October 4, 2018

Drawing Grid and Other Modeling Improvements

RISAFloor v13 includes a variety of modeling features which allows users to quickly create and manipulate geometry. These features include construction lines, saved selections and copy elements from floor to floor. Overall, these features can be used to help engineers streamline their modeling workflow within RISAFloor.

Tags: RISAFloor ES, RISAFloor, New, Construction Lines, Modeling

September 9, 2015 | RISA-3D, RISAFloor, New, Analysis

Why don’t the Beams in my Frame have axial force?

The beams in a lateral force resisting system, such as a braced frame or moment frame, typically carry a significant axial force. In the example below (with no diaphragms) the beam (M4) carries a significant axial tension. The axial force diagrams show that the beam (M4) is carrying 9.6 kips of tension (blue) because the beam is transferring the lateral force from brace M5 to M6. However, if a rigid diaphragm is created at the floor level then the axial force in M4 disappears: The question arises, how does the force now get from brace M5 down to brace M6? The answer is that the force is being carried entirely by the rigid diaphragm. See the image below, which explains why: If the explanation above isn’t clear, another way to consider this problem is to look at the movement of nodes. In a rigid diaphragm, none of the nodes are allowed to get any closer or farther away from each other, regardless of the load applied. In the example below, the distance “x” is always the same number. If it wasn’t then the diaphragm must have deformed (shrunk) in the x direction, but it can’t deform or shrink if it…

September 6, 2018 | RISAFloor ES, RISAFloor, New, Modeling

Copy Elements from Floor to Floor

RISAFloor v13.0 now includes the added ability to graphically copy elements from one floor to another floor. This feature will expedite the modeling process by giving designers more control over which beams, columns, walls and joints are carried over to another floor. To access the tool, click on the Copy Selected Items button to open the dialog box. Once the dialogue appears, choose the Copy to Another Floor radio button. To graphically copy specific elements to another floor within RISAFloor, first select the elements that you would like to copy. In the below example, columns (3-E) and (4-E), beams M15, M16 and M17 and wall WP1 are selected to be copied to the floor above the current floor. Click the Copy Selected Items button, selecting the floor above the current floor (Floor Level 3), while also selecting which element types (beams, columns, wall and joints) you want to copy. Once the selection is made click Apply. The selected items will now appear on Floor Level 3…

March 17, 2021 | RISAFloor, Decks, New

Video: Understanding Deck Types and Area Loads in RISAFloor

Occasionally buildings will have different types of decks as well as varying area loads within the same floor plan. One example of this is a floor plan with a partial roof. In this video, we will demonstrate how to consider this scenario in RISAFloor…