Linearization methods in earthquake analysis and design of hysteretic structural systems
In most buildings and structures designed to resist earthquake attack the protection of the structure is effected by inelastic deformation of structural elements and the energy dissipation that is produced by this inelastic behavior. It is therefore desirable in the design process, to have efficient and reliable approximate procedures to estimate the nonlinear dynamic behavior of the structure. This dissertation is concerned with the development of linearization methods, suitable for the earthquake analysis and design of yielding structures, to provide predictions of the actual nonlinear behavior of these structures. Current linearization techniques use conventional viscous damping model as the equivalent linear model for the nonlinear structure, and apply different approximation methods to determine the effective parameters of the linear model. However, there are several deficiencies in using the conventional model as the equivalent linear system. These deficiencies are described qualitatively and quantitatively in this investigation. An alternative equivalent linear model for hysteretic structures is proposed. The new linear system has the same degree of simplicity as the conventional viscous damping element and it is analogous to the Maxwell model of linear viscoelasticity. This alternative linear model is shown to be a suitable equivalent system for both bilinear hysteretic structures and nonlinear systems which have a smooth yielding transition. A wide variety of excitations from the harmonic type to an ensemble of nine different earthquakes are used. Optimum effective parameters of the new linear model subject to the ensemble of the earthquakes are computed by comparison of linear and nonlinear response spectra. The current linearization techniques are modified and some new approximate methods are presented. A recently proposed analytical procedure, called the average stiffness and energy method, is generalized.
- OSTI ID:
- 6601153
- Country of Publication:
- United States
- Language:
- English
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