SEISMIC BEHAVIOR OF THROUGH-DIAPHRAGM CONNECTIONS BETWEEN CFRT COLUMNS AND STEEL BEAMS-EXPERIMENTAL STUDY

摘要

This paper is an extension study to an experimental program involving one traditional and three novel through-diaphragm connections between concrete-filled rectangular tubular columns and steel H-beams. The proposed connection types utilize tapered diaphragm or triangular plates at the end of the beam to improve the seismic performance of traditional through-diaphragm connections. Based on the experimental results, the lateral force versus beam-column deformation response was assessed and the shear force versus shear distortion relationship in the panel zone was evaluated. It was observed that the improvement in connection details significantly enhanced the rotation capacity and shear stiffness. The deformation of the connections was also analyzed in terms of the contribution of the column, the beam, and the joint. In addition, the force transfer mechanism in the connections was investigated by analysis of the strain distribution The test results indicate that the proposed through-diaphragm connections are able to alleviate the stress concentration in the load transfer path and exhibit better seismic behavior. As a result, it can be concluded that the proposed connections are more suitable for applications in moment resisting frames in seismic regions.