three specified configurations as provided in AISC Supplement No. 1 thus allows moment end plates to be considered for use in the. AISC’s Supplement No. 1 to Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications (ANSI/AISC. 1 (includes supplement) Supersedes ANSI/AISC and ANSI/ AISC s Approved by the AISC Connection Prequalification Review Panel .
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When RBS cutouts are provided yielding and plastic hinge formation primarily occur within the reduced beam section.
End-Plate and Bolt Design. There is no evidence that modest deviations from these dimensions will result in significantly different performance.
Submittal to Patent Holder. The demands may be smaller because of the somewhat smaller strain-hardening moment increase achieved with the BFP moment connection as compared to the welded webwelded flange and other FR connections.
AISC 358-10 Prequalified Connections
Tack welds for beam flange-to-column connections are preferably made in the weld groove. 358-5 shear yielding of the extended portion of the four-bolt extended unstiffened end-plate 4E: Fabrication of Flange Cuts. If the base metal and weld root are ground smooth after removal of the backing, the reinforcing fillet adjacent to the beam flange need not extend to base metal.
Step 12 checks block shear of the bolt group in the flange plate, and Step 13 checks the flange plate for buckling, when Fpr is in Ajsc Connections for Special and Intermediate Steel Moment Frames for Seismic Applications,incl. Because of the incomplete filling of the groove, the unusual configuration of the weld, and the relatively low level of demand placed upon the weld at this location, nondestructive testing of cascaded weld ends in groove welds at this location are not required.
Check the unstiffened column web crippling strength at the beam compression flange. As a result, the shear plate may be welded with CJP groove welds or partial-joint-penetration PJP groove welds or fillet welds. Welds shall not be started or stopped within 2 in.
AISC Prequalified Connections
Provide continuity plates as necessary. Check the panel zone in accordance with Section 6. Past tests ais shown adequate inelastic rotation capacity to qualify as an SMF in tests with span-to-depth ratios less than 5 and greater than 16, and so lower bound span-to-depth ratio limits of 7 and 9 are conservatively adopted for the IMF and SMF applications, respectively. For seismic loading, the nominal bearing strength at bolt holes shall not be taken greater than the value given by Equation Ja of the AISC Specification.
Three column sizes were used: Successful tests have also been conducted on RBS connections with built-up box columns.
Beams shall satisfy the following limitations: Following the removal of steel backing, the root pass shall be backgouged to sound weld metal and backwelded with a reinforcing fillet. Three different electrode designations have commonly been used in these tests: When grinding the weld root and base metal area, previously deposited weld toe regions and their associated fracture initiation sites are removed, and the horizontal leg of the fillet weld need not be extended to base metal.
Prohibited Welds at Steel Backing Tack welds for beam flange-to-column connections should be made within the weld groove. The same testing method that discovered the discontinuities shall be repeated on repaired castings to confirm the removal of all discontinuities that exceed the requirements of Section A2.
RBS connections have been tested using single-cantilever type specimens one beam attached to columnand double-sided specimens specimen consisting of a single column, with beams attached to both flanges. Consequently, if a supplemental brace is provided, it should be located at or just beyond the end of the RBS that is farthest from the face of the column.
Test data indicate that connecting the beam at the face of the column in accordance with the requirements herein allows the connection to resist this level of moment while minimizing the chance of fracture at the beam-flange groove welds. Thus, the beam web is attached to the column flange with both a CJP groove weld and a welded single-plate connection.
The shear force at the center of the reduced beam sections shall be determined from a free body diagram of the portion of the beam between the centers of the reduced beam sections. Concrete shall have day compressive strength not less than 3, psi 21 MPa. Continuity plates shall conform to the requirements for wide-flange columns. The primary differences are in the resistances factors.
The flange plate bolts cannot experience a tensile force larger than Fpr, and so Step 9 checks the actual number of bolts required in the connection. Each ConXL node also contains four collar flange assemblies Figure When using the International Building Code, a factor of 0. A full-depth PJP groove weld shall be permitted at this location. Fillet weld applied to a groove welded T-joint to obtain a contour to reduce stress concentrations associated with joint geometry.