Stainless Steel Design: Effective Elastic Section Modulus

[Derekhamm]

In the ASCE Standard for stainless steel under the flexural strength determination section (Section 3), there is mention of; (a) elastic section modulus of the effective section, Se; (b)elastic section modulus of the full, unreduced section, Sf; and (c) the elastic section modulus of the effective section at a stress Mc/Sf in the compression fiber, Sc. However, there is no mention on how to determine these section properties or the reductions to determine them from the normal elastic section modulus, S, does anyone know how to determine these values?[b\]

 

[ishvaaag]

There must be in the text somewhere how to... the idea behind effective sections is to substitute one that give the appropriate section modulus for the level of solicitation, of which is of particular interest when the element is solicitated at yield strength. I think the original idea or implementation was from Von Karman and I accompany a printout of a Mathcad 2000 worksheet following Galambos IV that expounds this idea. There should be in the code definition enough to give whant demanded, something of that kind. For example, I think to remember till the nineties in Spain it was instructed for thin-wall structures to use the full unreduced section moduluses for service level deflection checks; that simplified enough such particular case.

And as the accompanying sheet illustrates, you can see less section working at full yield strength or the full section at a lower level of strength.