beam out of plane strenghth and stiffness (sample calculation) no lateral brace

[fesoyd1213]

If someone has a sample calculation or link on out plane strenght and stiffness of beam member. Kindly share. I have to design beam on OBCF AISC mention it needs lateral braces except for beams with sufficient out of plane strength and stiffness to ensure stability.

 

[BAretired]

Check the provisions of your code for lateral torsional buckling of beams.

BA

 

[DCBII]

AISC Appendix 6 (05 code) has strength and stiffness requirements for beam brace points. You must demonstrate that the beam flange has enough strength and stiffness to preclude the need for a brace.

For strength, apply the lateral brace force required to the beam flange that needs to be braced and compare the moment to the flange's flexural strength.

For stiffness, apply a unit load to the flange laterally at the brace point and calculate the flange's deflection. Divide the unit load by the deflection to get the flange stiffness and compare it to the required brace stiffness.

If the flange is strong enough and stiff enough on its own, a brace is not required.

 

[fesoyd1213]

Thanks.