March 3, 2021

Video: Using a DXF Underlay to Create Geometry in RISAFloor

Oftentimes the architecture of a building does not follow a simple rectangular nor radial grid. A quick and easy way to handle these scenarios within RISAFloor is to import the building geometry or grid system as a DXF underlay.

Tags: RISAFloor, New

March 25, 2015 | RISA-3D, RISAFloor, New, Unbraced Lengths

How are Unbraced Lengths coordinated between RISAFloor and RISA-3D?

In a RISAFloor model the columns and beams can be assigned unbraced lengths, or the program may calculate them automatically. This unbraced length information can then be used in RISA-3D. A great example is the frame below: The beams along Grid Lines 1 and 2 have fixed ends. Therefore their bottom flanges are in compression, so they need to be braced. The 12” deep gravity beams framing into them should provide sufficient bottom flange restraint for the lateral beams, so the Segment command was manually entered for the lateral beams: The program now considers the gravity beams (spaced at 7.5 feet o.c.) to brace the lateral beams: When the model is transferred into RISA-3D, the gravity beams are no longer present though. Not even a node exists at their end locations: How can we ensure that the RISA-3D model knows about the gravity beams providing bracing? In the RISA-3D Members spreadsheet the unbraced lengths all report “Floor”. This means that RISA-3D is using the unbraced length information from RISAFloor: When solving in RISA-3D the unbraced lengths from RISAFloor are then used for those members:…

November 2, 2018 | RISA-3D, New, Analysis, Masonry

Masonry Lintel Analysis using FEA

In RISA-3D, the current method of design for masonry lintels is Simply Supported where the masonry lintels are idealized into a simply supported pin-pin beam configuration. Now, masonry lintels can instead be analyzed using finite element analysis. With this method, the lintel will be fully integrated as part of the wall. In the Wall Design Rules spreadsheet, choose the FEA analysis method for the masonry lintel. With the FEA analysis method, the forces that are experienced by the lintel are based on finite element analysis rather than a simply supported beam condition. The shear and moment diagrams can be seen in the Opening section of the Wall Detail Report. Note: Reinforcement for the masonry lintel is only provided for the Simply Supported analysis method…

March 1, 2012 | RISA-3D, RISAFloor, RISA-2D, New, RISASection

How to Get a Code Check for Custom Cold Formed Steel Shapes

In order to get code calculations, RISA-3D and RISA-2D need to know what type of shape would be most similar to yours. This is because the program needs to use the correct code equations for your shape type. You can easily add your custom shape to the Cold Formed library of shapes. First, pick a similar shape type (Channel, Hat, Zee, etc.) and then add the section properties into the Shape Database. You can calculate the section properties manually or use RISASection to calculate the section properties for you. Step 1: Select a similar shape type. Step 2: Click Add to create new section. Step 3: Create a name and add section properties to the start shape. Then, click OK. Note: This step is the first attempt at creating the shape and the section properties do not need to be exact just yet Step 4: Select the new shape and click Edit. Now you can enter in all the section proprieties from your hand calculations or the RISASection calculations…