Smart structures, which incorporated structural health monitoring (SHM) systems into mechanical components to enable online damage detection, had a strong potential to reduce inspection and maintenance cost of aircraft structures, while simultaneously maintaining or increasing the level of safety. These technologies were still in the R&D phase and significant efforts are required before smart structures will become the industry norm.

One of the research needs concerned planning of inspection and maintenance for such structures. To be able to fully exploit the capabilities of novel monitoring technologies, it is indispensable that tools were developed to plan maintenance strategies for given safety philosophies (fail-safe, safe-life, damage tolerance) taking into account information obtained from SHM.

The goal of this project proposal was to develop a methodology and corresponding software algorithms for this task. Taking basis in the renewal theory as part of the general Bayesian decision analysis framework, tools for the life cycle optimisation of inspection/maintenance activities were developed. Based on the commercial Strurel software code for reliability analysis developed and owned by the consortium leader the software tool shall be able to assess the effect of different strategies on safety and cost and thus enable the identification of optimal maintenance strategies subject to constraints on safety. The methodology was applied to a stiffened panel provided by the ITD.