Applied Mechanics and Materials Vol. 120

Abstract: The uncertainty of system parameters is not considered in traditional transfer function model of electro-hydraulic servo system, and then the accuracy of analysis is affected. Therefore the physical model of electro-hydraulic servo control system is established in simulation software AMESim platform. The system controller model is builded in the control simulation software Matlab/Simulink platform. The co-simulation interface technology is used to achieve joint simulation of electro-hydraulic servo control system.

Abstract: In order to conduct kinematics Analysis accurately, mechanical model and mathematical model are established about bulldozer multi-freedom working device. Appling bar-groups method, the up-and-down movement of the bulldozer working device was analyzed based on planar linkage with the Assur group theory in the kinematics. The analysis theory of the application space agency carried through for rotary motion, roll motion, and a combination of the two movements, kinematics analysis, established the force balance equation and obtained for the mechanism optimization, structural design, strength and stiffness analysis of the bulldozers working device, provides a new method which is provided with considerable reference value to general mechanism design and analysis.

Abstract: Designing a high quality and low cost servo control system of micro-EDM is the key technique of high precision micro-EDM. The paper solves this problem by designing an embedded servo control system of micro-EDM. The servo system realized the FOC of PMSM by using embedded technique, which connect the servo controller and the pulse generator properly. The scheme of servo control system has the merits that it is low cost, flexible and self adjustment of discharging gap.

Abstract: The paper pointed out that the current control system and the control link of the coal belt conveyor was too complex, proposed an unattended control system which adapted to modern enterprise management.

Abstract: Oil spectrum analysis technology is an important method to research wear of mechanism without unpacking, based on the characteristics of limited amount of oil analysis samples and randomness of sample data changes to apply gray theory to prediction of wearing capacity of reciprocating engine. When gray modeling, if sample data does not meet smoothness conditions, firstly parametric process is carried out for the data in order to weaken randomness of the original random sequence, then equal interval process for initial data sequence is conducted and sequence of gray values is determined according to variation rules of sample data, finally, base on four-dimensional data to carry out unequal interval process by timing fitting method. Test confirms that gray modeling by timing fitting methods based on wearing law to determine gray values point can significantly increase prediction accuracy of wearing capacity.

Abstract: The internal flow field in stator of a torque converter was simulated. Based on the mixing-plane technology, using the method of CFD(Computational Fluid Dynamics) simulated the stator flow field. The flow field characteristic, the distribution of velocity and pressure in the stator were analyzed. The external performance of the torque converter was also calculated, and the results were compared with the experimental data. It was proved that the calculated results showed agreement with the experiment accurately.

Abstract: Based on reciprocating electroplated diamond wire saw cutting SiC wafers experiments, the influences law of wire saw diameter, wire saw quality, wire saw speed, wire saw wear and cutting fluid on cutting rate and wafers surface quality was studied. The results indicate that cutting rate increase with wire saw diameter and wire saw speed increase, and decreases with wire saw wear; wafers surface roughness increase with wire saw diameter increase and wire saw wear and a slightly lower with wire saw speed increase; TTV (total thickness variation) is risen slightly with wire saw diameter increase; wire saw wear and insufficient cutting fluid supply are the main factors to cause cutting time increase and wafers quality decline. And the experimental results were analyzed.

Abstract: The melamine phosphate (MP) was synthesized from melamine and phosphate acid. Aluminum oxide (Al2O3) was added into the MP during its synthesis. Fourier transform infrared spectroscopy (FTIR) was used to characterize the reaction products. The composites were prepared from polypropylene (PP) and intumescent flame retardant (IFR) additives of MP and pentaerythritol (PER). The effect of Al2O3 content on the properties of the composites was investigated by the limiting oxygen index (LOI), thermogravimetry (TG) and scanning electron microscopy (SEM). The results indicated that the LOI value of the composites could be enhanced obviously with suitable content of Al2O3. When the Al2O3 content was 6 wt% in MP, the LOI value increased to 35.5% from 31.0% for the composite without Al2O3, the amount of residual char at 600°C increased from 8.9 wt% to 13.9 wt%.

Abstract: Projects, construction equipment management is the process of the project and construction management of production factors is an important component. Construction equipment on the project configuration, use, cost accounting and other comprehensive systematic study, given the optimal configuration and dynamic management decision-making programs, to achieve their project goals.

Abstract: With fast development and general application of Virtual experiment technology, it has already been a tendency to apply this technique in experimental teaching, and this has become a very great education reform. From the analysis of the virtual laboratory based on theory, this paper expounds the classification of virtual laboratory and discusses the significance of virtual lab in Micro-control System of Experimental Teaching, meanwhile, it explores the application of this technique in teaching.