Composite truss UAV fuselage structure design method, electronic equipment and media

Abstract

The present application discloses a composite material truss UAV fuselage structure design method, electronic equipment and medium. The method may include: determining the bending moment distributed along the fuselage, and then determining the initial geometric parameters of the truss structure; calculating the inertia moment and the member strain according to the initial geometric parameters of the truss structure; calculating the equivalent material parameters, and then establishing a finite element model of the truss structure; establishing a full-scale fuselage truss structure model, and calculating the stability of a single compression rod; calculating the overall stability of the truss according to the finite element model, and completing the truss fuselage design. The present invention is used for the design of a flexible UAV fuselage structure with small loads and large deformations, and realizes the maximum utilization of material properties to make the UAV fuselage structure as light as possible. On the basis of ensuring the rigidity, strength and stability of the fuselage, it solves the problem of overweight caused by the existing fuselage design method in the flexible structure with small loads and large deformations.

Description

Technical Field

[0001] The present invention relates to the field of unmanned aerial vehicle (UAV) structural design, and more specifically, to a composite material truss UAV fuselage structural design method, electronic equipment, and a medium. Background Art

[0002] Since drones have extremely stringent requirements on structural weight, it is necessary to fully utilize the strength of materials. Especially when designing large-scale and large-deformation structures, truss structures can save materials compared to web beams, while reducing their own weight and increasing stiffness.

[0003] The traditional UAV fuselage structure is mainly a semi-monocoque frame, beam, and skin wall panel structure. This structure is mostly suitable for high stress and small deformation structures. However, for small load and large deformation flexible structures, this traditional design method is difficult to achieve design weight closure and often exceeds the given weight by a large margin.

[0004] Therefore, it is necessary to develop a composite truss UAV fuselage structure design method, electronic equipment and medium.

[0005] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. Summary of the Invention

[0006] The present invention proposes a composite material truss UAV fuselage structure design method, electronic equipment and medium, which can be used for the design of a flexible UAV fuselage structure with small loads and large deformations, and maximizes the use of material properties to make the UAV fuselage structure as light as possible. On the basis of ensuring the rigidity, strength and stability of the fuselage, it solves the problem of overweight caused by the existing fuselage design method in the flexible structure with small loads and large deformations.

[0007] In a first aspect, an embodiment of the present disclosure provides a method for designing a composite material truss UAV fuselage structure, comprising:

[0008] Determine the bending moment distribution along the fuselage and then determine the initial geometric parameters of the truss structure;

[0009] Calculating the moment of inertia and member strain according to the initial geometric parameters of the truss structure;

[0010] Calculate equivalent material parameters and then establish a finite element model of the truss structure;

[0011] Establish a full-scale fuselage truss structure model and calculate the stability of a single strut;

[0012] The overall stability of the truss is calculated based on the finite element model to complete the truss fuselage design.

[0013] Preferably, the initial geometric parameters of the truss structure include truss height, truss width, outer diameter of the longitudinal member, and inner diameter of the longitudinal member.

[0014] Preferably, the moment of inertia is:

[0015]

[0016] Among them, I x is the x-direction moment of inertia, I y is the moment of inertia in the y direction.

[0017] Preferably, the rod should be:

[0018]

[0019] Among them, ε zx Calculate the strain in the x-direction, ε zy is the calculated strain in the y direction, and E is the equivalent elastic modulus of the composite material.

[0020] Preferably, the equivalent material parameters are:

[0021]

[0022] in, A 66 =G LT , E L 、E T is the elastic modulus in the single layer direction, G LT is the shear modulus in the single layer direction, E x 、E y is the equivalent material parameter, A is the stiffness matrix parameter, h is the rod wall thickness, μ LT 、μ TL is the Poisson's ratio of a single layer in different directions.

[0023] Preferably, the beam elements and shell elements at the nodes of the full-size fuselage truss structure model are connected using MPC elements, and the truss nodes and main load-bearing members are established through the shell elements.

[0024] Preferably, the stability of a single compression rod is calculated using Euler's formula:

[0025]

[0026] Preferably, calculating the overall stability of the truss according to the finite element model and completing the truss fuselage design includes:

[0027] If the overall stability of the truss meets the design requirements, the truss fuselage design is completed. If not, the finite element model is re-established for iteration.

[0028] In a second aspect, an embodiment of the present disclosure further provides an electronic device, the electronic device comprising:

[0029] a memory storing executable instructions;

[0030] A processor runs the executable instructions in the memory to implement the composite material truss UAV fuselage structure design method.

[0031] In a third aspect, an embodiment of the present disclosure further provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the composite material truss UAV fuselage structure design method.

[0032] Its beneficial effects are:

[0033] (1) The present invention combines engineering and finite element methods to solve the design and calculation problems of composite truss structures more efficiently and accurately.

[0034] (2) Since parameter equivalence is performed in the finite element modeling process, parametric modeling of the truss fuselage can be performed, which greatly improves the modeling efficiency and shortens the design iteration cycle.

[0035] (3) The present invention can fully utilize the strength properties of the material, especially in the design of large-scale and large-deformation structures, to minimize the deadweight and increase the rigidity of the fuselage.

[0036] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be described in detail in the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0038] Figure 1 A flow chart showing the steps of a composite material truss UAV fuselage structure design method according to one embodiment of the present invention.

[0039] Figure 2 A schematic diagram of an end face of a truss fuselage structure according to an embodiment of the present invention is shown.

[0040] Figure 3 A schematic diagram of selecting two spans of a fuselage truss according to an embodiment of the present invention is shown.

[0041] Figure 4 A schematic diagram of a finite element model of a truss UAV fuselage structure according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0043] To facilitate understanding of the solutions and effects of the embodiments of the present invention, three specific application examples are given below. Those skilled in the art should understand that these examples are only for facilitating understanding of the present invention, and any specific details thereof are not intended to limit the present invention in any way.

[0044] Example 1

[0045] Figure 1 A flow chart showing the steps of a composite material truss UAV fuselage structure design method according to one embodiment of the present invention.

[0046] like Figure 1 As shown, the composite truss UAV fuselage structure design method includes:

[0047] Step 101, determining the bending moment distributed along the fuselage, and then determining the initial geometric parameters of the truss structure;

[0048] Step 102, calculating the moment of inertia and member strain based on the initial geometric parameters of the truss structure;

[0049] Step 103, calculating equivalent material parameters, and then establishing a finite element model of the truss structure;

[0050] Step 104: Establish a full-scale fuselage truss structure model and calculate the stability of a single strut;

[0051] Step 105 , calculating the overall stability of the truss based on the finite element model, and completing the truss fuselage design.

[0052] In one example, the initial geometric parameters of the truss structure include truss height, truss width, longitudinal member outer diameter, and longitudinal member inner diameter.

[0053] In one example, the moment of inertia is:

[0054]

[0055] Among them, I x is the x-direction moment of inertia, I y is the moment of inertia in the y direction.

[0056] In one example, the member strains become:

[0057]

[0058] Among them, ε zx Calculate the strain in the x-direction, ε zy is the calculated strain in the y direction, and E is the equivalent elastic modulus of the composite material.

[0059] In one example, the equivalent material parameters are:

[0060]

[0061] in, A 66 =G LT , E L 、E T is the elastic modulus in the single layer direction, G LT is the shear modulus in the single layer direction, E x 、E y is the equivalent material parameter, A is the stiffness matrix parameter, h is the rod wall thickness, μ LT 、μ TL is the Poisson's ratio of a single layer in different directions.

[0062] In one example, the beam elements and shell elements at the nodes of the full-scale fuselage truss structure model are connected using MPC elements, and the truss nodes and main load-bearing members are established through the shell elements.

[0063] In an example, the stability of a single strut is calculated using Euler's formula:

[0064]

[0065] In one example, the overall stability of the truss is calculated based on the finite element model. The completed truss fuselage design includes:

[0066] If the overall stability of the truss meets the design requirements, the truss fuselage design is completed. If not, the finite element model is re-established for iteration.

[0067] Specifically, according to the load (horizontal tail and vertical tail load) and the stiffness design requirements, the bending moment M distributed along the fuselage is calculated. x 、M y .

[0068] Figure 2 A schematic diagram of an end face of a truss fuselage structure according to an embodiment of the present invention is shown.

[0069] According to the fuselage bending moment distribution, the initial geometric parameters of the truss structure are determined by engineering calculation methods, including truss height H, truss width L, longitudinal member outer diameter D, and longitudinal member inner diameter d, such as Figure 2shown.

[0070] Calculate the moment of inertia in different directions as:

[0071]

[0072] Among them, I x is the x-direction moment of inertia, I y is the moment of inertia in the y direction.

[0073] Calculate the member strain as:

[0074]

[0075] Among them, ε zx Calculate the strain in the x-direction, ε zy is the strain calculated in the y direction, and E is the equivalent elastic modulus of the composite material. Since the allowable strain values ​​used are equal,

[0076] ε zy =ε zx =[ε]

[0077] Where [ε] is the allowable strain value of the member, which is obtained based on tests of different material systems or strength design requirements of engineering projects.

[0078] Truss nodes are generally nodes with a certain degree of rigidity. Due to the influence of node rigidity, rod bending and axial additional force occur. The additional force needs to take into account the axial deformation of the rod. The finite element model of the truss structure is established based on the preliminary obtained rod geometric dimensions and layup.

[0079] Composite rods are simulated using beam elements (bar elements), and the equivalent material parameters are calculated based on the material and ply information. The equivalent material parameters are:

[0080]

[0081] in, A 66 =G LT , E L 、E T is the elastic modulus in the single layer direction, G LT is the shear modulus in the single layer direction, E x 、E y is the equivalent material parameter, A is the stiffness matrix parameter, h is the rod wall thickness, μ LT 、μ TL is the Poisson's ratio of a single layer in different directions.

[0082] The equivalent shear modulus is

[0083] G xy =A 66 / h

[0084] The equivalent Poisson's ratio is

[0085]

[0086] Figure 3 A schematic diagram of selecting two spans of a fuselage truss according to an embodiment of the present invention is shown.

[0087] A full-scale fuselage truss structure model was established, and static and stability analysis was performed on the model. The beam elements (bar elements) and shell elements (shell elements) at the truss nodes were connected using MPC (RBE2) elements. Figure 3 As shown in the figure, shell elements are used to establish truss nodes and main load-bearing members.

[0088] Extract the beam element (bar element) force (FORCE) and calculate the stress and strain of the bar:

[0089]

[0090] The member strain and critical pressure are calculated by the beam unit force, the equivalent elastic modulus of the composite material, and the effective length of the compression rod. The effective length of the compression rod can be determined through experiments. The stability of a single compression rod is calculated using the Euler formula:

[0091]

[0092] Figure 4 A schematic diagram of a finite element model of a truss UAV fuselage structure according to an embodiment of the present invention is shown.

[0093] like Figure 4 As shown in the figure, the overall stability of the truss is obtained through the calculation of the overall finite element model, and all the calculation results are judged to see whether they meet the design requirements. If so, the truss fuselage design is completed. If not, according to the calculation results, the ply and geometric parameters are adjusted in a targeted manner, and the finite element model is re-established for iteration to finally achieve design convergence.

[0094] Ground tests on the UAV fuselage design using this method have shown that compared with traditional design methods, the application of this method has a significant weight reduction effect and the design iteration speed is increased by more than 30%.

[0095] Example 2

[0096] The present disclosure provides an electronic device, which includes: a memory storing executable instructions; and a processor running the executable instructions in the memory to implement the above-mentioned composite material truss UAV fuselage structure design method.

[0097] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0098] The memory is used to store non-transitory computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), a hard disk, flash memory, etc.

[0099] The processor may be a central processing unit (CPU) or other form of processing unit having data processing capability and / or instruction execution capability, and may control other components in the electronic device to perform desired functions. In one embodiment of the present disclosure, the processor is used to execute the computer-readable instructions stored in the memory.

[0100] Those skilled in the art should understand that in order to solve the technical problem of how to obtain a good user experience, this embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the scope of protection of this disclosure.

[0101] For detailed description of this embodiment, please refer to the corresponding description in the aforementioned embodiments, which will not be repeated here.

[0102] Example 3

[0103] An embodiment of the present disclosure provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for designing a composite material truss UAV fuselage structure is implemented.

[0104] According to an embodiment of the present disclosure, a computer-readable storage medium stores non-transitory computer-readable instructions, which, when executed by a processor, execute all or part of the steps of the aforementioned methods of the embodiments of the present disclosure.

[0105] The above-mentioned computer-readable storage media include, but are not limited to, optical storage media (e.g., CD-ROMs and DVDs), magneto-optical storage media (e.g., MOs), magnetic storage media (e.g., magnetic tapes or mobile hard disks), media with built-in rewritable non-volatile memory (e.g., memory cards), and media with built-in ROM (e.g., ROM cartridges).

[0106] Those skilled in the art should understand that the above description of the embodiments of the present invention is only for the purpose of illustrative purposes only to illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any given examples.

[0107] While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A composite material truss UAV fuselage structure design method, characterized in that: include: Determine the bending moment distribution along the fuselage and then determine the initial geometric parameters of the truss structure; Calculating the moment of inertia and member strain according to the initial geometric parameters of the truss structure; Calculate equivalent material parameters and then establish a finite element model of the truss structure; Establish a full-scale fuselage truss structure model and calculate the stability of a single strut; Calculate the overall stability of the truss based on the finite element model and complete the truss fuselage design; Wherein, the moment of inertia is: in, is the x-direction moment of inertia, is the y-direction moment of inertia; The rod strain is: in, Calculate the strain in the x-direction, Calculate the strain in the y direction, is the equivalent elastic modulus of the composite material; Wherein, the equivalent material parameters are: in, , 、 is the elastic modulus in the single layer direction, is the shear modulus in the single layer direction, 、 is the equivalent material parameter, A is the stiffness matrix parameter, is the rod wall thickness, 、 is the Poisson's ratio of a single layer in different directions.

2. The composite material truss UAV fuselage structure design method according to claim 1, wherein: The initial geometric parameters of the truss structure include truss height, truss width, longitudinal member outer diameter, and longitudinal member inner diameter.

3. The composite material truss UAV fuselage structure design method according to claim 1, wherein: The beam elements and shell elements at the nodes of the full-scale fuselage truss structure model are connected using MPC elements, and the truss nodes and main load-bearing members are established through the shell elements.

4. The composite material truss UAV fuselage structure design method according to claim 1, wherein: Euler's formula is used to calculate the stability of a single compression rod: 。 5. The composite material truss UAV fuselage structure design method according to claim 1, wherein: Calculate the overall stability of the truss based on the finite element model and complete the truss fuselage design including: If the overall stability of the truss meets the design requirements, the truss fuselage design is completed. If not, the finite element model is re-established for iteration.

6. An electronic device, characterized in that: The electronic device comprises: a memory storing executable instructions; A processor that runs the executable instructions in the memory to implement the composite material truss UAV fuselage structure design method according to any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the composite material truss UAV fuselage structure design method according to any one of claims 1 to 5.

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