NEHRP Clearinghouse

Title
Model Analysis of Nonclassically Damped Structural Systems Using Canonical Transformation.
File
PB88187851.pdf
Author(s)
Yang, J. N.; Sarkani, S.; Long, F. X.
Source
National Science Foundation, Washington, DC., September 27, 1987, 72 p.
Identifying Number(s)
NCEER-87-0019
Abstract
An alternate model decomposition method for dynamic analysis of non-classically damped structural systems is presented. The resulting decoupled equations contain only real parameters. Hence, the solution can be obtained in the real field. Several procedures are outlined to solve these equations for both deterministic and nonstationary random ground excitations. Prior work has shown that the effect of nonclassical damping may be significant for the response of light equipment attached to a structure. Therefore, the proposed solution technique is applied to find the response of a light equipment that is attached to a multi-degree-of-freedon structure. Numerical results obtained from deterministic and nonstationary random vibration analyses indicate that the effect of nonclassical damping on the response of tuned equipment is significant only when the mass ratio and damping ratio of the equipment are small. For detuned equipment, neglecting the effect of nonclassical damping generally results in an equipment response that is close to the exact results.
Keywords
Dynamic response; Functions (Mathematics); Damping; Ground motion; Numerical integration; Earthquake engineering; Transformations; Vibration; Equations of motion; Seismic effects; Structural analysis