A Caltech Library Service

Active interaction control for civil structures


Wang, Luo-Jia (1997) Active interaction control for civil structures. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/zsgm-ve62.


This thesis presents a civil engineering approach to active control for civil structures. The proposed control technique, termed Active Interaction Control (AIC), utilizes dynamic interactions between different structures, or components of the same structure, to reduce the resonance response of the controlled or primary structure under earthquake excitations. The primary control objective of AIC is to minimize the maximum story drift of the primary structure. This is accomplished by timing the controlled interactions so as to withdraw the maximum possible vibrational energy from the primary structure to an auxiliary structure, where the energy is stored and eventually dissipated as the external excitation decreases. One of the important advantages of AIC over most conventional active control approaches is the very low external power required.

In this thesis, the AIC concept is introduced and a new AIC algorithm, termed Optimal Connection Strategy (OCS) algorithm, is proposed. The efficiency of the OCS algorithm is demonstrated and compared with two previously existing AIC algorithms, the Active Interface Damping (AID) and Active Variable Stiffness (AVS) algorithms, through idealized examples and numerical simulations of Single- and Multi-Degree-of Freedom systems under earthquake excitations. It is found that the OCS algorithm is capable of significantly reducing the story drift response of the primary structure. The effects of the mass, damping, and stiffness of the auxiliary structure on the system performance are investigated in parametric studies. Practical issues such as the sampling interval and time delay are also examined. A simple but effective predictive time delay compensation scheme is developed.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:civil structures ; active control
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Civil Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Iwan, Wilfred D.
Thesis Committee:
  • Iwan, Wilfred D. (chair)
  • Beck, James L.
  • Hall, John F.
  • Heaton, Thomas H.
  • Housner, George W.
Defense Date:16 May 1997
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Funding AgencyGrant Number
Kajima CorporationUNSPECIFIED
NSFCMS- 9509877
Charles Lee Powell FoundationUNSPECIFIED
Kobori Research Complex of the Kajima CorporationUNSPECIFIED
Record Number:CaltechThesis:03142014-105804007
Persistent URL:
Related URLs:
URLURL TypeDescription DocumentTechnical Report EERL 97-04 in CaltechAUTHORS
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:8135
Deposited By: Kathy Johnson
Deposited On:18 Mar 2014 23:07
Last Modified:16 Apr 2021 23:18

Thesis Files

PDF - Final Version
See Usage Policy.


Repository Staff Only: item control page