PFR - Aerospace Engineering Sciences Senior Design Projects ...

Project Final Report – CUDBF April 30 th , 2009
ASEN 4028: Aerospace Senior Projects
The wing tip displacement was also compared with the COSMOSWorks FEM prediction
together in Figure 120. The measured values are in red asterisks and the FEM predicted
displacement is shown in black line. The model agrees with the measured deflection closely,
especially below a lift load of 30 lbs. The 3g, or 23.5 lbs, predicted deflection of 0.69 inches
agrees exceptionally well with the measured value of 0.71 inches, thus validating the FEM model
of the wing used within COSMOSWorks. The maximum breaking load of the wing was
recorded as 56 lbs, approximately 7.5 g’s; far exceeding the design required 3 g minimum wing
loading. The recorded maximum displacement before failure was 2.25 inches at the wing tip,
and 1.03 inches at the hinge location.
Total Deflection at Tip and Hinge Locations, (in)
2.5
2
1.5
1
0.5
0
Wing Loading Recorded Tip and Hinge Displacements with Error Bars
Wing Tip Deflection (Max = 2.25")
FEM Modeled Wing Tip Deflection
Hinge Point Deflection (Max = 1.03")
-0.5
0 10 20 30 40 50 60
Loaded Weight = Total Lift of Wing Half, (lbs)
Figure 120: Wing Tip and Hinge location Displacement vs. Loading Plot with FEM Model Predicted
Displacement
13.1.4 Avionics Subsystem Verification and Validation
In order to verify that the microcontroller was ready to be used in competition, two tests were
conducted. The first test was to determine if the battery could power the circuit board for the
duration of the missions. The battery was composed of three 1.5V watch batteries soldered
together. A code was programmed to the PIC (Programmable Integrated Circuit) to continuously
run. It was determined that the battery could supply sufficient power for 90 minutes and since
the missions were only ten minutes in duration, the battery was deemed reliable. The second test
was to determine if the microcontroller could receive false signals and release the payloads if the
plane were in flight. The microcontroller was programmed with the complete flight code and the
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