본 연구에서는 반복 재하실험에 의해서 단부 철근콘크리트 중앙부 철골로 이루어진 복합보의 접합부 형상에 따른 역학적 거동을 파악하고자 한다. 실험결과와 종국내력식을 비교 검증하고 합성효과, 내진성능 및 응력전달의 유효성을 검토한다. 각 실험체의 유형은 주근용접형, 정착판 보강형, 시어코넥터 보강형, 시어코넥터형으로 한다. 그 결과 정착판 보강형과 시어코넥터 보강형은 내력 및 내진성능이 우수한 것으로 평가되었으며, 철근콘크리트와 철골 접합부분이 일체성을 확보하여 응력전달에 유리한 것으로 나타났다. 그러나 기존의 종국내력식은 실험결과와 다소 차이가 있는 것으로 나타나 보다 명확한 종국내력식이 요구되고 있다.
This study sought to understand the mechanical behavior according to the shape of the connecting part of the hybrid beam. This part is composed of central steel. with the end reinforced by concrete in the experiment of cyclic loading. The experimental result was compared and verified with the ultimate strength formula. Likewise, the composite effect and the effectiveness of seismic capacity and stress transmission were examined. The types of each setup were as follows: main bars by welding type, reinforcing by end-plate type, reinforcing by shear connector type, and shear connector type. Results showed that the reinforcing by end-plate type and the shear connector type had excellent strength and seismic capacity as well as better stress transmission. This was due to the unity between reinforced concrete and the steel's connecting part. However, the experimental result was somehow different from the previously established ultimate strength formula. Thus, a definite ultimate strength formula is required.