October 30, 2020

Composite Steel Joists in RISAFloor

RISAFloor now includes the ability for engineers to model with and design CJ-Series composite steel joists according to SJI 200-2015 and including the design of top/bottom chords, bridging, joist seat depth as well as headed stud size and spacing.

Tags: RISAFloor, New, Composite Steel, Steel Joists

October 28, 2015 | RISAFloor, New, Joists

Tolerance Between SP Joists vs. Normal Joists

Have you been in RISAFloor performing a steel product design and noticed an (SP) extension to a joist designation? The following will discuss when the program designs for these special loading conditions. Steel products are designed to resist a uniform dead load (UDL), a uniform live load (ULL), and a uniform total load (UTL). The allowable loads for steel joist are based on the standard load and span tables for K, LH, DHL, and SLH Steel Joists. However, if a concentrated point load (even one with a small magnitude) is detected on a standard joist, the joist will be flagged as a Special (SP) Joist. Similarly, the distributed load on the joist cannot vary by more than 5% along the length of the joist. If it does then the joist will also be flagged as a SP Joist. The exception to this is some additional load variation is allowed within 10% of the end of the joist. A KCS joist can be designated for these special loading conditions. These joists do not have the “SP” label but are considered a special loading joist. KCS joists are checked versus the constant shear and moment capacity. RISAFloor also ensures the largest applied…

October 4, 2012 | RISA-3D, New, Joists

Using Virtual Joist Girders in RISA-3D

The Steel Joist Institute (SJI) has developed a Virtual Joist Girder table which converts common joist sizes into equivalent wide flange beams for use in RISA-3D. Link: SJI: Virtual Joist Girders Table When to Use Virtual Joist Girders The engineer should use these Virtual Joist Girders in their analysis model whenever the girders are part of a lateral frame. This should result in analysis assumptions for the strength and stiffness of the member that are closer to what the joist provider can realistically provide. This will lead to better communication between the EOR and the joist manufacturer, resulting in a quicker, more efficient design process. Can I Use Virtual Joist Girders in my Version of RISA-3D? Virtual Joist Girders are included as of RISA-3D v11 released December 2012. How to Use Virtual Joist Girders in RISA-3D The Virtual Joist Girder database will be listed as one of the database options on the Hot Rolled tab of the Shape Selection dialog as shown to the left. There is a new design list used referencing all the shapes in the SJI Virtual Joist Girder table. This design list is used as part of the RISA-3D optimization or redesign routines. A Virtual Joist…

February 15, 2022 | RISAFloor, New, Steel Joists, Joists

New Updates to Steel Joists in RISAFloor

As a floor-by-floor design software, RISAFloor includes robust features for the design of steel joists, including standard joists, long-span joists and composite joists. Version 16 of RISAFloor now includes design according to the latest specification (SJI 45th Edition) as well as expanded LH-series design tables. The new 45th Edition Catalog provides a more practical approach to better define the actual use of the products in the catalog. All of these changes below are aimed at making steel joists and Joist Girders safer, simpler to use and more economical. The LH-Series Load Tables have been expanded to incorporate shorter spans with higher uniform design loads as well as additional standard designations, particularly for floor systems. Because of these expanded LH-Series Load Tables, the Safe Load as well as the LH Load/Load weight tables are no longer needed and have been removed. LH-Series Load Tables layout has been reformatted to match the K-Series Load Tables. Tables outlining bearing conditions and bridging information have been updated to include the new LH-Series chord numbers. The Duct Opening Accessories page has been updated. Added page describing additional joist minimum shear criteria for web design. For more information about using steel joists in RISAFloor, visit the…