Effect of Hysteresis Type on Drift Capacity for Global Collapse of Moment Frame Structures for Seismic Loads

281 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.It is conjectured that different hysteresis behavior in moment frames subjected to seismic loads may lead to different levels of response because of degradation in strength and stiffness. To examine the existence and magnitude of this effect, this research aims to: (1) Determine the global collapse capacities of several classes of moment frame buildings under seismic loads. (2) Develop the basis for the seismic criteria for design and evaluation of moment frame buildings that reflect and account for the global drift capacity. (3) Evaluate the hysteresis effects on the demand level response and capacity/demand ratio of moment frame buildings under seismic loads. (4) Develop a nonlinear cyclic pushover procedure that can be used for estimating the global drift capacity of a specific building. To achieve these objectives, seismic analyses of 3-, 9- and 20-story moment resisting frame buildings were conducted to evaluate the effects of the hysteretic behavior of beam-to-column connections, structural stiffness, and structural strength on the collapse potential and the demand level response. Five hysteresis models: basic bilinear, strength degradation, stiffness degradation, stiffness degradation + strength degradation, and pinching are evaluated. The effects of hysteresis behaviors are very significant for both global drift capacities and demand level responses. Two interesting results for the mid-rise/high-rise buildings are that (1) strength degradation significantly decreases both the global drift capacity and the Sa capacity, whereas, (2) the existence of stiffness degradation increases the global drift capacity and the Sa capacity.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD