COMPOSITES EUROPE 2012 Blog

The Fraunhofer Institute for Structural Durability and System Reliability LBF presented a four-meter-high exhibit at the COMPOSITES EUROPE – which is equipped with sensor technology SHM-wing mock-up of a light aircraft.

Fiber composites offer special advantages because of their lightweight potential in the aviation sector. The lightweight advantages may be more complex because of the damage behavior in comparison with metallic materials therefore they are not always fully exploit. In the airline for example, the impact is from foreign bodies in composite structures is a particular risk factor, limits the applications and often leads to large safety factors that require a certain amount of oversizing. Sensors which recognize, for example in the wing not externally visible structural damage at an early stage can reduce the inspection effort. The operational safety of the structure is ensured by the design and inspections at regular intervals manually. Through automated monitoring with additional structure integrated sensors can be saved in future costs and weight.

The basic idea: Structural Health Monitoring (SHM) is like the nervous system of a component. Sensors and a transmitter register external influences and track damage.

In particular, foreign bodies, such as hail or bird strike are a great danger to aircraft using a split factor when setting stones on the runway or damage caused by falling tools for maintenance work occur. In composite structures, and sandwich construction such damage is rarely visible from the outside. The security operation is so far ensured through extensive inspections and appropriate interpretation of the components.

Thanks to the SHM systems can reduce cost, weight and maintenance, lightweight structures can play out so your advantage even more. Self reduced downtime and losing weight reduces fuel consumption. The inspection effort is reduced by the continuous monitoring of the aircraft envelope, even in remote areas. Sensors act as including electrical and optical strain gauges and piezoelectric accelerometers and fiber modules.

With the integration of different sensor technologies in the production of aircraft structures, the Fraunhofer LBF works interdisciplinary and intensively together with companies of the sensor technology and manufacturing.

Aircraft Wing Mock-Up with integrated SHM system

This exhibit is a full scale wing mock-up as a feasibility study for future Structural Health Monitoring (SHM) concepts. Three kinds of sensors – piezo transducers, optical and electricalstrain gauges – are integrated in the wing, some even in the GFRP-structure itself and are used for measuring strain in flight. Load-Monitoring of structural strain will enable to estimate the residual lifetime of a structure in the future. Thus the knowledge of the actual loading helps evaluating individual (and therefore longer) maintenance intervals, as well as exploiting the full lightweight potential.

About the Fraunhofer LBF

With its comprehensive expertise in the fields of structural durability, adaptronics and system reliability, the Fraunhofer LBF develops, evaluates and implements customised solutions for all safety components – ranging from the materials to whole systems and from the first idea to the product. It works in conjunction with the associated System Reliability and Machine Acoustics department (SzM) of the Technical University Darmstadt and benefits from the experience of a team of around 300 staff. Cooperation projects with renowned partners exemplify its particular closeness to the industry. Automotive and commercial vehicle engineering, rail transportation technology, shipbuilding, machine and plant engineering, aviation, energy technology and other sectors utilise the proven expertise and cutting edge technology provided in the laboratory and testing areas that extend across more than 17,000 m².

Be Sociable, Share!

•