On the Use of Acoustic Emission to Assess the Wear in a Tribosystem

Abstract

The article focuses on the analysis of acoustic emission signals generated under dry sliding friction conditions. Two tests were conducted using a TRB 3 tribometer with the disc made of 100Cr6 steel with a DLC coating, and pin made of corundum (Al 2 O 3 ) and steel 100Cr6, respectively. Two tests with the disc without DLC coating were also carried out. The audio data written in the 16-bit linear pulse-code modulation (LPCM) format were analysed using the SpectraPLUS software. An Aweighting filter and 1/1 and 1/3-octave band filters were used for sound level measurements.The analysis of the equivalent sound level calculated for 10-second time intervals was carried out. The highest A-weighted sound level occurred during the first 2 hours of the test with the disc having a DLC coating and pin made of 100Cr6 steel. At the end of this test, the sound level dropped by about 40 dB compared to the maximum. The lowest A-weighted sound level was recorded during the last 2 hours of the test with disc having a DLC coating and pin made of corundum.The time-dependent variability of sound parameters was predicted using the regression tree and random forest models, which proved to be accurate and easy to follow.

Development of accelerated comparative assessment of contact fatigue strength based on the analysis of acoustic emission of friction units

“…19–22 The modern development of non-destructive control methods, namely the AE method, makes possible to control the processes of both small and multi-cycle fatigue at all stages of its development. 23–26 To effectively estimate the technical condition of tribosystems (TS) in the process of laboratory tests and operation, it is necessary to use indicators that allow determining the rate of accumulation of damage and the transition to various mechanisms of destruction (wear), including fatigue damage. Indicators that determine the rate of wear are various energy criteria which reflect the process of energy dissipation (change) during friction.…”

“…Considering the possibility of determining the critical number of contact cycles at the time of destruction of the surface layer, and using the function describing the kinetics of damage development ( n cr f ( n ) ) using acoustic emission method, 23–26 we proposed to estimate fatigue strength by specific energy of destruction in one load cycle:…”

“…Additionally, the wear rate was measured by acoustic emission (AE). 23–26 This method allows you to record the wear rate over time from 20 ms in relative units. Thus, wear is recorded from the moment of separation of the first particles of material from the friction surface in real time during the entire test period.…”