Seismic analysis in Risa 3D
Seismic analysis in Risa 3D
(OP)
Hi !
I am using RISA 3D for seismic analysis with ASCE 7. The building is a gable frame with cranes. My question is : It is necessary to define diaphgragms in order to make the seismic analysis ?. The example of Risa don´t shows this necesity.
please reply
Thanks in advance.
jatfuentes
I am using RISA 3D for seismic analysis with ASCE 7. The building is a gable frame with cranes. My question is : It is necessary to define diaphgragms in order to make the seismic analysis ?. The example of Risa don´t shows this necesity.
please reply
Thanks in advance.
jatfuentes






RE: Seismic analysis in Risa 3D
As to your question I don't see the need of use of any diaphragm, but I see that the efficient design of these structures with any program would require the repeated practice in several models, and maybe several (final) models per structure. This way one would gleam the better of the program and own's accumen; but I have not had the luxury of recent repetition of this kind of problem.
In my view, since these structures can have not only bottom shoulder flanges, but apex bottom flanges as well in compression, even the flange bracing should be represented, but this turns almost impossible when attempting to retain the main members as frame (line) members. That would ask for representing the main members as plate elements and once there you may be loosing the sight of the member as such. and so the convenience of using more than 1 main model appears.
RE: Seismic analysis in Risa 3D