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Structural Analysis and Design
Wing Design The wing design of
the aircraft highly resembled that of a flying wing. The
structure was made from carbon fiber arrows which were relatively
inexpensive and extremely light weight. The carbon fiber
arrows acted as the backbone structure for the ribbing design of the
wingspan. The ribbing structure of the aircraft was made from
3/32" balsa wood (also used for its lightweight and
inexpensiveness). The ribs were placed at intervals of 4".
Wing Design:
Rib Spacing:
Aluminum pins were used to connect the end wings and center wings
together. The team's design called for a 5º
bend at the thirds of the wing. This was done by
bending the aluminum pins at 5º angles.
The bend in the design provided the aircraft with greater stability
in both windy and non-windy conditions. Also, the end wings
were removable to meet the packaging constraints set forth in the
requirements.
Tail Design The team's tail
design focused on increasing the stability of the entire aircraft.
Carbon fiber arrows were also chosen to be the main material for the
tail structure. The team chose a straight triangular truss as
the tail design. The design placed 3 longitudinal carbon arrow
shafts at intervals of 1.5". To reduce weight further, and to
increase the stability, a V-tail design was adopted for the
aircraft. This allowed for 2 servos to be used since the pitch
and yaw would be controlled by 2 surfaces. The angle between
the V-tail was chosen to be 110º, which resulted in a 2:1 ratio of
horizontal surface area to vertical surface area, making is a good
copy of the traditional rudder/elevator setup. The V-tail and
the triangular truss were connected by a tail brace.
Tail Design:
Superpatch Design
The superpatch was the part of the aircraft to which all other parts
were attached. A poly-carbonate plastic was chosen because of
its light weight and its reasonable strength to weight ratio.
The ribs that attached to the superpatch were made out of 3/32"
balsa wood and were put into place to make the entire structure
aerodynamic. The payload was attached to the superpatch, but
had no affect on the structural integrity of the plane. The
payload bay was designed to be enclosed by an aerodynamic shell,
designed to help reduce the drag. Superpatch Design:
Landing Gear
The landing gear the team selected was
pre-fabricated model airplane landing gear. The model chosen
was a 0.40-0.60 size carbon fiber gear design. This model was
capable of being adapted to fit the location specified by the
aircraft design for attachment, because it had no pre-drilled holes.
This landing gear was specified to withstand between 50 and 60
pounds of force and deflected enough to act as a suspension.
Landing Gear:
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