In the past two years, the aviation industry has suffered billions in losses due to the pandemic and is forced to make considerable savings. Technical measures can also help. The author Joseph Flaig of the British Professional Engineering Magazine considered in one Contribution the considerable savings potential that Structural Health Monitoring (SHM) holds.
At SHM, sensors, actuators and intelligent materials are used to detect minor damage to aircraft structures before they become larger and more dangerous. The widespread introduction of SHM could both significantly improve safety and reduce maintenance and repair costs, which are estimated to make up a quarter of the operating costs of an aircraft fleet, Flaig quotes from the researcher’s book “Structural Health Monitoring (SHM) in Aerospace Structures” Fuh-Gwo Yuo from North Caroline State University. The valuable time in the air can also be maximized in this way.
For example, one of the commercial SHM devices is the Smart Layer from Acellent Technologies. The device is an extremely thin dielectric film with a series of networked piezoelectric sensors that generate a voltage when deformed. It contains strain gauges, thermometers and fiber optic sensors to detect local damage and delamination – breaks in layers – as well as impacts.
Another option is CVM from Structural Monitoring Systemswhich enables real-time monitoring of crack formation and propagation. The sensor measures the differential pressure between fine “galleries”, in which there is a low vacuum, and galleries with atmospheric pressure. If there is no crack, the vacuum will remain at a stable level. However, if a crack develops, air flows from the atmosphere into the vacuum galleries and is measured by a transducer.
The devices can either be designed as self-adhesive polymer sensors or be part of a component. Embedded sensors have been the subject of research in recent years for their use in diagnosing complex defects in composite materials.
The US Army Research Laboratory for example, investigates the embedded strain measurement and damage monitoring in polymers with 3D-printed carbon nanotubes.
“The conductive nature of these materials could lead to an unprecedented level of multifunctionality, with potential for real-time SHM through embedded strain measurement and damage monitoring that will lead to a safe and accurate assessment of remaining life in vehicle components.”
Dr. Yelena sliozberg, US Army Research Laboratory
Above: Structural health monitoring can save aviation high costs. (Source: Pixabay | April_Kim)
Source and further information: Professional Engineering Magazine