Inspection Intervals Optimization for Aircraft Composite Structures Considering Dent Damage

Abstract

Many probability techniques have been proposed, but the inspection intervals for composite structures have not been comprehensively addressed. The present study focuses on the most frequent damage type, dent, and uses probabilistic approaches to analyze statistical characteristics of the damage based on maintenance data from a Chinese airline. Dent sizes are considered from three dimensions: the damage diameter, the damage depth, and the diameter/depth ratio. The life-cycle strength of a composite structure is obtained by Monte Carlo simulation, and the probability of failure is quantified corresponding to different inspection intervals. Maintenance cost is introduced, as another criterion, to optimize inspection intervals from both safety and economy. This method enables the dent damage to be assessed quantitatively, which can facilitate engineers from airlines or manufacturers to evaluate the damage tolerance of the composite structure and adjust their related inspection schedules flexibly.