Finite Element Modeling of Plate Structure for Loose-Part Mass Estimation in Nuclear Power Plant

摘要

The impact mass estimation of loose-parts is essential for successful condition monitoring and diagnostics in nuclear power plants. In general, center frequency method based on Hertz's impact theory and frequency ratio method are used for the mass estimation, but it is known that they have a lower reliability level. The objective of this study is to develop finite element analysis technique in order to estimate the mass of loose-parts. In this paper, finite element analysis technique to model the bending wave modes was reviewed by performing a series of impact wave propagation tests and finite element analyses. Also, the correlation between the plate thickness and the characteristic length, which is the travel length of impulse waves where the bending modes are built, was proposed. This study will be used to estimate the mass of loose-parts and to build the impact-mass index database, which can be applied on site for condition monitoring and diagnostics in nuclear power plant.