Search

The existing comparative analysis of the unbalanced moment mainly compares the differences between the calculated value and the experimental value of the unbalanced moment in different national codes and different calculation methods. There is less analysis on the change trend of the important parameters in the unbalanced moment calculation methods in national codes. A comparison of the provisions for unbalanced moment of reinforced concrete slab-column connections was studied based on Chinese code (GB 50010-2010), American code (ACI318-14) and European code (EN1992-04). The effects of concrete strength, longitudinal reinforcement ratio, the use of shear reinforcement and gravity-shear ratio on the unbalanced moment were studied through the calculation example and experimental results of 186 specimens. The results indicate that the calculation values of Chinese and American codes are conservative and dispersive, because the longitudinal reinforcement ratio and gravity-shear ratio on distribution coefficient of unbalanced moment were not considered, while the calculation results of European code are the closest to the test values.

A new structure of self-centering buckling restrained brace was proposed. The finite element model was established by ABAQUS software. The mechanical failure mechanism of this kind of self-centering buckling restrained brace was studied. The influence of the parameters such as the area of self-centering reinforcement and the sectional area of core tube on its hysteretic performance and self-centering ability was analyzed. The results show that with the increase of the area of the reset reinforcement, the hysteretic curve of the brace is more pinched, and the self-centering ability is increased by 46%; it was suggested that the weakening degree of the cross-sectional area of the core tube should not exceed 50%.

In order to study the main influencing factors of the ultimate bearing capacity of the PBL connector, the large-scale nonlinear finite element analysis software ABAQUS was used to establish the solid model of the PBL connector, and the accuracy of the model was verified by comparison with the test results. Based on this, the main influencing factors of the ultimate bearing capacity of PBL connectors are analyzed. The results show that it is feasible to apply ABAQUS to the finite element analysis of the mechanical properties of PBL connectors, which can be assisted by experiments and empirical formulas; The concrete strength, the diameter of rebar and the number of holes have a significant effect on PBL connectors’ force, but the diameter of holes has little effect.