Applied Mechanics and Materials Vols. 325-326

Abstract: The active magnetic regenerator refrigerator is currently the most common magnetic refrigeration device for near room temperature applications, and it is driven by the magnetocaloric effect in the regenerator material. In order to make this efficient, a graded configuration of the magnetocaloric material is needed. Tape casting is a common process in producing functional ceramics, and it has recently been established for producing side-by-side (SBS) functionally graded ceramics (FGCs). The main goal of the present work is to study the multiple material flows in SBS tape casting and analyze the influence of the different material properties, i.e. the density and the viscosity, on the interface between the flows, since this is highly important for the efficiency of the device. The Newtonian flow behavior with relatively high viscosity is assumed for each fluid and used in the simulation with a commercial CFD code (ANSYS FLUENT). The results show that the density change does not affect the interface between the adjacent fluids. The viscosity of the fluids plays the most important role in the behavior of the interface. Moreover, increasing the viscosity difference of the adjacent flows, Δμ, leads to increasing the diffusive region between the two fluids.

Abstract: In this study, the basic limitations of superalloys in high temperature performances will be explained and then after giving the important properties of MoSi₂ such as oxidation behaviour at relatively low temperatures (500°C-700°C) , some interesting composites of this material will be discussed as a candidate structural material in gas turbine engines.

Abstract: This paper introduces the program that the compound compression is achieved through adopting the grouping ways of the VRF air-conditioning compressor, and draws the conclusion that when using the refrigerant R410a, the compound compression is feasible for the evaporating temperature higher than-36°C. The application of the variable-frequency compressor of the air-conditioner and the method of thermodynamic calculation of the single-stage throttle and incomplete inter-cooling are discussed. For guaranteeing the optimal intermediate pressure and adjusting the volume ratio, to utilize the VRF air-conditioning compressor has strong advantages and good market prospects.

Abstract: This article describes a numerical analysis method based on ANSYS used to simulate the whole working process of coke pusher ram. Works have done included the following aspects: the coke pushing resistance curve has been determined; the basic ideas and methods which can treat contact problem, moving loads and other problems in the ANSYS have been introduced, provides a reference for the solution of similar problems.

Abstract: The mechanical actions measurement can highlight a series of mechanical phenomena occurring in the cutting process. During the experiments, we use a six-component dynamometer to measured the forces and the moments applied by the tool to the workpiece. In this paper, the authors present a method for determining the cutting tool position in drilling process, with purpose to transport of the moments (calculation of the torsor in each of the holes). Then can be achieved analyze of the forces and moments for every hole.

Abstract: This paper presents a novel intelligent turn-milling machine, which processes the plastic material on the surface of huge cylindrical aluminum tank equal-thickness. The workpiece is too huge and cannot be processed by traditional lathe for turning operation. In order to make the plastics smooth and equal-thickness, the distance between the cutter and the surface of the tank is kept constant according to the feedback of position sensor placed before the cutter. Via the position sensor, the data of the workpiece shape can be obtained real-timely and the cutter feeding can be controlled by NC system to trace along the workpiece parts figure intelligently. Finally, experimental results verify the effectiveness of the processing method.

Abstract: Machining of composite materials for the production of bolt holes is essential in the assembly of the structural frames of many industrial applications of GFRP. Abrasive water jet cutting technology has been used in industry for such purposes. This technology has procured many overlapping applications and as the life of the joint in the assemble structure can be critically affected by the quality of the holes, it is thus important for the industry to understand the application of abrasive water jet cutting process on GFRP composite materials. The aim of the present work is to to assess the influence of abrasive water jet machining parameters on hole making process of woven laminated GFRP material. Statistical approach was used to understand the effects of the predicted variables on the response variables. Analysis of variance (ANOVA) was performed to isolate the effects of the parameters affecting the hole making in abrasive water jet. The result shows that cutting feed, water jet pressure, standoff distance and abrasive flow rate are influential parameters upon the response variables of the abrasive water jet cutting process of GFRP composite, type 3240.

Abstract: In all processing plants there is a great influence to improve the performance of its overall operation, safety, efficiency and production by the need to reduce the failure of its equipment. Equipment failure; even on very rare occasions, can result in great economic and financial losses. As a result of many uncertainties originating from the design and operation of the equipment at a plant there are some failure risks that cannot be avoided. In this article, the reliability of a steel refining process was predicted. Two failure modes were investigated for each type of equipment from which the reliabilities were used to determine the overall plant reliability. The maximum plant reliability was found to be 98.0%. It was noted that even though a high reliability prediction was found, it is important to employ preventative maintenance on the plant to ensure the consistent operation of the equipment and maintain the reliability.

Abstract: The determination of actual stresses over the tool-workpiece interface has long been a matter of debate among researchers. Evaluation of the nature and the geometry of the wear contact area were always associated with many, sometime impractical, assumptions. The indeterministic fashion of edge wear and deformation requires a more realistic way to predict the actual wear contact area. In the current study, many wear area patterns are proposed considering the different wear modes of the cutting edge. The selection of the most correlated pattern to a specific edge deformation is justified using the relevant variations in the radial and the axial force components. For a regular wear over the entire cutting edge, a wear pattern that considers nose and/or flank is justified. When the cutting edge plastically fails, a pattern that considers only nose wear is preferred. As the cutting edge is subjected to many types of irregular disturbances of edge fracture and chipping, a wear pattern considering both flank and nose wear is selected.

Abstract: The vacuum pressure of vacuum circuit breakers (VCBs) is an important condition to ensure its operational performance, online monitoring of the vacuum pressure of VCBs is an important issue for reducing the accident rate of VCBs and the losses of personnel and property, achieving the intelligence of VCBs. In this paper, 10kV ring network switch cabinet (RNSC) is regarded as the object of study, to achieve its online monitoring. Through analyzing the magnetic field outside the vacuum arc extinguish chambers when the vacuum pressure of VCBs increases, a new method which is based on the comparison of the interphase magnetic field between the corresponding vacuum arc extinguish chambers in RNSCs then monitor the vacuum pressure of VCBs is proposed and demonstrated, and the result established a theoretical basis on the research of the online monitoring system of the vacuum pressure for the vacuum arc extinguish chambers.