A Method of Spacecraft Leak Detection Based on Acoustic Emission

Abstract

Acoustic emission signals are generated when leak occurs, and leak detection can be realized through the analysis of acoustic emission signals. This is an online nondestructive testing method, which is an important part of spacecraft leak detection. This paper describes the basic principle of acoustic emission leak detection of spacecraft, and introduces the basic composition and main parameters of the ground simulated leak experiment system. Using spectrum analysis, the characteristics of the acoustic signals from three different diameters leakage of 1.0 mm, 1.5 mm and 2.0 mm are obtained and compared with the background noise. The experiment data show that the main frequency of mechanical pump operating background noise is below 5 kHz, while the gas leak acoustic signal is a broadband signal, which is obviously distinguished from the background noise in the high frequency above 10 kHz. The smaller the diameter of the leakage hole is, the smaller the energy of the leak acoustic emission signal is and the more proportion of the high-frequency components is. Thus, the identification of different sizes leakage can be realized. The results of this paper are of great significance to the detection of spacecraft leak in orbit.