Parametric Study on Moment-Rotation Characteristics of Reverse Channel Connections (RCC) to Tubular Columns

The significance of this parametric study initiates from the need for further understanding of the behaviour of semi-rigid/partial-strength I-beam to tubular column connections. This research attempted to gain a qualitative understanding of the influence of the geometrical configurations and materials properties of reverse channel connections (RCC) on the moment-rotation (M-) response. It also introduces a double reverse channel connection (DRCC), where the reverse channel is split into two pieces, by leaving a gap in between, for better access to bolts. Hence, ABAQUS (v.6.12) software was used to develop three-dimensional (3-D) FE models for 206 specimens. The FE models developed were validated against the experimental results available from literature where 268 FE models were used for sensitivity analysis. The main emphasis of this research was on the stiffness, strength, sources of deformability, rotational capacity and failure mechanisms of the RCC. Based on the results of numerical M-curves, a standardized moment-rotation function for reverse channel flush end-plate connection (RCC) was introduced. This function is expressed in terms of the geometric parameters for the purposes of either predicting the connection behavior or incorporating the behavior into a frame analysis computer program. Out of the six currently available functions, the KishiChen and Richard-Abbott models were proved appropriate for fitting experimental M-data for RCC. The two functions were successfully used in this parametric study to express the relationships for 140 specimens, where the analytical and predicted data are in very good agreement. However, the results of the fitted functions indicate that the dimensionless form of Richard-Abbott function provides more accuracy than Kishi-Chen function. Furthermore, the comparison of Eurocode-3 model with numerical M-curves illustrated a significant overestimation of the knee region behaviour for most of the cases, particularly for RCC with low initial stiffness. Keywords: reverse channel, double reverse channel, moment–rotation curve, tubular column, HSS, stiffness, moment capacity, rotational capacity, standardized function, Kishi-Chen model, Richard-Abbott model.