Seismic Behavior of Steel Framed Structures with Infill Walls - Analytical Study

The objective of this numerical study was the investigation of the seismic behavior of steel framed structures with infill walls. The equivalent diagonal struts and shear spring model based finite element software SeismoStruct was employed for this purpose. The experimental test setup and the data obtained from the experiments were used to verify the two basic analytical models by using SeismoStruct software. Then, six new groups of frame models were formed by using the validated simple frame structures. The number of bays and stories were increased, and infill walls were introduced in alternative steel frames. The global structural performance parameters of top displacement, base shear, fundamental time period, out-of-plane displacement and local parameters of inter-story drift ratio and member deformation capacities were obtained for all models. These parameters were compared in each group of models to detect symmetry/asymmetry and vertical discontinuity based effects due to presence or absence of infill walls. From this study, it is concluded that infill walls can increase strength and stiffness of the systems depending on the location of them. Also, the orientation of vertical frame members have significant advantages such as decreased fundamental time period, zero-out-of-plane displacement for minor axis frame models.