Abstract Transformer bushings are vulnerable to ground motions during earthquakes due to the amplification by the cover plates of the transformer tank. In addition, the stiffening strategies and the seismic performance of sidewall bushings with L-shaped turrets are under-investigated. In this study, a full-scale transformer tank with top and sidewall bushing was tested, with and without stiffening using steel diagonal braces. In addition, a numerical model of the transformer-bushing system is established by idealizing the flexibility of the cover plate as rotational springs. The test results show that the flexibility of the sidewall cover plate contributes to the vulnerability of the bushing, and the sidewall bushing is more vulnerable than the top bushing. The motion at the top of bushings primarily contributes from the bending of the cover plates, while the sidewall cover plate needs sufficiently stiff stiffeners. The diagonal braces effectively reduce the stress and displacement responses of the sidewall bushing by constraining the rocking motion of the turret and increasing the damping ratio. However, the use of these diagonal braces can generate problems if the natural frequency of the tank is close to that of the bushing. Therefore, the transformer tank should be considered in the design of stiffening strategy. However, the diagonal braces are recommended for use when the natural frequency of the transformer tank is much larger than that of the bushing.

中文翻译：

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侧壁盖板上变压器套管的抗震性能及加固策略

摘要 由于变压器油箱盖板的放大作用，变压器套管在地震时容易受到地震动的影响。此外，L 形转塔侧壁衬套的加固策略和抗震性能正在研究中。在这项研究中，对带有顶部和侧壁套管的全尺寸变压器油箱进行了测试，使用钢斜撑进行加固和不加固。此外，通过将盖板的柔性理想化为旋转弹簧，建立了变压器-套管系统的数值模型。试验结果表明，侧壁盖板的柔性有助于衬套的易损性，侧壁衬套比顶部衬套更易损坏。衬套顶部的运动主要来自盖板的弯曲，而侧壁盖板需要足够的加强筋。斜撑通过约束转塔的摇摆运动和增加阻尼比，有效降低侧壁衬套的应力和位移响应。然而，如果油箱的固有频率接近套管的固有频率，则使用这些斜撑会产生问题。因此，在设计加固策略时应考虑变压器油箱。但是，当变压器油箱的固有频率远大于套管的固有频率时，建议使用斜撑。斜撑通过约束转塔的摇摆运动和增加阻尼比，有效降低侧壁衬套的应力和位移响应。然而，如果油箱的固有频率接近套管的固有频率，则使用这些斜撑会产生问题。因此，在设计加固策略时应考虑变压器油箱。但是，当变压器油箱的固有频率远大于套管的固有频率时，建议使用斜撑。斜撑通过约束转塔的摇摆运动和增加阻尼比，有效降低侧壁衬套的应力和位移响应。然而，如果油箱的固有频率接近套管的固有频率，则使用这些斜撑会产生问题。因此，在设计加固策略时应考虑变压器油箱。但是，当变压器油箱的固有频率远大于套管的固有频率时，建议使用斜撑。在设计加固策略时应考虑变压器油箱。但是，当变压器油箱的固有频率远大于套管的固有频率时，建议使用斜撑。在设计加固策略时应考虑变压器油箱。但是，当变压器油箱的固有频率远大于套管的固有频率时，建议使用斜撑。