Abstract: The influence of parameters to load performances of a high-speed externally pressurized
spherical gas bearing compensated by two-rows of orifices has been studied numerically based on
finite element method (FEM). Reynolds equation governing the flow field in the clearance space in
spherical coordinates system is transformed into a analogous style in Descartesian coordinates by
parameter substitution, and Galerkin weighted residual method is applied to reduce the order of
derivatives of the transformed equation. Pressure distribution on the gas-film is obtained by solving
of the equation. On the basis of theories, influences of rotating speed, nominal gas-film thickness
and supplying pressure to load carrying capacity and stiffness are analyzed. Comparison of
performances between hydrostatic and hybrid state of the bearing has also presented.
Abstract: Because of the deficiency of fixed kernel in bilinear time-frequency distribution (TFD),
i.e. for each mapping, the resulting time-frequency representation is satisfactory only for a limited
class of signals, a new adaptive kernel function named the radial parabola kernel (RPK), is
proposed. The RPK can adopt the optimizing method to filter cross-terms adaptively according to
the signal distribution, obtain good time-frequency resolution, and offer improved TFD for a large
class of signals. Compared with traditional fixed -kernel functions, such as Wigner-Ville
distribution, Choi-Willams distribution and Cone-kernel distribution, the superiority of the RPK
function is obvious. At last, the RPK function is applied to the analysis of vibration signals of
bearing, and the result proves the RPK function an effective method in analyzing signals.
Abstract: This research is concerned with the influences of cutting speed on the fatigue properties
of high speed milled Ti-6.5Al-2Zr-1Mo-1V (TA15) titanium alloy. Four different cutting speeds
ranging from 50 to 200m/min were used to mill the specimens for fatigue test, and the fatigue
properties of them were studied at two stress levels: 80—800MPa and 90—900MPa. The fatigue
lives of the specimens milled under different cutting speeds were compared. The fracture surfaces
were analyzed using scanning electron microscope (SEM), and cyclic stress-strain properties of
TA15 titanium alloy were investigated with a stress-strain gauge. The results showed that increasing
cutting speed can help to improve the fatigue properties of titanium alloy, especially at a relatively
low cyclic stress level.
Abstract: This paper analyzes the compaction structure of New Vane-Hydraulic Motor, design and
calculates the parameter of spring which is used at the bottom of the vane; it also calculates the
actual pressure angle which is operated between the vane and the stator in order to find a method to
diminish the size of pressure angle.
Abstract: As machining technology develops toward the unmanned and automated system, the
need for chip-breaking control is considered increasingly important. In this paper, chip-breaking
limit of 3-D complicated groove insert is proposed according to cutting experiments. The
mathematical formulation of chip section profile coefficient is established through the analysis of
influential effect of 3-D complicated groove on chip section profile. The chip-breaking model is
developed to predict the critical feed rate and the critical depth of cut in machining based on
analyzing the restricted effect of 3-D complicated groove on chips. Finally, a full experimental
validation of the analytical model is presented for chip breaking when the workpiece is steel, 45.
The testing results show the critical feed rate model and critical depth of cut model are reasonable
Abstract: An efficient flexible iterative algorithm with a general approach is presented for
calculations of surface form errors in peripheral milling of thin-walled workpiece. An efficient
finite-element model for tool/workpiece is presented to analyze the surface dimensional errors in
peripheral milling of aerospace thin-walled workpieces. The efficient flexible iterative algorithm is
proposed to calculate the deflections and the maximum surface form errors as contrasted with the
rigid iterative algorithm used in the literatures. Meanwhile, some key techniques such as the
finite-element modeling of the tool-workpiece system; the determinant algorithm to judge
instantaneous immersion boundaries between a cutter element and the workpiece; iterative scheme
for the calculations of tool-workpiece deflections considering the former convergence cutting
position are developed and the method for calculating the position and magnitude of the maximum
surface form errors are developed and presented in detail. The proposed approach is validated and
proved to be efficient through comparing the obtained numerical results with the test results.
Abstract: The Polycrystalline Cubic Boron Nitride (PCBN) cutting tools has have been developed
for high speed machining in modern automation manufacture. The machining surface roughness is
regarded as an important criterion to assess PCBN cutting tools performance. There are too many
problems in conventional detection method. In order to solve that problem, we present a new way
that is based on image analysis of machining surface texture to assess surface roughness. The new
method is consisted of three steps. It captures surface texture image when machining is finished or
pauses. Firstly, RGB histogram is adopted to analyze image pixel information. This means takes
advantage of histogram technique and provides more pixel distribution information than gray
histogram. Secondly, unsupervised texture segmentation is used based on resonance algorithm.
Thirdly, a new estimation parameter E that is the density of surface contour peak is put forward to
estimate machining surface roughness.
Abstract: In order to protect ERP system information from authorized users or non- trusted users, a
trusted role based access control model was proposed. Combined with the characteristics of
enterprises, trusted computation for user is designed to support roles assignment to the users.
Meanwhile, Object Lifecycle States (OLSs) are presented for efficient access control to objects.
Based on the value of trusted computation, users are assigned the corresponding roles to access
control various resources. Finally, there is an empirical research on an ERP System implemented in
a manufacturing enterprise.
Abstract: To enable designers to construct geometric models of MEMS devices in a
straightforward environment and get mask and process flow automatically, a 3D MEMS CAD
system for surface micromachined devices is proposed based on traditional design
software—SolidWorks. With Application Programming Interfaces (APIs) of SolidWorks,
component modules and databases of the system are developed with Visual Basic, such as
geometric model design module, mask and process flow generation module, process simulation
module, 3D feature database and material database. Their development method is discussed in this
paper. A practical example shows that surface micromachined devices can be designed efficiently in
the system without tedious fabrication process.
Abstract: A triangle mesh was reconstructed from an unorganized point cloud through two phases
of mesh growing based on different strategies, where regions with high point density usually grow
at the first phase and the remaining regions grow later. In each phase of mesh growing, the
smoothest regions always grow firstly and then largely avoid errors emerging in sharp regions. The
presented test technique of geometric integrity as well as the abnormality disposing method pledged
the reconstructed mesh has correct geometry structure. Experiments show that the algorithm is
efficient and effective.