Applied Mechanics and Materials Vols. 130-134

Abstract: Based on MTS-815.02 servo-controlled rock mechanics and acoustic emission (AE) integrated test system, the strength, shear deformation localization and damage AE-energy-rate characteristics process of coal specimen from Weihuliang Coal Mine under tri-axial loading were analyzed. A new model of Weibull distribution on the AE higher energy-rate emergence interval under tri-axial loading had been established, the total probability of coal sample localization failure in an interval is proposed. Then, the forecasting analysis of the coal fracture failure can be studied. The results indicate that the Weibull distribution of the AE higher energy-rate emergence were similar to the experimental results that measured. It is very important to the identification and ration prediction of coal failure in the mining.

Abstract: Multi-point stretch forming is a flexible manufacturing technique for three-dimensional shape forming of craft skin. Its die surface is constructed by many pairs of matrices of elements whose height is controlled by computer. It uses the curved surface of elements instead of the die surface. The element numberis an important parameter because it has great influence on the part quality. This paper simulates the forming process of paraboloid part and saddle-shaped part with different number of elements and studies the influence of element number on the shape accuracy of the part .That will provides guidance for the application of multi-point stretch forming.

Abstract: we demonstrate a wavelength interleaved DWDM Radio-over-Fiber (ROF) system for providing 1-Gb/s OFDM signal in downlink and 1-Gb/s OOK data in uplink simultaneously. In this scheme, we use only one arrayed waveguide grating device at the remote node to realize both the de-multiplexing and multiplexing functions. The experimental results demonstrate that this scheme is feasible to the future broadband high-speed OFDM-ROF access system.

Abstract: The outputs of constructing voronoi diagram with crystal growth algorithm are pixel points set. A whole methodology of extraction of pixel points set is introduced and magnifier scanning algorithm (MSA) which is used to identifying voronoi vertexes and edges is explained in detail. Experiments show that the methodology and MSA is clear and accurate to weighted voronoi diagram.

Abstract: A multifunctional electricity-saving socket was developed based on low power microcontroller STC5608AD as information processing core. This kind of practical electricity-saving socket has advantages of protection of exorbitant voltage and current, automatic sleep, remote control switch and such intelligent functions. This device can be used to reduce stand-by power consumption of televisions, computers, air-conditions and so on.

Abstract: The effects of BaB₂O₄ glass on the synthesis of Ba₂Ti₉O₂₀ were studied. The doping amounts of BaB₂O₄ varied from 0 to 10wt% and the compositions were sintered in the temperature range of 1200~1280^◦C for 2h. The benefit of BaB₂O₄ addition to the densification of the ceramics is apparently due to the liquid phase which accelerates the migration of reactant species, which results in the decreasing of the sintering temperature. With the amount of BaB₂O₄ increased, the microstructure and properties of the ceramics were also changed: BaTi₄O₉ became the major phase instead of Ba₂Ti₉O₂₀, bulk density decreased, and dielectric constant decreased accordingly, while dielectric loss kept small.

Abstract: A new way to recover the erosion thickness of polycycle basin accurately is introduced in this article，taking Kongdian formation of Jiyang depression in Bohai Bay Basin as an example. The Ek during paleogene period was denuded differently. As is lack of well data in deep zone，it is quite difficult to identify the stratas only by using seismic data. And the erosion thickness of Ek can not be recovered precisely by common methods. So a method based on structural evolution for recovering erosion thickness has been proposed. Divide areas of erosion by using structural evolution sections. Then based on part well data in main erosion area，the erosion amounts of local layers are calculated by means of the sedimentary rate，wave analysis and stratigraphic contrast methods. The result shows that：this method is more accurate than others，which can be used to recover the erosion thickness of the polycycle basin.

Abstract: Ellipse gyre surface has wide application due to its special optical property. High-precision manufacturing is more and more important. Here we performed an analysis to decreasing reduction of batch production cost. Firstly, the scheme of manufacturing of 2-axis NC machining is given. Secondly, a basis for calculation of row space with the ball-end cutter is provided. Lastly, the formula of the level and the axis feed is also provided. The feasibility and reliability of these models are proved with examples.

Abstract: Using electrochemical machining process in air difficult machining materials is already become the mainstream of aeronautical production techniques, and electrochemical micro-machining is the top priority, Through the study of each variable in the process of electrochemical micro-machining of titanium alloys, obtain the characteristics mechanism of electrochemical micro-machining of titanium alloys. Through the analysis of its mechanism, obtain the summarized trends and interrelationships of the various elements in electrochemical micro-machining of titanium alloys.

Abstract: In this study, heat transfer and melting process in a co-rotating twin screw extruder are studied based on two typical screw configurations, screw element and kneading blocks staggered 45°. In order to estimate the melting ability of two configurations quantitatively, FEM software, FLUENT is adopted to simulate the cases. It could be concluded that kneading blocks have higher temperature rise and more liquid fraction than screw element, and it takes less time and less distance for kneading blocks to finish melting. Simulation results also show that kneading blocks have more viscous dissipation than screw element. Therefore, we can come to the conclusion that the kneading blocks are more suitable for the melting zone of co-rotating twin screw extruders.