Advanced Materials Research Vols. 919-921

Abstract: Numerical simulation with the large eddy simulation, filter function, and Smagorinsky sub-grid scale model is adopted to simulate the compressible flow around a bluff body finite length circular cylinder and truncated cone in high Reynolds number. The law of the drag coefficient, lift coefficient and pressure coefficient obtained from models with various cross-wind speeds was discussed. Process of the vortex generated, shed and dissipated was analyzed and the relationship between the press filed, velocity filed and vortex filed was also analyzed. Average value of the drag coefficient, lift coefficient and pressure coefficient of the circle cylinder in subcritical region are greater than truncated cone. Values of pressure coefficient on the windward side of all the models are consistent. However, it various widely on the leeward side, even on the end face of the cone and cylinder.

Abstract: As baseball gets more and more popular the interest of fans increases. Since baseball game in its nature is influenced very much by weather the necessity of a domed stadium has been raised. At this moment a membrane structured domed stadium is under construction. As can be understood from the roof collapse of Minnesota Metrom by a heavy snowfall in 2011, the snow load occupies a very important part in membrane structure. To calculate the snow load snowdrift prediction is necessary and snow is piled mainly at the side or roof of a building. Hence, in this study a snowdrift wind tunnel test of a domed stadium was made to simulate snowdrift; using it the maximum depth of fresh snowdrift is estimated to be in the range of 3.4cm-37cm on the roof of a domed stadium.

Abstract: In this paper the stress and stability of the domestic highest natural draft cooling tower under wind load, weight and temperature load are simulated by ANSYS. The wind load is proved to be the key load that must be considered in the stage of the design of a cooling tower. The maximum internal force is compressive stress and appears at the bottom, and the maximum buckling appears at the throat of the tower. The simulation result can be used to check the cooling tower during the design phase to avoid the accident.

Abstract: According to the theory of collapse numerical simulation, the explicit finite element algorithm based on explicit dynamics was chose as the numerical calculation method. And combined with the plane RC frame collapse test and the example of ten layers frame structure, the wire frame model, integrated model and separate model were established and the alternate path method was adopted to study the simulate method of structural collapse. With the comparison of several aspects to the results, the rationality of the numerical simulation method and the applicability of the numerical models were verified respectively. At the same time, according to the complex pre-treatment process to the numerical simulation of structural collapse, an MFC program with the function of exporting APDL file which can generate wireframe models for structural collapse simulation in ANSYS/LS-DYNA was developed using VC++ language with the purpose of offering convenience to the numerical simulation process of structure collapse.

Abstract: Latticed shell string structure with inner and outer truss torus, radial cables of which emerge from the roof, is proposed. Ribbed latticed shell string structure with a span of 100m is taken as an example and the modal analysis is performed. The effects of the rises of radial cables and the curvatures of latticed shell on dynamic characteristics of this structure are also investigated. The result reveals some characteristics of modal of the latticed shell string structure with inner and outer truss torus, which could be referenced by structure designers.

Abstract: Due to web opening, stiffness and strength of steel composite beam decrease significantly. The common reinforcing method is setting stiffeners around the opening section; the paper presents two methods: herringbone stiffener and diamond stiffener. The finite element model is established with both material and geometrical non-linearity. Compared with other common methods, these two new methods are effective. Some reasonable suggestions are proposed for engineering application.

Abstract: The frame column and frame structure with column end of steel-concrete composite joint is a new-type architectural structure. To obtain the mechanical property of the new-type frame column and frame structure, comparative tests between 6 new-type columns and 3 ordinary columns and comparative tests between new-type frames and ordinary frames are carried out. This paper elabrately introduces the specimen design, experiment load, test program, test results and others. Thus, the transformation and failure characteristics of new-type long and short columns at different axial compression ratios and the transformation and failure characteristics of new-type grames at different prestresses are obtained. They are respectively compared with the ordinary long and short columns and frames. Results show that the seismic performance of the new-type column and frame structure is obviously superior to that of the ordinary ones. The tests can achieve the expected test objectives and are proved successful.

Abstract: The main contents of dynamic characteristic and response of external prestressing curved beam are as follows: The research is about frequency characteristic of external prestressing curved beam. With analysis of variable regulation, the natural frequency's theoretical formula can derived from natural vibration frequency under structure concrete damage .Resonance prevention of external prestressing curved beam is vital. Through explicit beam frequency, external cable and external excitation, and the relationship between above each other can prevent resonance destruction .By analysis of dynamic performance's parameter sensitivity , external prestressing curved beam can be obtained sensitivity parameter of dynamic performance .Model test study of dynamic external prestressing curved beam is also critical. Based on research achievements of existing theory, dynamic model test can be carried on, which would obtain vibration regulation of verification and comparison with structure data.

Abstract: This paper deals with the effect of splicing area design parameters on the mechanical behavior of beam-column connection with cantilever beam splicing. A series of models are designed based on the change of parameters. The mechanical behavior of beam-column connection with cantilever beam splicing is systematically studied by using the finite element analysis. The analysis results show that the number and arrangement of web bolt will have a great influence on mechanical behavior of the splicing joint when the number of flange bolt is designed by the precise design method; the number and arrangement of web bolt will have a less influence when the number of flange bolt is designed by the equal strength design method; Splicing area design parameters have little effect on the ultimate load and the initial rotational stiffness of the splicing joint; the number and arrangement of bolt is sensitive parameter for yield load of the splicing joint and the rotational stiffness in the the splicing area.

Abstract: Basis on the theory of mechanics of explosion, according to nonlinear finite element method shows that dynamic analysis software ANSYS/ls-dyna , the explosion wave propagation in the flat box sealed structure and the distribution of overpressure on the wall is studied under the action of explosion. Combining the reality of ^[Guo Zhikun experiment and basic data , ANSYS/ls-dyna is used to establish a standard size 4 studio flat box experimental model, within the model corresponding to the positioning of the drug to 220 units of TNT. Through ANSYS/ls-dyna visualization process study the transmission mechanism of shock wave in a flat trunk, acquisition of some points on the wall of the overpressure peak data caused by explosion, combined with experiments of the proceeds of the actual data values were analyzed.