Calculation on flexural bearing capacity of composite HSHP concrete encased steel beams

Design specifications for SRC structures in china are firstly presented, and the deficiencies in flexural design models for SRC beam are pointed out. Large numbers of composite HSHP concrete encased steel beams were experimented to study their mechanical behavior. The test results indicated that the relation of V-sb and V-h, which denote respectively shear splitting resisting capacity and the horizontal shear force, have significant effect on failure mode of composite HSHP concrete encased steel beams. Therefore, a new flexural design model for composite HSHP concrete encased steel beams is proposed, where the relation of V-sb and V-h is used as design parameters. In addition to the theoretical analysis, new equations for calculation on flexural bearing capacity are provided, in which two new factors, bond coefficient and section symmetry coefficient are introduced. Compared with the test results, it is clear that the proposed formulas can satisfactorily predict the ultimate flexural capacity. Research results may be useful for the analysis and design of composite HSHP concrete encased steel beams.