Advanced Materials Research Vols. 163-167

Abstract: This paper suggests a new connection protocol, adding cover-plate between shear links and column, which was used to enhance moment and shear carrying capacity of beam, relax the restriction and assure the sufficiency development of plastic deformation of the link, and dissipate more earthquake energy. Considering the scale ratio of 1:3, the experimental data was achieved by a specimen under cyclic loading, which was verified by nonlinear finite element analyses. Results indicate that the new type of eccentrically braced steel frame have enough stiffness and deformation capacity, draw link away from flange of column, and dissipate more earthquake energy. The single diagonal eccentrically braced frames adopted adding cover-plate protocol will ensure sufficient lateral stiffness under ordinary circumstances, including lateral loads due to wind and moderate seismic disturbances, have preferable resisting seismic behavior under rare earthquake, and be so practical and costly that it can be easily applied in present project.

Abstract: Based on experimental researches, a simple numerical analysis method was presented to simulate the full load-deformation process of bar-reinforced concrete filled steel tubular short columns subjected to axial compression. Firstly, the interaction process of steel tube and concrete was analyzed, and then, the simplified constitutive models of steel tube and concrete were established on the base of previous analysis results. Secondly, the relation between lateral and longitudinal strain of steel tube was analyzed based on experimental results, and a simple method was presented to calculate the lateral strain of steel tube. Finally, a program was worked out to simulate the full load-deformation process of bar-reinforced concrete filled steel tubular short columns. The program’s simulation results of both ultimate bearing capacity and load-deformation curves are in good agreement with the experimental results.

Abstract: This paper presents wind-induced vibration comfort evaluation of a special and complex sightseeing bridge in Shenzhen Wan Sports Center which is one of the sub-centers for the 2011 World University Games. In order to predict the reliable comfort performance of the sightseeing bridge, wind-induced vibration time history analysis under different directions based on wind tunnel test was applied. The peak acceleration on the bridge under different varying structural parameters was also discussed. The proposed peak acceleration which appears at mid-span of the bridge under 10-year return period wind load basically satisfies comfort requirement of China’s standard.

Abstract: This paper studies structural behaviour of the blind bolted connections to concrete-filled steel tubular columns by a serial of experimental programs, which conducted involving eight sub-assemblages of cruciform beam-to-column joints subjected to monotonic loading and cyclic loading. The moment-rotation hysteretic relationships and failure models of the end plate connections have been measured and analyzed. A simplified analysis model for the blind bolted connections is proposed based on the component method. It is concluded that the blind bolted end plate connection has reasonable strength and stiffness, whilst the rotation capacity of the connection satisfies the ductility requirements for earthquake-resistance in most aseismic regions. This typed joint has excellent seismic performance, so it can be used in the moment-resisting composite frame.

Abstract: Many in-fill materials are used to improve ductility of concrete filled steel tube (CFST), due to meeting need for a change of seismic design perspective form the previous emphasis on structural strength to emphasis on structural ductility and energy absorption. Among the various in-fill materials, steel fiber is gaining attention in the CFST column. This paper investigates effect of volume fractions of steel fiber to concrete on the behavior of short steel fiber reinforced concrete filled steel tube columns under axial compression. The volume fractions of steel fiber to concrete are 0.6, 0.9 and 1.2%. The results indicate that steel fiber reinforced concrete filled steel tube columns appears to have a significant increasing trend in ductility, and have a slight increasing trend in load capacity with volume fraction of steel fiber to concrete increasing. The failure mode of the composite columns is similar with that of CFST.

Abstract: According to the finite element analysis of a circulating fluidized bed boiler steel frame structure, the essay concludes to the calculation results of the main steel structure, moreover the structure and the composition of bars are adjusted and optimized which improve the safety of the structure reliability and reduce the volume of steel. All of the above contents have certain reference value on the similar structure.

Abstract: In steel construction, when beams have to be connected to a girder at the same elevation, beam flanges must often be coped to provide enough clearance for practical joint formation. The presence of a cope in a beam will reduce the strength of the beam in the coped region. To improve the strength of coped beams, web reinforcements at the coped region were proposed in previous research studies. This paper reports the results of the first phase of the experimental program. A total of 8 tests were conducted. The test parameters include the length of longitudinal stiffeners, cope depth to beam depth ratio, cope length to beam depth ratio, and doubler plate. The test results show that the strength of the coped beam specimens was significantly increased when stiffeners were used in the cope. The increase in strength due to the presence of the longitudinal stiffeners could be as high as 96%. The longitudinal stiffeners were able to prevent local web buckling from occurring at the cope, however, the final failure mode of the beams was yielding of non-reduced section followed by rigid body movement of stiffener. The doubler plate was able to increase the strength of the beams; however, the final failure mode of the beams was still local web buckling.

Abstract: The shrinkage/expansion behavior and bond carrying capacities of 4 short, micro-expansive concrete-filled steel tube (MCFST) and 3 short, conventional concrete-filled steel tube (CFST) columns were experimentally investigated. The results indicate that pre-stress is produced in the core concrete under the confined by the steel tube. Both expansive agent and water cement ratio have important influence on expansive behaviors of MCFST. The current work also indicates that the MCFST columns have higher bond strength than conventional CFST columns and this recommends a new method to improve the bond strength of composite structures.

Abstract: To understand the seismic performance of inclined joints with gusset plate between double C steel beam-column, in this paper, I used finite element method ABAQUS, and did a good performance in simulating seismic performance of inclined joints between double C steel beam-column. It executed six models by changing gusset-plate’s thickness and bolt space in this simulation. Elements of S4R can give a good description of cold-formed steel’s bearing-capacity, and coupling restriction simulated bolted connections well. This modeling method is facilitating, and the operation time of simulation is not long-playing, and calculation results are accurate. The results of this paper can give a reference to the engineering application of cold-formed thin-walled steel structure.

Abstract: The nonlinear FEM models of concrete-filled square tubular column with internal diaphragms and steel beams with reduced beam section bolt-weld joints, involving geometric, materials and contact nonlinear, were established. The 3D models of beam-to-column joints with internal diaphragms by 3D solid elements are founded. The bearing capacity behavior of joints under the monotonic loading are analyzed, including P-Δ curves, the stresses distribution of beam, the dissipating energy ability and destruction form. The analysis results show that the initial stiffness of joint with reduced beam section is close to that of non-reduced beam section joint. The bearing capacities of joints with reduced beam section are lower a little than that of non-reduced beam section joint. The plastic hinge in the joint with reduced beam section is removed to the reduced beam region.