Martin Hindley/LONDON
BRITISH AEROSPACE has revealed that the Eurofighter EF2000 is the world's first combat aircraft to be designed with an integrated structural health-and-usage monitoring system. The system is used to perform real-time airframe-fatigue calculations and to monitor "significant structural events and flight-performance parameters", says BAe.
The UK manufacturer hopes that the technology will lead to a significant reduction in the life-cycle costs of the EF2000. BAe believes that it will help to cut the number of man-hours required to perform airframe inspections and maintenance.
The system is needed because the structures of military aircraft are becoming more complex as their performance is optimised, and the number of man-hours required to maintain them is increasing dramatically. The system's inclusion in the EF2000 marks an initial phase of a wider BAe initiative aimed at exploring future so-called "smart" structural-health-monitoring equipment for combat aircraft, which would also be capable of detecting impact damage.
Designed as an integrated onboard system, the EF2000 health monitor has an array of sensors which provide real-time information on the performance of the airframe. BAe says that the system will calculate structural fatigue at up to 20 locations on the EF2000, allowing air force engineers to carry out residual-life analysis of the aircraft and perform effective maintenance planning for the fleet.
Real-time parametric data on altitude, speed and aircraft manoeuvres are captured from the digital flight-control system, and from the armament control system which provides information on the aircraft's armament configuration.
The data are fed into the onboard computer which then calculates the resulting fatigue damage to the airframe, by comparing it with 17,500 "templates" held in memory. Each template, derived from the results of ground-based airframe fatigue tests, corresponds to a particular aircraft configuration and set of flight parameters.
The process is repeated 16 times per second during a flight, building up a comprehensive history of fatigue damage at each monitored site on the airframe. Real-time analysis for direct strain measurement can be performed at the rate of up to 256 samples per second, BAe claims.
Source: Flight International
