http://www.constructioncalc.com/blog/userforum/topic/allowable-fb-reduction-based-on-unbraced-length Where Builders, Architects, Engineers, and Code Officials Meet en-US Tue, 07 Feb 2012 15:10:28 +0000 http://bbpress.org/?v=1.0.2 q http://www.constructioncalc.com/blog/userforum/search.php http://www.constructioncalc.com/blog/userforum/topic/allowable-fb-reduction-based-on-unbraced-length#post-34 Mon, 08 Mar 2010 11:13:19 +0000 Tim Garrison 34@http://www.constructioncalc.com/blog/userforum/ <p>ProBeam assumes a short Lu (unbraced length) such that buckling of the compression "flange" is not an issue. There is no feature at this time to make an analysis with a long Lu. That's a good feature for us to add for the next version.</p> <p>In the meantime if you have a long Lu, say greater than 6', the answer ProBeam gives will not be accurate, and could be dangerous. In such case you can add lateral bracing to the compression "flange" thus shortening the Lu, or use a stouter member - especially one more resistant to weak-axis bending. </p> http://www.constructioncalc.com/blog/userforum/topic/allowable-fb-reduction-based-on-unbraced-length#post-32 Mon, 08 Mar 2010 10:23:56 +0000 Salty 32@http://www.constructioncalc.com/blog/userforum/ <p>I don't see maximum allowable Lu (obviously I can get this from AISC manual). Is there any way to calculate Fb using a Lu greater than max allowable Lu to obtain full Fb? </p>