Method for avoiding excessive vibration of undercarriage in overhead state

A landing gear and state technology, applied to ground equipment, aircraft parts, transportation and packaging, etc., can solve the problems of excessive structural vibration, structural weight increase, excessive vibration, etc., and achieve the effect of simple model and high calculation efficiency

Active Publication Date: 2016-04-13
XIAN AIRCRAFT DESIGN INST OF AVIATION IND OF CHINA
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  • Abstract
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  • Application Information

AI Technical Summary

Problems solved by technology

If the rotation speed of the wheel exceeds the natural frequency of the aircraft structure, when the rotation gradually decays, it will be coupled with the structural frequency and resonate, resulting in excessive vibration of the structure
[0003] When this phenomenon exists, the wheel brake technology is generally used, but this requires the addition of a brake mechanism, resulting in an increase in structural weight
On the worst side, if the brake mechanism fails, there will still be excessive vibrations to occur

Method used

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  • Method for avoiding excessive vibration of undercarriage in overhead state
  • Method for avoiding excessive vibration of undercarriage in overhead state
  • Method for avoiding excessive vibration of undercarriage in overhead state

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Embodiment Construction

[0019] The present invention will be described in further detail below in conjunction with accompanying drawing, please refer to Figure 1 to Figure 2 .

[0020] Such as figure 1 Shown is a schematic diagram of a two-degree-of-freedom vibration model, including a rigid boundary 1, a runner 2, a runner frame 3, a mass 4, a spring 5, dampers 6 and 7, a rotating shaft 9, and a runner eccentric mass 10.

[0021] Such as figure 2 As shown, it is a schematic diagram of a wheel rotation model, including a runner 2 , a runner frame 3 , a rotating shaft 9 , and a wheel eccentric mass 10 .

[0022] A method of avoiding excessive vibration in the lift-off state of the landing gear, comprising:

[0023] 1. The runner frame 3, the runner 2, the rotating shaft 9 and the runner eccentric mass 10 together constitute the mass M 2 ;

[0024] 2. Adjust the wheel eccentric mass M 3 to change the magnitude of the rotational excitation;

[0025] 3. Adjust mass block M 1 , M 2 , spring sti...

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Abstract

The invention provides a method for avoiding excessive vibration of an undercarriage in an overhead state, which is characterized by comprising the following steps: 1, simulating the rotating excitation of an airplane wheel of the undercarriage by using an eccentric runner, wherein the frequency of the rotating excitation changes with time; 2, changing the eccentric mass M3 of the eccentric runner, and simulating the change of a vibration excitation amplitude; 3, simulating main movement rules of the undercarriage by using a 2-DOF (Degree Of Freedom) model; and 4, changing and matching mass blocks M1 and M2 and springs K1 and K2 so as to realize the design of natural vibration frequencies f1 and f2 of the first and second orders of the undercarriage structure.

Description

technical field [0001] The invention belongs to the field of dynamic design of aircraft landing gear, and in particular relates to a method for avoiding excessive vibration in the coupling between the rotational speed of the wheel and the structural frequency during the process of the landing gear wheel from high-speed rotation to stationary during the aircraft's lift-off process. Background technique [0002] When the landing gear of the aircraft is off the ground, the wheels of the landing gear are in a state of high-speed rotation. If the rotation speed of the wheel exceeds the natural frequency of the aircraft structure, when the rotation gradually decays, it will be coupled with the structural frequency and resonate, resulting in excessive vibration of the structure. [0003] When this phenomenon exists, the wheel brake technology is generally used, but this requires the addition of a brake mechanism, resulting in an increase in structural weight. On the worst side, if...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B64F5/00
Inventor 高飞
Owner XIAN AIRCRAFT DESIGN INST OF AVIATION IND OF CHINA
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