Techno Press
You logged in as. Techno Press

Structural Engineering and Mechanics
  Volume 91, Number 5, September10 2024 , pages 469-486
DOI: https://doi.org/10.12989/sem.2024.91.5.469
 


Effect of nonlinear soil-structure interaction on the seismic performance of 3D isolated transformers when scaling the response spectra using the improved wavelet method
Mohammad Mahmoudi, Abbas Ghasemi and Shahriar Tavousi Tafreshi

 
Abstract
    Electric transformers are major components of electrical systems, and damage to them caused by earthquakes can result in significant financial loss. The current study modeled a three-dimensional (3D) isolated electrical transformer under horizontal and vertical records from different earthquakes. Instead of using fixed coefficients, an improved wavelet method has been used to create the greatest compatibility between the response spectra and the target spectrum. This method has primarily been used for dynamic analysis of isolated structures with spring-damper devices because it has shown greater accuracy in predicting the response of such structures. The effect of the nonlinear soil-structure interaction on the probability of transformer failure also has been investigated. Soil and structure interaction modeling was carried out using a beam on a nonlinear Winkler foundation. The effect of the nonlinear soil-structure interaction during dynamic analysis of transformers revealed that the greatest increase in the probability of transformer failure was in the fixed-base condition when the structure was located on soft soil. This intensified the response of the structure and increased the probability of transformer failure by up to 27% for far-field and up to 95% for near-field ground motions. A comparison of the results indicates that the use of 3D isolation systems in transformers in areas with soft clay that are subject to near-field ground motions can strongly reduce the probability of failure and improve the seismic performance of the transformer.
 
Key Words
    3D seismic isolation system; improved wavelet method; nonlinear soil-structure interaction; probability of failure; spectral matching
 
Address
Mohammad Mahmoudi, Abbas Ghasemi and Shahriar Tavousi Tafreshi: Department of Civil Engineering, Faculty of Civil and Earth Resources Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2025 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: admin@techno-press.com