# Compression and bending on a cross section,how to make sure its static

1. Jul 4, 2013

### cesaramorim

The problem is the following, i have a rectangle as a cross section of steel, wich is bended and compressed.. i wanna use the equilibrium equations to make sure its static, but since the compressive force and the traction force aren't equal, the equilibrium equations make no sense

here's a diagram explaining it

[Broken]

Last edited by a moderator: May 6, 2017
2. Jul 4, 2013

### nvn

cesaramorim: No, I think your first equation instead should be, N = Fc - Ft.

And your second equation should not contain two plus signs.

Last edited: Jul 4, 2013
3. Jul 5, 2013

### cesaramorim

that's exactly it, because if you have axial force on the bend, it can't be 0, instead, the sum of axial forces caused by tension must equal the axial force applied on the section, i was misunderstunding with pure bending on concrete structures where that equation is valid because N is 0 in that case.

thank you very much

ps: yes the second equation has a typo, it means Fc*d1, instead of Fc+d1