Performance of concrete-encased CFST column-to-beam 3-D joints under seismic loading: Analysis

A numerical model of the concrete-encased concrete-filled steel tubular (CFST) column to steel beam joint was established to thoroughly discover the seismic performance of joints. The model was verified by experimental results in terms of failure patterns, hysteretic relationships and strain distributions. The stress and force distributions of different components were analyzed for joints under different loading phases, and comparisons were made between planar and 3-dimensional (3-D) joints. The parametric study was conducted to reveal effects of key parameters by verified numerical models. Furthermore, strength prediction models were proposed for both planar and 3-D joints, and the hysteretic model of panel zone for planar joint was established to describe the structural behaviour under cyclic loading.