CN111504897A - Airplane wheel arresting test system based on similar theory - Google Patents

Abstract

A wheel arresting test system based on similarity theory. It includes a loading system, an arresting material conveying system, and a motor drive system: the wheel arresting test system based on the similarity theory provided by the present invention has the advantages and positive effects: the volume is small, and the test based on the similarity theory is comparable to the real machine test of the same level. Compared with this, the research cost can be greatly reduced; the blocking force of the blocking system on the wheel under different loads and moving speeds can be tested, and the blocking effect of different blocking materials can be studied at the same time. It can provide technical testing means for ensuring the safety of airport runways and serve for the development of new types of arresting materials.

Description

A Wheel Arresting Test System Based on Similarity Theory

technical field

The invention belongs to the technical field of airport engineering, in particular to a wheel arresting test system based on similarity theory.

Background technique

With the increasing demand of the modern air transport industry, the accident of the aircraft overrunning the runway has already occurred, so it has become one of the most threatening problems in aviation accidents. The characteristic material arresting system (EMAS for short) is an effective civil aircraft arresting system. The application of EMAS can provide the same safety guarantee as the standard runway end safety area, so as to save the land area of the airport for the runway end safety area, which is beneficial to Enhance airport security capabilities. However, the performance of EMAS, the speed of the aircraft, the weight of the aircraft, etc. have an important impact on the arresting system. Due to the particularity of the project, the real machine experiment is difficult and expensive, so it is difficult to carry out the actual experiment. Most of the current research is finite element simulation. Chinese Patent Publication No. CN102854129A provides a device for testing an aircraft arresting system, which uses real wheels and loads, requires a large test site, and has a relatively high cost. Therefore, there is an urgent need for a small-scale barrier material testing device that can be applied to laboratory research.

SUMMARY OF THE INVENTION

In order to solve the above problems, the purpose of the present invention is to provide a wheel arresting test system based on the similar theory.

In order to achieve the above purpose, the wheel arresting test system based on the similar theory provided by the present invention includes a loading system, an arresting material conveying system and a motor drive system:

The motor transmission system includes: a guide wheel, a transmission bracket, a winch, a reducer, a motor and a tension sensor; the lower end of the transmission bracket is set on the ground, and the upper part is installed with a concentrically arranged motor, a reducer and a winch. The output shaft is connected to the reducer, and the output shaft of the reducer is connected to the center hole of the winch; the guide wheel is arranged on the transmission bracket at the front side of the winch;

The arresting material transportation system is arranged in front of the motor transmission system, and includes an arresting material layer, an arresting test vehicle and a steel strand; the vehicle body of the arresting test vehicle is a box body with an open top and a rear end, and two sides of the bottom surface. There are a plurality of pulleys in the part, and the rear end is provided with a pull ring; one end of the two steel strands is connected to both sides of the rear end of the car body through the pull ring, and the other end is connected to the tension sensor at the same time, and the other end of the tension sensor uses another The steel strand is wound on the winch through the guide wheel; the blocking material layer is laid on the front of the body of the blocking test vehicle;

The loading system includes a loading frame, a loading basket, an anchor bolt, a landing gear wheel, a laser displacement sensor and a vertical transmission system of the wheel; the loading frame is a table-type structure, and the lower end is fixed at On the ground on both sides of the blocking test vehicle, an opening is formed in the middle of the top surface; the loading basket is set right above the loading frame, and the interior is used to place loading weights; the upper end of the vertical transmission system of the wheel is connected to the bottom surface of the loading basket The middle part runs through the opening on the loading frame, and the lower end is connected with the central axis of the landing gear wheel; the laser displacement sensor is installed on the side of the vertical transmission system of the wheel, and the landing gear wheel is measured by emitting laser light to the loading frame vertical displacement.

The motor is a speed-adjustable motor.

The loading basket is a cube-shaped steel structure box

The wheel arresting test system based on the similarity theory provided by the present invention has the advantages and positive effects as follows: the volume is small, and the test based on the similarity theory can greatly reduce the research cost compared with the real machine test of the same level; At the same time, the blocking effect of different blocking materials is studied. It can provide technical testing means for ensuring the safety of airport runways and serve for the development of new types of arresting materials.

Description of drawings

Fig. 1 is the structural perspective view of the wheel arresting test system based on similarity theory provided by the present invention;

Fig. 2 is the front elevation view of the transmission support structure in the wheel arresting test system based on the similarity theory provided by the present invention;

Detailed ways

In order to further understand the content of the invention, features and effects of the present invention, the following examples are given as examples, and are described in detail as follows in conjunction with the accompanying drawings:

As shown in FIGS. 1 and 2 , the wheel arresting test system based on the similar theory provided by the present invention includes a loading system 15 , an arresting material conveying system 16 and a motor drive system 17 :

Wherein, the motor transmission system 17 includes: a guide wheel 9, a transmission bracket 10, a winch 11, a reducer 12, a motor 13 and a tension sensor 8; the lower end of the transmission bracket 10 is set on the ground, and the upper part is installed with a concentric motor. 13. The reducer 12 and the winch 11, the output shaft of the motor 13 is connected to the reducer 12, and the output shaft of the reducer 12 is connected to the center hole of the winch 11; the guide wheel 9 is arranged on the transmission bracket 10 on the front side of the winch 11 ;

The described arresting material transportation system 16 is arranged in front of the motor drive system 17, including the arresting material layer 6, the arresting test vehicle 7 and the steel strand 14; The box body has a plurality of pulleys on both sides of the bottom surface, and a pull ring at the rear end; one end of the two steel strands 14 is connected to both sides of the rear end of the car body through the pull ring, and the other end is connected to the tension sensor 8 at the same time. The other end of the sensor 8 is wound on the winch 11 by using another steel strand 14 through the guide wheel 9; the blocking material layer 6 is laid on the front of the vehicle body of the blocking test vehicle 7;

The loading system 15 includes a loading frame 1, a loading basket 2, anchor bolts 3, a landing gear wheel 4, a laser displacement sensor 5 and a vertical wheel transmission system 18; the loading frame 1 is a table-type structure, The lower end is fixed on the ground located on both sides of the arresting test vehicle 7 through the anchor bolts 3, and an opening is formed in the middle of the top surface; the loading basket 2 is set directly above the loading frame 1, and the interior is used for placing loading weights; The upper end of the vertical transmission system 18 is connected to the middle part of the bottom surface of the loading basket 2, the middle part runs through the opening on the loading frame 1, and the lower end is connected to the central axis of the wheel 4 of the landing gear; the laser displacement sensor 5 is installed in the vertical transmission of the wheel. On the side of the system 18 , the vertical displacement of the landing gear wheels 4 is measured by emitting a laser to the loading frame 1 .

The motor 13 is a speed-adjustable motor.

The loading basket 2 is a cube-shaped steel structure box.

The similarity theory is used for design to meet the geometric similarity, quality similarity and mechanical similarity between the model and the prototype.

The core of the wheel arresting test system based on the similarity theory provided by the present invention is the interaction between the wheel of the landing gear and the arresting material. Therefore, when designing the similar system, the key parameters need to be considered. In the experimental system, seven independent physical quantities are designed: length l, velocity v, gravitational acceleration g, density ρ, force F, tire pressure p, concrete strength f _c .

According to the first similarity theorem (π theorem) and the characteristics of the analytical model, four similarity criteria (dimensionless) are proposed as follows:

The physical meaning behind it is the wheel load factor, speed factor, tire pressure index and the wheel load strength ratio of foam concrete. The model and prototype can be considered similar only when the above four criteria are the same for both the model test and the prototype test.

The similarity ratio between the model and the prototype (the ratio of the value of the model to the prototype) is defined as λ _l , λ _v , λ _g , λ _ρ , λ _F , λ _p , λ _fc , respectively. According to the π theorem and similarity criterion, if the model is similar to the prototype, there are:

In the model test, the same material as the prototype is generally used, and the test is carried out under 1g, that is:

λ _ρ =λ _g =1 (2)

Therefore, the relationship between the similarity ratios of various dimensions can be obtained as follows:

The working principle of the mechanism arresting test system based on the similar theory provided by the present invention is described as follows:

1. Select a loading weight of suitable weight and place it in the loading basket 2, thereby pressing down the landing gear wheel 4 through the wheel vertical transmission system 18;

2. Place the arresting test vehicle 7 at the starting point in front of the landing gear wheel 4, with the axis aligned with the marking line;

3. Lay a layer of blocking material layer 6 to be tested on the front of the blocking test vehicle 7, and use a vernier caliper to measure the initial thickness of the blocking material layer 6;

4. Turn on the laser displacement sensor 5 and the tension sensor 8;

5. Set the speed of the motor 13, start the motor 13, and drive the winch 11 to rotate through the reducer 12, thereby pulling the arresting test vehicle 7 through the steel strand 14 to move backward until the landing gear wheels 4 are all pressed over the arresting material layer 6;

6. During the movement of the pulling and arresting test vehicle 7, use the laser displacement sensor 5 and the tension sensor 8 to collect the vertical displacement of the landing gear wheel 4 and the traction force of the steel strand 14 respectively;

7. Turn off the motor 13, stop the data collection of the laser displacement sensor 5 and the tension sensor 8 and record;

8. Unload the loading weight from the loading basket 2. At this time, the loading basket 2, the wheel vertical transmission system 18 and the landing gear wheel 4 in the loading system 15 will be lifted to the top of the arresting test vehicle 7;

9. Reverse the motor 13 and push the arresting test vehicle 7 back to the original position;

10. Measure the compacted thickness of the barrier material layer 6, and then select four positions to calculate the average value.

Claims (3)

1. The utility model provides a wheel blocks test system based on similar theory which characterized in that: the airplane wheel arresting test system comprises a loading system (15), an arresting material conveying system (16) and a motor transmission system (17):

wherein the motor drive system (17) comprises: the device comprises a guide wheel (9), a transmission bracket (10), a winch (11), a speed reducer (12), a motor (13) and a tension sensor (8); the lower end of the transmission bracket (10) is arranged on the ground, the upper part of the transmission bracket is provided with a motor (13), a speed reducer (12) and a winch (11) which are concentrically arranged, the output shaft of the motor (13) is connected with the speed reducer (12), and the output shaft of the speed reducer (12) is connected in the central hole of the winch (11); the guide wheel (9) is arranged on the transmission bracket (10) and positioned at the front side of the winch (11);

the blocking material conveying system (16) is arranged in front of the motor transmission system (17) and comprises a blocking material layer (6), a blocking test vehicle (7) and steel strands (14); the body of the arresting test vehicle (7) is a box body with an open top surface and an open rear end, a plurality of pulleys are arranged at two side parts of the bottom surface, and a pull ring is arranged at the rear end; one ends of the two steel strands (14) are connected to two sides of the rear end of the vehicle body through pull rings, the other ends of the two steel strands are simultaneously connected with the tension sensor (8), and the other end of the tension sensor (8) is wound on a winch (11) through a guide wheel (9) by the aid of the other steel strand (14); the blocking material layer (6) is laid on the front part of the vehicle body of the blocking test vehicle (7);

the loading system (15) comprises a loading frame (1), a loading basket (2), foundation bolts (3), undercarriage wheels (4), a laser displacement sensor (5) and a wheel vertical transmission system (18); the loading frame (1) is of a table structure, the lower end of the loading frame is fixed on the ground positioned on two sides of the obstruction test vehicle (7) through foundation bolts (3), and an opening is formed in the middle of the top surface of the loading frame; the loading basket (2) is arranged right above the loading frame (1), and a loading weight is placed in the loading basket; the upper end of the wheel vertical transmission system (18) is connected to the middle of the bottom surface of the loading basket (2), the middle part of the wheel vertical transmission system penetrates through an opening on the loading frame (1), and the lower end of the wheel vertical transmission system is connected with a central shaft of the undercarriage wheel (4); the laser displacement sensor (5) is installed on the side face of the wheel vertical transmission system (18), and the vertical displacement of the undercarriage wheels (4) is measured by emitting laser to the loading frame (1).

2. The airplane wheel arresting testing system based on the similarity theory as claimed in claim 1, wherein: the motor (13) adopts a speed-adjustable motor.

3. The airplane wheel arresting testing system based on the similarity theory as claimed in claim 1, wherein: the loading basket (2) is a box body with a square steel structure.

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