Traction taking-off fatigue test method of nose landing gear external cylinder suspension joint of aircraft

Abstract

The invention provides a traction taking-off fatigue test method of a nose landing gear external cylinder suspension joint of an aircraft. The traction taking-off fatigue test method comprises the following steps that a static strength test is conducted on an external cylinder suspension joint test sample piece; a fatigue test is conducted, wherein loads in the X, Y and Z directions are loaded coordinately by adopting a sine wave cyclic loading mode with the stress ratio being 0.06 and the loading frequency being 2 Hz; the fatigue test is conducted by being divided into two stages that in thefirst stage, the load loading cyclic frequency is 7500 times, one-time visual check is conducted every 500 times, if a fatigue damage phenomenon occurs, the test is stopped, parameters are recorded, otherwise the test piece is subjected to crack detection, and the test piece enters into the second stage after being detected to be qualified; and in the second stage, the load loading cyclic frequency is 7500-15000 times, one-time visual check is conducted every 500 times, if the fatigue damage phenomenon occurs, the test is stopped, parameters are recorded, otherwise the test is continued untilthe ending, and cyclic times is recorded. According to the fatigue test method, the fatigue performance and the life of a partial structure are testified in advance by testing the test piece, and thedevelopment cost is lowered.

Description

technical field [0001] The invention belongs to the field of aircraft structure design, in particular to the field of aircraft structure testing, in particular to a fatigue test method for towing and take-off of an aircraft nose landing gear outer tube suspension joint. Background technique [0002] In order to ensure the load-carrying capacity and life requirements of the nose landing gear used for towing take-off in marine environment, the structural form and load-carrying capacity of the nose landing gear are obviously strengthened. The nose landing gear needs to bear a large traction load, and the vertical load is about More than 2 times of that, and the suspension joint of the landing gear needs to bear the full traction load. As a newly designed landing gear, if the full-size landing gear is directly used for fatigue tests, there are disadvantages such as long production and manufacturing cycles of test pieces, long test bench design and manufacturing cycles, long test...

AI Technical Summary

Problems solved by technology

As a newly designed landing gear, if the full-size landing gear is directly used for fatigue tests, there are disadvantages such as long production and manufacturing cycles of test pieces, long test bench design and manufacturing cycles, long test cycles, and high development costs, and the test does not pass the subsequent change cycle. longer

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