STUDY OF THE BLAST RESISTANCE OF SEISMICALLY DESIGNED STEEL PLATE SHEAR WALL FRAMES

During recent years, the occurrence of terrorist attacks and explosive events has increased the need to investigate the response of structures under blast loading. Due to the nature of blast loading, a lateral resisting system must damp energy to behave properly against blast loading. Steel plate shear wall system, which features a high level of stiffness, flexibility, and energy absorption, can be used as a means of the lateral resisting system against blast loading. In order to gain a better understanding of responses of the buildings and lateral resisting systems with different characteristics, the study of the behavior of the lateral resisting systems under blast loading conditions is essential. In order to achieve the aforementioned goal, 20 seismically designed steel frames with a number of stories of 3, 6, 9, 12, and 15 and different widths were modeled and analyzed under four explosive scenarios in OpenSees software (nonlinear dynamic analysis). The response of stories drift and acceleration, as well as the ductility ratio of the steel plate shear wall, were studied. The results of the study showed that tall buildings with steel plate shear wall system had behaviors far better than short buildings. The dominant behavioral modes of tall, medium height, and short buildings are flexural, combined shear and flexure, and shear modes, respectively. It is also observed that, in medium- and high-rise structures, the maximum horizontal acceleration of roof occurs in free vibration, while, in low-rise structures, this amount is experienced during loading. In addition, for all structures, the maximum horizontal displacement of the roof occurs in free vibration so that, with the increasing number of stories, this amount occurs later. In the other part of the study, it was shown that, in the same way, as we know for SDOF systems, in MDOF structures, the usual damping in systems with no control device is not significantly affected by the structure response to the explosion.