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- Title
- Response of secondary systems to seismic excitation.
- Creator
- HoLung, Joseph Anthony., Florida Atlantic University, Lin, Y. K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In this dissertation the response of secondary systems to seismic excitation is investigated. A secondary system is a piece of equipment or a lighter appendage to a more massive primary structure which receives external excitations indirectly through its host structure. Assumption of linear behavior for both primary and secondary system is made in most parts in the analysis. Parametric excitations due to vertical ground motion and hysteretic behavior of the primary system under severe loading...
Show moreIn this dissertation the response of secondary systems to seismic excitation is investigated. A secondary system is a piece of equipment or a lighter appendage to a more massive primary structure which receives external excitations indirectly through its host structure. Assumption of linear behavior for both primary and secondary system is made in most parts in the analysis. Parametric excitations due to vertical ground motion and hysteretic behavior of the primary system under severe loading are treated in two separate chapters. A general procedure is first developed to formulate the system of equations for a combined primary-secondary linear system in which secondary systems are attached to a primary system at an arbitrary number of locations. Successive chapters are devoted to studying the effects of different factors on the behavior of a particular type of the combined system; namely, a multi-story primary structure supporting a secondary equipment, idealized as a single-degree-of-freedom linear oscillator. We list the following major findings of this study: (1) The two approximation procedures to calculate the response of a secondary system to seismic excitations developed in this dissertation are accurate and efficient, and can be applied to light or moderately heavy equipments. (2) Parametric studies suggest that greater amplification occurs as an equipment is tuned to lower building modes. (3) The equipment response is sensitive to the equipment mass, damping in the building, and the location of the equipment. (4) Soil compliancy can affect equipment response significantly. A greater number of modes should be employed when soil-structure interaction effects are important. (5) Protective devices between the equipment and the supporting floor of a building can reduce the equipment response by an order of magnitude. In this dissertation we consider cushioning devices constructed of linear, viscoelastic materials. (6) Vertical ground motion and gravity effect can both increase equipment response. (7) If a building is forced into the nonlinear regime due to intense seismic excitations, the equipment response can be quite sensitive to the parameters of the nonlinear model.
Show less - Date Issued
- 1988
- PURL
- http://purl.flvc.org/fcla/dt/11915
- Subject Headings
- Seismology, Earthquake engineering
- Format
- Document (PDF)
- Title
- Response analysis of structures including effects of soil-structure interaction.
- Creator
- Yu, Jun., Florida Atlantic University, Yong, Yan, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The objective of the study is to determine the structural response to external force and earthquake excitations with consideration of soil-structure interaction. The physical model concerned herein is an N-story building on a rigid or flexible foundation embedded in a layered soil medium. In this substructure approach, the soil medium and the structure are treated as one-dimensional waveguides and their motions are characterized as wave scattering. To include effects of soil-structure...
Show moreThe objective of the study is to determine the structural response to external force and earthquake excitations with consideration of soil-structure interaction. The physical model concerned herein is an N-story building on a rigid or flexible foundation embedded in a layered soil medium. In this substructure approach, the soil medium and the structure are treated as one-dimensional waveguides and their motions are characterized as wave scattering. To include effects of soil-structure interaction, the foundation response is expressed as a summation of influence functions, which are defined as the response to a simple stress distribution over the contact surface between the soil and foundation. The analysis, therefore, is carried out without solving integral equations. The coupling effect is recovered by using equilibrium, compatibility and reciprocal conditions. As a result, the structural response solution is expressed in terms of parameters of a seismic source and external excitations, and can be used in a statistical analysis if uncertainties of these parameters are taken into account.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/12425
- Subject Headings
- Soil-structure interaction, Earthquake engineering, Structural dynamics, Foundations
- Format
- Document (PDF)