CALCS PROC056
DEPTH OF BHD STIFFENERS TO SUPPORT SEAT

NOTATION

Mmoment, applied, seat
Pforce, applied, seat
f0stress, direct, max, immediately under seat, bhd
fzstress, allowable, at depth z
l0length, support, immediately under seat
lzlength, support, at depth z
zdepth, thru bhd, below seat

APPLICATION

bulkhead supporting seat frame member, under moment and vertical force loading

OUTPUT

depth at which load disperses to acceptable level for regular stiffening arrangemet

SEE ALSO

PROC055

THEORY

BS5400

GUIDANCE

Linear variation in direct stress is assumed across the loaded width l. The seat frame member must consequently be adequately stiff and strong under this loading.

INPUT FORMAT

LET A0=:Y0=:I0=:L0=:P=:M=:fz=:PROC056

EXAMPLE

Call Statement

LET A0=362.8:Y0=161.7:I0=2.854E6:L0=277.9:P=175.3:M=2.434E4:fz=1.101:PROC056

Output

PROC056 DEPTH OF ADDITIONAL BULKHEAD STIFFENERS, Rev 290599
A= fz= 1.101
B= -P/A0= -0.4832
C= -M*Y0/I0= -1.379
K1= (-B+SQR(B^2-4*A*C))/(2*A)= 1.36
Z= L0*(K1-1)/2= 50.01
K2= (-B-SQR(B^2-4*A*C))/(2*A)= -0.921
Z= L0*(K2-1)/2= -266.9
END056