Link between flight maneuvers and fatigue

Abstract

Structural integrity management is in a key role when operating with an ageing fleet. Preventive actions aid in keeping structures healthy and ensuring the designed lifetime for the aircraft. Our research focuses on exploitation of collected usage data by identifying actual in-flight events that cause the major fatigue life expenditure of the fatigue-critical structural details. In order to build a link between the events and damage, we have developed software for flight maneuver identification. As a latest advancement, we have created data models for several flight maneuvers and constructed a model library, referred to as template library. The library instructs the software about what the interesting events look like in the data. Our software together with the template library allows us to perform maneuver-specific fatigue assessment and achieve knowledge concerning the fatigue-criticality of various flight maneuver types. This lays a foundation for detailed analysis of the identified, nominally similar, maneuvers and identification of small crucial actions within the maneuvers that are behind the fatigue. In this paper, we consider the issues related to maneuver-specific fatigue assessment and present analysis results for four structural details of F-18 aircraft with a template library of seven flight maneuvers. We summarize the requirements and prospect of our fatigue analysis approach and prove its applicability.