SEISMIC RESPONSE EVALUATION OF THE LINKED COLUMN FRAME SYSTEM Mohammad MalakoutianChair of the Supervisory Committee:Professor Jeffrey W. Berman Civil and Environmental EngineeringThe Linked Column Frame system (LCF) is a new structural steel frame system capable of achieving enhanced seismic performance and safely providing continued occupancy of buildings impacted by moderate earthquake events. The LCF consists of two components: a primary lateral system, denoted the linked column, which is made up of dual columns interconnected with replaceable link beams; and a secondary moment frame lateral/gravity system that is a flexible moment resisting frame with beams having fully restrained connections at one end and simple connections at the other.The linked columns are designed to limit seismic forces and provide energy dissipation through yielding of the links, while preventing damage to the moment frame under certain earthquake hazard levels. A design procedure is proposed that ensures the links of the linked column yield at a significantly lower story drift than the beams of the moment frame, enabling design of this system for two distinct performance states: rapid repair, where only link damage occurs and relatively quick link replacement is possible; and collapse prevention, where both the linked column and moment frame may be damaged.Nonlinear dynamic analyses of prototype buildings were conducted using OpenSees and the results identified how the system's parameters impact the ability of the LCF to achieve the performance objectives and the adequacy of the proposed design procedure. It was found that in general the LCF system provides collapse prevention for longer return period events and enables rapid repair following earthquakes with shorter return periods.The seismic performance factors for the LCF system, including the response modification coefficient, R, the system overstrength factor, Ω 0 , and the deflection amplification factor (C d ) were established following recently established procedures described in FEMA P695 (2009). These parameters are necessary for inclusion of the system in the building codes.Finally, models were developed in support of the experimental validation of the system's performance being done using hybrid simulation at the Network for Earthquake Engineering Simulation Laboratory at the University of California, Berkeley. Using the modeling techniques developed here, the numerical portion of the hybrid simulation specimen has been developed and used to predict the experimental response. The experiments are being conducted by collaborators at Portland State University.
The Linked Column Frame (LCF) is proposed as a steel seismic load resisting system consisting of two components: a primary lateral system made up of dual columns interconnected with link beams (denoted linked columns); and a secondary moment frame. Previous research has developed a procedure that ensures the links of the linked columns yield at a significantly lower story drift than the beams of the moment frame, enabling design of this system for three distinct performance states: linearly elastic; rapid repair, where only link damage occurs and quick link replacement is possible; and collapse prevention. This paper discusses additional analyses that have been performed to establish recommended values for seismic design parameters, including the response modification coefficient, R, the system over-strength factor, Ω, and the deflection amplification factor (C d ). A suite of archetype LCF buildings were developed and incremental dynamic analysis was performed according the procedures in FEMA P695.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.