Advanced Materials Research Vols. 850-851

Abstract: This article uses Finite-difference time-domain (FDTD) method in the spray quenching process of the backup roll, which calculated the temperature field, the phase transformation and the hardness of the backup roll. The results showed that there was high temperature gradient on the surface of back up roll at the beginning of the spray quenching process and the tempeurature decreased rapidly. The beginning of the spray quenching process is a key stage. The radius martensite content decreases from outside to inside gradually, the maximum depth that martensite occurs was about 150mm from the surface. Martensite point affected the surface hardness very slightly, whereas impacted the hardening depth strongly.

Abstract: The slips on packer play an important role on supporting packer and locking rubber tube after they have been anchored, and their performance directly affects the oil yield and production safety. In this paper, the contact between a type of packer slips and casing is analyzed using the finite element software Abaqus, the stress and displacement fringe graphs of the casing under working conditions are obtained, and it offers the guidance on optimal design for packer slips.

Abstract: This paper is about the vibration system of cement concrete pavement resonant breaker design and simulation. Finished the design and simulation of vibration system model and got the vibration characteristics and its parameters in detail by using virtual prototype technology and finite element method.

Abstract: The service life of reinforced concrete structure has been greatly influenced by corrosion of steel, however, impressed current cathodic protection (ICCP) system is able to control corrosion of steel, especially which is corroded by chloride along the coast areas. In this work protection current and related technical parameter in both intake and outfall structure has been investigated in the seawater cooling structure along the coast area of Persian Gulf in Saudi Arabia. The most suitable protection current density provided by ICCP system is 5mA/m² for reinforced concrete structure in the severe marine corrosion area in Middle East.

Abstract: The textile industry is China's traditional advantage industry. The demands of the textile industry productions efficiency and cost control are much higher than before. LL680 loom frames finite element model was made and analyzed for the companys demand of high-speed improvement, then used experiment to verify. The results show that the modeling method is right and it provide a viable model for structural improvement.

Abstract: Molecular water in lubricants causes unavoidable damage in mechanical tribo-systems. To illustrate the characteristics of water in oil, three typical hybrid states, including dissolved, free, and emulsified states, were discussed focusing on the physical structures, hazards, and electric properties. Aiming at the on-line monitoring of molecular water in engine oil, a conductivity-based sensor was proposed. Two enamel wires, with partial naked surfaces, were winded around an insulated pole in parallel to serve as a probe. A higher cell constant was obtained with a high sensitivity. A multi-channel sensor with four probes was designed for on-line monitoring. The performance of the sensor was examined experimentally. As main result, the sensor has explicit effects on detecting free and emulsified water. The sensor also has a good linearity and repeatability when water content increasing from 0% to 3%, and has a high reliability under the disturbances of air and metal debris.

Abstract: Instead of mechanical commutator for DC motor, Brushless DC motor used electronic commutator. And brushless DC motor (BLDCM) extended the effective using time of a motor and eliminated some problems caused by the mechanical commutator, such as electromagnetic interference, brush wear, frequent maintenance and etc. At the meantime, brushless DC motor inherited a few advantages from DC motor, like wide speed range, large torque, stable operation, low noise, and high power density; there is great significance in researching BLDCM control system. This paper researches the application of fuzzy control strategy in BLDCM (brushless direct-current motor) control system. The design and simulation of BLDCM control system based on DSP controller also presented in the paper.

Abstract: The YSJZ hydraulic umbrella drill has been widely used in mine construction. Due to its big structure size, the weight brings difficulty in lifting. In order to solve this problem the whole umbrella drill model should be established, and then analysis some structures of the umbrella drill based on the finite element analysis. It can be expected to reduce the weight while improving the stiffness and strength of each part. It turns out that it can achieve the desired effect.

Abstract: In order to improve economic performance of a new type underwater turbine engine, objective function with maximizing inner efficiency in design condition is constructed based on establishing design calculation model of single stage impulse turbine engine. By using GA algorithm, optimization match study is finished among four parameters, such as working back pressure of turbine engine, mean diameter of turbine cascade, air-in inclination angle and diffuse angle of nozzle, and whose effect on inner efficiency is studied respectively. Results show that, for the engine studied, inner efficiency has sensitivity to working back pressure, while not to diffuse angle of nozzle. Which has been improved by 6.24% after optimization design in design condition, and working substance consumption per second has been decreased by 5.87% correspondingly, so economic performance of the studied engine has been improved obviously. The established model and its calculation results provide initial model and parameters for thermodynamic simulation for turbine engine in off-design condition.

Abstract: The stress nephogram was obtained through analyzing the stress of die using the finite element software. Cause of die crack is determined from the stress nephogram, and repair plan is presented. The repair plan is analyzed by finite element and is validated by experiment.