Advanced Materials Research Vols. 430-432

Abstract: The paper reports an investigation on a continuous model for dynamics of cables, taking bending stiffness and sag extensibility into account. The new approach involves the use of derived sensitivity coefficients associated with various cable parameters of interest, and use these coefficients to achieve optimal cable performance. The fatigue damage is calculated in the time domain through an adequate cycles counting method. A discussion of the influence of the Irvine parameter on the total fatigue damage is then performed. A Monte Carlo parametric analysis on a case-study,representative of a suspended cable typical of overhead power-line applications, especially in cyclic exposure, exceeds the present chromate-based systems.introduces a discussion on the convergence of the modal expansions and highlights the respective importance of the different classes of non-linear terms included in the model.

Abstract: This thesis proposed a method of testing the relative dynamic stiffness for the whole machine of the high-precision CNC. That is to cut the specimen, then to test the cutting force in all directions and the spindle vibration of the actual processing respectively. It can determine the relative dynamic stiffness of the machine. According to testing results of the relative dynamic stiffness and the structural characteristics of the machine, it can make a program to restrain the suppression vibration. Comparing the dynamic stiffness before vibration suppression and after, vibration resistance of the machine significantly has been improved which validate the effectiveness of the program.

Abstract: The creation method is studied based on AutoCAD, the steps how to use the AutoCAD2010 software to create text style and several typical special characters are stated for some examples, and an effective method for inputting special characters rapidly and accurately in engineering drawing is provided.

Abstract: In order to improve the model accuracy of reliability evaluation, the Three-Parameter Weibull Distribution model of time between fault was established by introducing location parameters. The correlation coefficient optimization method based on the adaptive genetic algorithm was firstly applied to estimate the location parameter of the Three-Parameter Weibull Distribution. Shape parameter and scale parameter were obtained by the least square method. The time between failures of these series machining center submitting to three-parameter weibull Distribution was checked by the test hypothesis of goodness-of-fit distribution. Finally, the machining center was carried out reliability evaluation based on the Three-Parameter Weibull Distribution model.

Abstract: Electro-hydraulic servo systems (EHSS) are widely used in many industrial applications, and to determine the control strategies to exhibit high robustness and high precision remains the focus of attention. In order to improve the control performance of EHSS, a novel control method, based on fractional PID (FPID) controller, is proposed and designed for the EHSS. The transfer function of EHSS is constructed using first-principle method. The feasibility and availability of the proposed controller are examined by numerical simulation. The control performances of fractional FPID are well assessed based on performance indexes, including response time, tracking accuracy and robustness. The results of the simulation verify that FPID controller is of excellent control performance, and is suitable for the control of EHSS.

Abstract: Radiative transfer equation (RTE) in Cartesian coordinates can be considered as a special kind of convective-diffusive equation with strong convection characteristics. For this convection dominated problem, standard finite element solutions often suffer from spurious oscillations. To avoid this problem, the upwind finite element methods based on streamline upwind (SU) and streamline upwind Petrov-Galerkin (SUPG) schemes are developed to solve multidimensional radiative heat transfer in semitransparent uniform and graded index media. Comparison between these two upwind schemes on the solution of RTE is carried out. The SUPG scheme is demonstrated to be better than the SU scheme as far as solution accuracy is concerned and have good accuracy in solution of radiative heat transfer in semitransparent graded index media.

Abstract: This article describes a research on two degrees of freedom turntable with large panel array, proposed an electric-driven method with self-locking function and modular structure mode. And we designed the large panel array two degrees of freedom turntable with 6m × 6m board. The pointing accuracy of the two-axis is 0.01°, azimuth and pitch angle are range to ± 20°, It’s wind resistance level is 8 and have many advantages such as long-term self-locking, safe, reliable, light weight and so on. This article focuses on the turntable’s driving principles and structures; finite element analysis shows that the structure we designed is reasonably practicable, safe and reliable.

Abstract: In this paper, the geometric model of the hydraulic excavator with two degree of freedom was built, and then the dynamic model based on the multi-body dynamic software RecurDyn was built, and then the lateral stability and longitudinal stability of the hydraulic excavator on different gradients were analyzed, the result showed the tipping feather of the hydraulic excavator truly, and this paper provides guidance for choosing the hydraulic excavator’s working conditions.

Abstract: A new design method of gas detection system was given based on the new DSP processor TMS320F28335. The experiment system takes six metal-oxide semiconducter gas sensors as well as temperature and humidity sensors in comprising the sensor array module, followed the excellent detection principle how to choose, and choose CH₄ and H₂ as the test samples and use dual-BP neural-network with the temperature and humidity compensation function as the method to recognize and measure single gas and mixed gases respectively. The result shows that the measuring instrument has higher measuring accuracy and overcomes the shortcoming of other methods, and has important practical application value.

Abstract: In order to improve large amount of computing and slowly convergence speed, an improved radial basis function (RBF) neural network is raised in this paper. According to feature that the more recent data should be the more important in time-series data, it converts width value from original constant value to step function and accelerates the iterative convergence by using nearest neighbor clustering algorithm only at center, training weight by using gradient descent algorithm to correct network parameters and deleting input neurons adaptively. Network size is streamlined through network optimization training. Simulation shows that the restored image is good in visual and quantitative with faster image restoration processing. The algorithm based on improved RBF neural network has significantly improved the image restoration compared to other methods, but also well keeps image detail.