Figure 4: Base-Upright Structure used for Testing Figure 5: First 8 Mode Shapes of the BU Structure A FEM of the BU is available and has been shown to be very well correlated to other measured test data from previous studies [29, 30]. The BU FEM was created using plate elements for all the components and has approximately 58,000 DOFs. Rigid links were used to tie the L-brackets to the plates along the two main, 24 inch edges of the L-brackets. Solid cylindrical elements were used at the bolt locations with the appropriate mass to mimic the effect of the bolts. The BU FEM was fixed at the four locations corresponding to the points tied to the ground in the actual structure. An eigensolution was performed on the BU FEM to determine the mode shape information. For reference, the analytical frequencies and mode shapes for the first 8 modes are shown in Figure 5. The displacement data is recorded at 8 patches using digital image correlation (ARAMIS [34]) technique and at 8 target locations using dynamic photogrammetry (PONTOS [35]) technique as shown in Figure 6. The 8 targets used for PONTOS are located on top of the 8 ARAMIS patches. Both sets of data provide similar information and are provided for redundancy. Figure 6: PONTOS Target Locations and ARAMIS Patches 206
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