The Accelerated Combined-Effects Simulation (ACES) test apparatus, a new test chamber custom designed under the direction of the Air Force Research Laboratory (AFRL) at Wright-Patterson Air Force Base, Ohio, USA through a Small Business Innovative Research program award, allows AFRL researchers to recreate the broad range of simultaneous environmental conditions that military assets are exposed to, including ultraviolet (UV) radiation, temperature, humidity, and various gaseous environments.
Additionally, dynamic fixtures allow test specimens to be pulled and flexed to further simulate the structural stresses experienced by aircraft during flight conditions. The ability to include all these variables in one testing event is important because it simulates a more realistic operational scenario without long-term outdoor exposure testing.
“Under real-world conditions, corrosion begins around areas such as seams and fasteners,” says materials research engineer Nicholas Wilson. “Dynamic stresses cause pulling at fasteners, the paint starts to crack, moisture gets underneath, and a corrosion cell develops under the coating. This type of corrosion is what we are now able to replicate with the ACES chamber.”
The test chamber includes six dynamic fixtures to hold and apply stress to test fixtures, as well as a lighting system for easy observation of test activities. Luminaries above the chamber recreate the full solar spectrum for testing specimens under realistic solar conditions.
When the luminaries are not in use, insulating pads can be moved into position to help regulate chamber temperatures, which can be raised to >150 °C and lowered to –60 °C.
Source: Holly Jordan, Wright-Patterson AFB, www.wpafb.af.mil.