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.
Nonlinear Numerical Analyses of a Fabricated Connection of Concrete-Filled Steel Column to Steel Beam Under Low-Reversed Cyclic Loading
RESEARCH ARTICLE Nonlinear Numerical Analyses of a Fabricated Connection of Concrete-Filled Steel Column to Steel Beam Under Low-Reversed Cyclic Loading Chunyi Cui, Kun Meng, Yan Kong, Yannian Zhang and Wenxin Zuo Department of Civil Engineering, Dalian Maritime University, Dalian 116026, China School of Civil Engineering, Shenyang Jianzhu University, Shenyang 110168, China School of Civil and Mechanical Engineering, University of Birmingham, Birmingham, B15 2TT, United Kingdom
Reduction of gas flow nonuniformity in gas turbine engines by means of gas-dynamic methods
Gas flow nonuniformity is one of the main sources of rotor blade vibrations in the gas turbine engines. Usually, the flow circumferential nonuniformity occurs near the annular frames, located in the flow channel of the engine. This leads to the increased dynamic stresses in blades and as a consequence to the blade damage. The goal of the research was to find an acceptable method of reducing the level of gas flow nonuniformity as the source of dynamic stresses in the rotor blades. Two different methods were investigated during this research. Thus, this study gives the ideas about methods of improving the flow structure in gas turbine engine. On the basis of existing conditions (under development or existing engine) it allows the selection of the most suitable method for reducing gas flow nonuniformity.