Advanced Materials Research Vols. 482-484

Abstract: Due to the difficulties while studying the third-body interface experimentally, the simulation model of the non-fluidized particulate lubrication, which utilized the discrete element method (DEM), is proposed. The results indicate that the peak of load profile and friction force profile is located in the middle of tilting pad under particulate lubrication, which is different from fluid lubrication. The exact position of the peak is moving to the outlet zone with the increasing of shear elastic modulus. Particles with higher shear elastic modulus can decrease the friction factor and increase the load capacity of tribosystem, which provided helpful guidance to engineering application. Meanwhile, the wear should be under control. The study of the micro characteristics which included the average contact force, body energy, contact friction energy and particle kinetic energy has been carried out at the same time, which revealed the connection between macro and micro characteristics of particulate lubrication.

Abstract: Magnetic fluid drag reduction which is based on the character of magnetic fluid by adhered magnetic fluid inside to the boundary surface of duct for fluctuating in synchronism with current flowing in order to make stiffness boundary surface replaced flexible boundary surface is introduced. The deformation process and flowing state of magnetic fluid coating is discussed and analysed. It is found that due to reflux in it, magnetic fluid could reduce drag only at the moment that the reflux volume of magnetic fluid is equal to the flowing volume of magnetic fluid while the thickness of magnetic fluid coated layer is appropriate.

Abstract: Lignin/epoxy resin composites were prepared by blending lignin with epoxy resin cured by polyamide. The effect of the content of lignin and polyamide on the mechanical properties of the lignin/epoxy resin composites was studied systemically. And the structure for the blend of lignin and epoxy resin without the curing agent was characterized by Fourier transform infrared spectroscopy (FTIR). The results of mechanical properties test showed that the bending strength of the composites decreases gradually with increasing the content of lignin, while the impact strength increased firstly and then decreased. The bending strength of lignin/epoxy resin composites showed a trend of increasing firstly and then decreasing with the increase of the content of polyamide, while the impact strength exhibited an opposite trend. The density for the composites increased with the addition of lignin, and polyamide exhibited an inconspicuous effect on density of the composites. The FTIR analysis results showed that the epoxy resin could be cured by lignin without polyamide, which concluded that the lignin could catalyze the cross-linking of epoxy resin or react with epoxy resin, and this bonding effect would beneficial to the properties of lignin/epoxy resin composites.

Abstract: A new method for selecting warship combat system during the period of warship alternatives conceptual design was discussed in the paper. After computing the overall measure of performance (OMOE) and overall measure of risk (OMOR) of all combat sub-system using analytic hierarchy process and utility function, the design variables representing this equipment alternatives were selected using discrete particle swarm. Niche technique was used for constructing non-dominated sort set and TOPSIS method was adopted to sort the final pareto solution. The results of selecting equipment alternatives in warship combat system show that DMOPSO (discrete multi-objective particle swarm optimization) can search the overall pareto solution effectively.

Abstract: In this note, condition for consensus of general nonlinear high-order multi-agent systems is analyzed based on the idea of space transformation. Consensus can be assured by sufficient connection of network and the dissipative property of the entire system regulated by relative Lyapunov function, with two independent variables.

Abstract: In this study, in order to keep the feed rate of the tool electrode the same as the dissolution rate of the workpiece material in the pulse ECM, a method was proposed to detect and control the gap-width according to the relationship between the current waveform and the gap-width. First, the relationship between the current waveform and the gap-width was investigated experimentally. It was found that there is a correlation in the transient overshoot of the current waveform and the gap-width. Based on this correlation, a system used to detect and control the gap width during machining was developed. This system is composed of the circuit that detects the change in the current waveform and the algorithm that processes the detected signals from the circuit. The effectiveness of the gap-width detecting and controlling method was verified by experimental results.

Abstract: With the development of the auotomobile industry, the body-in-white has to meet the dual requirements of lightweight and NVH performance. This study put forward a new lightweight design method considering NVH performance. An example of lightweighting a non-load-bearing body-in-white was given to illustrate the design flow of this method and certificate the effectiveness and applicability. In order to accurately find out the neutral contribution panels which almost have no influence on the interior acoustic field, a new parameter, the weighted acoustic contribution, was introduced to analyze and evaluate the panel synthetical acoustic contribution to multiple peak frequency at multiple field points. Consequently the whole body-in-white’s weight was reduced by 14.673kg and the interior acoustic field remained basically unchanged.

Abstract: Conventional direct torque control(DTC) of induction motor has the problem of large torque ripple.In addition,the speed sensor has its deficiency.A novel DTC system based on multiple neural networks optimized by Genetic Algorithm is proposed and the structures of the proposed system are designed.Genetic algorithm was used to optimize the initial weights and thresholds of the neural networks,All parameters of the neural networks were obtained by offline training.A simulation model of induction motor DTC system was developed in Matlab／Simulink,the simulation results show the feasibility and effectiveness of the scheme

Abstract: As we know, the hydraulic problems, the ordinary gear flowmeter pulsation of the flow rate and the pressure pulsation of the defects, remain to be solved. The article started from the analysis of Instantaneous flow characteristics for general gear flow-meter, with the control variables method, relationship between the number of gear teeth and flow pulse rate was studied.The rule was discovered that while gear's number of teeth is bigger, the flow and press pulsation for general gear flowmeter is less. The paper conducted the simulation research on instantaneous flow characteristics for general gear flow-meter. The results show that: while z1=z2=30, the flow pulsation rate equals 7.05%. While z1=z2=8, the flow pulsation rate equals 24.45%. While z1=19, z2=14, the flow pulsation rate equals12.73%. This research has provided the theoretical basis for the gear flow-meter's design.

Abstract: The coordination mechanism of enterprise network resource refers to the rules which the enterprise network members are able to comply with and unity action in order to achieve the expected goal. The rules mainly include: opportunity discovery mechanism, communication mechanism, strategy consultation mechanism and the learning mechanism of enterprise network, as well as the evaluation of coordination effect. The aim of constructing maturity model of enterprise network resource coordination is to make the agent of enterprise network understand the situation of network resources, and provide path description for improving coordination of network source, improving coordination mechanism. Maturity model of enterprise network resource coordination should be considered in four dimensionalities: coordination costs, coordination process, coordination method and learning ability. According to the dimensionality level or quality, enterprises network source coordinated maturity model may divided into four levels: the initial level, polymer level, standard level and optimization level.