Shelf Front Loaded Ceiling Force Math

shelfTopForceCalc.py

from math import sin, atan, degrees

numberOfShelves = 13
shelfSpacing = 8.0 ##inches
shelfBaseOffsetFromFloor = 4.0 ##inches
l_s = 5.0 ## inches, length of the shelf before the pole to the books
poleHeight = 106.0 ## inches, 8' 8" in inches
sumM_b = 0

for shelfNumber in range(0,numberOfShelves):
    print "shelf number: ", shelfNumber
    l_p = shelfBaseOffsetFromFloor + (shelfNumber * shelfSpacing)
    print "l_p: ", l_p, "l_s: ", l_s
    theta_s = atan(l_s/l_p)
    l_h = l_s / sin(theta_s)
    print "Shelf angle from base: ", degrees(theta_s), "Shelf hypotenuse from base: ", l_h
    M_b = 25 * l_h
    print "Moment from shelf: ", M_b, "in * lbs"
    sumM_b = sumM_b + M_b
    print ""

print "---------------------------------------"
print "total shelf moments: ", sumM_b, "in * lbs"
print ""
poleTopRightingForce = sumM_b / poleHeight
print "Pole righting force from plaster: ", poleTopRightingForce, "lbsf"