Hello all,
I am modeling a multi story steel structure building using STAAD.pro , every story is an RC metal deck floor , which requires modeling a diaphragm
and I have faced a big problems in the diaphragm definition.
I know that I can define the diaphragm by the following methods
1- Floor Diaphragm
it's really amazing in the earthquake analysis , it's also help me to know the story shear, story load , drift ..etc. , also the earthquake tab is amazing !
but I am facing a problem which RUINS my structure, that the floor diaphragm in staad is only RIGID .. which lead to make the NORMAL force in every horizontal member of a truss or beam in the diaphragm floor = ZERO , which not logic and impossible !!
2- Master/Slave Nodes
by making a master node and assigning rigid ZX , but it makes me lose the out put of story load, story shear , drift ..etc.
also it didnt help in the normal forces issue , it's still = ZERO , also it let me lose the earthquake tab !!!
3- Slab definition
it's slightly not bad option to model that semi reigid diaphragm , I think it works in analysis results and the axial force output.
but it let me lose each story shear, load, drift , CR, CG , and also the earthquake tab ..
so how could I model a suitable diaphragm for my structure to let the model analysed well, and to extract the data I want !!!
Thank you in advance for helping ,