The rods connect the ribs of the radiators. The bulk components such as the active part, the insulators and the lower boxes were modelled using the solid elements (second order elements C3D20R). The thickness was assigned to the shell elements and the values were taken from the real sheet metal parts of the transformer. insulators and lower boxes), were modelled using the shell elements (second order elements S8R). The components, with the exception of some parts (i.e. The distribution type which was used is mass proportional. The nonstructural mass is equal to the mass of the oil in the transformer tank.
The frequency step result provides a valuable input to the remaining steps of the seismic test. The work presents the results for some approaches mentioned above and outlines the advantages and the disadvantages of each method. The oil behavior was included using the nonstructural mass, the hydrostatic pressure, acoustic elements or a combination of them. A few numerical analyses were performed in order to find the most accurate method.
One of the biggest issues that a simulation engineer can face is how to model the oil behavior in the transformer tank. In this paper, the results of accelerometer measurements for some single points were also depicted. This allows to have the complex image of how the whole surface vibrates.
The great advantage of this device is the ability to measure the vibration not only in the single points, as the accelerometers do, but also its ability to measure the whole surface. The vibrometer is able to quickly and accurately determine the resonant frequencies and their corresponding mode shapes of complex objects across a wide range of frequencies. The work that is presented in this paper shows the frequencies and mode shapes measurement done using the advanced vibrometer. The resonant frequencies and the corresponding mode shapes obtained through the numerical analyses were compared with the results obtained in the real frequency search test performed on the single-axis shake-table. The frequency search test is the second step of the three-step seismic test which was performed using Abaqus software. the response spectrum analysis/the sine beat analysis/the time history analysis or another type of the analysis defined by the seismic standard (IEEE, IEC, ASCE, etc.).
the gravity or another static load can be applied), The seismic test was performed through the following steps: For the numerical analyses, the resonant frequencies for the distribution transformer were found during the seismic test.
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