October 30, 2020

Exclude Results based on Selection in RISAFloor and RISAFoundation

New to RISAFloor and RISAFoundation is the ability to exclude results by selection. Excluding results from your model is useful when there are certain elements whose results aren’t of interest to you. Removing this clutter from the results will enable you to concentrate on the elements you are most interested in.

Tags: RISAFloor, Results, RISAFoundation, New

June 1, 2011 | RISAFloor, New, Wood, Unbraced Lengths

How to Assign a Wood Roof Member’s Unbraced Length in RISAFloor

In RISAFloor, the beams are susceptible to two forms of buckling; Euler buckling and lateral-torsional buckling. The unbraced length is determined in RISAFloor using the deck properties and framing. Le2 = Lbyy → Defaults to Segment Le1= Lbzz Le-bend-Top → Defined in Deck Properties Le-bend-Bot The rafter is susceptible to two forms of buckling. The first is Euler buckling, which is a column-type buckling about the rafter’s y-axis. The blocking typically braces against this so the Le2 value should be set to the spacing of the blocking (typically 4 feet). It may not be appropriate to consider the decking as bracing against Euler buckling because of the depth of the rafter relative to the depth of the sheathing nail. Le2 is defined in the Beams spreadsheet. The second form of buckling is lateral-torsional buckling, which is a beam-type buckling of the top flange of the rafter. The deck typically braces against this and this value is automatically set based on the Unbraced Length property of the Deck. The deck is nailed to the rafter every 6-feet so that would be a good value to use as the Unbraced Length of the deck. Incidentally, the blocking is also considered (by default)…

June 3, 2025 | Featured, RISA-3D, New, Instability

The Ultimate Guide to Instability Warnings in RISA-3D

Modeling instability can be one of the most frustrating errors to troubleshoot in structural software. Whether you're a new user or a seasoned pro, instability warnings in RISA-3D can bring your workflow to a halt if not properly diagnosed and resolved. This master article brings together all the most common types of instability, provides guidance on identifying the issue, and links to existing resources that walk you through the resolution process. To supplement this written guide, check out the Troubleshooting Mini Tutorial in the RISA Learning Center (RLC). Common Instability Types and How to Resolve Them Below are the five most common causes of instability in a RISA-3D model, along with diagnosis tips and links to deeper resources: 1. Member End Releases at Boundary Conditions Symptom: Instability warnings at the base of columns or ends of beams. Diagnosis: Look for members where moment releases are applied directly at nodes with pinned or fixed boundary conditions. Why It’s a Problem: This removes all rotational fixity at the connection, creating a hinge with no resistance to rotation. Resolution Resource: How do I avoid instability warnings in a RISA-3D model? 2. Pinned End Releases at Every Member Framing into a Single Node Symptom:…

February 7, 2023 | Featured, Structural Engineering

7 Tips to Consider When Switching Structural Engineering Software

Are you looking to switch your structural engineering software? With so many options, knowing which one is right for your team or project can take a lot of work. These tips will help you navigate the process of switching software, from evaluating your needs and researching different types of engineering software to completing the transition and staying current with updates. 1. Your Needs Every project and firm will have different requirements when it comes to software selection. Before deciding which software package is best for you, it’s best to have a full assessment of what you have and what you need. You also need to consider software features from an engineering standpoint – such as design capabilities, BIM reporting, and 3D modeling functions – and only select a software package that offers those features. 2. Timing They say timing is everything. When planning a switch, consider if there are any current projects or commitments that need to be completed first. If so, factor in how long these will take and how much time you'll need to become accustomed to your new software before transitioning completely. You also want to make sure that you're not paying for multiple software programs at…