Understanding Acoustic Emission Testing- Reading 1 Part B-A

■ Aerospace Structures
Most aerospace structures consist of complex assemblies of components that
have been design to carry significant loads while being as light as
possible. This combination of requirements leads to many parts that can
tolerate only a minor amount of damage before failing. This fact makes
detection of damage extremely important but components are often packed
tightly together making access for inspections difficult. AET has found
applications in monitoring the health of aerospace structures because
sensors can be attached in easily accessed areas that are remotely located
from damage prone sites. AET has been used in laboratory structural tests,
as well as in flight test applications. NASA's Wing Leading Edge Impact
Detection System is partially based on AE technology. The image to the right
(above) shows a technician applying AE transducers on the inside of the
Space Shuttle Discovery wing structure. The impact detection system was
developed to alert NASA officials to events such as the sprayed-on-foam
insulation impact that damaged the Space Shuttle Columbia's wing leading
edge during launch and lead to its breakup on reentry to the Earth's
atmosphere.
Charlie Chong/ Fion Zhang