Development of a method for determining the wear of artillery barrels by acoustic fields of shots

Yevhenii Dobrynin,Viktor Boltenkov,Maksym Maksymov

doi:10.15587/1729-4061.2020.206114

Abstract

A possibility of assessing the level of wear of artillery barrels by acoustic fields of shots was studied. Despite the importance of knowledge on the current barrel state, existing methods of wear assessment are not sufficiently prompt. These methods give rather rough estimates of wear or require expensive equipment. Unlike the known methods, the method proposed in the article is prompt, does not require large expenses, can be combined with a training firing, and is easily automated. Characteristics of the shock and muzzle waves generated by a gunshot were studied and differences in their parameters for barrels without wear and those with a critical wear level were shown. Initial shell velocity serves as a criterion indicator of wear. It was shown that according to the acoustic characteristics, a shot from the barrel having any degree of wear is equivalent to a shot from a gun of a smaller caliber. A computational experiment was conducted on real acoustic signals recorded during the firing of a 155 mm howitzer. Informative attributes of acoustic signals from shots were selected. They make it possible to automatically classify barrels into two classes: barrels suitable for use and barrels with wear exceeding the critical level. It was shown that the application of the support vector method (SVM) makes it possible to confidently classify barrels by the level of their wear based on the temporal and spectral attributes of the shock and muzzle waves. A cumulative analysis of spectral characteristics was used in the analysis of acoustic signals from shots. This has a significantly increased likelihood of correct barrel classification. The results are useful for practical use in artillery units in the field conditions. The study results enable the development of an automated system for assessing the barrel condition with high promptness. This ensures sufficient accuracy in assessing the level of barrel wear in the combat practice

Highlights

The barrel is one of the main units in present-day artillery systems
Wear is usually divided into erosion wear arising from thermomechanical effects of powder gases; mechanical wear caused by mechanical effects of leading elements of the shell on the channel surface and chemical wear brought about by chemical interaction of powder gases and the barrel metal [2]
Known methods for assessing barrel wear can be divided into two classes: firing methods, that is, those requiring firing from the diagnosed barrel and firing-free methods

Summary

Introduction

The barrel is one of the main units in present-day artillery systems. It is a part of an artillery gun designed to direct a shell during shooting and impart the required velocity to it [1]. The methods used today for assessing wear of artillery barrels are either obsolete and rather approximate or based on modern technologies requiring expensive job-dedicated equipment. The latter methods are very costly and time-consuming. According to [5], analysis of the acoustic fields accompanying firing can be used to find out Applied physics the type of guns, shell caliber, and other data characterizing the artillery system. Such prospects are presented in [5] at a level of general considerations. Study of the possibility of assessing wear of the artillery gun barrels by the acoustic fields generated by shots is a fairly relevant scientific and applied problem

Literature review and problem statement

The aim and objectives of the study

A simulation model of acoustic signals when firing from worn barrels

A computational experiment with the classification of the barrel wear level

Conclusions