Experimental Analyses of Mechanical Performance of CFST Column to Assembled Steel H-Beam Connections
The mechanical performance of a new proposed type of cross-shaped connection with concrete-filled steel tubular (CFST) column and assembled steel H-beam was investigated. Cyclic loading tests on the cross-shaped connections are carried out by using MTS servo loading system. Comparative analyses are conducted based on the experimental results including hysteretic curves, skeleton curves and stiffness degradation curves as well as ductility coefficients of cyclic loading tests. Furthermore, effects of geometric parameters of ring-stiffened plate, axial compression ratio and backing plate on the deformation performance of cross-shaped connections are analyzed. The results show that the increase of width of ring plate and the shape change of ring plate from square to circle can both significantly improve the ductility and the hysteretic characteristics of connection. It is emphasized that the specimen with square ring plates is of better deformation performance but lower bearing capacity than the ones with circular ring plates. Besides, the backing plates always have positive effects on the hysteretic characteristics, ductility and energy dissipation of the CFST column connections. Conversely, the increase of axial compression ratio contributes negatively to both the bearing capacity and deformation performance of the connection specimens. It can be concluded that the presented cross-shaped connection is of good deformation performance relating to hysteretic characteristics, energy dissipation and ductility, which can provide reference towards engineering practice with potential perspective application.
Moment-capacity and rotational stiffness of endplate connections to concrete-filled tubular columns with flowdrilled connectors
A test programme to obtain experimental data on the behaviour of endplate beam to column connections has been conducted. The reported tests concern joints made between universal beams and tubular columns using endplates bolted directly to the column face with ordinary bolts screwed into threaded holes formed using the flowdrill process. Results obtained from tests are presented in a series of three papers; this final paper reports tests conducted with concrete-filled tubes and the results are compared with those from a parallel series of tests in which the tubes were unfilled. Significant differences in strength and stiffness were observed.
Use of external T-stiffeners in box-column to I-beam connections
Abstract The effects of various types of stiffeners on the connection behaviour between box-column to I-beams has been studied both experimentally and analytically using the finite element method. The external T-stiffener has been found to provide the most suitable form of stiffening in terms of stiffness, strength, ductility and ease in fabrication which are the basic criteria for a good moment connection. A simple design method to determine the dimensions of the external T-stiffener for both the two-wat and four-way connections has been proposed. A method for predicting the moment-rotation characteristic of the connection using a least-square curve-fitting procedure is also described. Finally, two four-way full-scale specimens designed in accordance with the design guidelines were tested to failure. The experimental results as well as results from finite element analysis show the validity of both the design guidelines and the proposed moment-rotation functions.