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Abstract:
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In this dissertation , the seismic behavior and design of AAC -infilled steel moment frames are investigated systematically . The fundamental vehicle for this investigation is the ATC -63 methodology , which is intended for the establishment of seismic design factors for structural systems . The ATC -63 methodology is briefly reviewed , including the concepts of archetypical structures , design rules and mathematical models simulating the behavior of those archetypes . A limited experimental investigation on the hysteretic behavior of an AAC -infilled steel moment frame is developed , conducted , and discussed . Using the experimental results of that investigation , the draft infill design provisions of the Masonry Standards Joint Committee (MSJC ) are extended to AAC infills , and a mathematical model is developed and calibrated to simulate the behavior of AAC infills under reversed cyclic loads . Prior to application of ATC -63 methodology to AAC -infilled steel moment frames , the methodology is applied to an example steel moment frame to demonstrate the methodology and verify understanding of it . Then , archetypical infilled frames to be evaluated by the ATC -63 methodology are developed using a series of pushover analyses . Infill configurations whose total lateral strength in a particular story exceeds about 35 % of the lateral strength of the bare frame in that story are observed to provoke story mechanisms in the frame . Based on this observation , archetypical infilled frames are selected conforming to two infill configurations : uniformly infilled frames , and open ground story frames . Each infill configuration includes archetypes whose ratio of infill strength to bare -frame strength at each story is less than 35 % , and archetypes whose ratio is greater than 35 % . The former archetype is typical of steel moment frames infilled with AAC ; the latter archetype is typical of steel moment frames infilled with conventional (clay or concrete ) masonry . The ATC -63 methodology , specialized for application to infilled frames , is applied to the archetypical infilled frames developed above . The performance of those archetypical infilled frames is evaluated , and seismic design factors are proposed for AAC -infilled steel moment frames . The extension of this work to other types of infilled frames is discussed . |