Overview
An acute need existed to be able to develop the capability of reliably monitoring aircraft structural health in real-time. Real-time structural health monitoring will improve the overall safety and make it possible to replace corrective or preventive maintenance modes with much more efficient predictive or proactive maintenance procedures, thus reducing the associated costs. Similarly, vibrations and noise levels are still too high in certain aircraft. Systems based on smart materials, defined as solid-state actuators activated by external fields, can address all these factors.
The objective of the ARTIMA project was to achieve a significant improvement in aircraft reliability through the application of smart materials. These materials are considered ideal, both for reducing the probability of failure through vibration control and for detecting in time the defects that have already occurred.
The project provided the momentum to produce realistic industrial solutions for real-time structural health monitoring and aircraft vibration reduction. The most promising methods were tested on large-scale specimens, including a portion of a commuter aircraft fuselage. A network consisting of several production companies, research institutes and universities achieved the project's goals. The expertise developed as part of this project will be ideal to stimulate the creation and development of small, high-tech enterprises.
The project:
- developed a real-time structural health monitoring system for real aircraft parts with acceptable reliability (low rate of false alarms and missed defects)
- developed a practical, robust Active Constrained Layer Damping treatment for aircraft
- developed a rotor blade icing detector capable of measuring ice thickness on the rotor blade, and the ice distribution and accumulation rate. PZT-based systems will be tested
- investigated the feasibility of applying encapsulated PZT actuators and Magnetic Shape Memory Actuators for wing vibration control.
ARTIMA's objectives were achieved through the collaborative effort of eleven organisations from seven countries. Smart materials, such as piezoplates, and Magnetic Shape Memory Materials drove the active systems in structural health monitoring and vibration damping applications that were developed. Optical (FBG) sensor systems were applied for passive load monitoring and damage detection. These systems were be tested in a realistic environment on a portion of the rear fuselage of a commuter aircraft and in another airframe part.
The extra benefit of this project, which contributed to both damage detection and vibration control, was the development of a new icing detection system. Icing may be considered as 'reversible damage'. It does do damage, but it mainly affects the less tangible factors, such as aerodynamic qualities. The resulting deterioration may create excessive vibration levels and lead to a total hull loss.
The project began by specifying the parameters of specimens to be tested. This work was organised as Work Package 1. Work Package 2 covered the analytical studies intended to better define the characteristics of systems to be tested, and developed the necessary models and algorithms. The work done in this Work Package help in making important decisions regarding the analytical tools used in the following portions of the project. Work Package 3 is where the small-scale specimens were designed and fabricated. These specimens were used to evaluate practical issues associated with implementing the selected systems, and to validate the models and algorithms developed in the course of Work Package 2. Large-scale specimens were designed and fabricated, as part of Work Package 4. The lessons learned in the course of Work Package 3 were extensively applied in the process of the large specimen fabrication. All the specimens fabricated previously were tested as part of Work Package 5. Results of these experiments were analysed as part of Work Package 6. These results and the experience acquired during the project formed a basis for making design recommendations, a part of Work Package 7. A smooth flow of work was assured and the inevitable problems were solved as part of Work Package 8.
Funding
Results
The ARTIMA project tested the most promising materials and methods on large components, including a metallic corporate jet body or fuselage, rotor blades and an active unmanned aerial vehicle wing.
Thus, the ARTIMA project represented a final push to provide realistic industrial solutions for aircraft safety using state-of-the-art smart materials and technologies. Results of the ARTIMA project regarding SHM are expected to significantly increase safety while providing a substantial decrease in operating and maintenance costs. In addition, outcomes with respect to vibration control and noise reduction should further enhance safety and improve passenger comfort. Enhanced safety and comfort of European aircraft will provide a competitive edge for the European aerospace industry regarding design and manufacturing as well as consumer satisfaction and confidence.
The ARTIMA project took advantage of the wide knowledge accumulated over the last two decades by its participating organisations concerning the development of smart materials and their applications. The most promising methods have been tested on large-scale specimens, including rotor blades, composite control surfaces, an active unmanned aerial vehicle (UAV) wing, and a metallic corporate jet fuselage, apart from representative laboratory specimens.
Real time structural health monitoring (SHM) will not only improve the overall safety, but will also make it possible to replace corrective or preventive maintenance with much more efficient predictive or proactive maintenance procedures, thus reducing operation cost. Similarly, vibrations and noise levels will be significantly reduced by the use of smart actuators, which involve no moving parts, they can provide distributed actuation, and they can be integrated into metallic and composite structures with ease.
Project goals were achieved thanks to the fruitful network consisting of several manufacturing companies, research institutes and universities, leaded by Aernnova (Spain). These were DLR, Eurocopter and EADS (Germany), the FOI (Sweden), IFFM (Poland), IST (Portugal), Tecnatom and UPM (Spain), and USHF (United Kingdom).
The one-day workshop gave a broad idea of the state of the art in SHM and vibration control methods, covering the advances reached within the project in the fields of numerical simulation, laboratory work, full-scale structure instrumentation, and real-world applications. It was held at the Technological Park close to the monumental city of Vitoria, in
Technical Implications
ARTIMA project resulted in:
- Development of reliable, real-time, built-in damage detection systems;
- Development of reliable and effective vibrations control systems;
These will significantly improve the reliability of future and existing aircraft.