Advanced Materials Research Vols. 143-144

Abstract: Synchronized hydraulic bulging forming technology on three-layer-metal tubes was studied. The possibility of three-layer-metal tubes formed by hydraulic bulging method was discussed and proved by elastic-plastic theory. The calculation formulas about the bulging pressure, the residual contact stress and the relationship between them were derived and the main process parameters were analyzed. Finite element analysis was carried out on bulging forming process using MSC. Marc. Practical bulging forming experiments were conducted and well compounded three-layer-metal tubes with tight interfaces were obtained. Through the comparison of the results of theoretical analysis, numerical simulation and practical experiments, proper parameters for the bulging process were obtained and the theoretical analysis was verified and proved.

Abstract: This paper briefly summarizes structure of actual three gorges reservoir geological hazards monitoring system and introduces methods of monitoring data acquisition and transfer in detail. This paper describes software architecture of using GPRS, Centralized Database Management, Distributed Data Management techniques to provide wireless data communication for geological hazards monitoring system. In this paper the work can be used to clean development mechanism and system provides reliable and low-cost way collect monitor data, regardless of position remote sites website or distribution of monitoring and data collection units.

Abstract: Based on micro-jet spraying technology, by spouting fluidized bed, aquatic feed encapsulating mechanism and experimental process were introduced, experimental conditions and parameters were discussed.Granular aquatic compound feed encapsulating experiments were done by spouting fluidized bed, the relationship between membrane thickness and microencapsulated time was analysed, stability indices of microencapsulated feed in the water was determined, the test results show that based on micro-jet spraying technology, feed encapsulating experiment parameters controlled easily, microencapsulated feed in smooth shape and good stability, the loss rate of microencapsulated feed in dissolution is less than that of unmicroencapsulated feed, and the spouting fluidized bed in low cost and power consumption , handled easily , so has great promotional value.

Abstract: Tool life is an important index to judge machinability of cutting tool. Wear standard is a necessary considered factor to give tool life. Microwave printed board is composite material, wear standard should be found by tool wear experiment under definite machining environment. Life-span data of cutting tools with different combination of cutting parameters is collected through machining experiment. And then based 2 mathematic models: extended Taylor empirical equation and quadratic response surface equation, with regression analysis method, the mathematical models of relationship between cutting parameters and tool life were given respectively. Through comparison of two regression methods, response surface equation based wear equation is given, determining calculating method of tool life for High-speed Machining of Aluminum Base Microwave Printed Circuit Board. Described method can be popularized according to change of machining conditions.

Abstract: For physical models, conventional techniques have difficulties in monitoring internal displacements during laboratory testing. In this paper, based on fiber Bragg grating (FBG) sensing technology, a bar-type fiber optic displacement sensor is developed for small-scale models. When the model deforms due to loading or unloading, the embedded displacement sensor can capture the displacement profile along the bar length using the strain data from quasi-distributed FBGs. Laboratory calibration tests have showed that the displacements measured by the FBG sensing bar are in good agreement with those from conventional displacement transducers. For the physical models of a gravity dam and a cavern group, the FBG sensing bars were successfully installed in predefined holes, together with conventional gauges. During testing, the FBG sensing bars measured the displacement distributions within the models. The fiber optic monitoring results demonstrate the deformation characteristics of surrounding rock masses induced by overloading and underground excavation and indicate the overall stability conditions of these two geo-structures.

Abstract: Contact fatigue is the primary failure form in the closed and well lubricated gear driving. Residual stress is an important factor influenced the fatigue. In this paper a relationship between the compressive residual stress and the gear contact fatigue strength was established basis on static shakedown analysis with elastic-plastic contact theory. The contact stress was obtained by hertz theory, and the residual stress induced by the gear meshing was simulated though finite element method. Base on the residual stress distribution obtained in previous step, three different pressures according to James theory was loaded into the contact zone. It was shown that the gear plastic deformation was unchanged if the secondary loading was no more than the initial load. The results suggest that residual compressive stress could improve the contact fatigue strength.

Abstract: An in-situ measurement technique of the surface roughness of ultra-precision machining by optical characteristic effects is fundamental thanks to the probe-less which would avoid the contact damage on the surface. Since the plastic lens molding reprints the roughness from the mould core fabricated by machining, the tool marks induce the poor surface of the plastic lens. By a laser with a short wavelength of He-Ne of 632 nanometers, the machined surface would reflect the input light. Several samples with different surface roughness of the aluminum by varying the feed rate of the ultra-precision machining are used to be measured by the He-Ne laser. The 1 x 16 photo-diode array with the pitch of 2.0 mm is constructed to measure the distribution of the optical scattering effect under the light source of He-Ne laser. Results show that the higher surface roughness gives a more expanse distribution of the light scattering. Besides, the BSDF of the machined surface is proportional to roughness. Using the ratio of the main and side measuring channels of the photo-diode array would give a suitable approach to construct the relationship between the light scattering and surface roughness. Therefore, the laser and the photodiode array would predict well the roughness of the ultra-precision machined surfaces of aluminum. The on-line measurement technique for the roughness by reflected light scattering effect from the ultra-precision machined surface is constructed nice in this study.

Abstract: In order to protect the lives and property of mine workers, the influence of rocks materials slope induced by coal mining was presented. Based on geological data, a case of the mining areas of Fengmaoding anti-dip slope in China was studied using simulation analysis methods. Results show that deformation and fracture of this slope was influenced by mining subsidence, and the rock and soil layer made subsidence deformation in the vertical direction under geostatic pressure. After the deformation became stability, it would make failure strain in the horizontal direction. If initial stress of the slap’s failure in surface exceeded the shear resistance,the slope gradually slipped down, and the landslides occurred finally.

Abstract: To study the feasibility of double-curved PDM into casing, the mechanical model of Φ172 mm double-curved PDM into Φ244 mm straight casing is established. The effect of different structure corners on the feasibility is analyzed for the PDM into casing; and the law of stress distribution is discussed in the paper. The simulation results show that the Φ172 mm double-curved PDM can enter Φ244 mm straight casing favorably by self-gravity when the first structure bend is equal to 1° and the second structure bend is equal to or less than 1.5°. When the second structure corner is equal to or more than 1.75°, PDM needs extra to enter into casing. Within the bounds of common structure corners,when the PDM into casing, the maximum stress value of the double-curved PDM is much lower than yield strength.

Abstract: This paper describes a distributed system for monitoring the cameras and controlling the pan tilt zoom, banners and slogans. The system satisfies that users can operator the devices in any computer in the LAN of the express way system, and all video stream can be showed in both a video matrix and any computer in the LAN of the express way system as well. We employ web service and converter between network and serial communication line to implement the anywhere-accessing requirement.