Applied Mechanics and Materials Vols. 241-244

Abstract: With the depletion of shallow-layer oil and gas pools inLiaohe oilfield, buried hill stratigraphic reservoirs in Liaohe oil field are becoming main objectives for exploration in recent years, especially in high-risk areas of Xinglongtai deep the Hing ancient buried hill resources are particularly rich. Since 2007, Liaohe oilfield increased investment for Buried Hill reservoirs with deep horizontal drilling developt the buried hill reservoir. Liaohe has completed 36 deep horizontal, with a total footage of 183920m, the average depth of 5109m. Improving drilling speed of "buried hill deep horizontal and branch horizontal wells”, and reducing drilling costs are of great urgency. “Hing buried hill deep horizontal, horizontal wells,” with composite drilling technology, supporting the optimization of PDC bits, the high-pressure jet drilling, the MWD borehole trajectory control and optimization of drilling parameters, the new drilling fluid technology and so on. With a large number of horizontal wells put into Buried Hill stratigraphic reservoirs, oil and gas production of average deep horizontal well increase of 2-5 times. Besides, the previous recovery and production of oil and gas reservoirs significantly improved to create an objective economic and social benefits.

Abstract: With the development of Mars exploration, NASA has been preparing plans for a crewed mission to Mars in the next few decades. One challenge associated with crewed missions to the Mars is the high ballistic-coefficient and human-class payloads. Because of the high ballistic-coefficient, the maximum limit value of the reference flight path angle is always the reference flight path angle meeting the downrange and altitude for the constant flight path angle algorithm. So this paper presents an improved algorithm which the terminal velocity is controlled by dynamic pressure controller, and the controller is used to modulate the velocity and altitude to meet final constraints. Simulations results of a Mars entry scenario illustrate that the improved algorithm achieves the final constraints within allowable tolerances.

Abstract: Reliability is an important index to indicate the quality of products. The definition, composition and working principle of deceleration electric wheel are described in this article. The reliability of the system is analyzed with stress analysis method, score estimation method and device counting method. It offers the theoretical support for such a system to be put into actual design and production.

Abstract: A mathematic model of the electric servo system was founded in this paper and several groups of data collection and data processing were executed to check up the model veracity. This paper described the data processing steps and analyzed the contrast of test and simulation results. This model is effectual to describe the performance of this kind of servo in respect that the results are mainly consentaneous.

Abstract: This paper analyzes the composition and principle of the pneumatic actuator system, establishes the model and deduces the transfer function of the system, and gets the simulation result through the model and the transfer function. It designs the digital controller which meets performance requirements, then calibrates the ADC, and develops the control program based on the GPIO mode of the TMS320F2812, which produces 8 channels differential PWM signals. It turned out that the simulation results agree with the experimental results, and both reach the expected performance, realizing the design of the digital controller for the pneumatic actuator.

Abstract: Vibration feeder is the device of subsequent orientation feeding using vibration for the granular or power materials. This device could be used in food, medicine, chemistry and so on. We announce the phenomenon of materials handling based on testing and analyzing the granular materials in the multi-source piezoelectric vibratory feeder. The results show that the vibratory spreads is the traveling wave in this device, when the device is operated. The elastic particle is the elliptic movement at the end of the stuff box. The dynamic of material movement mainly come from the traveling wave caused by particle elliptical movement, the destruction to the grain’s natural balance status caused by the vibration and the geometric position-limit guiding structure of the device and so on.

Abstract: Linear oscillatory motors with short stroke represent an excellent alternative in linear compressor applications. A novel halbach-type transverse-flux linear oscillatory motor (HTLOM) with two stators was presented, which has the advantage of without moving iron core, compact structure, light weight, easy-stacked stator and smooth thrust force characteristic. Based on the principle analysis, the static thrust force was calculated by three-dimensional (3-D) finite element analysis (FEA). Then the dynamic simulation was presented for the resonant characteristics of current, displacement, active and reactive power and power factor versus frequency. The analysis result shows that the novel HTLOM with two stators is suitable for linear compressor application, and its maximum efficiency can be achieved at velocity resonance by spring stiffness selection. The conclusions are very significant for the further driving control in industrial usage.

Abstract: In order to analyze the transmission characteristics of the knuckle-triangle working mechanism for servo mechanical presses, an experimental prototype was set up, and a wireless measurement system was developed, to measure the kinematic and dynamic characteristics of the working mechanism. The working principle of the dynamic measurement was expressed. The forming force applied to the slide was measured by a donut-shaped load cell. The driving torque applied to the crank was measured by a resistance strain gage. To collect the testing signals of the forming force and driving torque conveniently and synchronously, a wireless measure system based on WiFi is proposed. Moreover, when the input crank rotates at different angular speeds, the slide stroke curves were measured by a grating scale. The experimental results showed that the developed system can perform wireless measurement, and provide experimental basis for the analysis of kinematic and dynamic characteristics of the working mechanism with servo input.

Abstract: A novel CNC system for line contact machining is put forward to mill ruled surface efficiently. The motion control card based on FPGA is designed in the system for line contact machining. To meet the complex interpolation requirements of CNC system, NC embedded PC structure is used to improve the performance of the CNC system. Computer input and output program by C + + Builder are operated in DLL with WinIO component, to realize the communication between PC and movement control card. Three interpolation modules are simulated in Quartus II. Simulation result shows that linear interpolation, circular interpolation and complex interpolation function are realized on the motion control card based on FPGA, and the line contact machining can be realized in the CNC system efficiently.

Abstract: The conventional structural design of wallboard of electrostatic precipitator casing uses the wall structure of stiffened flat sheet which consumes a great amount of steel. Consequently, a new structural idea was explored to optimize the conventional design which applied profiled steel sheet and located wall beam and wall column. The codes were written which designed and analyzed the wall structure of casing. On the basis of a practical project, as the design parameters were varying, the codes were used to automatically compute the strength, stability, stiffness and steel consumption of profiled steel sheet, wall beam and wall column of the corresponding design case. Then, the design with the minimum steel consumption was selected as the optimum one among all the cases which could satisfy the design requirements. The characteristics of the optimum section shape were generalized. The influence of structure layout on the minimum total steel consumption of casing wall structure was investigated. The total steel consumption of casing wall structure is comparatively small when wall column and wall beam divide the whole wallboard into several smaller blocks whose aspect ratio is about 1.6-2.9. Compared with the original wall structure of stiffened steel sheet, the optimized wall structure composed of profiled sheet, wall column and wall beam can save steel significantly which can be applied widely in large-scale electrostatic precipitator casing structures.