| Summary: | 碩士 === 正修科技大學 === 機電工程研究所 === 102 === Taiwan is situated in between two highly active tectonic plates, the Circum-Pacific Seismic Belt at the east and the Philippine Sea Plate at the west. The Philippine Sea Plate frequently collides with the Eurasian plate, causing intensive seismic activities. Seismic activities in this area are characterized by shallow hypocenter and high intensity and therefore large-scale devastations have been recorded throughout history. On March 11th 2011, a magnitude 9.0 earthquake hit Japan’s Fukushima region, and the nearby Fukushima Daiichi Nuclear Power Plant (Futaba District) was severely damaged. Irreversible damage on the power network, which was the main power source to the six boiling water reactors (BWR), left the power company no choice but to switch on the emergency diesel power generator in order to maintain the functions of the electronic and cooling systems. To make things worse, the earthquake triggered deadly tsunami. Gushing saltwater flooded the emergency power generator room and destroyed the emergency diesel power generator. The cooling systems were permanently shut down and, as a consequence, the nuclear reactors became overheated. Hydrogen exploded inside the reactors, causing release of radioactivity in massive scale. This incident brought the world to reexamine the safety of their nuclear plants, especially on the aspect of sustainability associated with earthquake. In the wake of the Fukushima earthquake, issues of nuclear safety resurfaced and gained wide attention in Taiwan. We found that the majority of the nuclear power plants in Taiwan have not been designed to sustain violent earthquake and therefore shock isolation systems for nuclear power plants emerged as a significant subject of research.
This dissertation presents a dynamic analysis on damping isolator under simulated earthquake vibration. Analysis was conducted using computer-aided design software Solid Works to produce a 3D model of the damping isolator, which was then imported into ANSYS Workbench, along with the material coefficients of the damping isolator (Young’s modulus, Poisson’s ratio and density), for finite element analysis. From the finite element analysis, we derived the natural vibration frequency and modal characteristics and made an observation on the effect of the damping isolator under a simulated earthquake. Statistics derived from the analyses were entered into a comparison to determine whether the designed damping isolator can effectively prevent damage to the power generator during earthquake.
Keywords: isolator, damping, dynamic characteristics
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