Width-to-Thickness Ratios for SMF per AISC 341-16 with ideCAD
How does ideCAD control Width-to-Thickness Ratios for special moment frames according to AISC 341-16?
Column, beam, and brace members of frames, that resists high ductility level are automatically controled and reported according to Table D1.1.
The structural frame members, such as columns and beams with highly ductile members, are controlled according to Table D1.1 and reported in steel column and steel beam reports.
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Limiting Width-to-Thickness Ratios for Compression Elements for Moderately Ductile and Highly Ductile Members | ||||
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Description of Element | Width-to- Thickness Ratio | Limiting Width-to-Thickness Ratio | Example | |
λhd | λmd | |||
Flanges of rolled or built-up I-shaped sections, channels and tees; legs of single angles or double-angle members with separators; outstanding legs of pairs of angles in continuous contact | b/t |
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Flanges of H-pile sections per Section D4 | b/t | not applicable |
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Stems of tees | d/t |
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Walls of rectangular HSS used as diagonal braces | b/t |
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Flanges of boxed I-shaped sections | b/t |
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Side plates of boxed I-shaped sections and walls of built-up box shapes used as diagonal braces | h/t |
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Flanges of built up box shapes used as link beams | b/t |
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Webs of rolled or built-up I shaped sections and channels used as diagonal braces | hw/t |
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Where used in beams or columns as flanges in uniform compression due to axial, flexure, or combined axial and flexure:
| b/t h/t |
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Where used in beams, columns, or links, as webs in flexure, or combined axial and flexure:
| h/tw h/t h/t | For Ca ≤ 0.114 For Ca > 0.114 where | For Ca ≤ 0.114 For Ca > 0.114 where | ![]() |
Webs of built-up box sections used as EBF links | h/t |
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Webs of H-Pile sections | h/tw | not applicable |
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Walls of round HSS | D/t |
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