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.
Parametric Study on CFST Column - Steel Beam Connection Under Cyclic Loading
This paper deals with the finite element modelling of a CFST columnsteel I beam connection with external diaphragm (external stiffener) in ANSYS. Five finite element models of CFST column – steel beam connection with different tube thickness are modeled and named as J1, J2, J3, J4 and J5. The models are analysed under a constant axial load on the CFST column and a cyclic load at the steel beam. The stress distribution in the diaphragm, column, and in the steel beam is studied in different cycles. As the steel tube thickness of CFST column increased there is a considerable reduction in the area under different stress range in steel tube. The maximum compressive principal stress in concrete is reduced due to the increased confinement provided by the steel tube. In the entire five models the failure was reported in the beam indicating a weak beam strong column connection Keywords— Concrete filled steel tubular column, Finite element, ANSYS
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.