Experimental Methodology for Acoustic Diagnostics of Shock Absorbers

Abstract

The application of acoustic measurements brings about a new diagnostic method for evaluating the conditions of shock absorbers. In shock absorber diagnostics, it is advantageous to observe and understand what phenomena occur during the working cycle in the inner tube. Using a non‑destructive and non‑contact method can avoid dismantling whole device. For the research of this new acoustic method, a classic sound meter, an automotive and a train shock absorber were used. FFT analysis and concurrent filtration were applied for the measurement evaluation of obtained data. It has been proven that applying acoustic methods can lead to diagnostics of aeration in the shock absorbers. A defective shock absorber changes its damping characteristics as well as noise radiation compared with the properly functioning one; these differences in noise are measurable and quantifiable. The results show that characteristics of acoustic radiation of the aerated shock absorbers relate to the shock construction type.

Keywords

• automotive shock absorber
• acoustic diagnostics
• aeration
• cavitation