FAQ 000739 EN

Modeling | Structure RFEM RSTAB

I want to increase the roof slope by 5 degrees for an existing model after the fact. In the "Edit" menu, I found two functions that I could use: "Rotate" and "Shear."

What is the difference between these functions? Which function is more efficient for my purpose?

Answer

The "Shear" function is the right choice for this purpose, because it allows you to shift the nodes of the members in accordance with the required rotation angle. By doing this, the length of the members changes.

To do this, select the nodes of the left roof pitch. Select the "Shear" command on the "Edit" menu. In the dialog box, specify the desired angle and the axis for the rotation. Next, select a point of the starting plane for the rotation. In this example, this is one of the end points of the posts. By using the "Shear" function, the nodes of the members are displaced, as are the loads on the members and nodes. Repeat the procedure for the other side of the roof, but don't select the ridge nodes this time and change the sign of the direction of rotation.

If you use the "Rotate" function for this issue, the length of the members would remain the same and the nodes of the top and bottom chord would not have the same x-y-coordinates. The nodes of the top chord would be slightly displaced in the x-direction.

RFEM Main Program
RFEM 5.xx

Main Program

Structural engineering software for finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids and contact elements

RSTAB Main Program
RSTAB 8.xx

Main Program

The structural engineering software for design of frame, beam and truss structures, performing linear and nonlinear calculations of internal forces, deformations, and support reactions