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Shear Strength
When a shear stress is applied to an object, the force rise to
cut or slice through,
like a knife cutting through butter.
A clevis bolt, which is often used to secure a cable to a part
of the airframe, has a
shear stress acting on it.
As shown in Figure, a fork fitting is secured to the end of the
cable, and the fork
attaches to an eye on the airframe with the clevis bolt.
When the cable is put under tension, the fork tries to slide off
the eye by cutting
through the clevis bolt.
This bolt would be designed to take very high shear loads. (the
amounts of force
that is needed to cut it in two)
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Airplane on the ground, wing undertension and compression.
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Bearing Strength
Bearing strength can be characterized by a sheet of metal being
able to
withstand being torn aware from a rivet in a joint.
The bearing strength of a material is affected by both its
thickness and by the
size of the rivet in the sheet.
A joint is said to bear up when the landing gear makes contact
with the runwayupon landing and the wing droop downward an then
spring back into the normal
position.
The spring back recovery result from the tensile stress produce
by the bearing
strength of the metal against the shear strength of the rivets
to have a certainamounts of elasticity. ( the amounts of force that
will cause the rivet to tear out
from the metal )
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2017T bearing
( T
solution heat treated )
Recessed Dot head.
AN Material Code - AD
aluminum alloy.
Shear Strength (psi)34,000
Bearing Strength (psi)113,000
Used in construction of skins.
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10. SUBSTRUCTURES
1. COMPRESSION RIB
A heavy-duty rib made with heavy cap strips and extra strength
webs.
A compression rib is designed to withstand compression loads
between the
wing spars.
Have Compression and Tension force.
2. BULKHEAD
A structural partition in a wing or fuselage.
Provide additional strength.
Have Compression and tension force.
3. FUEL CELL BAY
engine fuel storage
Have tension force
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4. RIBS
Space at intervals throughout the wing structure and form shape
of the leading
edge , camber and trailing edge.
have bending and compression force.
5. DRAG WIRES
The wires that extend from the front spar to the rear spar and
there are runing
diagonaly from inboard to outboard oppose the force tend drag
against the wingand pull it backward.
Have tension force
6.ANTI-DRAG WIRES
Wires that run between the front and rear spar and run
diagonally from outboard to
inboard Have tension force
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7. FORMER
A frame of light wood or metal that attaches to the truss of the
fuselage or wing in order
to provide the required aerodynamic shape.
Have Tension, Bending and Compression force.
8. STRINGER
A thin metal or wood strip running the length of the fuselage to
fill in the shape of the
formers Have Tension, Bending and Compression force.
9. COMPRESSION STRUT
A brace that fits between two structural members. The members
tends to move toward
each other in compression.
Between upper and lower spar section. Have Compression
force.
10. SPAR
Runs the length of the from the root to tip.
have bending and compression force.
