AISC 358 Connection Type Limits
Intermediate Moment Frame systems and Special Moment Frame systems have stringent connection detailing specifications and limits. Selecting the best prequalified connection for your system can be confusing given the many stipulations and options available.
In the March 2023 SEU session, Matt Mester, PE, SE, from MiTek, Inc., presented Steel Moment Frames: Design Principles & AISC 341/358 Provisions. Matt identified the four types of moment frames allowed by the building code, and how to choose a system based on the seismic criteria. He then reviewed the design provisions contained in AISC 341 for SMF, IMF, and OMF systems. Matt also reviewed the AISC 358 connection types and why you would choose one for your project.
Matt included some very useful slides in his presentation which summarize the limitations for the prequalified connection contained in AISC 358. The limitations include span/depth ratios, beam and column depth and weight limits, as well as flange thickness limits as shown in the slides below:
These useful charts are a great quick reference when you need to identify which prequalified connection might work best given certain beam and column sizes on your next project. Click on the slide to print a PDF copy to keep on hand when you start detailing your next IMF or SMF project.