D. Mostofinejad and M.davoodnabi,
Volume 21, Issue 1 (7-2002)
Abstract
In most cases, structural engineers assume a concrete floor to be a rigid diaphragm. Although this simplification is in most cases acceptable, it should be noted that such an assumption may be distrusted due to certain problems. Concrete structures with staggered shear walls are among those whose analysis should be conducted with special concern for the behavior of their floor diaphragms. However, in the structures with staggered shear walls, the horizontal shear due to lateral loads is transmitted to the lower stories through the floor diaphragm since the walls are not usually located over each other in consecutive stories. Therefore, the rigidity of the floor diaphragm is of great importance. In the present study, a parametric analysis was performed to investigate the effect of the rigidity of the floor diaphragm on the load-carrying procedure of the structures with staggered shear walls. The investigated parameters were the number of stories, the ratio of length to width of the plan, and the thickness of walls and diaphragms. Furthermore, the study was carried out for both rectangular and I-shaped plans. All analyses were dynamically performed by ANSYS 5.4 using acceleration spectrum recommended by Iranian Building Code Standard No. 2800. Finally, the behavior of these structures and comparison of the frequencies, the maximum lateral displacements and the shear in the walls and columns as the responses of rigid and flexible diaphragms were highlighted and outlined.
Keywords: Reinforced concrete, staggered shear wall, load carrying, floor diaphragm, rigidity.
S. M. Seyed Sharafy, S. Hatami,
Volume 37, Issue 2 (3-2019)
Abstract
Diagonal Strap bracing is one of the most applicable lateral bracing systems in light steel framing (LSF). In practice, one or more panels of Gypsum Wall Boards (GWBs) is used for the cladding of strap braced frames. Usually, the effect of these GWBs in modelling and design is neglected by designers, but this effect can affect the seismic performance of the system In this paper, firstly, a simple numerical method is developed to model the monotonic and cyclic behavior of cold-formed strap braced shear walls together with GWBs. Then, the effects of GWB on the lateral characteristics and seismic performance levels of shear walls are evaluated. It is found that neglecting GWB in the lateral design or modeling of LSF is not rational and GWB can increase the dissipation of earthquake energy, lateral strength and stiffness of the walls. Also, the shear wall composed of strap bracing and SWBs reaches a certain performance level in a less drift ratio in comparison to to only strap braced system
