
November 8, 2017
2018 IBC Coming Soon!
The International Code Council just released the 2018 International Building Code (IBC) in August 2017.
Light-framed construction has become increasingly prevalent in mid-rise and modular development, driven by its cost-efficiency, speed of construction, and adaptability. But with flexibility comes complexity. Engineers designing with wood and cold-formed steel (CFS) must navigate a unique set of challenges: diaphragm behavior, segmented shear walls, buckling sensitivity, and code-specific checks that differ from traditional hot-rolled steel or reinforced concrete structures. This article explores practical modeling and design approaches for light-framed buildings, focusing on how structural engineers can balance constructability, analysis clarity, and compliance with governing codes. Diaphragm Behavior: Not Always Rigid In light-framed buildings, flexible diaphragms are often assumed due to the nature of wood sheathing or light-gauge decking. However, as buildings increase in size and irregularity, this assumption deserves scrutiny. Flexible diaphragm assumptions work well in rectangular buildings with regular framing, but irregular load paths or large openings may require semi-rigid modeling to capture torsional behavior. Engineers should consider the influence of diaphragm stiffness when assigning lateral forces, especially in hybrid systems where part of the structure may be stiffer or tied into concrete cores. In projects where semi-rigid diaphragm analysis was warranted, integrating tools like finite element meshing helped visualize how in-plane stiffness impacted overall response—particularly in designs…
Read More
The International Code Council just released the 2018 International Building Code (IBC) in August 2017.
The Steel Joist Institute (SJI) sizes and capacities from the 44th Edition Standard Specifications Load Tables and Weight Tables for Steel Joists and Joist Girders are now available in RISAFloor v12. There were no changes from the 43rd to the 44th Editions so you’ll see that these two are grouped...
The new British Annex (BS EN1993-1-1:2014) for the European Hot Rolled Steel material code is now available in RISA-3D v16 and RISAFloor v12.
You can now set the L-Torque length for the EN1993-1-1:2014 code in RISA-3D and RISAFloor. In previous versions of the Eurocode, RISAFloor and RISA-3D used the full member length as the torque length when calculating torsional buckling. Now, per EN1993-1-1:2014 Section 13.3.2, we’ve added the...
The consideration of Live Load reduction is a feature that has been in RISAFloor from the very beginning. However, recent changes to the interface make it significantly easier for you to understand how live load reduction is affecting the design forces in your structure.
RISAFloor now has the ability to double-click a member to open the Member Information dialog. This feature has been in RISA-3D but now it is available in RISAFloor. Double click any member in your model and the Member dialog box opens. It has three tabs: General, Properties and Design.
The CSA A23.3-14 code has been implemented in RISA-3D v15.0, RISAFloor v11.0, and RISAFoundation v9.0.
Our monthly "Structural Moment" newsletter is the best way to keep up with RISA’s product updates, new releases, new features, training events, webinars and more...