عملکرد لرزه ای قاب های فولادی پیش ساخته
Abstract
۱٫ Introduction
۲٫ Description of the experimental test on the RCED braced frame
۳٫ Quasistatic analysis of the tested RCED braced frames
۴٫ Nonlinear time history analyses of multistory braced frames
۵٫ Conclusions
Declaration of Competing Interest
Acknowledgement
References
Abstract
The application and research of prefabricated steel structures (PPSs) have developed rapidly in China. To improve the seismic resistance of PPSs, alternative bracing systems have been developed. The seismic performance of steel frames with recentering energy dissipative (RCED) braces is investigated numerically through quasistatic and nonlinear time history analyses. A one-bay braced frame model was first created in ABAQUS and calibrated by previous experimental tests. Subsequently, a comparative study on the dynamic performances of the multistory steel frames with RCED braces and self-centering energy dissipative braces was conducted. Six far-field earthquake records were adopted, i.e., Northridge, Imperial Valley, Kobe, San Fernando, Loma Prieta, and Kocaeli, Turkey. Finally, a parametric study was performed to investigate the effects of tendon diameter and pretension magnitude of high-strength bolts on the seismic performances of the RCED model under the Kocaeli earthquake.
Introduction
Prefabricated steel structures (PSSs) are a new type of structure that embodies the definition of a green building [1,2]. PSS models are manufactured in factories and assembled with bolt connections on site [3]. Compared with traditional steel buildings and structures, PSSs can reduce more energy, shorten construction period, reduce contamination, and protect the environment in its life cycle. A steel braced frame is a reliable structure that can resist earthquake. The traditional seismic design of structures is based on the anticollapse concept. The energy of an earthquake is dissipated by the plastic hinges formed in beam-to-column joints or the yielding of braces. When braces are buckled, the load-bearing and energy dissipation capacities of the braces are affected significantly. Hence, researchers worldwide have developed various types of buckling-restrained braces (BRBs) [4–6]. Traditional BRBs have successfully solved the buckling problem of braces, while steel frames with BRBs will experience large peak deformations and excessive interstory drifts in rare earthquake events. Some evidence has shown that the repairing cost will be higher than the reconstruction cost if the residual interstory drift is larger than 0.5% [7]. Additionally, the P-delta effect is significant in this type of structures and causes successive load cycles to pull the structure further in the same direction [8]. Based on the considerations above, self-centering systems have been developed by researchers. These types of systems can pull a structure back to its initial position after each load cycle, which can eliminate post-earthquake residual drifts. The following materials are frequently used for self-centering systems: posttensioned (PT) tendons, shape memory alloys (SMAs), and springs.