AFRL Tests Advanced Imaging Technology for High-Temperature Acoustic Environments

  • Published
  • By Holly Jordan
  • Air Vehicles Directorate
WRIGHT-PATTERSON AIR FORCE BASE, Ohio --  AFRL researchers tested advanced imaging technology designed to aid stress detection in structures subjected to jet engine exhaust and its associated high temperatures, noise, and vibration. The proof-of-concept testing, held at Edwards Air Force Base, California, involved an ARAMIS optical digital image correlation unit and a forward-looking infrared camera system. The intent of this effort was to prove the combined capacity of these imaging systems to collect data in an operational on-aircraft environment. The B-2 served as a suitable environment for testing these new imaging technologies. Throughout testing, the ARAMIS/FLIR technology performed successfully up to levels of 70% maximum engine output. Data collected from each engine run will facilitate more thorough ongoing analysis.

The ARAMIS system, produced by Trilion Quality Systems, employs two optical cameras, each of which views an article of interest in order to capture contrasting paint patterns on the article's surface. The system's built-in special software then analyzes pattern movement and calculates displacement measurements in a three-dimensional plane. These measurements enable ARAMIS to determine the article's total strain. Meanwhile, the FLIR camera reads the overall temperature across the article's surface. Researchers using data captured by the ARAMIS and FLIR camera systems can view the full-field mechanical stresses of a given test article simply by backing out the strain caused by thermal expansion. This data, used in conjunction with computer modeling tools, can be very valuable when testing primary aircraft structures in extreme thermal and acoustic environments wherein traditional testing methods are unsuitable.

Ultimately, AFRL anticipates using this combined-camera-system approach to detect deflections, which can be used to quantify stress patterns. Plans for future tests of the ARAMIS/FLIR camera system are in the works. During this upcoming testing, the technology will undergo ruggedization in order to better withstand the thermal and acoustic effects of jet engines running at maximum throttle.