Fcr for flexural-torsional buckling
Fcr for flexural-torsional buckling
(OP)
I am checking th capacity of an existing compression member. The example in my LRFD 1st Edition Manual of Steel Construction shows that:
Fcr = Fy * e^(-.419*lam^2) when: lam <= 1.5
In my case, lam >1.5
What is the Equation for Fcr in this case?
I'm am used to using Fcr = Fy * Q * .686^(Q*lam^2) and Fcr = Fy * .877/(lam^2) equations as needed. But I do not know the complementary equation for the one shown above.
Thanks for the help.
Fcr = Fy * e^(-.419*lam^2) when: lam <= 1.5
In my case, lam >1.5
What is the Equation for Fcr in this case?
I'm am used to using Fcr = Fy * Q * .686^(Q*lam^2) and Fcr = Fy * .877/(lam^2) equations as needed. But I do not know the complementary equation for the one shown above.
Thanks for the help.






RE: Fcr for flexural-torsional buckling
RE: Fcr for flexural-torsional buckling
Fe = (PI^2 x E) /[(KL/r)^2] Similar to Lambda
Fcr = [0.658^(Q x Fy/Fe)] x Fy ; for Fe > 0.44 Q x Fy
Fcr = 0.877 Fe ; for Fe < 0.44 Q x Fy