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The Earthquake Response of Deteriorating Systems


Gates, Nathan Craig (1977) The Earthquake Response of Deteriorating Systems. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/E3AQ-B348.


This thesis is concerned with the earthquake response of deteriorating systems. A model for stiffness degrading or deteriorating systems is used to describe six different single-degree-of-freedom systems. A numerical investigation of the response of these six systems is performed using an ensemble of twelve earthquakes. The response is studied at nine nominal periods of oscillation. The numerical results are presented as response spectra corresponding to six different ductilities.

An approximate analytical method for calculating the earthquake response of deteriorating systems from a linear response spectrum is presented. The method, called the average stiffness and energy method, is based upon the premise that a linear system may be defined which is in some sense equivalent to the deteriorating system. The criterion for equivalence in this method is that the average stiffness of the deteriorating system be equal to the stiffness of the linear system and the average energy dissipated by the linear system be the same as the average energy dissipated by the deteriorating system.

The new analytical method is compared to existing methods. Comparison with the numerical results is also made. Based upon these comparisons, it is concluded that the average stiffness and energy method represents a significant improvement over currently available methods for predicting the earthquake response of deteriorating and nondeteriorating systems.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Applied Mechanics
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Applied Mechanics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Iwan, Wilfred D.
Group:Earthquake Engineering Research Laboratory
Thesis Committee:
  • Unknown, Unknown
Defense Date:29 March 1977
Other Numbering System:
Other Numbering System NameOther Numbering System ID
EERL Report77-03
Funding AgencyGrant Number
Record Number:CaltechTHESIS:04212017-094508970
Persistent URL:
Related URLs:
URLURL TypeDescription
ttps:// ItemTechnical Report EERL 77-03 in CaltechAUTHORS
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:10143
Deposited By: Benjamin Perez
Deposited On:21 Apr 2017 17:25
Last Modified:13 Aug 2021 23:54

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