Optimal replacement policy with minimal repair and preventive maintenance of an aircraft structure subjected to corrosion

This study focuses on a replacement policy using preventive maintenance and periodic inspections with minimal repairs for a deteriorating aircraft structure suffering from corrosion damage. The type of structure component operates normally when its cumulative corroded depth that does not exceed the maintenance allowance threshold and satisfies the reliability requirement. We assume that the number of minimal repairs and preventive maintenance time are both stochastic variables with a independent geometric distribution, and the lifetime has a Weibull distribution. An optimal replacement model is formulated to minimize the expected cost rate with two constraints: corrosion threshold and reliability level. The optimal time interval \(T^{*}\) between the two successive periodic inspections with minimal repairs and the number of preventive maintenance \(N^{*}\) can be obtained by an improved iteration algorithm using the golden section method and quadratic interpolation method based on stochastic simulation. Finally, a numerical example using parameters sensitivity analysis is illustrated to verify the proposed model and algorithm.