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

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…

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…

March 9, 2023 | Featured, RISA-3D

Reading Angles Using the Distance Tool in RISA-3D

When using the Distance tool in RISA-3D, the program outputs Rxz, Rzy, Ryz. These angles represent the angle the Distance Tool line makes with respect to the each respective plane. Rxy represents the angle the distance line makes with respect to the XY plane. The Rxy, Rxz and Ryz angles refer to the angles for a member with respect to each 2-D plane defined by xyz. For instance, Angle Rxz refers to the angle between the member and the xz plane, i.e., angle between the member and its projection to xz plane. In the example below, we are interested in determining the Rxy angle. If we apply the software's theory to member M1, and project the member onto the XY plane, we can determine the angle the member makes with respect to the XY plane:…