Response spectra used for seismic response evaluation are generally characterized by smooth shapes derived from ground motion prediction equations as a function of earthquake magnitude and distance. However, recorded earthquake ground motions exhibit peak and valley variations in response spectra, and this study investigated the effects of these characteristics on the nonlinear response of structures. To define the peak and valley variations in the spectrum, a smooth reference spectrum is required. For this purpose, a reference spectrum based on the design spectrum shape was derived for each ground motion spectrum. The variability of the structural response was evaluated for smooth input response spectra and response spectra with peak and valley characteristics, while varying the natural period and ductile behavior of the structure. The results showed that the peak and valley characteristics amplify the variability of the nonlinear response of structures. In addition, this variability was found to differ depending on whether the analysis was performed using the static capacity spectrum method or nonlinear dynamic analysis. Based on the results, the effects of the spectral peak and valley on the nonlinear response were discussed according to the analysis method.

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1. 서 론
2. 비선형 거동 시 응답스펙트럼 요철의 불확실성
    2.1 응답스펙트럼의 요철 특성
    2.2 비선형 응답의 요철에 의한 영향
3. 기준스펙트럼 및 단자유도 이선형 거동 모델링
    3.1 기준스펙트럼 작성
    3.2 연성도에 따른 유효감쇠비 및 유효주기
    3.3 감쇠수정계수를 이용한 응답스펙트럼 보정
    3.4 지진동 별 동일한 내진성능을 가지는 구조물 모델 구성
4. 해석 Case 및 예제
    4.1 평가대상 구조물의 연성도 및 유효주기
    4.2 계측지진동의 응답스펙트럼 및 기준스펙트럼
    4.3 입력지진동
    4.4 응답 산정 방법
5. 요철에 의한 응답 해석 결과 및 분석
6. 결 론
/ 감사의 글 /
/ REFERENCES /

• 변영준(부산대학교 사회환경시스템공학과 박사과정) | Byun Young Jun (Ph.D. Student, Department of Civil Engineering, Pusan National University)
• 김정한(부산대학교 사회환경시스템공학과 교수) | Kim Jung Han (Professor, Department of Civil Engineering, Pusan National University) Corresponding author