Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 10 2022 12 22 Evaluation of the seismic performance of isolated electrical transformers under pulse-like excitations Evaluation of the seismic performance of isolated electrical transformers under pulse-like excitations 4007 4034 4849 10.22060/ceej.2022.21271.7672 FA Mohammad Mahmoudi Department of Civil Engineering, Faculty of Civil and Earth Resources Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran Abbas Ghasemi civil departement/ Engineering Faculty/ Central tehran Branch of Islamic Azad University/Tehran/Iran Shahriar Tavousi Tafreshi Department of Civil Engineering, Faculty of Civil and Earth Resources Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran Journal Article 2022 04 05 Damage sustained by electrical transformers in past strong earthquakes led to irrecoverable and severe economic losses. The seismic performance evaluation is associated with the loss of proper functioning of the transformer. This study deals with modeling existing isolated electrical transformer structures to evaluate the effects of variables that may affect seismic performance and dynamic characteristics. The results probabilistically determine the seismic performance acceptability of study isolated electrical transformer structures based on the impact of key structural response parameters on the seismic performance of the transformer. Analyses of systems for a wide range of parameters are performed. The effects of horizontal and vertical near-fault pulse-like ground motions, the displacement capacity of the seismic isolation system, limit states of electrical bushings, and details of the isolation system design are considered. Also, the probability of failure of the transformer under near-fault excitations with pulse-like characteristics is investigated. The results of this study demonstrate that three-dimensional seismic isolation systems can improve the seismic performance for a wide range of parameters and can be further effective compared with only horizontal seismic isolation and offer the lowest probabilities of failure for all cases of transformer and isolation system parameters. Damage sustained by electrical transformers in past strong earthquakes led to irrecoverable and severe economic losses. The seismic performance evaluation is associated with the loss of proper functioning of the transformer. This study deals with modeling existing isolated electrical transformer structures to evaluate the effects of variables that may affect seismic performance and dynamic characteristics. The results probabilistically determine the seismic performance acceptability of study isolated electrical transformer structures based on the impact of key structural response parameters on the seismic performance of the transformer. Analyses of systems for a wide range of parameters are performed. The effects of horizontal and vertical near-fault pulse-like ground motions, the displacement capacity of the seismic isolation system, limit states of electrical bushings, and details of the isolation system design are considered. Also, the probability of failure of the transformer under near-fault excitations with pulse-like characteristics is investigated. The results of this study demonstrate that three-dimensional seismic isolation systems can improve the seismic performance for a wide range of parameters and can be further effective compared with only horizontal seismic isolation and offer the lowest probabilities of failure for all cases of transformer and isolation system parameters. https://ceej.aut.ac.ir/article_4849_ec1f764517b7ffb52057af6df18142b7.pdf