b) Finite element analysis: the optimization frame recalculates the strength and rigidity of the newly generated finite element model, and obtains the maximum stress value of the structural component according to the calculation result;
(c) And (3) fitness function calculation: substituting the mass and maximum stress value of the structure into the equation
To be provided with
As the fitness function of the population individual, a series of updated finite element models are obtained
S203, for the convergence judgment of the optimization process, the genetic algorithm can complete convergence according to the corresponding convergence criterion.
S300, structural detailed design stage: and determining the layout and size parameters of the structural components of the aircraft by adopting a structural layout and size mixed optimization method, establishing a finite element model of the whole structure of the hypersonic aircraft, carrying out finite element analysis under design load, and evaluating an optimization result. And if the optimization result is good, the aircraft structure system is designed in detail, otherwise, the basic structure model of the aircraft structure component is changed, and the layout and size mixed optimization design of the component is carried out again.
Examples
In order to clearly show the advantages of the present invention, the following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings.
Step (1): an optimal design state of the structural component is determined.
As shown in FIG. 1, the invention firstly divides the hypersonic aircraft into two parts of a fuselage and a wing, and establishes a base structure finite element model of the whole aircraft and the parts. Secondly, determining structural design characteristic points such as a maximum overload point, a maximum dynamic pressure point, a maximum lifting coefficient point and the like according to the ballistic characteristics of the aircraft, analyzing the stress condition of the whole aircraft structure at the structural design characteristic points, and determining the optimal design state of the wings and the fuselage of the aircraft by taking the maximum structural stress as a selection principle.
Step (2): and (4) optimally designing the structural component.
The structural layout and dimensional parameters of the wing and fuselage are optimized in turn using the method shown in fig. 2. The method represents whether the wing spars, the wing ribs and the fuselage frames are deleted in the optimization process in a form of 0/1, represents the structural sizes of the wing spars, the wing ribs and the fuselage frames in a real number form, further represents the structural layout and the size parameters of the wings and the fuselage in a chromosome form as shown in figure 4, adopts a genetic algorithm for optimization, and determines the final form. Because the connection relationship exists between the wing and the fuselage, the invention adopts a separation strategy as shown in figure 6 to respectively optimize the wing and the fuselage. When the wing is optimized, the influence of the fuselage on the wing is simulated under the condition of a fixed support boundary, and the influence of the wing on the fuselage is simulated by the support reaction force at the wing root of the optimal structure of the wing.
And (3): and (5) carrying out finite element analysis and evaluation on the structure of the whole machine.
The adoption of the separation optimization strategy for the wings and the fuselage can cause the difference between the structural stress level of the wings and the fuselage and the real situation, so finite element analysis and evaluation need to be carried out on the whole structure of the aircraft to verify the correctness of the separation optimization strategy.
And (4): detailed design of wing and fuselage structures.
In order to improve the optimization efficiency, the structural layout and the size of the wing and the fuselage are optimized in a mixed mode by adopting a simplified finite element model: the skin, fuselage frames, spars and ribs of an aircraft are simulated in shell units, the fuselage stringers, etc. in beam units. And the detailed design of the aircraft structure establishes a more detailed finite element model according to the structure layout and size mixed optimization result, and performs finite element analysis.
The structural optimization method provided by the invention mainly aims to determine the structural layout and size parameters of the hypersonic aircraft by adopting a structural optimization technology according to the typical trajectory and aerodynamic load of the hypersonic aircraft, further determine an initial design scheme of an aircraft structural system and provide structural quality parameters for the aircraft trajectory design.
Another objective of the present invention is to provide a system for designing the overall structure of a hypersonic aircraft, which includes:
the design state determining unit is used for analyzing the bearing characteristics of the aircraft reference structure by taking the typical ballistic and aerodynamic data of the hypersonic aircraft as input, and determining the design state of each part of the aircraft structure;
an optimal parameter determination unit for determining optimal layout and dimensional parameters of the structural components by means of a hybrid optimization method according to the design state of each structural component of the aircraft;
and the evaluation optimization unit is used for establishing a finite element model of the whole structure of the hypersonic aircraft according to the optimal layout and the size parameters, performing finite element analysis under design load to design the structure in detail, and evaluating an optimization result.
A third object of the present invention is to provide an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the complete hypersonic aircraft structural design method when executing the computer program.
A fourth object of the present invention is to provide a computer-readable storage medium, which stores a computer program, and the computer program, when executed by a processor, implements the steps of the complete hypersonic aircraft structure design method.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.