Seismosoft | Earthquake Engineering Solutions

Hi everybody
For The perform IDA analysis of 2D SMF Steel Frame which one of the Beam Column Elment Types you propose to me??FB?DB?FBPH?
and in FBPH method How can i compute the plastic hinge length(Lp/L) in steel column?
Thanks

Hi OmidFaghih. I'd recommend you take a look at the Verification Manual and , in particular, at Ch4-­#8208;steel-­#8208;01.spf. In this problem inelastic force-based elements were used with 4 integration sections. As noted in the Help System, the infrmFB element is generally the preferred element as no discretization is required in the usual cases.

With the infrmFB element there is no need to compute hinge lenghths as the inelasticity is distributed through the fiber element, inherenet to the model formulation. If you, for some reason, decide to use the inelastic plastic hinge element, then you will need a plastic hinge length and the following excerpt from the Help System (Element Class section, infrmFBPH sub-section) should be a starting point to assist in such calculations:

"In addition, the plastic hinge length needs also to be defined, with the user being referred to the literature [e.g. Scott and Fenves 2006, Papadrakakis 2008, Calabrese et al. 2010] for guidance."

The Verification Manual and Problems along with the Help System built into SeismoStruct really are fantastic resources and I highly recommend that they be studied thoroughly by users. This forum is also an incredibly valuable source of information, so I hope these comments help to answer your question.

Best of luck OmidFaghih.