Seismic assessment of steel frames with knee brace by design base on performance

Seismic resistance structures must have sufficient ductility to absorb and dissipate earthquake energy and enough stiffness to minimize the structural damages due to excessive drift. To meet these, knee braced steel frame (KBF) was proposed which combines good ductility and lateral stiffness resulting an energy dissipating frame. Recently, a similar system was proposed and named as chevron knee bracing system (CKB) which in comparison with the former system has a better energy absorption characteristic and at the same time retains the elastic nature of the structures. In this article, relation between seismic performance and structural parameters of the two above mentioned systems are investigated and compared. Frames with similar dimensions but various heights in both systems are designed according to Iranian code of practice for seismic resistant design of building, and then based on a non-linear push over static analysis; the seismic parameters such as behavior factor are compared.

کلیدواژه ها:

seismic performance ، knee bracing frame ، chevron knee brace ، performance level