August 7, 2015
How to Create a Custom Shape in RISA
There are a couple options in RISA-3D and RISAFloor to create a custom shape not available in the program databases. This is a great opportunity to use RISASection for the convenience of the program’s capabilities to calculate section properties, in which case you can refer to the following blog: http://risa.com/news/how-to-import-risasection-shape-into-risa3d/. However, you can still create a custom shape without RISASection which is discussed in this blog.
A custom shape addition depends on if you want a code check for your section or you’re more interested in the analysis only and don’t require a code check. The type of material and shape type is also a factor in how you create a custom shape. We will explore the available options below.
Option 1: Code Check Desired
Perhaps you have a built-up section including a wide flange with a channel. You would like a code check on the section based on the wide-flange. Open up your shape selection dialog box under the Hot Rolled tab by clicking on the red arrow in the Shape cell.
Once here, select WF and click Add.
In the Add Shape dialog box that pops up, you will enter in the section properties and select Calc Props then OK.
You will now notice at the bottom of the database shapes list, your custom shape will be available to use in your model. The code check will be based on a hot rolled WF since these are the selections we made previously.
In turn, if you would like to create a custom shape for a different section type and still receive a code check, simply make your selection under the Shape Type options (tube, pipe, etc.). If you have a different material other than hot-rolled (cold-formed, wood, etc.), the same process is followed under the applicable material tab.
Option 2: No Code Check Needed
You may have a custom section that does not fit into any shape type category, and therefore you won’t be able to accurately get a code check. We suggest adding your custom shape as a general section under the General tab. You will open up the Shape Selection dialog box by clicking on the red arrow in the Shape cell.
Once in the Shape Selection dialog box, you can select the applicable Shape Type. For this example we will choose Arbitrary and Add.
In the Add Shape dialog box you will enter in the custom shape properties and click OK.
The custom shape will now be available to use in the model.
With Option 2, an analysis will be performed on the member and you will be able to pull all information from the Results toolbar such as deflection, forces, etc. However, you will see an “N/C” for the code check for all general members.