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Nonlinear Dynamic Analysis of Three-Dimensional Base Isolated Structures (3D-BASIS).
Nagarajaiah, S.; Reinhorn, A. M.; Constantinou, M. C.
National Science Foundation, Washington, DC., August 3, 1989, 132 p.
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Base isolation for seismic protection has received considerable attention in the engineering community. Natural or synthetic rubber pads, Teflon bearings sliding on stainless steel, and combinations of displacement control and energy dissipation devices are used to reduce the energy input into building structures. The present report describes the development of a comprehensive analytical model and a computer program 3D-BASIS, for analysis of three-dimensional base isolated multistory buildings. Modeling various types of isolation devices with strong nonlinearities such as hysteretic and frictional devices or their combination is discussed. The superstructure, comprised of shear walls, frames and nonstructural elements, is assumed to remain elastic. Comparison of response computed using the program 3D-BASIS with various existing programs and experimental results is considered. The hysteretic model considered in the report can reproduce bi-axial inelastic behavior of high damping rubber bearings with shear-stiffness degradation, steel dampers, viscoelastic dampers, bilinear behavior of lead-rubber bearings, and hysteretic behavior of friction interfaces effectively.
Dynamic response; Ground motion; Buildings; Earthquake engineering; Earthquake resistant structures; Base isolation; 3D-BASIS computer program; Seismic effects; Nonlinear analysis; Mathematical models