T形多腔钢-混凝土组合构件压弯性能研究

The multi-partition steel-concrete composite members (MSCM) can be flexibly used as composite columns, composite shear walls with restricted width and normal composite shear walls by altering the sectional height to thickness ratio. In particular, T-shaped MSCM is usually used on the outer edge of the structure to reduce the exposure of the indoor structural column. To investigate the mechanical behavior of T-shaped MSCMs with the sectional height to thickness ratios varied from 3 to 8 under eccentric compressive load, four T-shaped MSCM specimens were designed and constructed to test and observe their respective behavior and failure modes. The deformation behavior, failure modes and bearing capacity of all specimens were obtained. Then the finite element (FE) software ABAQUS was employed to investigate the mechanical behavior of T-shaped MSCMs under eccentric compression. Comparison between the predicted and test results indicates that the developed FE model could adequately simulate the mechanical behavior of T-shaped MSCMs. Thereafter, parametric analyses were performed to study the influences of the sectional height to thickness ratio, concrete strength, steel strength and thickness of steel plate on the mechanical behavior of MSCMs under eccentric compression. The results indicate that all specimens fail due to global bending. The sectional height to thickness ratio has the most significant effect on MSCMs' axial load and bending moment interaction diagram. In addition, the confinement of the multi-partition steel tubes on inner concrete is non-uniform in each partition, in which the confinement is larger at the corner while smaller around the inner diaphragm. The minimum confinement exists at the middle of the free steel plate in each partition. Based on the analysis above, a simplified formula was suggested to predict the load capacity of T-shaped MSCMs under both compression and bending.