January 3, 2012

How to Append or Merge Multiple Models Together in RISA-3D

RISA-3D allows you to append, or merge, multiple models into a single model file. This may be helpful if you model single floors in separate files and want to stack them together.

Before appending the files together, you must be sure that each file has the same Units and Global Axes defined. Once this has been verified, open a model and go to File > Append. Then choose the model you wish to add to the currently open model.

Here is a model with a masonry wall structure and a roof truss model that were created in separate files, complete with loading, design parameters, load combinations, etc.

Starting in the masonry wall file, the roof trusses file was now appended in.

We can see that the truss model is dropped in and the current model is unselected. This allows you to use the move tools to align the appended model with the current model.

Tags: RISA-3D, New

April 9, 2013 | RISA-3D, Results, New

Internal Force Summation Tool Basics

The Internal Force Summation Tool has the ability to "cut through" elements in the model and produce a summation of forces that corresponds with a given load combination. For this example, we will use the following model and review the summation of forces in the horizontal concrete plates. First, click on the 'Select Elements by Property' button and once the dialogue opens, choose the 'Plates' tab. With the dialogue open, enable the checkbox for 'Materials' and select 'gen_ConcNW'. Then click 'Select' to graphically select all the concrete plates. With the concrete plates selected, click on the 'Coordinates' tab and input the Coordinate range as shown in the image below along with choosing 'Select/Unselect' from the 'Nodes' drop-down box. The click 'Select' to graphically select the nodes based on the defined selection criteria. With the concrete plates and nodes selected graphically, click 'Close'. Next, click the 'Dim Lock' button found on the 'Selection Toolbar' in order to lock and dim all unselected parts of the model. Your model should now look like this: With the appropriate elements selected, solve either a single combination or a batch solution. After the solution is complete, click on the 'XZ' view button found on the…

March 31, 2011 | RISA-3D, RISA-2D, New

How RISA-3D Handles Single Angles

The bending and axial code checks for single angles differ somewhat from other shape types, because single angles behave quite differently in bending and compression depending on how they are braced along their length. Single angles can act about their geometric axes if they are fully braced against twisting along their length. Otherwise they will bend and buckle about their principal axes. RISA-3D will automatically assume that full bracing is not present, and that bending and buckling will occur about the principal axes. This is a conservative assumption. In the Detail Report of a single angle bending about its principal axes, the moments are reported as (Mz’) and (My’), which are the bending moments about the principal axes. If you want the code check for your single angle to be based on bending and buckling about the geometric axes, then you must specify to the program that the angle is fully braced against twisting along its entire length. You can do this by entering an unbraced length of zero for both the Lcomp top and Lcomp bot values. The program will use the values of Lbyy and Lbzz to determine the compression capacity of the angle…

May 3, 2017 | RISA-3D, New, Aluminum, Unbraced Lengths

Updates to Aluminum Single Angle Bending

The bending and axial code checks for single angles differ somewhat from other shape types, because single angles behave quite differently in bending and compression depending on how they are braced along their length. Single angles can act about their geometric axes if they are fully braced against twisting along their length. Otherwise they will bend and buckle about their principal axes. RISA-3D automatically assumes that full bracing is not present, and that bending and buckling will occur about the principal axes. In the Detail Report of a single angle bending about its principal axes, the moments are reported as (Mz’) and (My’), which are the bending moments about the principal axes. If you want the code check for a single angle to be based on bending and buckling about the geometric axes, then you must specify to the program that the angle is fully braced against twisting along its entire length. You can do this by entering an unbraced length of zero for the L-torque value. The program uses the values of Lbyy and Lbzz to determine the compression capacity of the angle. Note that unlike steel single angles, per the aluminum code the compression capacity is always based…