Earthquake Response of Elastic Single-Degree-of-Freedom Systems with Nonlinear Viscoelastic Dampers |
| |
Authors: | Wen-Hsiung Lin Anil K Chopra |
| |
Affiliation: | 1Graduate Student, Dept. of Civil and Environmental Engineering, Univ. of California at Berkeley, Berkeley, CA 94720-1710. 2Johnson Professor, Dept. of Civil and Environment Engineering, Univ. of California at Berkeley, Berkeley, CA 94720-1710.
|
| |
Abstract: | Investigated are the steady-forced and earthquake responses of single-degree-of-freedom (SDF) systems with a nonlinear viscoelastic damper (VED), which consists of a nonlinear fluid viscous damper (FVD) connected in series to a linear elastic bracing element (chevron or inverted V-shaped braces). For a wide range of bracing stiffness, nonlinear dampers are advantageous because they achieve essentially the same reduction in system responses but with a significantly reduced force. Damper nonlinearity has little influence on the structural response in the velocity-sensitive region of the spectrum even if the bracing is fairly flexible, but differences up to 16% were observed in other spectral regions. As expected, supplemental damping reduces structural response and the response reduction depends on the bracing stiffness, with this dependence varying with the spectral regions. For practical applications, a procedure is presented to estimate the design values of structural deformation, structural force, foundation shear, and damper force directly from the earthquake design (or response) spectrum. Finally, a procedure is presented to determine the damper and bracing properties necessary to limit the structural deformation to some design value or to the structural capacity. |
| |
Keywords: | Earthquakes Degrees of freedom Seismic response Damping |
|
|