NEHRP Clearinghouse
- Title
- Modal Analysis of Arbitrarily Damped Three-Dimensional Linear Structures Subjected to Seismic Excitations.
- File
- PB2010100922.pdf
- Author(s)
- Chu, Y.; Song, J.; Lee, G. C.
- Source
- Federal Highway Administration, Washington, DC.; National Science Foundation, Arlington, VA. Earthquake Engineering Research Centers Program., January 31, 2009, 232 p.
- Identifying Number(s)
- MCEER-09-0001
- Abstract
- Modal analysis is a powerful approach that is used to analyze the responses of a structure under dynamic loadings. This approach allows the equation of motion to be decoupled in the modal coordinate space, and subsequently used to evaluate the dynamic response of a structure in the modal coordinate system, which significantly simplifies and accelerates the response calculation. Past research has shown that the modal analysis approach is applicable in earthquake engineering, resulting in its widespread use. For example, the seismic design and analysis of structures with added damping devices is based on the modal analysis concept, in which the motion within a plane and the assumption of classical damping are usually made. However, three-dimensional (3-D) structures with complex geometric shapes enhanced with added damping devices may be highly nonclassically damped, possess over-damped modes, and exhibit significant out-of-plane motions. These uncertainties may affect the accuracy of the modal analysis approach in practice. This report presents a theoretical framework for the seismic analysis of arbitrarily damped 3-D linear structures.
- Keywords
- Structures; Seismic excitations; Three-dimensional (3-D) structures; Modal analysis concept; Earthquake engineering; Three-dimensional structures; Theoretical famework; Damping devices; Modal analysis approach