Ali Keyhani - Assistant Professor, Civil Engineering Department, Shahroord University of Technology, I.R.Iran
Mehdi Darbanian - Faculty of Civil Engineering, IAU, Shahrood Branch, Civil Department I.R.Iran
Reza Darbanian - Graduated MSc, Civil Department, KNTU, I.R.Iran,

Aim of this paper is investigative effect of effective parameters on behavior of diaphragm on the seismic response in concrete structure with symmetric and asymmetric in plan, including; number and story level, distributed element of VLLR with plan size ratio and other effective subjects. For this purpose, 3 concrete structures with different story level i.e. 4, 8 and 12 level are renowned as low, mid and high rise modeling did in ETABS and SAP2000 software. Result indicates, increasing in flexibility of diaphragms causes increasing in period of time so then, decreasing in seismic coefficient. Also, assuming of rigidity diaphragm in analyze and design of frame of systems is an ideal, in other wise, in braced structures, it’s not correct.

Rigidity of diaphragm, seismic response, symmetric and asymmetric structures, linear static analyze, shear wall structure