Potential Benefit of Structural Health Monitoring System on Civil Jet Aircraft

Abstract

Structural health monitoring represents an interesting enabling technology towards increasing aviation safety and reducing operating costs by unlocking novel maintenance approaches and procedures. However, the benefits of such a technology are limited to maintenance costs reductions by cutting or even eliminating some maintenance scheduled checks. The key limitation to move a step further in exploiting structural health monitoring technology is represented by the regulation imposed in sizing aircraft composite structures. A safety margin of 2.0 is usually applied to estimate the ultimate loading that composite structures must withstand. This limitation is imposed since physical nondestructive inspection of composite structures is really challenging or even impossible in some cases. However, a structural health monitoring system represents a viable way for a real time check for the health status of a composite structure. Thus, the introduction of structural health monitoring should help into reducing the stringent safety margin imposed by aviation regulation for a safe design of composite structures. By assuming a safety margin reduction from 2.0 to 1.75 thanks to the installation of permanently attached sensors for structural health diagnostics, this paper assesses the potential fuel savings and direct operating costs through a multidisciplinary analysis on a A220-like aircraft. According to the foreseen level of technology, addressed through the number of sensors per square meter, a DOC saving from 2% up to 5% is achievable preserving, at the same time, all the key aircraft performance.

Laboratory Results of a Real-Time SHM Integrated System on a P180 Full-Scale Wing-Box Section

“…As the tables show, it is clear that the edge detection principle at the base of the methodology is able to detect the damage onsets (Figures 23 and 24). It is also important to remark that numerical studies have demonstrated that the effect of the damage over the strain field extends larger than the current damage size [20]; therefore, it can be expected to find out readouts at the inner and outer boundaries of the damage borders.…”

“…Hence, in the absence of a jump/edge, the cumulative damage index (2) will be small. On the contrary, if an edge is present, then the two function values in (2) will be quite different from zero [20].…”

“…A wide review of recent applications of sensing technologies for SHM systems employing embedded sensors shows an interesting analysis of FBG capabilities with respect to other devices mounted on aircraft and other structural systems [ 19 ]. A more general scenario is reported in [ 20 ], where a number of significant examples are cited. In detail, the authors refer to the distinction among passive or active methods, depending on the characteristics of the methodology to rely on the response of the structural system as it is [ 21 ] or introducing some external energy to drive specific actions to induce some specific effect able to be measured by a dedicated network [ 22 ].…”

A Systematic Literature Review of the Predictive Maintenance from Transportation Systems Aspect

“…PdM techniques encourage non-damaging testing methods such as acoustic, infrared, sound level, oil analysis, vibration analysis and thermal image recognition that measure and collect real-time data of equipment through sensors. Classification of sensor data with the aid of AI or statistical techniques is the most basic building block of PdM activities in order to estimate time of the failure or RUL of the equipment [17][18][19][20].…”