Bending Test #1
Used a 10.5 in x 4.5 in balsa piece to support the testing loads.
Weight One: 1.8lb plate
Weight Two: 3.0lb plate
Weight Three: 4.4lb plate (very small displacement)
VIDEO
Observed failures after the test with Weight Three:
Weight Four: 5.2lb plate (small displacement)
Weight Five: 6.2lb plate (small displacement)
Torsion Test #1
Glue the fuse to a balsa plate and attach a wooden rod on the top.
Rod length: 10.5 in
Right side overhang: 2.25 in
Left side overhang: 2.25 in
Apply force to the tips of both ends of the rod and observe the changes in the angle.
Tested by twisting to the left and the right.
The final test conducted was by twisting it counterclockwise until failure.
Observations:
1.
Balsa tends to fail along the grain direction.
2. With a counterclockwise torsion direction, the right side experienced shear failure to the immediate left of
the plywood longerons.
Improvements:
1.
Add more structural panels along the sides.
2.
Add gussets to the first and last panels to support against twisting.
3. Replace the first and last bulkheads with plywood or with two balsa bulkheads glued together that have
opposite grain directions.
4.
Make plywood longerons taller to increase shearing area.
5. Add stringers across the fuselage.