Concrete-Filled Tube (CFT) has been used as a column of building and bride pier. CFT member consists of outer steel tube and in-filled concrete. Since the concrete is under tri-axial stress state by outer steel tube, the strength and deformation capacity of the in-filled concrete increases. This is called confinement effect of CFT. To simulate this confinement effect, modified stress-strain relationship of the in-filled concrete is generally used. However this approach is not a direct method to simulate the confinement effect, and more novel simulation technic is needed for in-depth understanding of the confinement effect. In this study, direct method for simulating the confinement effect of CFT was proposed, where the modified strain-stress relationship was not used. From the results, the proposed method agrees well with the test results.

ABSTRACT
 1. 서 론
 2. FEM 모델링
 3. 해석 결과
 4. 결 론
 References

• 문지호(강원대학교 토목공학과) | Moon Jiho