rectangular reinforced concrete cracked analysis but with axial tension

[geopat69]

hi people..

Im after some advice on rectangular reinforced concrete that is cracked but with axial tension. Lots of books on moment only analysis with either cracked or uncracked sections.

I have a spreasheet that easily does 1) uncracked section with moment and axial tension or compression,2) cracked section with moment only.

But I Need to know how to handle (2) above with axial tension. Please note it is not as easy as one may think as the neutral axis depth may not exist if there is large tension and small moment!

 

[geopat69]

BTW.. my spreadsheet essentially uses trial strain distribution.

 

[Denial]

I am currently putting the finishing touches to a spreadsheet that I think will do what you want, and I hope to put it up on my website within a week. If your need is urgent send me an e-mail with your e-mail address and I can send you a preliminary version. (You can find my e-mail address from my website

http://rmniall.com.)

 

[IDS]

The spreadsheets here:

http://newtonexcelbach.wordpress.co...2-sls-design-of-reinforced-concrete-sections/

will do what you want.

That link is for SLS analysis (i.e. linear elastic properties for steel and concrete in compression), but the RC Design Functions spreadsheet (for rectangular sections) also has a function for ULS if that is what you want.

There will always be an NA position, but it may be outside the section, in which case the concrete is providing no force and the analysis is equivalent to an I beam with top and bottom flanges at the reinforcement positions, and zero web thickness.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Denial]

Geopat69.
It took a bit longer than I had hoped, but that spreadsheet I mentioned in my 25May13@20:20 post above is now on my website.