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Development of E2E Maintenance architecture process and methods enabling a reliable and economic air transport system

Periodic Reporting for period 3 - DEMETER (Development of E2E Maintenance architecture process and methods enabling a reliable and economic air transport system)

Reporting period: 2018-12-01 to 2019-11-30

The project “Process and Methods for E2E Maintenance Architecture development and demonstrations and solutions for technology integration” (DEMETER) is oriented in “Process and Methods for E2E Maintenance Architecture development and demonstrations and solutions for technology integration” within the work package WP 3.6 “Maintenance”. The overall objectives of DEMETER is to support the development and evaluation of a value driven End-to-End (E2E) maintenance service architecture enabling the replacement of systematic scheduled maintenance by condition based maintenance. The following cost reductions are targeted with an E2E maintenance service architecture :
• Reduction of the aircraft technical induced operational disruption by 0.2% to 0.5% with cost savings per year between 133M€ and to 334M€,
• Reduction of the current average delay time of 28 minutes by 2 to 4 minutes enabled by enhancements in line maintenance support tools, remote expert support and enhanced diagnostic efficiency. This can provide approximately 195M€ to 395M€ savings per year.
In order to meet the expectations in WP 3.6 with economic and ecological technologies the following technological objectives are faced within the DEMETER project:
1. Definition and development of service oriented architecture for legacy fleet.
2. Evaluation of the efficiency and performance of an E2E architecture.
3. Integration of key fundamental technology bricks, e.g. structure health monitoring, into condition based maintenance concept.
4. Improve the technology readiness level of the promising structural health monitoring systems from TRL 4 to 6.
5. Analysis of design rules, system and performance requirements
6. Development of algorithms prototype and, overall validation of the E2E platform and its technology.
7. Develop and adapt the simulator to integrate the results from other WP demonstrators and demonstrations and to enable the E2E maintenance platform evaluation
A service oriented E2E maintenance architecture and service solution for the legacy fleet operating in the European airspace today can enable the reduction of the maintenance effort, due technical faults or performance degradation observed on aircrafts flying.
The process of an E2E maintenance architecture incorporate global and local sensor data of an aircraft combined with model based load and damage assessment and the ability to predict the remaining life of aircraft components before failure (prognostic) are used to adapt the today’s given scheduled maintenance plan. More importantly, with such condition-based maintenance, the amount of unscheduled maintenance can be reduced and combined with an increase in safety. Utilizing SHM systems the structural mass can be decreased without decreasing the safety of the aircraft.
The necessary maintenance can be done more efficiently through faster and more accurate troubleshooting. Less waste of materials reduces the maintenance costs even further. A cost reduction can be achieved in an improved spare parts stock prediction. In all, the overall platform operational availability, utilization and safety can be increased while costs can be decreased with a condition based maintenance system.
The project was divided into 2 main areas and was carried out by two partners, the German Aerospace Center and the Netherland Aerospace Center. The first focus with about one third of the budget was the evaluation of technologies. These technologies were developed in the second focus of DEMETER and in two sister projects of CleanSky 2. The evaluation should compare the previously assumed technological advantages with those achieved in the projects. Therefore an evaluation concept based on questionnaires and evaluation matrices was developed. The evaluation approach was developed together with M2P from the AIRMES project. Therefore all technical results from both projects were collected and evaluated with the AirTobs tool. The overall results were described in deliverables 4.1 and 4.2.
In the second part of DEMETER, which accounts for about two thirds of the budget, research was conducted on usage and structural health monitoring systems. Usage monitoring uses flight data and converts them into usable information with the help of simulation models. This enables the real usage at selected positions of the aircraft to be analyzed and thus to change the maintenance interval from a previously fixed planning to a variable usage-based planning. In DEMETER, different models such as flight simulation, stress calculation, structural fatigue assessment and maintenance planning were networked and analyses were carried out. The input data for the flight maneuvers can be extracted from the flight recorders or, in the case of DEMETER, data from Flight Radar24. The considered Use Case was the engine mount. It could be shown that such a usage monitoring evaluation chain can be built up in a decentralized, modular way. The modules are flexibly exchangeable and the respective partial services can be offered separately in the future. The developed data exchange concept is flexible and expandable.
While a Usage Monitoring System uses existing data to make an assessment, Structural Health Monitoring Systems use sensors at specific positions in the structure to monitor it. Two systems were considered. First, strain sensors (Fibre Bragg Sensors) were used to check load paths. Here, the engine mount was also used as a use case. If a load path fails due to damage, the system automatically reports the need for repair. The second technological approach is based on the area-wide monitoring of structures using guided ultrasonic waves. A concept evaluation showed that 5% structural mass can be achieved with such a system due to an adapted aircraft design. In the project this technology was further developed to compensate for environmental influences and to detect the damage by means of machine learning algorithms. Once the damage has been detected, an evaluation of the damage itself is helpful in deciding whether a repair is necessary. For this purpose, methods have been further developed to make this possible. It is possible to transfer impact damages based on structural health monitoring systems and classical non-destructive testing methods into a model. By analyzing the damage, the residual strength can be calculated and evaluated if a repair is necessary.
The results of the DEMETER project have been disseminated in a number of conference and journal publications. Researchers in the project provided parts of the measurement data on the open platform Open Guided Wave (http://openguidedwaves.de/) and a final conference was organized and conducted.
Fig. 3 Specimens for environmental effects compensation experiments
Fig. 2 Generic experimental validation of a SHM concept for joints
Fig. 1 E2E Evaluation Workshare