In this study, the Highway N Substation was analyzed with a finite element model (FEM) for its vulnerability. The 'rigid' bus and electric switch components were characterized with full scale shake table tests. Each component of the substation was carefully modeled with due considerations of mass density, stiffness and geometries. Based on the FEM, modal analysis was conducted to identify the natural frequencies of the structure along with their corresponding mass participation factors. In response spectrum and time history analyses, the dynamic responses of main components, such as 'rigid' buses and switches, were evaluated. The magnitude and location of the maximum moments were identified. The shake table tests on three Turner Electric's TMX switches indicated that the first three natural frequencies of the switches are approximately 7.41 Hz, 15.2 Hz and 22.9 Hz, respectively. They are significantly higher than their corresponding frequencies of the entire substation system. The tested switches consistently fractured at the base of their metal shaft, a critical component of the switch open-and-close mechanism, due to stress concentration and local manufacture defect.


Civil, Architectural and Environmental Engineering

Second Department

Geosciences and Geological and Petroleum Engineering


United States. Department of Transportation
Research and Innovative Technology Administration (RITA)


United States Department of Transportation Grant No. DTRT06-G-0014

Keywords and Phrases

Power substation; finite element model; modal analysis; response spectrum analysis; time history analysis; shake table test

Report Number

NUTC-R213 & NUTC-R228

Document Type

Technical Report

Document Version

Final Version

File Type





© 2009 Center for Transportation Infrastructure and Safety/NUTC program, Missouri University of Science and Technology, All rights reserved.

Publication Date

01 Oct 2009