Optimal inspection planning and repair under random crack propagation

Operation of damage-tolerant structures or components subject to random crack propagation requires constant monitoring by non-destructive inspections and systematic maintenance actions. Optimization of inspection schedules and repair strategies is a compromise between costs of inspections and repairs, and expected costs of failure. This paper advances the state of the art by: considering accurate polynomial chaos model of the random crack propagation process; considering number of inspections and crack repair size as design variables and; by performing sensitivity analysis of optimal inspection schedules and repair strategies with respect to the assumed costs of inspection and failure, as well as to the level of loading.