Locomotive Diesel Engine Stress Wave Analysis

Vibration analysis on internal combustion engines poses unique challenges not ordinarily encountered on rotating machinery. Stress wave analysis for engine fault detection is emphasised in this paper. A time waveform consisting of peak values observed over sequential discrete time intervals is captured and subsequently analysed. The analyses are the (a) peak values (measured in g´s), (b) spectra computed from the peak value time waveform, and (c) the autocorrelation coefficient computed from the peak value time waveform. Samples of various faults are presented to illustrate the stress wave analysis methodology. The classes of faults are (a) over combustion, (b) crank shaft, (c) valve bridge, and (d) good cylinder. It is demonstrated that stress wave analysis make possible the identification of the defect and the severity of the defect