Applied Mechanics and Materials Vols. 152-154

Abstract: Because of deep mining and the serious dynamic pressure appearance in Zhaogezhuang coal mine, this paper has statistical and analyzed phenomena of dynamic pressure appearance, and proposed the engineering defects method to relief the pressure for high stress zone of working face and roadway according to the actual situation, which can transfer the stress distribution of coal rock and release impact energy. Based on the numerical simulation analysis of pressure relief on cavity defects, it has analyzed the feasibility of pressure relief using engineering defect, acquired good effect of pressure relief and achieved the safety of coal mining in the 2337E working face.

Abstract: This paper describes the commonly used for oil drilling directional sensor’s structure and the measured parameters, provides a method for dynamic position measurement while drilling string rotation, detailed analyzes on how to calculate a real time accurate gravity tool face based on a precisely theoretical derivation, and the calculated value by this method verified by experimental results. This article provides a measurement technology solution for any rotary steerable tool developing and it can be applied to such a purpose.

Abstract: Lithium difuoro(axalato)bonate (LiODFB) was synthesized in dimethyl carbonate solvent and purified by the method of solventing-out crystallization. The structure characterization and thermal stability of LiODFB was performed by Fourier transform infrared (FTIR) spectrometry, nuclear magnetic resonance (NMR) spectrometry and thermogravimetric analyzer (TGA). LiODFB was exposed to 50% humidity air at 25°C for different time, then dried at 80°C for 12h, and the electrochemical properties of the cells using 1 mol/L dried LiODFB in ethylene carbonate + dimethyl carbonate + ethyl(methyl)carbonate were investigated. The results show that, pure crystallization LiODFB has been obtained; it has good thermal stability with a thermal decomposition temperature of 248°C; exposed to humidity air, it is firstly converted into LiODFB•H₂O; with the exposed time increasesing, more and stronger impurity peaks in the XRD patterns of LiODFB are observed, both the discharge specific capacity and the capacity retention decrease gradually

Abstract: In this paper, the leaves of 5 kinds of hydrophobic plants including lotus, canna, green poplar, grape and pumpkin were selected, whose contact angles were 150.6º, 135.5 º, 110.4 º, 101.3 º and 94.8 º respectively by contact angle instrument measuring. These plant leaves were adhered to rectangular box by double-sided adhesive tape, as experimental model.The maximum supporting force of these models on water surface were measured by analytical balance, and the supporting force increases as contact angle, the dimple pressed by the model on water surface can increase its supporting force. Through mechanical analysis, the mathematical model of the supporting force was established, the relationship between depth of dimple and contact angle was analyzed by the mathematical model.

Abstract: he basic principle of the correlation velocity measurement is introduced, the influence factors for accuracy of the correlation velocity measurement are analyzed, the installation position and mode of the sensor, the real-time simplification error and the discrete sampling error are especially discussed according to the general and basic principle of the correlation velocity measurement system, and the corresponding measures are provided.

Abstract: The mechanical-electrical coupled dynamic model of the tilting train is established in order to study the failure effects of tilting control system. Four kinds of movement of the driving actuator are compared, specifically including: normal tilting, no tilting, insufficient tilting and tilting on the contrary. The results has shown: when the tilting is insufficient or no tilting, the influence to the dynamic is small, the curve-passing speed reduces obviously; when tilting on the contrary, the dynamic performances of front bogie become worse and the curve-passing speed decreases much more.

Abstract: In this work, an approach called sectionalized motion control (SMC) was proposed in order to achieve control with high precision and low energy consumption for the entire AGV tracking process. In this method, according to the characteristics of the AGV’s early, middle and terminal motion phases, the neural dynamics-based tracking, energy-efficient tracking, and model predictive technologies were adopted. Furthermore, a simulation using Matlab software was performed in order to verify the proposed approach. The simulation results showed that SMC is capable of providing smooth, energy-efficient, robust and globally stable control for the AGV system.

Abstract: In this paper, fuzzy self-tuning controller is introduced first. The fuzzy model is built according to the experience of PID parameter tuning with fuzzy set theory. Parameter tuning is achieved by use of fuzzy ratiocination and decision according to actual response, which is applied for control towards robot. Mathematical model of two-link robot has been built as well as its geometric and dynamical equations through coordinate transformation and matrix operation. Finally, fuzzy PD controller with self-tuning method is applied to realize control towards robots. Simulation in Matlab has been carried out whose result shows that the control method proposed in this paper has better performance than the traditional ones.

Abstract: In research of the low temperature parts of atmospheric pressure device, by using BP neural network, the connection of PH value, Cl^-, H²S and Fe⁺² was setup which can predict Fe⁺² content accurately, and obtain the requirement accuracy, hence more accurate corrosion can be predicted and providing more suggests for corrosion protection.

Abstract: The partial high points, always appearing when the hot strip is being rolled, not only negatively influence the quality of the hot strip, but also make a long term effect on the profile control. Via quantifying and separating the partial high points and analyzing the calculation of the strip crown, we can obtain the calculation method of the error resulted from the high points; then, on the basis of the way that the high points affect the profile and flatness control system, we can present some tactics to lessen the high points’ effect.