A Ground Calibration Method for Torsion Arm Load of Dual-wheel Strut Type Nose Landing Gear

Abstract

The invention relates to a ground alignment method for the load of the torsion arms of a double-wheel supporting pillar type nose landing gear. The invention aims to quantify and determine the load ofthe torsion arms of a nose landing gear in a ground test and a flight test so as to verify the structure and strength design of the torsion arms and provide reliable input information for the verification and evaluation of the shimmy performance and turning performance of the front wheels of an aircraft. The method includes the following steps of: 1, determining the load and transmission of torsion arms; step 2, formulating the strain gauge layout of the torsion arms; step 3, selecting the calibration status of the load of the torsion arms; step 4, completing the calibration load condition ofthe torque arms; and step 5, optimizing a calibration load balance method. With the method of the invention adopted, known calibration load applied by the load measurement of the upper and low torsion arm of the nose landing gear and strain response corresponding to the known calibration load can be accurately obtained, and therefore, limitations of methods for realizing torsion arm structure monitoring only through stress measurement or non-destructive detection in the prior art can be eliminated.

Description

technical field [0001] The invention is patented in the field of aircraft flight test, and relates to a method for ground calibration of the torsion arm load of the double-wheel strut type front landing gear. Background technique [0002] When the aircraft approaches and slides the rudder to face the direction of the runway, the oil pressure of the rudder hydraulic actuation system will be transmitted back to the front wheel control system, causing the front torsion arm to be loaded laterally to balance the rudder hydraulic pressure. When the aircraft is ground-operated to turn and run straight, the front wheels of the front landing gear that retreat a certain distance relative to the axis of the forward-leaning strut are subject to the instantaneous disturbance of the rudder correction course or the instantaneous lateral excitation of the road surface, which will also cause the front wheel to produce a rotation around the axis of the strut. Torsion and swing, this torsional...

AI Technical Summary

Problems solved by technology

[0003] For the front-lift torsion arm used in flight, in the past, in China, only the structural strain and external wear were detected visually, but the internal load was not measured, so it was impossible to know the real load of the torsion arm structure, which was extremely unfavorable for the development of the torsion arm. Structural strength design and verification and improvement

Both indoor fatigue tests and field flight practice have shown that the torsion arms of many types of aircraft landing gears have too many serious deformations or damages. However, in actual use, it is caused by complex loading, high-frequency alternating loading fatigue, etc.

Images