PFR - Aerospace Engineering Sciences Senior Design Projects ...

Project Final Report – CUDBF April 30 th , 2009
ASEN 4028: Aerospace Senior Projects
locations, the required whiffle tree configuration was designed as seen in Figure 116, where ∆
corresponds to a distance of 5 inches.
() = −0.001 + 0.0215 + 0.807
Equation 35: Estimated Wing Loading Function
Figure 116: Whiffle Tree Final Design
The results from the test were then compared to a predicted max tip displacement of 0.62 inches
at 3 g loading, and with a COSMOSWorks FEM model prediction of 0.69 inch max tip
displacement. The COSMOSWorks FEM model and loading analysis are shown in Figure 117.
Figure 117: COSMOSWorks FEM Model of Tip Displacement
The whiffle tree then distributed a single load applied on the bottom rung to model the actual lift
curve along the wing. The whiffle tree system was composed of multiple straps and metal beams
placed onto the wing and taped into place to avoid slippage during testing. Weight was applied
in 5 lb increments to the bottom rung of the whiffle tree to a loading of 3 g’s (22.5 lbs), which
the wing was designed to withstand. The deflection at this point was then measured by using a
ruler to measure the difference between the wing tip and an above the wing beam reference.
This beam reference was a spar mounted above the wing onto the 2”x4” board where
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