Abstract:

The fatigue failure of engineering structures is the results of damage accumulation in service. For components with slow-growing cracks, suitable maintenance program can be arranged to avoid the occurance of safety and/or functional problems. To evaluate the maintenance economy, a quantitative criterion is proposed by the authors recently. In this paper, economic life analysis for replacing components, such as hubs of aircraft wheels, is explored. It was found that there is a period for economical maintenance, and the limits of the period,TL and Tu, may be numerically calculated by above criterion. If the lifetime of the allowable critical damage is Tc, which may be estimated by any available method for fatigue lifetime prediction, the economic life may be written as Ta = min{Tu, Tc}- The economic life of aircraft hubs is finally discussed.

Key words: economic life, maintenance cost, damage growing with service time