Advanced Materials Research Vols. 317-319

Abstract: In this paper, the method of the nested refinement for triangular mesh and some relevant conclusions are considered. The Κ level triangular grid nested refinement on the plan domain Ω and some related properties are discussed , and the convergence results are obtained for the first boundary value problem of Poisson equation under the nested refinement of triangular finite element.

Abstract: A scalable Graphics User Interface Architecture for open Computer Numerical Control (GUIAC) application is presented in this paper. The GUIAC is based on Windows Presentation Foundation (WPF) and Model-View-ViewModel (MVVM) design pattern. The WPF and MVVM pattern are used to decouple the User Interface (UI) presentation and business logic. This method makes the CNC application UI presentation design and the CNC application logic implementation work in parallel for improving the development and maintenance efficiency. Using the extensible application markup language can reduce the UI presentation design workload. The GUIAC has a loosely coupled structure with three layers. The experiment results of developing the CNC application using GUIAC show that the application graphics user interface is scalable and maintained easily.

Abstract: Two kinds of quaternary aminated β-cyclodextrin ionic liquids were synthesized and used as stationary phases in capillary gas chromatography. The influences of different counter ions (tetra- borofluoride, bis-trifluoromethanesulfonylimide) were studied. The results indicated that quaternary aminated β-cyclodextrin ionic liquids possessed good column coating properties and a chromatographic separation abilities. The Grobs mixture, alkanes, alcohols and aromatic position isomers, such as xylene, nitrotoluene, dichlorobenzene and cresol were separated well. These quaternary aminated β-cyclodextrin ionic liquids have potential to separate some complex compounds including alcohol, amine, ester etc.

Abstract: In conventional machining of free form surfaces, incomplete information exchange between CNC and CAD/CAM results in many limitations need to be rectified. In the paper, a new structure of CNC based on STEP-NC is proposed. A 5-axis real-time interpolator for NURBS surfaces machining is realized. A STEP-NC controller has been developed, which is a software modular CNC system. The CNC system has been installed on a tilt-rotary type 5-axis machine tool. The milling experiment has been performed.

Abstract: For the machining centers which have distinguishing features of small samples and high-reliability, we proposed a Weibull-distribution-based method of Bayesian evaluation to calculate their reliability in this paper. The reliability test platform for machining centers was built and a reliability testing method which was based on the impellers’ machining process was adopted in order to get the field testing samples. Then we selected the machining centers’ reliability of a fixed time as the random variable to determine its prior distribution. The posterior distribution of products’ reliability could be obtained by combining the prior distribution and the field test samples with the application of Bayesian method. Finally, we could calculate the lower confidence limit for the products’ reliability under a given confidence level and the reliability’s mean under typical mission time.

Abstract: Based on the investigation and study of the topography and composition of the buildups, combined with production process of silicon steel, the major causes of forming buildups of carbon sleeve are analyzed from the factors such as the quality of carbon sleeve, furnace atmosphere, dew point, adjusting steel roll, intermediate steel roll, running speed of carbon sleeve and so forth. Meanwhile, some countermeasures to reduce the formation of the buildups are put forward.

Abstract: This paper presents a technique for the position servo system of numerical control (NC) machine tool by utilizing the optimal quadratic controller. The mathematical model of the position servo control system is structured, which of the plant model is identified by making use of recursive least square method. The fundamental method of designing the optimal quadratic controller is proposed. Simulation of the optimal quadratic controller and PID controller are implemented by using MATLAB. The results of simulation show that the proposed control method of positional servo control system has better dynamic characteristics and better steady performance.

Abstract: Thermal error of machine tool is the main in total machine tool error, and obviously impairs the accuracy of the machined workpieces. Ram is a very important component of heavy-duty floor type boring-milling machine, and its thermal deformation is a significant source causing errors in machining process. Aiming at the thermal elongation of heavy type milling boring machine tool ram, the machine tool thermal errors are measured and compensated. Temperature compensation function in NC system is applied. Experiment results shows that 90% ram positioning error can be compensated.

Abstract: As a non-invasive, functional measurement method, bio-impedance technology has been obtained certain application in clinical, however, it has still been in studying in most application fields. By reviewing the current development status of bio-impedance technology, the paper analyzes the future emphasis of development and technology direction, in order to make bio-impedance technology gain more widely clinical application.

Abstract: Positioning accuracy of servo feed unit makes an important effect to processing precision in CNC machine tools. The effects in positioning accuracy mainly are the precisions of mechanism and servo system. And the actions of tuning controller gains should directly affect the servo system precision. This paper, a servo system model and its P/PI controller has been formulated and simulated, using an AC servo feed unit as a tested. Through tuning gains of P/PI controller, analyses and control the effects for the feed unit positioning accuracy. Ultimately, experiments have been carried out to test feed unit by laser interferometer. Its shows that tuning gains of P/PI controller, which given in paper, has effectively improved the positioning accuracy of servo feed unit.