Advanced Materials Research Vols. 443-444

Abstract: Based on the modified Maxwell-Wagner model, the molecular dynamics method is applied to simulate the three-dimensional structural changes of the electrorheological (ER) fluids in an electric field and a poiseuille flow field. And it is analyzed that the structure-force dynamic coupling is characterized significantly by capture effect. The simulation results show that: when the electric field is applied, a chain network will capture the upstream particles in the flow field causing the local electric field force changed. Eventually a body-centered tetrahedron (BCT) is formed, and the structure-force dynamic coupling characterizes significantly. For an ER fluids in a electric field, there exist a threshold of pressure gradient. Its significance of structure-force dynamic coupling is related to electric field intensity, pressure gradient or flow velocity.

Abstract: Thepresent paper presents a design procedure and prototype of detection system, which uses high-precision grating displacement sensor as the main test instrument for detecting bogie wheelset alignment parameters in horizontal plane. Wheelset rim inside distance, wheelbase difference and diagonal difference of newly completed bogie are obtained automatically and accurately in once measurement, moreover, detection is not limited to different bogie wheelbase and different size of wheels. Furthermore, measurement and control system and software are designed; detection results should be saved, queried and printed. The precision of the detecting system could reach to 0.02mm. Compared with foreign similar equipments, the advantages of this detection system is improving the detection accuracy and reducing costs.

Abstract: In the paper, the interface crack of rubber - metal ring under the radial displacement load was studied by nonlinear finite element method, changes of the tear energy with crack dimension which extending from extrusion end and tensile end along the axial and circumferential direction to the interface was analyzed. The result is that there is a certain possibility of axial extension in the tensile end. The crack propagation is most likely to occur along the circumferential direction while is impossible along either axial or the circumferential direction in the extrusion end.

Abstract: Considering the prediction of thermal machine tool error data this paper proposes using GM (1,1) model of gray system to predict machine tool thermal error data. Through comparing with the calculated result between traditional GM(1,1) model and the optimized GM(1,1) model, more satisfactory results can be achieved, and indicating that this model can predict the distribution of machine tool thermal error data more accurately. So the optimized GM (1,1) model can be used to provide a more reliable methodology in controlling the digital machine tool.

Abstract: High-speed milling (HSM) has advantages in high productivity high precision and low production cost. Thus it can be widely used in the manufacture industry. However, when the speed of spindle-tool reaches a higher speed range, the gyroscopic effect will become an important part of its stable milling. In this paper, a dynamics model of HSM system was proposed considering the influence of gyroscopic moment due to high rotating speed of end milling, and solution it. Then, the natural frequencies of end-milling model were researched by using analyse software. And analysis the stability of end-milling that considered gyroscopic effects under different speeds, obtain the Campbell Diagram. Get the trajectory of one point in end face milling. Then draw the fitting trajectory and ideal trajectory of the point in milling. Compare the actual trajectory, fitting trajectory and the ideal trajectory. So it can provide a basis for stability prediction of high speed milling.

Abstract: The spindle shaft of heavy load deflection angle milling head is an important functional component of 5-axis CNC machine tool, which has characteristics of high torque and high power, used for large and complex free-form surface processing. The spindle shaft is modeled as Timoshenko’s beam by including the centrifugal force and gyroscopic effects. The effects on inherent characteristic of the spindle shaft of heavy load deflection angle milling head are analyzed owing to axial force and spindle shaft speed. Simultaneously, numerical solution of spindle shaft is gotten. And, the numerical results are well agree with the exact modeling, which illustrates that the theoretical modeling of spindle shaft is correct and the exact dynamic characteristics of spindle shaft is obtained. The analytical modeling results of spindle shaft are effective and helpful for design and improvement of spindle shaft of heavy load deflection angle milling head.

Abstract: Acylation of acenaphthene with benzoyl chloride to 5-benzoylacenaphthene catalyzed by [Bmin]Cl/AlCl₃ ([Bmin]⁺ = 1-butyl-3-methylimidazolium cation) ionic liquid was investigated. Pure 5-benzoylacenaphthene was obtained and the structure of 5-benzoylacenaphthene was identified by GC/MS, FT-IR and ¹H NMR spectra. The yield of 5-benzoylacenaphthene was up to 85.2 % and the selectivity towards 5-benzoylacenaphthene was up to 89.6 %. The [Bmim]C1/A1C1₃ ionic liquid catalyst shows well catalytic activity after running for 5 times. The facile product separation and the recycling performance of the ionic liquid catalyst is expected to contribute to the development of clean and environmentally friendly strategy for the synthesis of 5-benzoylacenaphthene.

Abstract: The reciprocating compressor contains crank-rod mechanism whose unbalanced inertia force mainly accounts for mechanical noise and vibration during the working process. Through the analysis of fit between the diameter of the compressor piston and the crank eccentricity, influence of imbalance force on the compressor vibration and noise is obtained under no change in other parts. The tests of vibration and noise are followed for the purpose of verification. The results show that the vibration and noise control will be better if a small piston diameter and a big crank eccentricity are utilized.

Abstract: With the development of auto industry and aviation industry,the cam quality requirements higher and higher. The NURBS curve has excellent natures that can smooth the cam grinding path and improve its processing quality. Combined with existing CAD software and CNC systems, respectively, from reverse and forward two aspects of NURBS curve to illustrate the non-uniform B-spline principle and given the relevant formulas. Choosing X-C coordinates points of the cam grinding as the research object, adopt reverse and forward NURBS curve interpolation to fit the cam grinding path. Analysed the fitting error caused by line segment fit NURBS curve and cam lift error caused by NURBS interpolation. Summarized the advantages and disadvantages of two ways Nurbs interpolation discussed the method to improve NURBS interpolation for cam grinding.

Abstract: Paper properties, including physical properties and optical properties, fiber quality analysis and COD in the pulp effluent were used to investigate the effects of substituting Mg (OH)₂ for NaOH on the properties of poplar APMP in this paper. The results from fiber quality analysis showed that increasing the substitution levels of Mg (OH)₂ for NaOH in the poplar APMP could increase the content of fiber fines,the pulp had shorter average length,and levels of kinking and curl reduced.The results of paper properties analysis ,including physical properties and optical properties ,showed that the bulk and light scattering coefficient of handsheets could be improved,while the physical strength and brightness couled be decreased after using Mg (OH)₂.The research for COD in the pulp effluent showed that it could reduce content of COD in the pulp effluent after substituting Mg (OH)₂ for NaOH on the properties of poplar APMP,so that clean production can come true easierly,while it could retrench the cost of production and yield good economic returns.