3-D Digital Image Correlation Method (Nsa3)

3-D Digital Image Correlation Test (Nsa3)
Full-field Surface Displacement

An initial compression test of a composite stub wing cover panel with three stiffeners and a center notch was performed at NASA Langley Research Center. The dimensions of the Kevlar-stitched, resin-film infused, graphite-epoxy panel were 1.06 m long, 0.482 m wide, and 12 mm thick with a 183 mm notch. Since strain gages covered most of the skin side of the panel, the pattern was applied around the gages and lead wires, as shown in the following figure.

Front Panel 2 Dim.jpg (79188 bytes)

Breaking the surface into five disjoint regions resulted in acquiring five separate data sets that had to be recombined into a single data set. The maximum measured displacement in the W (out-of-plane) field was 2.765 mm, the V_max (vertical) displacement was –3.555 mm, and the U_max (horizontal) displacement was 0.701 mm. An animated GIF is provided to illustrate the panel deformation. Out-of-plane buckling in the Z direction can be clearly seen in the panel profile during the test. A contour map displayed on the profile surface illustrates the deformation in the X direction.

U Displacements on Profile

The VIC-3D data for out-of-plane displacement was compared to DCDT measurements for a single point on the panel. The DCDT was located on the web of the central stiffener, approximately 46 mm above the notch centerline, and the VIC-3D measurements were obtained at the same position on the opposite side of the panel. The data from both systems was in good agreement.

Go Home!