12.3.1 Beam Limitations
Beams shall satisfy the following limitations:
- (1) Beams shall be rolled wide-flange or welded built-up I-shaped members.
- (2) Beam depth is limited to
- (a) For T-stub Yield-Links, a maximum of W36 (W920) for rolled shapes. Beam depth for built-up members shall not exceed the maximum depth of the permitted W36 (W920) shapes.
- (b) For end-plate Yield-Links, minimum W8 (W200) to maximum W12 (W310) for rolled shapes. Beam depth for built-up members shall comply with the minimum and maximum depths permitted for W8 (W200) to W12 (W310) sections.
- (3) There are no limits on the beam web width-to-thickness ratio beyond those listed in the AISC Specification. The beam flange width-to-thickness ratio shall not exceed as defined in AISC Specification Table B4.1b. Flange thickness shall be designed in accordance with Step 10 in the Design Procedure and shall not be less than 0.40 in. (10 mm).
- (4) Lateral bracing of beams and joints: there are no requirements for stability bracing of beams or joints beyond those in the AIS C Specification.
- (5) The protected zone shall consist of the Yield-Links, the shear plate, and the portions of the beam in contact with the Yield-Links and shear plate.
User Note: Limits on beam weight and span-to-depth ratio are not required for the SST moment connection because plastic hinging in the connection occurs solely within the Yield-Links. Span-to-depth ratio is typically limited to control moment gradient and beam shear, both of which are limited by the shear plate connection within the design procedure.
12.3.2 Column Limitations
Columns shall satisfy the following limitations:
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(1) Columns shall be any of the rolled wide-flange shapes, built-up I-shapes, or flanged cruciform sections permitted in Section 2.3.
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(2) The beam shall be connected to the flange of the column.
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(3) Column depth is limited to a maximum of W36 (W920) for rolled shapes. Column depth for built-up members shall not exceed the maximum depth permitted for W36 (W920) shapes.
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(4) There is no limit on the weight per foot of columns.
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(5) There are no additional requirements for flange thickness.
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(6) Column width-to-thickness ratios shall comply with the following:
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(a) Where column-to-foundation connections are designed to restrain column end rotation, column width-to-thickness ratios shall comply with AISCE Seismic Provisions Table D1.1 for highly ductile members within the first story.
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(b) At other locations and for other conditions, column width-to-thickness ratios shall comply with the AIS C Specification.
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(7) Lateral bracing of columns shall be provided in accordance with the AISC Seismic Provisions.
Exception: When columns are designed in accordance with Section 12.9 and the maximum nominal flexural strength, , outside the panel zone is limited such that , it is permitted that bracing be provided at the level of the top flange of the beam only.
12.3.3 Bolting Limitations
Bolts shall conform to the requirements of Chapter 4.
The following exceptions apply:
- (1) The following connections shall be made with ASTM F3125/F3125M Grade A325 or A325M bolts installed either as snug-tight or pretensioned, except as noted. For pretensioned applications, ASTM F3125/F3125M Grade F1852 bolts are permitted.
- (a) Yield-Link flange or end plate-to-column flange bolts
- (b) Buckling restraint plate bolts installed snug tight
- (c) Shear-plate bolts
- (2) The Yield-Link stem-to-beam flange bolts shall be pretensioned ASTM F3125/ F3125M Grades A325, A325M, A490, A490M, F1852, or F2280 bolt assemblies. Faying surface preparation between the Yield-Link stem and beam flange is not required, but faying surfaces shall not be painted.