In piping systems, trapeze hangers are subjected to vertical and horizontal seismic loads and stiffeners are used. In this study, monotonic compression tests were conducted with the removable stiffeners using three variables: stiffener clamp fixing position, section length, and installation direction. The maximum load reinforced with stiffeners could withstand a compressive load of 11kN by applying a safety factor of 10%. It could be estimated that the fixing clamp spacing or the length of shape and load had a proportional relationship. And the stiffener must be fixed in the direction of the strong axis on hinge parts. Also the stiffener buckiling load design proposes to use a method of calculate the flexural buckling compressive strength of and unreinforced full threaded bolt.

Abstract
1. 서 론
2. 실험 계획
    2.1 실험 방법
    2.2 실험체 계획
    2.3 실험 재료
3. 실험 결과
    3.1 좌굴 양상
    3.2 최대 하중
    3.3 스티프너의 압축하중 평가
4. 결론
5. References

• 오창수(우석대학교 일반대학원 소방·안전공학과 박사과정) | Chang-Soo Oh (Graduate Student, Fire Protection and Safety Engineering, Woosuk University)
• 공하성(우석대학교 일반대학원 소방방재학과 교수) | Ha-Sung Kong (Associate Professor, Fire and Disaster Prevention, Woosuk University) Corresponding Author