A study to determine the onset of catastrophic wear of a processing tool by statistical parameters of acoustic emission

Sergii Filonenko,Anzhelika Stakhova

doi:10.15587/1729-4061.2019.184959

Abstract

In the present study, experimental research was carried out to determine the effect of the processing tool wear on the mutual change in the average statistical amplitude parameters of acoustic emission signals. Acoustic emission signals were recorded when turning silumin. The research was aimed at finding parameters to determine the occurrence of critical wear of the processing tool. It is shown that the recorded signals are continuous. The statistical amplitude parameters of the acoustic emission signals were processed under normal and catastrophic wear of the processing tool. It has been determined that the development of normal and catastrophic wear of the tool leads to a decrease in the values of the statistical amplitude parameters of the recorded signals. However, no peculiarities were found in their change to determine the developing type of wear. Meanwhile, at different time intervals, there was an anticipating increase or decrease in one of the statistical amplitude parameters of the acoustic emission signals. The processed parameter was a coefficient characterising a mutual change in the statistical amplitude values of the recorded signals. It has been determined that absence of the tool wear is characterised by stable values of the calculated coefficient in time. The occurrence and development of catastrophic wear leads to an outburst of the value of the calculated coefficient with its subsequent accelerated decrease to the destruction of the tool. The emergence and development of normal wear leads to an increase in the value of the calculated coefficient with a subsequent transition to a sawtooth change and a gradual decrease of its size. The obtained regularities can be used when devising methods for controlling and monitoring the condition of the tool during the mechanical processing of materials, including monitoring the state of the processing tool in robotic industries

Highlights

The method of acoustic emission (AE) is widespread in researching technological procedures of mechanical processing
The aim of the present study is to identify the effect of wear of the processing tool on the mutual change in the statistical amplitude parameters of AE signals
The study has determined the regularities of changes in the statistical amplitude parameters of the experimental AE signals under no, normal and catastrophic wear of the processing tool

Summary

Introduction

The method of acoustic emission (AE) is widespread in researching technological procedures of mechanical processing. This is due to the high sensitivity of the method to the processes of deformation and fracture of materials, as well as its low inertia to them. The problem is complicated by the influence of various factors on the parameters of recorded AE signals The presence of these problems results in general patterns of change in the statistical parameters of AE signals, which are used to develop methods for controlling and monitoring the state of the cutting tool. The general tendencies in reducing the statistical parameters of AEs make it possible to determine the development of tool wear without identifying its type (normal, catastrophic), which reduces the reliability of the methods for controlling and monitoring the state of the cutting tool. It is important to determine the regularities characterising the mutual change in the statistical parameters of AE during the development of various types of wear of the processing tool as it helps devise methods for monitoring its condition, and first of all, solve the problem of identifying the occurrence of critical wear of the processing tool

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Discussion

Conclusion