Probabilistic Approach to Component Useful Life Prediction
Vladimir Zeljkoviæ,
Miodrag Jankoviæ,
Radomir Vukoje
Life estimation is widely used to set the useful/operational time of components and equipment. This paper gives an approach to mean life and useful life estimation. The maintenance policy is based on useful life determination. Practical application is illustrated by reliability testing of jet engine blades. The new blades as well as the blades after 400, 800 and 1200 operating hours were cyclic-tested to failure and the recorded data were analyzed. The lognormal distribution was applied for data analysis. The useful life for new components and the expired life for components from exploitation were determined. The regression line plotted on reliability testing data for new and aged jet engine blades gave the point of hundred per cent life for predetermined reliability. To ensure safe engine operation, blade replacement and engine overhaul have to be planned before the point of hundred per cent required reliability life is reached.
Key words: technical maintenance planning, reliability testing, reliability analysis, useful life, blade.