Seismic Analysis of a United States Navy Structure Using Finite Element Modeling

The objective of this project was to investigate a United States Navy structure and evaluate the potential of the lifting rod, supporting a large mass at the top of the structure, to disengage from the structure due to seismic activity. A concern about the seismic loading of the structure was raised by an inspection team. The concern was that, in the event of an earthquake, the lifting rod would disengage from the structure due to vertical seismic actions. In order to accomplish the objective, seismic analyses of the structure were performed using finite element modeling. The geologic and tectonic settings of the site were investigated and the expected earthquake sources were determined. A probabilistic seismic hazard analysis was performed for the site, including a deaggregation of the earthquake sources affecting the site. The results of the probabilistic seismic hazard analysis were used to select three sets of bedrock acceleration time histories. Artificial acceleration time histories were generated based on the results of the probabilistic seismic hazard analysis and three of the time histories were selected. A finite element model of the structure was created using ABAQUS and seismic analyses were performed by applying the acceleration time histories. The results of the model were analyzed to determine whether or not the lifting rod disengaged from the structure. Plots of contact force vs. time indicated that there were a total of three increments of time where the lifting rod lost contact with the structure. Plots of relative vertical displacement vs. time indicated that there were no increments of time where the lifting rod was lifted up enough to detach. Plots of energy vs. time indicated that there were no increments of time where the kinetic energy of the mass was greater than the potential energy required for detachment. It was determined, based on the information at hand and within the hypotheses discussed in this document, that the lifting rod was not at risk of becoming detached.

Name thesis:degree_name

MS

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Engineering and Applied Science: Civil Engineering

Grantor dc:publisher

University of Cincinnati

Year dc:date

2012

Author dc:creator

• Nash, Jacob

Contributors dc:contributor

• Rassati, Gian

• Civil Engineering
• seismic analysis
• finite element analysis
• united states navy

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=ucin1353154520

OAI identifier oai:identifier

oai:etd.ohiolink.edu:ucin1353154520