22 Nonlinear Response of a Thin Panel in a Multi-Discipline Environment: Part I—Experimental Results 243 100 a b 200 300 400 500 600 700 800 900 100 200 300 Pixels Pixels 400 500 100 200 300 400 500 100 200 300 400 500 600 700 800 900 Fig. 22.8 Full field measurement of panel temperature using FLIR: (a) without the quartz window, and (b) with the quartz window. Note that the temperature scales are different and that the maximum panel temperature in (a) is 77 ıC and approximately 22ıC in (b) due to the IR filter effect of the quartz window To prepare for this last test objective, the exploration of interesting post-buckled nonlinear behavior, an integral frame/panel test specimen from the second year of testing was used to study panel buckling and post-buckling behavior. This thermal testing was also used to assess the halogen lamp heating arrangement required for panel buckling during RC-19 experiments. This thermal experimental setup for the heating test is shown in Fig. 22.9. The panel is bolted to a section of the RC-19 tunnel wall to better represent the upcoming wind tunnel experiments. Two Lowel Pro-light TM halogen lamps were used to heat the surface of the panel. As shown in Fig. 22.8, the heat from the lamps led to a non-uniform temperature field on the surface of the panel; however, the panel/frame temperature differential did lead to buckling. The full-field static deflections were measured using a pair of high-resolution (6 Megapixel) Allied Vision Prosilica GT 2750 DIC cameras. The full-field temperatures were measured using a high-resolution FLIR Systems SC6000 infrared camera shown in Fig. 22.9. The accumulated experience from the two previous RC-19 wind tunnel experiments, and the more recent thermal experiments, are providing the foundation for the upcoming, final RC-19 experiments. A sampling of results, emphasizing the nonlinear nature of the experiments, will be presented and discussed in the following section. 22.3 Preliminary Results and Discussion The principal purpose of the experiment was to measure the effects of the turbulent boundary layer and shock impingement on the response of the panel specimen while simultaneously recording the full-field surface pressure and panel dynamic displacement. It is the goal of the SSC to provide a relevant experimental data set for the validation of this class of aerostructural problem. It has also always been the intent to explore interesting nonlinear experimental behavior, and the following examples elucidate this last objective. In the first year of testing, two experimental configurations demonstrate both the sensitivity of the panel response to SBLI and the potential for the panel to behave nonlinearly. In Fig. 22.10, two different experimental cases are examined, where the shock generator is first flush with the tunnel bottom wall, e.g., no SBLI effect, and
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