CN114707286A

CN114707286A - 3D printed aeroelastic model with similar structure and design method thereof

Info

Publication number: CN114707286A
Application number: CN202111434937.6A
Authority: CN
Inventors: 胡家亮; 吴江鹏; 脱朝智
Original assignee: Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Current assignee: Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2022-07-05

Abstract

The application provides a method for designing a pneumatic elastic model with a similar structure, which comprises the following steps: scaling the real airplane component structure according to the design scale ratio; determining the structural shape and size of the aircraft component after scaling according to the designed rigidity ratio; comparing the deviation between the structural weight and the actual aircraft component scaling weight according to the designed weight ratio, and calculating and determining the counterweight position, the counterweight weight and the counterweight body size through weight distribution; checking whether the model meets similar requirements through simulation analysis, if not, adjusting the structural shape or size of the airplane part after counterweight or scaling until the model meets the similar requirements; and printing the model by a 3D printing technology to complete the construction of the aeroelastic model. The model constructed by the method can meet the requirements of the aeroelastic model on the structure arrangement, the aeroelastic appearance, the rigidity and the weight distribution simulation, is accurate in simulation, improves the precision and the reliability of the aeroelastic test, and is small in processing workload and difficulty and short in period.

Description

3D printed aeroelastic model with similar structure and design method thereof

Technical Field

The application belongs to the technical field of aeroelasticity of airplanes, and particularly relates to a 3D printed aeroelasticity model with a similar structure and a design method thereof.

Background

Aeroelastic dynamic stability is one of the important problems that must be faced in aircraft design, and accidents caused by insufficient aeroelastic dynamic stability often lead to the death of the aircraft. The aeroelasticity test is a necessary link in the research and design of aeroelasticity dynamic stability, and is an important means for predicting and verifying the aeroelasticity characteristic of the airplane and improving the design, and the verification method comprises a wind tunnel test, a model free flight test and the like. The aeroelastic model used in the test needs to accurately scale and simulate the real aerodynamic shape, rigidity and weight distribution of the airplane so as to meet the requirements that the dynamic characteristics and the aeroelastic dynamic stability are similar to those of the real airplane in proportion.

The current aeroelastic model is limited by a plurality of conditions such as processing technology, material characteristics, size requirements, rigidity requirements, weight requirements and the like in the design process, and only can meet the requirement of structural dynamics similarity, namely the structural dynamics of the model is similar to that of a real airplane or part in proportion. The model adopts a simplified metal beam frame as a bearing structure, removes partial structure of a real structure and carries out equivalent design through the principle of rigidity and the like, adopts a wood or hard foam box section as a dimensional frame, simulates pneumatic appearance by adhering a paper film on the dimensional frame, and simulates weight distribution by fixedly connecting a lead block or high-density alloy on the bearing structure.

The fuel oil model cannot accurately simulate real structural arrangement, the pneumatic appearance simulation precision is low, the machining and assembling processes are complex, the calculation amount of the model structure simplified from a real structure and equivalent design process is large, the difficulty is high, and errors are easy to occur.

Disclosure of Invention

It is an object of the present application to provide a 3D printed structurally similar aeroelastic model and a method of designing the same to solve or mitigate at least one of the problems of the background art.

In one aspect, the present application provides a method for designing a structurally similar aeroelastic model, including:

scaling the real airplane component structure according to the design scale ratio;

determining the structural shape and size of the aircraft component after scaling according to the designed rigidity ratio;

comparing the deviation between the structural weight and the scaling weight of the real aircraft part according to the designed weight ratio, and calculating and determining the counterweight position, the counterweight weight and the counterweight body size through weight distribution;

checking whether the model meets similar requirements through simulation analysis, if not, adjusting the structural shape or size of the counterweight or scaled aircraft part until the model meets the similar requirements;

and printing the model by a 3D printing technology to complete the construction of the aeroelastic model.

Further, before the simulation analysis, the method further comprises:

according to the structure of the real airplane part, local support or filling is added at the unstable part of the airplane.

Further, materials in 3D printing include metals, photosensitive resins, plastics, and nylons.

In another aspect, the present application provides a 3D printed structurally similar aeroelastic model comprising a skin, longitudinal members, cross members, control surfaces and control surface internals and connection structures for simulating the main force-bearing components of a real aircraft and a counterweight for simulating the weight distribution of the real aircraft;

the skin, the longitudinal member, the transverse member, the control surface internal member and the connecting structure are subjected to scaling on a real aircraft component structure according to a design rigidity ratio of a design scale ratio to obtain the shape and the size of the structure;

the weight body compares the deviation of the structural weight and the real aircraft component scaling weight according to the designed weight ratio, and the determined position, weight and size of the weight body are calculated through weight distribution;

and printing the skin, the longitudinal members, the transverse members, the control surfaces, the control surface internal members, the connecting structures and the balance weights in the model by a 3D printing technology.

Further, the longitudinal members include scaled structures corresponding to beams, stringers, and longitudinal walls, etc. in a real aircraft structure.

Further, the cross member includes a scaled structure corresponding to a rib, a reinforcing frame, a bulkhead, and the like in the structure of a real airplane.

Further, the 3D printed material includes metal, photosensitive resin, plastic, and nylon.

Furthermore, a bearing structure component in the model is subjected to 3D printing by adopting non-metal photosensitive resin, plastic or nylon and the like, and the bearing structure component comprises a skin, a longitudinal member, a transverse member, a control surface, an inner member of the control surface and a connecting structure.

The 3D printing structure similar aeroelasticity model can meet the requirements of the aeroelasticity model on the arrangement of the structure, the pneumatic appearance, the rigidity and the weight distribution simulation, has enough strength, can accurately simulate the arrangement and the pneumatic appearance of a real airplane structure, improves the precision and the credibility of the aeroelasticity test, and has small design and processing workload, small difficulty and short period.

Drawings

In order to more clearly illustrate the technical solutions provided by the present application, the following briefly introduces the accompanying drawings. It is to be expressly understood that the drawings described below are only illustrative of some embodiments of the invention.

FIG. 1 is a flow chart of a method for designing a structurally similar aeroelastic model according to the present application.

Fig. 2 is a schematic view of a 3D printing structure-similar aeroelastic model of the present application.

Fig. 3 is a schematic view of the internal structure of a 3D printing structure-similar aeroelastic model of the present application.

Reference numerals are as follows:

1-covering

2-control surface

3-end rib

4-connecting structure

5-longitudinal structural member

6-Cross-Member

7-counterweight body

8-control surface internal structure

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application.

In order to accurately simulate the arrangement of a real airplane structure and have higher pneumatic appearance simulation precision, the application provides a 3D printed structural similarity aeroelastic model design method.

As shown in fig. 1, the method for designing a aeroelastic model with a similar structure provided by the present application comprises the following steps:

s1, scaling main structures such as skins, longitudinal members and transverse members in the structural component of the real airplane according to the design scale ratio;

s2, determining the attributes of the structure after scaling according to the design stiffness ratio through the generational calculation of stiffness and the like, wherein the attributes comprise the size, the shape and the like, such as the thickness of the skin, the section shape and the size of the edge strip;

s3, comparing the deviation between the structure weight and the real aircraft component scaling weight according to the design weight ratio, and determining the counterweight position, the counterweight weight and the counterweight body size through weight distribution calculation;

s4, adding local support or filling at a volatile stable position according to the component structure of the real airplane;

s5, verifying whether the model meets the similar requirement through simulation analysis, if not, locally adjusting the structural attribute after the counterweight or scaling, namely iterating the steps S2-S4 until the model meets the similar requirement;

and S6, finally, processing and molding the whole of the pneumatic elastic model with the similar structure by adopting a 3D printing technology. The material used in 3D printing may include metal, photosensitive resin, plastic, nylon, or the like. Preferably, for the force bearing structural components in the model, such as skins, longitudinal members, transverse members and the like, non-metallic photosensitive resin, plastic, nylon or the like is used for 3D printing.

As shown in fig. 2 and 3, the aeroelastic model (wing part) constructed by the method is a schematic diagram, and the 3D printed structural similarity aeroelastic model comprises a skin 1, a longitudinal member 5, a transverse member 6, a control surface 2, a control surface internal structure 8, a connecting structure 4 and a counterweight body 7. The longitudinal members 5 correspond to structures such as beams, stringers and longitudinal walls in an airplane structure, the transverse members 6 correspond to structures such as ribs, reinforcing frames and partition boards in the airplane structure, the longitudinal members 5 and the transverse members 6 form a supporting framework of a model, and the skin 1 is laid on the supporting framework. At the edge of the supporting framework, a connecting structure 4 is provided, which connecting structure 4 acts as a joint for the connection of the model to a fuselage model (not shown). A control surface inner member 8 is provided on the right side of the support framework, and a skin is laid on the control surface inner member 8 to form the control surface 2. The counterweight bodies 7 are distributed on the supporting framework according to the counterweight requirement.

In the aeroelastic model with the similar structure, a skin 1, a longitudinal member 5 and a transverse member 6 form a main bearing structure of the model together, and a control surface 2 simulates a real aircraft control surface structure; the counterweight body 7 is used for supplementing the weight of the structure and ensuring that the model accurately simulates the weight distribution of the airplane; the connecting structure 4 is used for connecting the model with other mechanisms, and the model is ensured to have enough connecting strength.

The 3D printing structure similar aeroelasticity model can meet the requirements of the aeroelasticity model on the arrangement, the pneumatic appearance, the rigidity and the weight distribution simulation of the structure, has enough strength, can accurately simulate the arrangement and the pneumatic appearance of a real airplane structure, improves the precision and the credibility of the aeroelasticity test, and has small design and processing workload, small difficulty and short period.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A3D printing method for designing a structural similarity aeroelastic model is characterized by comprising the following steps:

comparing the deviation between the structural weight and the actual aircraft component scaling weight according to the designed weight ratio, and calculating and determining the counterweight position, the counterweight weight and the counterweight body size through weight distribution;

2. The 3D printed structurally similar aeroelastic model design method of claim 1, further comprising, before the simulation analysis:

3. The 3D printed structurally similar aeroelastic model design method of claim 1, wherein the 3D printed material comprises metal, photosensitive resin, plastic and nylon.

4. A3D printed structural similarity aeroelastic model is characterized in that the model comprises a skin, a longitudinal member, a transverse member, a control surface internal member and a connecting structure which are used for simulating main bearing parts of a real airplane, and a counterweight body which is used for simulating weight distribution of the real airplane;

the skin, the longitudinal member, the transverse member, the control surface internal member and the connecting structure are subjected to scaling on a real aircraft component structure according to a designed rigidity ratio of a designed scale ratio to obtain the shape and the size of the structure;

5. The 3D printed structurally similar aeroelastic model of claim 4, wherein the longitudinal members comprise scaled structures corresponding to beams, stringers and longwalls in a real airplane structure.

6. The 3D printed structurally similar aeroelastic model of claim 4, wherein the cross-members comprise scaled structures corresponding to ribs, reinforcing frames and bulkheads in a real airplane structure.

7. The 3D printed structurally similar aeroelastic model of claim 4, wherein the 3D printed material comprises metal, photosensitive resin, plastic, and nylon.

8. The 3D printed structurally similar aeroelastic model of claim 7, wherein the force bearing structural components in the model are 3D printed with non-metallic photosensitive resin, plastic or nylon, and the force bearing structural components comprise skins, longitudinal members, transverse members, control surfaces, and operation surface internals and connection structures.