Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Search Results

Now showing 1 - 2 of 2
  • Item
    Full scale experiment and finite element modeling of support structures of substation equipment for evaluation of ground motion amplification
    (2012) Nandam, S.; Ramesh Babu, R.; Venkataramana, K.
    Post earthquake performance of porcelain insulators installed for high voltage substation equipment, in general, revealed their vulnerability to failure, not due to any quality deficiency, but due to failure of their supporting structures. Most of the equipment in standalone state, withstood to tests of induced vibrations conforming to International standards. The same tested equipment, when erected in position over its supporting structure failed to sustain earthquake ground accelerations, as the supporting structure adversely contributed to amplification of the ground seismic motions while traversing to the top of the structure or the base of the insulator. This paper critically examines salutary effects of damping of vibrations on a typical instrument- transformer, using a rubber based elastic damper, with particular reference to the connected porcelain insulators, in partial containment of amplification of earthquake acceleration or in minimizing attendant distress on them. The analytical study carried out is based on experimental studies conducted on the equipment using shake table and then correlating the results obtained using finite element analysis, on the full scale model to draw meaningful conclusions. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.
  • Item
    Experimental and finite element analysis of power transformer
    (Structural Engineering Research Centre, 2014) Nandam, N.; Ramesh Babu, R.R.; Venkataramana, K.
    Post earthquake studies have clearly shown that the seismic performance of substation is very weak and results in damage causing huge direct and indirect loss to the power utilities. Considerable time is spent to repair, retrofit or replace the damaged substation equipment and to restore power supply. Many substation equipments failed when installed in the substation due to moderate earthquake forces though these equipment were experimentally qualified. Power transformer is one of such critical equipment of substation. Vibrations due to earthquake amplified by the transformer tank causes failure in the porcelain bushings mounted on the top of the transformer tank. An attempt has been made in this study to identify resonance frequencies and corresponding damping ratios of a typical transformer by both experimental and numerical methods. In addition, ground acceleration amplification is also calculated from shake table experiments and response analysis of finite element model.