Advanced Materials Research Vols. 317-319

Abstract: Electricity transformer is an important, widely used electrical equipment. Current the iron beam sectional of the electricity transformer is based on experienced standards which can not achieve the best economic benefits. According to practical technology, we build a basic optimization model about multistep iron beam section. And we also give a reasonable design on the tolerance zone between the diameter of iron beam sectional circumcircle and the diameter of the winding steel-flue, as well as the arrangement about the oil path in the iron beam, which has a big realistic significance and application value. We come up with five reasonable model assumptions to simplified the problem, turning the tolerance zone design problem into the function extreme one. We adopt "Ideal assumption first, specific modification second" method on designing the oil path, considering all kinds of situations to obtain optimization. The core algorithm is dynamic programming which is much faster, much more stable than using Lingo. All the solving and analyzing on math models are based on C++ programming language.

Abstract: The nanofiber based filtering media, made up of fibers of diameter less than 1000 nm, have been discovered as new filtering media for effective filtrations. The present study has been made of the influence of various process parameters on the fibrillation characteristics of Lyocell fibers which focuses on how the Lyocell fiber changes with the intensity of beating. Meanwhile the drainage properties and media properties of Lyocell fiber with different beating degree are characterized. The results show that the length, diameter, distortion and degree of fibrillation of Lyocell fiber changes obviously by beating, and a mass of nano-fibril appeared after intensive beating. The Lyocell fiber is cut off rapidly at first, and then fibrillateion starts to appear during the process of beating. At the same time, comparing with the length of the fiber, the beating degree of Lyocell fiber is more sensitive to the degree of fibrillation. What’s more, the drainage time of Lyocell fiber with strongly beating is over ten times than that of the original or ratherish beaten one; Comparing with the media made from original or light beaten pulp, media thickness made from the strongly beaten fiber decreases almost two times, tensile strength increases nearly four times, and air permeability decreases about seventy times.This study has shed some light on the major properties of Lyocell fiber and paves the way for further application of Lyocell fiber in filed of high precision filtration media.

Abstract: The processing state identification for CNC machine tool is not only key to achieve intelligent control, also is an important part for stability of real-time monitoring. This paper presents a basic model which used CNC machine tool spindle current signal mapping to the processing load signal, and then by the different load conditions cutting tests, compared with the Winger - Ville distribution(WVD) of those signals. Intuitive to find that time-frequency distribution compared with the traditional spectral analysis, not only is capable of with time-varying characteristics of the non-stationary signals, and more effectively reflect the state of machining process, and the instability of the processing status of the border with more strong discrimination capability.

Abstract: Low density polyethylene and linear low density polyethylene (LDPE/LLDPE (60wt.%/40wt.%))as basic materials, intumescent flame retardant ammonium polyphosphate (APP) was added into them to obtain fire retardant systems. The molding parameters, fire retardant properties, mechanical properties and processing properties of samples were examined. It was showed the rotational speed of main screw was 28-34rad/min. when samples were molded, cylinder temperature was 185-195°C, mold temperature was 85-115°C, preheating time was 5-10min and filling time was 8-21s. APP had good fire retardant and smoking suppression functions. Adding 30% (wt.%) APP can obtain grade of FV-0. With APP content increasing, the mechanical and processing properties of materials decreased.

Abstract: The application of fiber reinforced polymer (FRP) rebar to large Span Spatial Structure is one of the topics in forward position nationwide and internationally. The properties of FRP rebar, such as high tensile strength, light weight, strong resistance to corrosion and fatigue, material design ability and weight reduction and so on, pave the way to its application to Large Span Spatial Structure. Based on the summary of relevant studies at home and abroad, the applications and research of FRP, such as CFRP poles, Composite Laminated Plate and FRP light roof, rebar to Large Span Spatial Structure are introduced in the paper. Finally, the prospects and some problems needed to further researched are put forward.

Abstract: This paper presents a nonlinear adaptive backstepping current hysteresis speed controller which can be used in both the constant-torque region and the field-weakening region for an interior permanent magnet synchronous motor (IPMSM). By using the proposed method, the adjustable speed range can be extended to 4 times that of the base speed. In addition, the d-axis current is suitably adjusted to increase the output torque of the IPMSM. Simulation results show that the implemented system has satisfactory performance, including good transient responses, good load-disturbance-rejection responses, and good tracking ability.

Abstract: Plate-cone reticulated shell is a new type of space structures with good mechanical behavior and technical economy. In this paper, a continuum analysis method for plate-cone spherical reticulated shell which is equated to three layers thin shell is put forward. Based on mechanical characteristics of plate-cone spherical reticulated shell, the equivalent stiffness is derived through the theory of elasticity. Then, plate-cone spherical reticulated shell is equated to a special type of three layers thin shell working interactively, the governing differential equations are derived on the basis of the theory of thin shells, these differential equations being from the displacement method and the mixed method of derivation. The solution of this system of differential equations gives the displacements and internal forces of plate-cone spherical reticulated shell.

Abstract: A real time strain measuring device has been designed in allusion to multi-angle influence on springback in shaped parts. The strain has been studied at the shaping of part with different bend angles’ numbers. The multi-angle draw-bending forming and springback mechanism have been observed by metallurgical structure searching.

Abstract: Emulsion is a semi-synthetic metalworking fluid product containing mineral oil, with cooling, lubricating, rust and other major functions and the most advanced formulation technologies. This paper reports the working principle, the main performance parameters and application of emulsion as the working medium to a new type of non-circular gear motor emulsion structure in the mine machinery, and analysis the seal material selection of non-circular gear emulsion motor and the surface treatment of over-current end.

Abstract: This paper firstly introduces the frame system of digital city and the process of 3D city modeling, and discusses the method of CSG modeling of buildings. This method extracts CSG primitives according to building features, then makes geometric transformation and regular Boolean operation on these primitives to form 3D model of buildings. The process of modeling and inner topological relationship of buildings can be represented by this method.