Advanced Materials Research Vols. 671-674

Abstract: A new geometric nonlinear formulation for large-deflection static problems involving complex space truss structure is presented. Based on the finite element method, the proposed formulation uses nodal positions rather than nodal displacements to describe the problem. The strain is determined directly from the proposed position concept, using a Cartesian coordinate system fixed in space. The proposed formulation is simple and yields good results. Numerical results indicate that the proposed formulation is validity.

Abstract: Simple joint is a common connection in tubular structures, it refers to one or more components soldered directly on the surface of the other member. Local buckling occurs in panel zone when the joint under heavy load, such local buckling will reduce the bearing capacity and stiffness. In order to improve bearing capacity of tubular joints, the joint needs to be strengthened. In this paper, the bending performance of the joint will be enhanced by welding a sleeve inner the surface of panel zone of chord member. By ANSYS finite element program, the bearing capacity of the joint with different parameters of inner sleeve was analyzed. The results showed that compare to sleeve length variation, bearing capacity of the joint experiences obvious change with variation of sleeve thickness.

Abstract: Simple joint is a common connection in tubular structures. Local buckling occurs in panel zone when the joints bear heavy loads, and local buckling will reduce the bearing capacity and stiffness. In order to improve the bearing capacity of tubular joints, the joints need to be strengthened. In this paper, the bending performance of the joints will be enhanced by welding a tile shaped plate outside the surface of panel zone of chord member. By ANSYS finite element program, the bearing capacity of the joint with different tile shaped plate was analyzed. The results showed that the bearing capacity of the joints experience obvious change with variation of thickness, whereas the bearing capacity has no change with variation of radian.

Abstract: When the shock wave caused by explosion in geotechnical medium encountered buried pipeline, the buried pipeline may be destroyed. Use the LS-DYNA program to describe the deformation of buried pipelines under explosion ground shock. The results indicate that the process of the stress on pipe is instantaneous, and the back of buried pipelines against explosion center suffers greater instantaneous pulling stress in axis direction. The stress on the pipes, which is brought by the weaponary explosion, is involved with the distance between the pipe and explosion center and the diameter of pipe, among which the former involves greater. And the smaller pipe would get greater shock.

Abstract: By the analysis of seven factors’ influence on the ultimate bearing capacity, the ductility coefficient and the energy consuming ability of the T-shaped concrete-filled steel tubular column and comparison to the significance degree of influence through the orthogonal test ,which are the axial compression ratio, the strength of the concrete, the thickness of the steel tube ,the strength of steel tube, load angle, length and limb high ratio. The result shows that: limb high ratio effects the ultimate load of the T-shaped concrete-filled steel tubular column most; the concrete strength effects the ductility coefficient most; the steel tube strength effects the equivalent viscous damping coefficient most.

Abstract: Five-hundred-meter Aperture Spherical radio Telescope (FAST) is supported by cable-net structure, which enables its surface to form a paraboloid in real time under active control. FAST is now entering project construction and implement stage, however there are always a considerable amount of errors existed in practice which would result in the deviation of the structure from its ideal model. Therefore, structural parameter sensitivity analysis was indispensable discussed. In the paper, the variation ranges of structural parameters were rationally determined. Base on local sensitivity analysis and global sensitivity analysis method, Using the finite element model investigated the influence of different structural parameters change on the static behavior, gets the conclusions that the impact of several key design parameters on the tension force of cable-net is large. The results indicate that of all types of the structural parameters, the error of the length of cable plays the most important role, and the global sensitivity analysis indicates that the tension force range of cable-net is -18% to 27%.

Abstract: A 3-D finite element model (FEM) using ABAQUS was established to simulate the performance of the composite joints with reinforced concrete column and steel beam. Accurate material model, element type, and solution method were discussed in the model. The results from FEM are good agreement with the test results. Some composite joints, reinforced concrete (RC) column to steel beam were modeled based on the model. The mechanism of the composite joint was investigated based on the FEM.

Abstract: In this paper, according to achievements about the failure behavior of soil around the Push-extended Multi-under-reamed Pile and the ultimate bearing capacity under compression, they are qualitative or quantitative analyzed that the variation factors affect the ultimate bearing capacity of the Push-extend Multi-under-reamed Pile, in order to further improve and revise the calculating formula for the ultimate bearing capacity of the Push-extend Multi-under-reamed Pile, and then to provide more reliable theoretical basis for the design of pile foundation.

Abstract: In view of the large axial force column underpinning of the complex rotational transportation engineering，a new underpinning structure which with six diagonal bracings was proposed in this paper. Using SAP2000 software built four different calculating models with different support forms, and analyzed internal forces of members of the underpinning structure, discussed the load distribution effects on change of parameters including the inclined angle α between the inclined support and column, the angle θ between the inclined support horizontal projection and axis, inclined support section sizes, coupling beam section size and whether there are the horizontal forces. The results show that the load distribution effects of whole model and of single column model have little difference, but the single column model underestimates the axial forces of the inclined supports. α and θ have a great influence on load distribution effect, and smaller α is better. The load distributed result can be very good to meet the requirement of rotating shift engineering.

Abstract: In the evaluation of the seismic performance of masonry-infilled RC frames, the main difficulty is determining the type of interaction between the infill and the frame, which has a major impact on the structural behavior and load-resisting mechanism. This paper addresses the connection modes of the RC frames and masonry panels in regulations in China. The method of flexible connection suggested in standard has not been widely used in actual engineering, and rigid connection was adopted in universal. The finite element model with interface element is advisable for simulating the interaction of the frames and panels, and the accuracy of the nonlinear finite-element models has been evaluated with experimental data. The comparison of the numerical and experimental results indicates that the models can successfully capture the highly nonlinear behavior of the physical specimens and accurately predict their strength and failure mechanisms.