Integrated aircraft risk analysis framework for health monitoring systems – a case study for structural health monitoring

Commercial aviation is characterized by severe competition and rigorous safety requirements. Even though dedicated Structural Health Monitoring (SHM) systems have been proposed over 70 years ago to improve airframe maintenance efficiency and enable lighter structures, a widespread commercial use failed to appear until today. In this line, an integrated analysis framework is proposed, connecting monitoring performance to potential useful life extensions considering structural fatigue. The analyzed monitoring system relies either on SHM or operational loads monitoring (OLM) alone or a combination of both, utilizing either the Dempster–Shafer theory (DST) or a Hidden Markov Model (HMM) for information fusion. Using this approach, the influence of varying SHM performance characteristics is evaluated for a representative part under varying loadings and initial crack distributions. Results indicate that the commercial usage of SHM is only economically viable in combination with OLM, enabling significant gains in useful life, impossible with independent SHM systems. It is argued that emerging unified data platforms providing usage statistics over the entire aircraft lifecycle serve as enabler for the broad introduction of SHM in commercial aviation.