Diagnostic aspects of natural vibration frequencies of selected internal combustion engine components

Abstract: The article presents a new approach to the vibroacoustic diagnostics of an internal combustion engine. An estimation of the natural vibration frequencies of selected internal combustion engine components based on impulse tests has been proposed. The results of the impulse tests were used to build dynamic models of internal combustion engine systems.

Dynamic models of internal combustion engine systems can be used to assess their technical condition.

1. INTRODUCTION

Medium and high-power compression-ignition (CI) internal combustion engines are mainly used as propulsion units for rail vehicles. Diagnosing their technical condition allows for the implementation of condition-based maintenance strategies, prevents most unplanned downtime, and, by detecting damage at an early stage of development, reduces the scope and costs of repairs and maintenance [1,5].

A separate aspect is the safety of transport and its punctuality.

To assess the technical condition or the operating state (functional and operational parameters) of an internal combustion engine, measures and characteristics of the vibration signal generated by the internal combustion engine are increasingly being used [2,3,4].

Obtaining diagnostically useful information contained in vibrations is not easy.

Scientific work financed from science funds in the years 2008-2011 as a research project

No. N N502463034

The difficulty of identification and inference about the technical condition or operation of engine components or subassemblies based on commonly used measures and characteristics of the vibroacoustic (VA) signal results, among other things, from the complex nature of vibrations generated by the engine, the processes occurring within it, the coexistence of many vibration sources, and complex kinematics.

The paper will present a concept for diagnosing internal combustion engines using an analysis of the natural vibration frequencies of the engine structure. (…)