March 26, 2021

Video: Design Buckling Restrained Braced Frames in RISA-3D

The ability to design buckling restrained braced frames has been added to RISA-3D when you integrate your model from RISAFloor. In collaboration with CoreBrace, this new feature came as part of the release of RISA-3D v19.0.0 and RISAFloor v15.0.0.

Tags: Seismic, RISA-3D, New, BRBF

March 26, 2021 | Seismic, RISA-3D, New

Capacity Limited Design in RISA-3D

With the release of RISA-3D v19.0.2, you can now design special concentrically braced frames (SCBF) as well as buckling restrained braced frames (BRBF) according to the capacity-limited design. The objective of capacity-limited design is to ensure columns and beams in braced frames are designed to resist the capacity-limited seismic load effect based on brace expected strengths. The steps below illustrate the workflow for SCBF capacity-limited design in RISA-3D. For more information regarding design of BRBF in RISAFloor and RISA-3D, please refer to the following article: Available codes for the capacity-limited design of members include: AISC 360-10 (AISC 341-10) AISC 360-16 (AISC 341-16) If AISC 341-10 is selected, the members will be designed for the lesser of the capacity-limited and overstrength load combinations. If AISC 341-16 is selected, the envelope load combination will be used for design. Whether you’re integrating your model from RISAFloor or if you’re creating your model natively in RISA-3D, you will need to be sure to assign the proper seismic design rules to your members for capacity-limited load combinations to be considered. You can define your seismic design rules in the Seismic Design Rules spreadsheet, and assign the defined rules to members within the Properties Panel under…

June 29, 2021 | New, Deflection, Printing, RISACalc

Batch Printing & Beam Deflection Ratio Checks Now Available in…

As our team is hard at work updating and improving RISACalc based on customer feedback and requests. This latest release (Version 2.1) now includes two new features; deflection ratio checks for beam components and batch report printing. Beam Deflection Ratio Checks When designing individual beams, users can now set up the deflection ratio limits in the Design section and then view the deflection ratio results in the Detail Report for single and multi-span beams. Batch Printing of Reports With most project including multiple components, the need to print (or PDF) as many reports as desired at one time can be critical. Users can now print multiple Detail Reports using the batch print button in the primary RISACalc toolbar, allowing for a more efficient documentation workflow…

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)…