Abstract
This paper presents the ultimate strength and moment-shear interaction diagrams of composite beams with rectangular and circular web opening. The experimental work of the investigation reported herein is consisted of tests of 6 composite beams and 2 steel beams. From this study, we could find out the following conclusions; 1. The ultimate strength of composite beams with web opening is not concerned with shape of web opening. 2. Composite beams with high moment-shear ratios were failed by stress concentration in the vicinity of bottom tee and high moment. 3. Composite beams with high moment-shear ratios tended to the reduction of initial stiffness and ultimate strength because of the bigger bending moment on web opening. 4. The ultimate moment by analytical model of composite beams with web opening considered T. V. Galambos' analysis considerably agree with experimental results.
