On Oct 2, 10:16 am, "Rick" wrote:
wrote in message

s.com...

I have a T beam web 6'-6"x3/8" thick, flange 31.5" x 3/4". The T beam
is 76'-6" long.Let me know if you can help to find the Section
Modulus.

thanks,

Ray

Break the cross section into two rectangles. Find the area of each and y, the distance
their centroids are from the bottom. Multiply the area of each by the y of each. Add those
up, then divide by the sum of the areas. That gives the centroid of the cross section.

Next, calculate the moments of inertia of each section, then use the parallel axis
transfer theorem to calculate their I at the centric of the cross section and add them up.

Now you can calculate the section modulus.

As I recall, that's how we did it in the old days, someone else will tell you the answer
from some computer program shortly!

ANYBODY that knows of or has a proven subroutine to calculate the
section modulus of any reasonable cross section by spreadsheet, or
whatever, please let me know. I am sick and tired of doing this by
hand!!! A Tee section is tedious but straight forward; try an I-beam
section where each of the 4 flange legs is a different thickness!

Wolfgang