Cracked moment of inertia of reinforced concrete beam 1

Wrote this some time ago. See if it matches what you derived.


Check out Eng-Tips Forum's Policies here:
faq731-376

RC Design Functions has an EStress function that returns the curvature with no concrete tension stress, cracking moments, and also curvature including tension stiffening effects, for a rectangular beam with two layers of reinforcement.

It will also do creep calculations over any time span.

Beam Design Functions will find curvature for beams with any cross section and reinforcement layout.



Doug Jenkins
Interactive Design Services

I always use this method, from Designers Guide to EN 1992-2 authored by in my view the best bridge engineer in the UK, Chris Hendy. I think I might get my wrist-slapped if I post any more of it, but I think the parameters are self-explanatory.

d = effective depth
Es = Youngs Modulus Steel
Ec,eff = Concrete Youngs Modulus



Alternatively you can use a program like Oasys Adsec which should (in theory) give a very similar answer depending on the moment applied (clearly there is a region where itll be somewhere between "crakced" and "uncracked".

gl

Thank you all for your responses. I will start with JAE's file and see what it gives and if it matches what I calculated. Then I will try out IDS and ukbridge. I may have some follow up questions in the next few days. Thank you all again for taking the time to respond and your help.