In the fluid-structure interaction analysis, the finite element formulation is performed for the wave equation for dynamic fluid pressure, and the dynamic pressure is defined as a degree of freedom at the fluid nodes. Therefore, to connect the fluid to the structure, it is necessary to connect the degree of freedom of fluid dynamic pressure and the degree of freedom of structure displacement through an interface element derived from the relationship between dynamic pressure and displacement. The previously proposed fluid-structure interface elements use conformal finite element meshes in which the fluid and structure match. However, it is challenging to construct conformal meshes when complex models, such as water purification plants and wastewater treatment facilities, are models. Therefore, to increase modeling convenience, a method is required to model the fluid and structure domains by independent finite element meshes and then connect them. In this study, two fluid-structure interface elements, one based on constraints and the other based on the integration of nonsmooth functions, are proposed in nonconformal finite element meshes for structures and fluids, and their accuracy is verified.

1. 서 론
2. 유체-구조물 연결 요소 정식화
    2.1 기존 방식
    2.2 비평활(nonsmooth) 함수 적분에 근거한 연결요소
    2.3 구속조건에 근거한 연결요소
3. 적용 예제
4. 결 론
감사의 글

• 조정래(한국건설기술연구원 구조연구본부 선임연구위원) | Cho Jeong-Rae (Senior Research Fellow, Department of Structural Engineering Research, Korea Institute of Civil Engineering and Building Technology)
• 이진호(부경대학교 해양공학과 부교수) | Lee Jin Ho (Associate Professor, Department of Ocean Engineering, Pukyong National University) Corresponding author
• 조근희(한국건설기술연구원 구조연구본부 연구위원) | Cho Keunhee (Research Fellow, Department of Structural Engineering Research, Korea Institute of Civil Engineering and Building Technology)
• 윤혜진(한국건설기술연구원 구조연구본부 연구위원) | Yoon Hyejin (Research Fellow, Department of Structural Engineering Research, Korea Institute of Civil Engineering and Building Technology)