| Standard | Title | Reference Tools | Reference Table |
|---|---|---|---|
| ANSI/AISC 358-22 | Prequalified Connections for Special and Intermediate Steel Moment Frames (seismic) | - | - |
What this standard covers
ANSI/AISC 358 (Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications) provides moment connections that have been tested and prequalified, so they may be used without project-specific qualification testing.
AISC 341 requires that moment connections in special and intermediate moment frames be qualified by testing. AISC 358 removes that burden for a defined set of connections by publishing designs that have already been demonstrated to deliver the required rotation: reduced beam section, bolted and welded unstiffened and stiffened extended end-plate connections, bolted flange plate, welded unreinforced flange with welded web, Kaiser bolted bracket, ConXtec collar and others.
Each prequalified connection carries strict limits on member size, span-to-depth ratio, material, bolt and weld details, and fabrication. The prequalification only holds within those limits: a connection detailed outside the stated range is no longer prequalified and must be qualified by testing under AISC 341.
What you will find in it
- Prequalification limits
- The member sizes, span-to-depth ratios, materials and detailing bounds within which each connection remains prequalified.
- Reduced beam section
- The connection that deliberately weakens the beam flange a short distance from the column to move the plastic hinge away from the face.
- Extended end-plate connections
- Bolted end-plate connections in stiffened and unstiffened forms, with the end-plate thickness and bolt layout governed by the required moment.
- Bolted flange plate
- Connection transferring beam flange force through bolted plates, with checks on the plate, the bolt group and the beam net section.
- Welded unreinforced flange
- The welded connection with a welded web, with the weld details and access hole geometry that the qualification depends on.
- Design procedures
- The step-by-step procedure given for each connection, including the probable maximum moment at the hinge and the resulting column demands.
When to use this standard
Use AISC 358 when designing moment connections for special or intermediate steel moment frames and you want to avoid project-specific qualification testing. Confirm that every member, material and detail falls inside the prequalification limits - the standard is only usable within them.
How it fits with the other standards
AISC 358 is used with AISC 341, which sets the qualification requirement it satisfies, and with AISC 360 for the underlying member and connection strength. Bolting follows the RCSC Specification and fabrication follows AISC 303.