Applied Mechanics and Materials Vols. 405-408

Abstract: In order to research the influence of bolt pretension on the flexible flange joints stiffness further, ANSYS finite element model was built on the basis of experimental investigations, and was used to research the influence of bolt pretension on the axial rigidity, shear rigidity and bending rigidity. The calculation results indicated that the axial rigidity, shear rigidity and bending rigidity were all increased along with the increase of bolt pretension, and the increase of axial rigidity was most obvious.

Abstract: The mode localization phenomenon in mistuned cyclically periodic structures has been a hot spot in the past few decades. According to numbers of documents, the fundamental concepts, mechanism, main research methods, and the main results of mode localization are introduced; the current research status of the mode localization is summarized. The possiblity of mode localization in a telescope reflector model has been analyzed by using Finite Element Method. We also illustrate the problems for further studies, including: the unified modeling and analysis theory with more extensive applicability and better analytical accuracy; determining how to properly introduce mistuning parameters that can reflect the true state of the structure; constructing mode localization factor which can sensitively and effectively reflect the effect of mode localization; developing new damage identification method considering the influence of mode localization; how to make use of the localization characteristic to control the vibration level of the important sub-structure and improve the sensitivity of the periodic structure to the random detuning.

Abstract: This paper presents a numerical method to simulate singel vortex based on unsteady RNAS model, and the influece of such a single vortex on the flow characteristics around a square cylinder is discussed.

Abstract: This paper proposes the least-squares finite element method (LSFEM) for simulating the free surface flows in multi-step free overfalls. Motion of the free surface flows is represented with two-phased surface profiles by solving the Navier-Stokes equations. The fluid is considered to be incompressible and the dynamic and kinematic boundary conditions of free surface are described in an Eulerian coordinate system. In this simulation, the volume of fluid (VOF) method and continuous stress force (CSF) models in association of color function are incorporated for the determination of the interface between water and air. The simulation results from the LSFEM model are carefully verified for the unit-step free overfall case. The quantitative comparisons in terms of the parameters such as different inflow rates, reattached length, water height after the fall and critical depth with previous numerical results or experimental measurements are shown to be in good agreement. In order to understand more about the complicate free surface profile of a dual-step free overfall, the LSFEM model is simulated for different inflow rates. In comparison with the available experimental data, it is shown that the LSFEM can effectively simulate the multi-step free overfall flow phenomena. Our study presents some regression formula for the dual-step free overfall, it is hoped that these formula will be helpful for the engineering designs and applications.

Abstract: In this study, the methods for combining statistical energy analysis (SEA) and the finite element method (FEM) for the vibration analysis of structures are studied. Using the two methods simultaneously isnt entirely extend a primarily low frequency method, the finite element method, and high frequency method, SEA, to the mid frequency region are addressed. This approach is intended to extend the frequency range for a FEM based vibration analysis . A new finite element elementl for elevated slab ballastless track is proposed in which the new model can be used for modeling the track structural constituents of elevated slab ballastless track. Using finite element method and Hamilton theory, the coupled equation of vehicle-track-bridge can be established. In calculating example, both the rail displacement induced by single four-layer beam model. Specifically, it showed that the method yields very good result and high performance in the numerical example of previous research.

Abstract: A refined theory of transversely isotropic beam posting inside Winkler foundation is derived without ad hoc assumptions. Based on elasticity theory, the displacement field and stress states of isotropic body are studied. From boundary conditions, the refined theory of transversely isotropic beam posting inside Winkler foundation is given. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory.

Abstract: In order to improve the modeling efficiency for finite element analysis pre-processing, a parametric modeling method of underground powerhouse for finite element analysis is proposed. By inputting the basic geometric parameters, different types of underground powerhouse models are built by using this method. The basic ideas, basic principle and the process of this parametric modeling are presented. And the parametric modeling procedure is coded by using VC++, interactive interface and display window are designed by using MFC and OpenGL. Finite element model of Houziyan underground powerhouse which is built by using the procedure proves that this method greatly improves the efficiency and precision of modeling.

Abstract: Introduced the basic situation of aircraft tanker truck, carried out the performance tests of the tanker truck with ZX120-100 and ZX120-100-GY self-suction oil pump in the plateau. The test result shows that the self-suction capability of ZX120-100-GY centrifugal oil pump is better than ZX120-100 centrifugal oil pump, and refueling performance of 2004-12000 aircraft tanker truck with ZX120-100-GY centrifugal oil pump is good which can afford the demand of the aircraft.

Abstract: All kinds of products can be conditionally divided into two types, ie. those that can be regenerated and those without the possibility of undergoing regeneration. Regeneratives are those products which, in the event of failure are eligible for repair. To this category, almost all types of machines, mechanisms and devices can be assigned to. Products that are not regenerative are those that, which in the event of failure do not qualify for regeneration in a given situation or because of principle. These include gears, springs, bearings and electronic components. Indicators for the reliability of products that can be regenerated differ from those which may be defined for parts or elements that are not to be regenerated. The concept of reliability index is understood as the quantitative characterization or evaluation of one or more of their characteristics or features. The length of work or the volume of work accomplished can be called work done during that time is assessed over time or related to its indicators. Parts, until they become defective, may work 100 hours, 10 cycles, 10000 km, etc. However, in terms of related concepts distinguish between work done to the first failure, the work between defects (for parts which are subject to regeneration). Given that the regenerable and non-regenerable calculation of indicators are different and will be subject to separate consideration.

Abstract: At present the hole digging pile is excavated in artificial by digging the hole .This method usually works in low efficiency, high labor intensity of workers and poor security situations. So through the analysis of the artificial excavating pile 's requirement, there is necessary to create a new structural of a machine with the help of pneumatic conveying system to dump soil. In this paper the authors introduce a hand-held excavator which has the above structure in excavating. This machine adopted a motor as a power device, used secondary gear reducer to achieve speed-down, and drill bit was driven by the transmission shaft to complete the excavation. The machine has the digging ability of 240mm excavation pit diameter, simple structure design. It can meet one man operation requirements, and can be carried easily.