CN105444999A - Static test loading method for long straight wings of small unmanned air vehicle - Google Patents

Abstract

A static test loading method suitable for a long straight wing of a small unmanned aerial vehicle, characterized in that the loading device includes: a wing chord strap (2), which constrains the spanwise movement of the wing chord strap (2) The spanwise straps (4) are located at the wing loading point suspension rings (8) on the chord straps (2), between the left and right wings below the wing, connecting the spanwise straps of the left and right wings ( 4) locking device (3) and load sandbag (7). The present invention adopts strap frame design, by binding a number of high-strength straps along the chord and span directions on the surface of the wing to form an external load transmission frame, thereby converting the weight of the sandbags mounted into the weight of the aircraft wing (6). Structural loads, for static test loading of structures. The loading method and device are easy to use, reliable in loading, low in cost and strong in adaptability, and are suitable for static tests of long straight wings of various medium and small unmanned aerial vehicles.

Description

A static test loading method suitable for long straight wings of small unmanned aerial vehicles

technical field

The invention relates to a static test loading method for a long straight wing of a small unmanned aerial vehicle, belongs to the field of static strength tests of aviation aircraft structures, and is suitable for loading the static strength test of a wing of a small unmanned aerial vehicle with a large aspect ratio.

Background technique

UAV is an important means of battlefield reconnaissance in modern warfare. Due to its small size, good visual stealth effect, low manufacturing cost, flexible and convenient transportation, and high battlefield mobility, small UAVs are ideal for front-line spying and reconnaissance of the enemy, information relay, auxiliary communication and other tactics in modern warfare. An important weapon for the mission. This type of UAV usually has a long straight wing structure with a large aspect ratio, carries the necessary communication and reconnaissance equipment loads, and has a certain ability to stay in the air. Famous foreign drones, such as the "Scan Eagle" drone, belong to this type.

The aircraft structural strength test usually refers to the structural static test, which is to test the bearing capacity of the aircraft under the design load by loading a certain magnitude of static load on the surface of the aircraft and measuring the deformation and strain state of the structure, so as to provide Provide guarantees for flight safety and structural safety. The wing is the main lifting surface of the aircraft and the most important load-bearing component of the whole aircraft, which is crucial to the safety of the aircraft structure. For small unmanned aerial vehicles, due to the relatively large span-wise size of its wings, the structure is relatively "slender", and the wings are its main load-bearing components. Therefore, compared with other components such as the fuselage and empennage, the The strength problem is the most prominent. The static strength test technology of conventional aircraft is relatively mature, and there are special loading equipment, which can simulate any load state of the aircraft in flight. However, this kind of equipment is relatively heavy and requires a fixed test site, with a certain test scale and cost. It is also relatively high, and is not suitable for low-cost small UAV static tests.

In addition, the static test of aircraft structure needs to apply a certain magnitude of force on the surface of the structure to simulate the load distribution in flight. Due to the small size of the small drone's structure, especially the small chordwise scale of the wing, the wing-mounted equipment is easy to cause abnormal protrusions, and the details of the wing structure are various. Therefore, the distributed loading on the wing surface of the small drone High difficulty.

Therefore, it is necessary to develop a static test loading method that is suitable for the structural characteristics of small UAVs, is easy to use, low in cost, and has certain versatility, and develops corresponding supporting test devices to realize the static load of small UAVs. Purpose of test load.

Contents of the invention

The inventor realized that the loading method and device for the static test of the wing of a small unmanned aerial vehicle should be able to realize the load distribution along the span of the wing, and the position of the loading point should be kept relatively fixed during the test, that is, the chord, There should be no sliding in the span direction, and it should be able to load step by step during the test process to simulate loads of different magnitudes. It should also be low in cost, easy to disassemble and assemble the loading device, and the installation of the loading device does not require any modification to the aircraft body structure.

In view of the above needs, the inventors have provided a static test loading method suitable for small unmanned aerial vehicles with long straight wings and The scheme is easy to use, low in cost, does not affect the body structure, and has certain versatility.

According to one aspect of the present invention, there is provided a static test loading device suitable for a long straight wing of a small unmanned aerial vehicle, characterized in that it comprises:

Wing chord straps; wing spanwise straps that constrain the spanwise movement of wing chord straps; wing loading point rings located on wing chord straps; located between wing lower surface, left and right wings Between, the locking device connecting the left and right wingspan straps; loading sandbags.

According to another aspect of the present invention, a kind of static test loading method of long straight wing of small aircraft is provided, it is characterized in that comprising:

A) Several stations are set along the span of the aircraft wing as loading points and strap stations to simulate the distribution of loads in flight along the span direction;

B) At each station, wrap the wing chordwise straps around the wing chord direction and lock them tightly, so that the load is evenly transmitted to the wing spanwise station section through the straps during the static test;

C) Mount the sandbag load at the position where the strap on the upper surface of the wing is 1/4 of the chord length from the leading edge, and the mounted position simulates the position of the action point in the chord direction of the wing; the aircraft is in an inverted attitude;

D) The upper and lower surfaces of the wing are provided with longitudinally connected spanwise straps along the spanwise direction of the wing, which are connected by adhesive buckles, which is not only convenient for quick assembly, but also provides sufficient spanwise restraint, and the connection is stable. Prevent the loading point from slipping along the span during the test;

E) A locking device is arranged between the left and right longitudinally connected spanwise straps on the lower surface of the wing, for connecting the left and right spanwise straps and mounting them on the aircraft fuselage.

Advantages of the present invention include:

1) The position of the loading point is relatively fixed, the positioning is reliable, and it has sufficient binding force; 2) The loading device is easy to install and disassemble, and can be quickly installed and loaded without any changes to the aircraft structure; 3) It has the ability to load step by step , can realize the stepwise increase or decrease of the load; 4) strong practicability, low cost and easy transformation, and can be applied to the situation where the structure of the small UAV is complex and there are many irregular protrusions.

The main scope of application of the present invention: the application object is mainly small unmanned aerial vehicles with long straight wing configurations, and it can also be used in conventional light aircraft with medium or large aspect ratio configurations.

Description of drawings

Fig. 1 shows a macroscopic schematic diagram of a loading device according to an embodiment of the present invention.

Figure 2 shows the installation and connection of the wing chordwise straps (2).

Fig. 3 shows a connection schematic diagram of the locking device (3) connecting the left and right wing spanwise straps (4) according to an embodiment of the present invention.

Figure 4 shows the loading of the load sandbags (7) on the wing.

Fig. 5 has shown that in an example of the present invention, the actual effect of the wing chord strap (2) and the wing span strap (4) being restrained on the wing (6) of the test aircraft object (1).

Fig. 6 has shown above-mentioned example of the present invention, under the wing maximum loading state, the harshest loaded physical effect of the wing hardpoint suspension ring (8) and the hook (9) of the load sandbag (7).

Fig. 7 shows the implementation effect of the whole aircraft in the maximum mounted state in the above example of the present invention.

Fig. 8 shows the strain result curve measured by the static test in the above example of the present invention.

detailed description

The present invention adopts strap frame design, by binding a number of high-strength straps along the chord and span directions on the surface of the wing to form an external load transfer frame, thereby converting the weight of the sandbags mounted into the weight of the aircraft wing (6). Structural loads for carrying out static tests on an aircraft object (1). The aircraft object (1) is a small unmanned aerial vehicle with a long straight wing configuration, and the main structural components are a fuselage (5) and a wing (6).

The technical scheme of the specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

According to one embodiment of the present invention, the loading device for long straight wings of a small unmanned aerial vehicle is shown in Fig. 1 , Fig. 2 , Fig. 3 and Fig. 4 . The main body of the loading device of the present invention is designed with a canvas strap. That is, several stations are set along the span direction of the aircraft wing (6) as loading points and strap stations, and the load distribution in flight is simulated at the same time; at each station, the wing chord straps (2 ) around the chord direction of the wing, and lock it with the adhesive buckle (11). The aircraft is in an inverted attitude) near the 1/4 chord length point of the leading edge, there is a metal lifting ring (8) for mounting sandbag loads, and the position of the lifting ring (8) simulates the effect of the chord direction of the wing point position; the upper and lower surfaces of the wings are provided with longitudinally connected spanwise straps (4) along the spanwise direction of the wings, which are also connected by adhesive buckles (11), which are convenient for quick assembly and provide sufficient The spanwise constraint and the connection are stable to prevent the loading point from slipping along the spanwise direction during the test; a locking device (3) is provided between the left and right longitudinal connecting straps (4) on the lower surface of the wing to connect the left and right The wings are longitudinally connected with straps (4) and mounted on the aircraft fuselage (5). According to one embodiment of the present invention, the locking device (3) has a structure similar to a lock ring (shown in Figure 3). In a specific embodiment according to the present invention, the spanwise strap (4) passes through the bottom of the locking device (3) and goes around the device's winding post (12), and then from the winding post (12) Pass through the gap with the device (as shown in the upper left of Figure 3). By adjusting the length of the straps passing through the locking device (3), the tightness of the left and right wing spanwise straps (4) can be adjusted, and locked by the adhesive buckle (11), which is the left and right straps Provide sufficient span constraints. Simultaneously, the spanwise binding strap (4) makes the device have a certain self-locking effect by means of the restraining reaction force of the post (12) of the locking device (3). The mounted load is simulated by a load sandbag (7) with a hook (9) on the top and a hanging ring (10) on the bottom, which can realize the step-by-step loading of the static test.

Example: The test object is a small long straight wing UAV with a wingspan of about 1.7 meters. The weight of the aircraft is about 20kg. During the test, it can be loaded step by step with a load increment of 20%; the maximum load in the test can reach 44kg, the mounting method is still valid, and no mounting point moves or falls off; static test results (strain changes with load increments) It shows that the linearity of this loading scheme is good (as shown in Figure 8), which meets the basic requirements of aircraft static test. The total production cost of the static test loading device in this example is only more than 600 yuan, but usually the outsourcing cost of this kind of static test is as high as tens of thousands or even hundreds of thousands of yuan, and a fixed test site and special supporting facilities are required And test prototypes, the cost is high.

Figure 5-Figure 7 is a picture showing the scene of the test example, and Figure 8 is the curve of the test result. As can be seen from the test result curve of Fig. 8, the wing surface strain value measured by the loading device and method of the present invention has a linear relationship with the increase of load, and the linearity is good, indicating that the present invention is effectively loaded step by step, and the test data It is stable and has little dispersion, which is an ideal static test result.

Claims (7)

1. The static test loading method of the long straight wing of small aircraft, it is characterized in that comprising: A) several stations are set along the span direction of the aircraft wing (6), as loading points and strap stations, to simulate the distribution of the load in flight along the span direction; B) At each station, wrap the wing chord strap (2) around the wing chord direction and lock it tightly, so that the load can be evenly transmitted to the wing spanwise station through the strap during the static test bit profile; C) Mount the sandbag load at the position where the strap on the upper surface of the wing is 1/4 of the chord length from the leading edge, and the mounted position simulates the position of the action point in the chord direction of the wing; the aircraft is in an inverted attitude; D) The upper and lower surfaces of the wings are provided with longitudinally connected spanwise straps (4) along the spanwise direction of the wing, which are connected by adhesive buckles (11), which is convenient for quick assembly and can provide sufficient spanwise Constraints, and the connection is firm, to prevent the loading point from slipping along the span during the test; E) a locking device (3) is arranged between the left and right longitudinally connected longitudinal straps (4) of the lower surface of the wing, for connecting the left and right wing span straps (4) and Mounted on the aircraft fuselage (5). 2. according to the static test loading method of the long straight wing of small aircraft of claim 1, it is characterized in that: The step C includes: setting a metal suspension ring (8) at the position where the sandbag load is mounted, for mounting the sandbag load, and the position of the suspension ring (8) simulates the position of the action point in the chord direction of the wing. 3. according to the static force test loading method of the long straight wing of small aircraft of claim 1, it is characterized in that: the aircraft is an inverted posture; 4. according to the static test loading method of the long straight wing of small aircraft of claim 1, it is characterized in that: In the step B), the wing chordwise straps (2) are locked with adhesive buckles (11). 5. according to the static test loading method of the long straight wing of small aircraft of claim 1, it is characterized in that: In the step D), the spanwise straps (4) are locked with adhesive buckles (11). 6. according to the static test loading method of the long straight wing of small aircraft of claim 1, it is characterized in that: The locking device (3) is a structure similar to a lock ring, and is used to adjust the tightness of the left and right wing spanwise straps (4) to provide sufficient spanwise straps (4) for the left and right wing spanwise Constrained, and has a certain self-locking effect. 7. according to the static test loading method of the long straight wing of small aircraft of claim 1, it is characterized in that: The mounted load is simulated by a load sandbag (7) with a hook on the top and a ring on the bottom, which can realize the step-by-step loading of the static test.