유한요소해석 기반 충격하중에 의한 평판 구조물 내 굽힘파 전파거동 분석

국문 초록 (Abstract)

금속이물질(loose part)에 의한 충격현상은 원자로냉각제계통의 구조건전성에 영향을 미칠 수 있는 주요요인 중 하나이며, 금속이물질의 질량추정은 원자력발전소의 안전운전을 위해 필수적인 기술이다. 금속이물질의 질량을 정확하게 추정하기 위해서는 충격하중 하에서 구조물내 굽힘파(bending wave) 전파거동을 정확하게 모사할 수 있어야 한다. 현재 임의의 충격하중에 대한 Lamb의 일반해 및 Hertz의 충격이론은 금속이물질의 충격에 의해 발생되는 굽힘파의 특성을 분석하기 위해 사용되고 있지만, 금속이물질 충돌에 의해 발생하는 가속도 응답에 대한 정확한 정보를 제공할 수 없다. 본 연구에서는 충격하중에 의해 발생되는 굽힘파를 모델링하기 위한 FEA 기법을 검토하였다. 또한, FEA에 기반하여 평판의 두께와 특성길이(충격입력 지점으로 부터 굽힘파가 형성되기 까지 필요한 충격파의 전파거리) 사이의 상관관계를 제안하였다.

다국어 초록 (Multilingual Abstract)

Loose parts can cause component damages in nuclear power plants; thus, the mass estimation of loose parts is crucial in safety management. To accurately estimate the mass of loose parts, it is essential to precisely simulate the bending wave propagation behavior in a structure under impact loading. Lamb’s general solution for an arbitrary impact force function and Hertz impact theory have been used to identify the characteristics of the bending wave impacted by a metallic loose part. However, these approaches cannot provide accurate information on acceleration response. In this study, the bending wave propagation behavior in plate structures under impact loading by a simulated loose part (metal sphere) was modeled using the finite element analysis (FEA) technique. The impact response characteristics of the impact response signal from a metal sphere were analyzed by FEA and was verified with experimental results. In addition, the correlation between the plate thickness and characteristic length of the plate was presented.

목차 (Table of Contents)

• 초록
• Abstract
• 1. 서론
• 2. 평판구조물에서의 충격파 전파거동
• 3. 충격파 전파 실험 및 해석
• 4. 굽힘파 특성거리
• 5. 결론
• References

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