THE APPLICATION OF ACOUSTIC EMISSION TECHNIQUE TO FATIGUE CRACK MEASUREMENT

摘要

The applicability of acoustic emission technique to measure fatigue cracks in aluminum alloy specimens has been investigated. It has been shown that a SN ∝ Km type of acoustic emission law can be applied to the slow crack growth region (da/dn < 25 x 10-4 mm/cycle) and may be used to verify the crack length changes. However, there are several variables, such as the metallurgical and the physical treatment of the specimen, that can affect the level of acoustic activity of a fatigue specimen. It is therefore recommended that the acoustic emis¬sion technique be supplemented by other nondestructive evaluation methods to obtain quanti¬tative data on crack growth.