Electrical instruments and devices contained in cabinets for controlling nuclear power plants require seismic qualification; likewise, in-cabinet response spectrum (ICRS) is necessary. Gupta et al. (1999) suggested the Ritz method, where rocking, frame bending, and plate bending behaviors of cabinets are considered, as a method for determining ICRS. This research proposes a method to determine the rocking stiffness of cabinets, which represents its rocking behavior. The cabinet is fixed on mounting frames and is connected to the base concrete by anchors. When horizontal excitation is applied to the cabinet, the mounting frames at anchors are locally deformed, the mounting frames are bent, and then rocking in the cabinet becomes evident. A method to determine equivalent vertical spring stiffness representing the local deformation of the mounting frames at anchors is then proposed. Subsequently, the rocking stiffness of this mounting frame is calculated upon assumption of the mounting frame as an indeterminate beam.

A B S T R A C T
1. 서 론
2. 예제 캐비닛 제원
3. 앵커연결부 국부변형의 등가수직강성
    3.1 장착프레임 유한요소해석
    3.2 등가회전스프링으로 지지된 상부판 해석
4. 장착프레임 전도강성
    4.1 1차 부정정 구조
    4.2 2차 부정정 구조
    4.3 Shell 해석
    4.4 등가전도강성 비교
    4.5 앵커연결부 등가수직스프링계수 검토
5. 결 론
REFERENCES

• 정연하(국민대학교 건설시스템공학과) | Chung Yon Ha (Department of Civil and Environmental Engineering, Kookmin University)
• 홍기중(국민대학교 건설시스템공학과) | Hong Kee-Jeung (Department of Civil and Environmental Engineering, Kookmin University) Corresponding author
• 조성국(이노스기술(주)) | Cho Sung Gook (Innose Tech)