High-speed 3D DIC random dynamic strain measurement of a panel subjected to Mach 2 flow

An ongoing experimental study of high-speed fluid structure interaction by the Structural Sciences Center of the United States Air Force Research Labs is presented. Previous work incorporated novel full field measurement techniques like high-speed 3D digital image correlation (DIC) and fast reaction pressure sensitive paint (PSP) for full field characterization of the phenomena. To further quantify the complex nature of the experiment, full field strains calculated from the DIC displacement results were included in the most recent analysis. Most recent tests also addressed thermal loading including buckling and resulting snap-through response. The real-time strain results from a single foil strain gauge indicated the level of strains at the panel edge were not sufficient to produce high cycle fatigue failure. However, full field DIC strain results showed that areas near the center of the panel experienced levels of dynamic strain that would cause panel cracking in relatively short order. Post test panel inspection revealed a 76mm crack along the spanwise trailing edge.