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Modeling and Identification in Structural Dynamics


Jayakumar, Paramsothy (1987) Modeling and Identification in Structural Dynamics. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/1wwx-ca82.


Analytical modeling of structures subjected to ground motions is an important aspect of fully dynamic earthquake-resistant design. In general, linear models are only sufficient to represent structural responses resulting from earthquake motions of small amplitudes. However, the response of structures during strong ground motions is highly nonlinear and hysteretic.

System identification 1s an effective tool for developing analytical models from experimental data. Testing of full-scale prototype structures remains the most realistic and reliable source of inelastic seismic response data. Pseudo-dynamic testing is a recently developed quasi-static procedure for subjecting full-scale structures to simulated earthquake response. The present study deals with structural modeling and the determination of optimal linear and nonlinear models by applying system identification techniques to elastic and inelastic pseudo-dynamic data from a full-scale, six-story steel structure.

It is shown that the feedback of experimental errors during the pseudo-dynamic tests significantly affected the higher modes and led to an effective negative damping for the third mode. The contributions of these errors are accounted for and the small-amplitude modal properties of the test structure are determined. These properties are in agreement with the values obtained from a shaking table test of a 0.3 scale model.

The nonlinear hysteretic behavior of the structure during strong ground motions is represented by a general class of Masing models. A simple model belonging to this class is chosen. with parameters which can be estimated theoretically, thereby making this type of model potentially useful during the design stages. The above model is identified from the experimental data and then its prediction capability and application in seismic design and analysis are examined.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Civil Engineering
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Civil Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Beck, James L.
Group:Earthquake Engineering Research Laboratory
Thesis Committee:
  • Beck, James L. (chair)
  • Hall, John F.
  • Iwan, Wilfred D.
  • Jennings, Paul C.
  • Knowles, James K.
  • Scott, Ronald F.
Defense Date:21 May 1987
Funding AgencyGrant Number
Record Number:CaltechTHESIS:02272019-105053083
Persistent URL:
Related URLs:
URLURL TypeDescription ItemTechnical Report EERL 87-01 in CaltechAUTHORS
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11411
Deposited On:27 Feb 2019 19:15
Last Modified:19 Aug 2021 23:55

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