Applied Mechanics and Materials Vols. 166-169

Abstract: Mechanism of composite pre-reinforced micro pile soil-nail and pure soil-nail retaining structure in foundation-pit engineering are analyzed in this paper through general three dimension nonlinear numerical simulation software. Research contents include whole construction process simulation of construction such as excavation by steps, piles and soil-nail installation and panel manufacture etc. By the comparison of mechanical characteristics between the pure soil-nail and composite soil-nail retaining structures in the same slope engineering example, differences of tension distribution range of soil layer, deformation features, mechanical characteristics of support and axial force distribution along nails etc. are analyzed. Research results are verified by in-site projects and measured data. The action mechanism and working performance of composite soil-nail retaining support are also systematically studied and theoretical basis can be provided in the similar application.

Abstract: The existing “structure load code” did not give wind load shape coeeficient of rhombic plane and saddle-shaped roof .On this issue, numerical wind tunnel method has significant advantages such as low cost,fasting,collecting more comprehensive results.Using information of CFD and the software of FLUENT, using RNG - turbulence model, simulating a landform rhombic plane, the paper had numerical simulation of average wind pressure coefficient for rhombic plane and saddle-shaped roof building. It focused the effect on the numerical simulation for bending-span ratio. Finally it provided reference for reasonably determining the average wind pressure coefficient of rhombic plane and saddle-shaped roof building.

Abstract: The target of this test is to research the mechanical characteristics of two-way curved arch bridge reinforced by BFRP，and prove that the method is effective. Considering the cause of old and dangerous two-way curved arch bridge, Aohan, static and dynamic characteristics of the bridge are studied by being reinforced by BFRP .Reinforcement of arch rib with BFRP can reduce the compressive stress in the apex of arch, springing and other key sections, and enhance the bending and torsion resistance properties of the structure. After reinforcement, it has a better overall performance and keeps a flexible working condition.And if the load becomes 1.9 times that of road -Ⅱ,it has enough extra ability to be functionable. The method to reinforce arch bridge type is effective and deserves the cost.The result of the research is important and valueable to bridges in the similiar situations.

Abstract: Using ANSYS software, the paper analyze the seismic response to Kobe one-dimensional seismic wave of multi-storey reinforced concrete frame structure, and make comparison with the calculation of response spectrum method.

Abstract: 12 RC columns were made, including nine RC columns wrapped with BFRP, three RC columns without any reinforcement, to conduct the comparative study of axial compression. The result shows that the bearing capacity of the RC columns reinforced with the fibers increases obviously.The displacement ductility factor increases, but its increase rate becomes slow with increasing layers of fiber cloth, so the most economical layer number is 3. Based on the confinement mechanism of FRP cloth and the calculation formula of the bearing capacity for common RC column, the formula of the bearing capacity for reinforced RC column with BFRP cloth is proposed. The result of calculation basically tallies with the number in experiment.

Abstract: Numerical simulation is utilized to estimate the structural behaviors such as ultimate strength, fracture mode and curling effect of single shear bolted connections fabricated with aluminum alloys. In the Kim’s previous research, the validity of finite element analysis was verified through the comparison of test results and analysis results. In this paper, curling deformation and strain development between test result and analysis result were investigated. Also, additional parametric studies are performed for bolted connections with other variables of edge distance and end distance, which are not considered in the existing experiment. The conditions of end distance and edge distance for curing occurrence were discussed.

Abstract: The simplified calculating model for fiber plasterboards filled with concrete core columns with different spacings was established. The method for calculating the moment-curvature relationship of concrete core column and the force-displacement skeleton curves of shear element was then proposed. The test data of fiber plasterboards filled with concrete core columns with different spacings were analyzed based on this model. The calculated curves agreed well with the experimental ones, which proves that this model has the advantages of clear mechanical conception，simple calculation and relatively good accuracy，and is convenient for calculating integral structure.

Abstract: Hot extrusion process of Al-Zn-Mg-Cu alloy billet had been simulated under different temperature of billet and container. It was proposed that due to large deformation and friction, maximum temperature of the billet occurs on the skin near extrusion export and is under three direction tension stress state, where surface is likely to crack if temperature surpassed the incipient melting point. The right temperature of the billet and container is 425°C~450°C and 400°C respectively with the constant extrusion speed 0.8mm/s

Abstract: In the design of steel structure, the requirements for the high- strength bolts in slip-critical connections are not identical in China and America. The Steel Structure Design Codes (GB50017-2003) is used in China, while the latest Specification for Structural Steel Buildings (ANSI / AISC 360-10) is used in the United States. In this article, requirements on the high- strength bolts in slip-critical connections in these two specifications are compared to find out the differences.

Abstract: This paper presents a nonlinear analysis of square steel tube columns filled with steel reinforced concrete subjected to bi-compression bending load. Calculated results agree well with the tested results. Further, Different parameters of members were analyzed using nonlinear analysis procedure. Results showed that Slenderness ratio, stirrup ratio and eccentricity ratio have tremendous influence on capacity and initial stiffness. Steel reinforced ratio and eccentricity angle have secondary influence on capacity and initial stiffness.