Subject: Re: RE: Special Moment Resisting Steel Frames (SMRF)
From: "Rick Byrd" <Rbyrd(--nospam--at)rmbyrd.com>
Date: Thu, 17 Feb 2000 07:36:33 -0800
Charlie, The Rw he's referring to is from the UBC. If the tests data that is available is not exactly the same member size, the building department or governing jurisdiction may require the full scale mock-up. What is your experience with this?
>>> Charlie Carter <carter(--nospam--at)aiscmail.com> 02/17 7:23 AM >>>
You're quoting an R factor (4.5) that doesn't match up to the established
categories in the 1997 AISC Seismic Provisions. Therein, Special Moment
Frames (SMF) have R = 8, Intermediate Moment Frames (IMF) have R = 6 and
Ordinary Moment Frames (OMF) have R = 4. Each of these systems has a
resulting force demand that is intended to correspond to the level of
ductility that can be derived from the member proportions and connection
detailing required for the system.
Moment-frame connection testing is required in all cases, unless you take R
= 3 or less and just design the frame according to the basic AISC
Specification for Structural Steel Buildings. However, you can often rely
upon existing tests to justify the connection design you're considering,
thereby avoiding the expense of project-specific testing. For the reduced
beam section (dogbone), there is a lot of testing that has been completed to
date. You can find it in SAC documents.
From: Elly rejuso [mailto:Erejuso(--nospam--at)rmbyrd.com]
Sent: Wednesday, February 16, 2000 8:12 PM
Subject: Special Moment Resisting Steel Frames (SMRF)
If a SMRF is analyzed using an R=4.5 and the connections designed are "Dog
Bone" type, is there a mock- up test required for the beam-to-column