Applied Mechanics and Materials Vols. 477-478

Abstract: Columns are prone to sinusoidal buckling and repeated instability on the effect of drilling pressure and fluid pressure during drilling operation. The resulted large area of random contact to borehole wall would affect the drilling efficiency. It made the backreaming and loading hard and the drilling pressure low. Using energy method, taking flexural deformation energy and external potential energy of strings, hole section (slant hole, bending hole, level hole) and annular clearance etc. into consideration, derived the counting function of force that sinusoidal buckling occurred on coiled tubing when it contact with the wellbore, establishing the mechanical analysis method of calculating for sinusoidal buckling of slim lined construction roof bolt and string borehole. It proves an effective method for the applying of coiled tubing drilling pressure and the optimization of process parameters.

Abstract: The limit state function (LSF) is implicit to many structure reliability analysis problems, which may make some classical reliability method complicated to be applied. One of the surrogate methods-support vector classification (SVC) was applied in the structural reliability analysis herein which has not been applied to structure reliability analysis until recent years. Then the advanced first order second moment method (AFOSM) can be applied. The expressions of structure system reliability sensitivity to basic variable were deduced. The flow of how to call the SVC program was presented. An example was shown to compare the SVC based method with some other classical reliability analysis methods. The results are accurately accepted and the advantages of SVC are analyzed.

Abstract: The structure of bogie frame is meshed by hexahedral and tetrahedral elements respectively. FE analysis is taken based on the loads defined by JIS E 4207 standard and the stress distributions of two separate models are obtained. To clarify the accuracy of two kinds of finite element models, the bench test of the bogie frame is carried out. It shows that both the hexahedral and tetrahedral models are valid according to the comparison between FE results and experimental values when the structural model is regular. However, for complex structure model 10-node tetrahedral model takes precedence.

Abstract: The hot preflex cooling and compound straightening are the last two consecutive deformation processes and determine the straightness, residual stress and cross-sectional size for fabricating hundred-meter heavy rail products. The compound straightening process needs to be adjusted by the preflex cooling status. For studying the straightness, residual stress and cross-sectional size of heavy rail products, the preflex cooling model (including the residual stress) of heavy rail after cooling should be taken as straightening model for studying the compound straightening. In this paper, the results by ANSYS implicit analysis (geometry model and stress state of the cold heavy rail) is fully imported to the compound straightening by ANSYS/LS-DYNA explicit analysis through an implicit-explicit conversion method, which resolved the connection problem of coupling and analysis models for solving complex models in multi-physical fields. It is very significant for solving the similar problems in engineering.

Abstract: The dynamic response of the square honeycomb sandwich plates subjected to blast loading was simulated and analyzed by using the finite element software ABAQUS.With the given mass per unit area,core sheet spacing and height,the optimal relative density of the core was obtained under blast loading of three levels.With this optimal relative density,the sandwich plates have the best shock resistance ability and the top and bottom face sheets have the smallest deflection subjected to impulsive load.The sandwich plates were compared with the solid plates having the same mass per unit area.The results show that the sandwich plates have higher strength and energy absorption capability.Furthermore,influence of geometrical parameters including core sheet spacing,thickness,height and face sheet thickness on the face sheetss maximum deflection were discussed.

Abstract: The initial buckling displacements are taken as initial conditions to solve the dynamic postbuckling problem. Non-dimensional dynamic postbuckling equilibrium equations denoted by the displacements are derived and solved by use of the finite difference method. The results reveal the regulation that the dynamic postbuckling deformation develops from the initial low step mode to the subsequent higher step modes under elastic compression wave.

Abstract: Hydraulic spool valve is the key components in fluid transmission and control technology. This paper analyzes flow field of the combination valve based on the CFD software. It gains the characteristic of flow rate and steady flow force, and it offers reference for design of the hydraulic combination valve.

Abstract: Port plate is one of the key parts in axial piston motor. The main researching object of this paper is the port plate of axial piston motor. According to different positioning ways of the port plate, the strength of port plate is calculated by the finite element software ANSYS. From the results of the analysis, certain suggestions are also provided to help further positioning ways design of the port plate of axial piston motor.

Abstract: This paper presents a study that correlates the capacity of two advection schemes in foreseeing flow separation inside a boundary layer wind tunnel (BLWT herein after). The geometry of the BLWT forces the generation of a turbulent separation bubble. Numerical simulations were carried out with the commercial Computational Fluid Dynamics software ANSYS-CFX^®. The high-resolution advection scheme is shown to be more appropriate than the upwind scheme in predicting flows where properties are subject to strong gradients, such as pressure and velocity.

Abstract: Horizontal stabilizer is one part of lift wing structures, which can assure the security of aircraft stability and maneuverability. The paper discussed the visual method based on the numerical simulation and calculation of the aircraft horizontal stabilizer FEM model to aerodynamic forces. Visual method can make the designers understand the internal forces transmission between girder and rib, and help them finish the qualitative analysis of influence of structural-load carrying capacity. It can be used for evaluating the effects of size deviation during manufacturing procedure. It can help designers facilely beforehand measuring and judging the influence of load distribution on the aircraft horizontal stabilizer in first time on the war, when some part of the structures have been destroyed. By combination of visual method and background data, we can get a new complete system to help non-strength designers finish their work in strength condition, and create more value.