Abstract: Structural redundancy is an interesting point in
seismic design of structures. Initially, the structural redundancy is
described as indeterminate degree of a system. Although many definitions are presented for redundancy in structures, recently the
definition of structural redundancy has been related to the configuration of structural system and the number of lateral load
transferring directions in the structure. The steel frames with infill walls are general systems in the constructing of usual residential buildings in some countries. It is
obviously declared that the performance of structures will be affected by adding masonry infill walls. In order to investigate the effect of
infill walls on the redundancy of the steel frame which constructed
with masonry walls, the components of redundancy including redundancy variation index, redundancy strength index and
redundancy response modification factor were extracted for the
frames with masonry infills. Several steel frames with typical storey number and various numbers of bays were designed and considered.
The redundancy of frames with and without infill walls was evaluated by proposed method. The results showed the presence of infill causes increase of redundancy.