In this paper, we study the applicability of Tuned Mass Damper(TMD) to improve seismic performance of piping system under earthquake loading. For this purpose, a mode analysis of the target pipeline is performed, and TMD installation locations are selected as important modes with relatively large mass participation ratio in each direction. In order to design the TMD at selected positions, each corresponding mode is replaced with a SDOF damped model, and accordingly the corresponding pipeline is converted into a 2-DOF system by considering the TMD as a SDOF damped model. Then, optimal design values of the TMD, which can minimize the dynamic amplification factor of the transformed 2-DOF system, are derived through GA optimization method. The proposed TMD design values are applied to the pipeline numerical model to analyze seismic performance with and without TMD installation. As a result of numerical analyses, it is confirmed that the directional acceleration responses, the maximum normal stresses and directional reaction forces of the pipeline system are reduced, quite a lot. The results of this study are expected to be used as basic information with respect to the improvement of the seismic performance of the piping system in the future.

Abstract
 1. 서 론
 2. TMD 설계 개념
  2.1 TMD 기본 개념
  2.2 구조물 감쇠 고려
  2.3 TMD 설계 방법
 3. 수치 연구
  3.1 적용 TMD 설계
  3.2 주파수응답해석
  3.3 지진응답해석
 4. 요약 및 결론
 References
 요 지

• 곽신영(한국원자력연구원 구조지진안전연구실) | Shinyoung Kwag (Structural and Seismic Safety Research Team, Korea Atomic Energy Research Institute) Corresponding author
• 곽진성(한국원자력연구원 연구로설계종합실) | Jinsung Kwak (Research Reactor System Engineering Team, Korea Atomic Energy Research Institute)
• 이환호(한국원자력연구원 연구로설계종합실) | Hwanho Lee (SFR System Design Division, Korea Atomic Energy Research Institute)
• 오진호(한국원자력연구원 연구로설계종합실) | Jinho Oh (Research Reactor System Engineering Team, Korea Atomic Energy Research Institute)
• 구경회(한국원자력연구원 SFR계통설계부) | Gyeong-Hoi Koo (SFR System Design Division, Korea Atomic Energy Research Institute)