The Effect of Out-of-Plane Displacement of Lateral Bracings on the Dynamic Performance of Steel Structures
The method of distributing lateral load-bearing elements in a structure influences the building’s performance against seismic loads. In practice, the distribution style of these elements is specified by architectural, structural and economic constraints. In the current research paper, the effect of out-of-plane displacement of lateral load-bearing elements on the dynamic behavior/response of the structure, including the displacements, relative inter-storey drift, columns’ axial force distribution as well as ductility and over-strength, has been investigated in threefold18- and 24-storey steel building model with 1:1 plan ratio that incorporates diverse models with various arrangements of different lateral load-bearing elements. It was found out that the out-of-plane displacement of the lateral load-bearing elements cannot be recounted as harmful to the structure and that, if it is done carefully, it would be accompanied by advantages to the structure amongst which the reduction in the relative drift of the storeys, reduction in the storeys’ total displacement, reduction in the columns’ force and balanced distribution of the axial forces on the columns, reduction and, in some of the cases, perfect elimination of the upward thrust in the columns can be pointed out. In the meanwhile, this method of arranging the lateral load-bearing elements can provide better responses if implemented in nearly square buildings with 1:1 plan ratio and heights below 50 meters. Of course, some other effects have to also be taken into account in performing such a displacement including the rigidity status of the diaphragms and concentration locus of the stresses. Moreover, the way the lateral load-bearing elements are displaced is also of a great importance.