Drag Members
Drag Members
(OP)
I noticed in the webinar videos the beams between lateral frames are assigned to "gravity". Am I wrong thinking these beams should be "lateral" since they will act as a drag member to get load from the diaphragm to to lateral frames?





RE: Drag Members
This is somewhat speculative, so hopefully some members more familiar with the software chime in.
RE: Drag Members
If the diaphragm is to be a "flexible" diaphragm then it is VERY important to make those drag / collector members LATERAL so that the lateral force distribution will be done properly in the RISA-3D model.
Similarly if the diaphragm is "semi-rigid" then it is a good idea to have the drag / collector members in the lateral model. Though it's not a catastrophic problem if they are not in there like it would be for the perfectly flexible diaphragms.
If the diaphragm is "rigid" then it doesn't matter. The diaphragm is going to take the load to the walls or frames regardless of whether those drag/collector members are in the lateral model or not.