Abstract:
The suspended zipper-braced frame (SZBF) is a modified version of inverted V braced
frame in which zipper struts are added between the brace locations at the mid-span of floor
beams and a hat truss is added between top floor to transfer the unbalanced vertical forces
induced by brace buckling into the upper floors. Two reference steel braced frames, 3
storey (low rise) and 9 story ( mid-rise) SAC model buildings, designed for the Los
Angeles area are analyzed and the seismic performance of the structures with the
conventional steel bracing (SZBF and chevron braced frame) are investigated and
compared with the Shape Memory Alloys (SMA) SZBF. In this study, a 2-D finite
element (FE) analysis of the SZBF is carried out in order to assess the seismic
performance of the SZBF by exploiting the super elastic (SE) behavior of SMA. The
nonlinearities of both geometric and material aspects are included in the FE models.
Nonlinear static pushover analyses and incremental dynamic analyses under 20 earthquake
excitations have been conducted. Results obtained from the analyses confirm the
suitability of SMA braces to improve the seismic performance of SMA SZBFs to help
achieve performance-based design objectives for steel buildings in high seismic zones by
uniformly distributing inter-storey drift ratios over the height of the building and thus
reducing the vulnerability of failure due to soft storey mechanism.
Description:
At the very beginning we would like to express our deepest gratitude to Almighty Allah
for giving me the strength and ability to accomplish this thesis work. During the time of
my conducting thesis work I received a lot of support from various corners.
First and foremost, I am highly obliged to my thesis supervisor, Dr M. Shahria Alam
whose inspiration gave me a lot of support to do my thesis work. Then, my co-supervisor
Kamrul Islam, who has allowed me to encroach upon his precious time right from the very
beginning of this thesis work till the completion. His expert guidance, affectionate
encouragement and critical suggestion provided me necessary insight into the thesis
subject and paved the way for a meaningful ending of this thesis work in a short duration.
Without his constant supervision, valuable advices and suggestion from time to time I
would not have to be able to complete the whole thesis in a right manner.
I am also very much indebted and grateful to Lecturar Khadiza of MIST and Capt Sazzad
who have helped me in doing this thesis work.
I am also grateful to the authors of the books, journals papers etc those had been aids to
my thesis work as mentioned in the bibliography.
