October 20, 2016

Shear Splices between Slabs

In RISAFoundation v8, you can add a shear splice between slabs so that it acts like a hinge. This is useful for modeling the effects of shear keys or dowel joints between slabs.

Tags: Slab, RISAFoundation, New

November 14, 2024 | Featured, Structural Engineering

Engineering Resilence: Lessons from Fall Hurricane Season

As structural engineers, the fall hurricane season presents unique challenges that push the boundaries of design. Hurricanes Helene and Milton, both from 2024, stand out for their rapid intensification and the vast areas they impacted. With Helene sweeping across Florida’s Big Bend and Milton ranking among the most intense Atlantic hurricanes in history, it’s clear that structural resilience is more important than ever. Here’s how engineers can dive into the technical details of hurricane-resistant design and take valuable lessons from these storms. 1. Wind Loads and Lateral Resistance Hurricanes like Helene and Milton bring with them fierce winds, often reaching over 140 mph, causing massive lateral forces on structures. Wind load analysis is one of the most important aspects of hurricane design, particularly for tall buildings and long-span structures. Engineers use software like RISA-3D to model these forces and design the structure's lateral load-resisting system (LLRS), which might include shear walls, braced frames, or moment frames. For example, in Helene’s path, structures with poorly designed lateral systems were more vulnerable to wind-related failures. By analyzing factors like gust effects and torsional irregularities, engineers can identify weak points and ensure a building’s frame and cladding systems remain intact under extreme wind…

July 3, 2025 | Featured, RISA-3D, New, Steel Connections

From Sketch to Steel: Streamlining Fabricator Coordination

In structural steel projects, the transition from design to fabrication is a common source of coordination challenges. One of the biggest pain points? Connection design. Whether it’s miscommunication on end reactions or unclear design intent, connection assumptions can break down in the gap between engineering and detailing. By using RISA-3D and RISAConnection—and leveraging direct integrations with SDS2 and Tekla Structures—structural engineers can streamline the handoff to fabricators, reduce errors, and improve collaboration. This post walks through how to support real-world coordination using these tools in practice. 1. Model and Analyze the Steel Frame in RISA-3D Start by building your structural steel frame in RISA-3D. Define geometry, assign member sizes, apply loads, and analyze the model. Once you're satisfied with the analysis results, RISA-3D provides the connection forces—axial, shear, and moment reactions—for each member end. 2. Export Connection Forces to RISAConnection Next, send selected members and their design forces to RISAConnection. This direct integration eliminates the need to manually transfer loads or recreate geometry. Once in RISAConnection, you can: Choose from a library of shear, moment, and braced connections Model the full geometry, including bolt patterns, welds, and gusset plates View pass/fail results for each limit state, with clear failure mode…

October 30, 2020 | RISA-3D, Walls, RISAFloor, New, v15, v19, Cold Formed Steel

Cold Formed Steel Wall Design Now Available

Cold-formed steel framing is a durable, reliable and cost-effective option for low-rise and mid-rise building projects. With the release of RISA-3D Version 19 and RISAFloor Version 15, cold formed steel (CFS) walls are now available for analysis and design. Walls that have been designated as lateral in RISAFloor will be transferred into RISA-3D when utilizing the Director feature. Currently, CFS walls are only available when the AISI S100-16: ASD or LRFD code is selected from the Model Settings. To draw CFS walls in RISA-3D, simply choose CFS from the Wall Material dropdown menu in the Properties Panel. The design for the CFS walls will follow the criteria assigned in the Design Rules. The Wall Design Rules may be modified through the Wall Design Rules spreadsheet, or through the Wall Definition Editor by selecting the ellipsis to the right of the Design Rule in the Properties Panel. CFS wall sheathing material options include Wood Structural sheathing, Steel Sheet sheathing, Gypsum board panels and Fiberboard. The sheathing material may be selected in the Wall Design Rules spreadsheet or within the Wall Panel Definition Editor. The program will design the optimal sheathing size based on the thickness requirements and shear demands. The Segmented…