Wing Rib Analysis Shear Center for 3 Stringer Closed Cell
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Transcript of Wing Rib Analysis Shear Center for 3 Stringer Closed Cell
Calculation of line of action of the SHEAR CENTER for the three-stringer closed cell
Vertical Force Pz = 2000 lbsThickness of Rib web tab = 0.08 in.Thickness of Rib sec b-c tbc = 0.06 in.Thickness of Rib sec a-c tac = 0.04 in.Length of Rib web a-b Sab = 10 in.Length of Rib sec b-c Sbc = 10 inLength of Rib sec a-c Sac = 25 inCell enclosed area Ao = 100 sq.inCell circumference C = 45 inDist at which P acts from web d = 5 in
The web shear flows can be found by static:
-10000 = qac*2*AoHence qac = -50 lbs/in
qac*Sbc = qbc*Sbcqbc = -50 lbs/in
qab*Sab+qac*Sac = Pzqab = 150 lbs/in
The cell with the 2000lbs load applied at 5 inches away from a-b will undergo bending and rotaionA balance shear flow qt is then applied to this cell to twist it back to its original position.the angle of twist is
Therefore counterclockwise is positive.
the resulting shear flows represent the shear flows in the cell when the 2000lbs.load is applied at shear center.the final shear flows are shown below.
From åMb=0 about lower point on the web:
From åFx = 0
From åFz = 0
Calculation of line of action of the SHEAR CENTER for the three-stringer closed cell
The cell with the 2000lbs load applied at 5 inches away from a-b will undergo bending and rotaion
counterclockwise is positive.
the resulting shear flows represent the shear flows in the cell when the 2000lbs.load is applied at shear center.
INPUTSL NO DESCRIPTION SYMBOL VALUE UNITS
1 Vertical Force 2000 lbs
2 Thickness of Rib web 0.08 in.
3 Thickness of Rib sec b-c 0.06 in.
4 Thickness of Rib sec a-c 0.04 in.
5 Length of Rib web a-b 10 in.
6 Length of Rib sec b-c 10 in
7 Length of Rib sec a-c 25 in
8 Cell enclosed area 100 sq.in9 Cell circumference C = 45 in
10 Dist at which P acts from web d = 5 in
OUTPUT
Shear Flow on a-c -50 lbs/in
Shear Flow on b-c -50 lbs/in
Shear Flow on a-b 150 lbs/in
Balance shear Flow qt 22.73 lbs/in
Resulting Shear flows 27.27 lbs/in
27.27 lbs/in
172.73 lbs/in
The resulting shear flows depends on the direction of the shear flows.
Shear Center ee = 2.73 in.
Calculation of line of action of the SHEAR CENTER for the three-stringer closed cell
Pz =
tab =
tbc =
tac =
Sab =
Sbc =
Sac =
Ao =
qac =
qbc =
qab =
qt =
qfac =
qfbc =
qfab =
Calculation of line of action of the SHEAR CENTER for the three-
The web shear flows can be found by static:
-10000 = qac*2*AoHence qac = -50 lbs/in
qac*Sbc = qbc*Sbcqbc = -50 lbs/in
qab*Sab+qac*Sac = Pz
qab = 150 lbs/in
The cell with the 2000lbs load applied at 5 inches away from a-b will undergo bending and rotaionA balance shear flow qt is then applied to this cell to twist it back to its original position.
the angle of twist is
Therefore counterclockwise is positive.
-31250 qt(Sac)/tac -8333 qt(Sbc)/tbc 18750qt((Sac/tac)+(Sbc/tbc)+(Sab/tab)) = 20833.3333333333qt = 22.7272727272727
the resulting shear flows represent the shear flows in the cell when the 2000lbs.load is applied at shear center.the final shear flows are shown below.
From åMb=0 about lower point on the web:
From åFx = 0
From åFz = 0
qt(Sab)/tab
