Applied Mechanics and Materials Vols. 130-134

Abstract: A metro power traction simulator system is designed and implemented. Designation method of the flywheels which simulate the metro vehicle moment inertia is given. A train runtime diagnosis system is completed by adopting MVB protocol. The dynamic simulation of metro power traction system is realized under the control of train runtime diagnosis system. The feasibility and utility are proved by the experiment results.

Abstract: A virtual prototype model of five-axis CNC machine tool has been constructed. Through the ADAMS software, the process of the machine is simulated and the dynamic analysis is carried out. The experimental model analysis on the column of the machine is practised with the software ADAMS, the weak link of the column is found out and a modification scheme is put forward for the design of the column structure. Improvement of structure of the column can effectively raise the working accuracy .Currently, five-axis CNC machine tool is the only way to solve parts processing such as impeller, special propeller, turbine rotor , large diesel engine crankshaft ,etc. Therefore, it is very important to carry out the dynamic analysis of the five axis CNC machine. In this paper, a rigid-flexible multi-body dynamics model for a five-axis CNC machine tool is set up, in which the column parts are modeled by flexible bodies. Aimed at the improvement of the machining accuracy, the effect of different structures of column are analyzed.

Abstract: This paper analyzed the reasons of motor speed loss under variable load in variable-speed pump-control-motor governing system, and pointed out that oil compressibility caused by load change is one of the reasons. Speed drop compensation coefficients ware derived, and the compensation method under variable load in variable-speed pump-control-motor governing system was built. The simulation results show that the compensation method can well compensate motor speed loss in variable load.

Abstract: By using Computational Fluid Dynamics (CFD) method,numerical simulation of gas flow distribution of ESP transform to baghouse in cement kiln head of 6000 t/d production. Through numerically simulation,air volume of every filter bag cell and head-on gas flow velocity distribution of filter bag were displayed. By adjusting the configuration parameter of the gas flow distribution device during the numerical simulation, it gives the result that the manner of installing gas flow distribution device, when the windage of the air volume of every filter bag cell is not more than 5% and the press drop of the dust collector with clean filter bag is 300 Pa. The calculated results showed good agreement with the measured results in the field. The simulation results were carried out by transformation. The dust emission concentration of precipitator is 26.6 mg/m³, and the dust running resistance is less than 1000Pa, can achieve the performance assessment requirements.

Abstract: A new kind of 3-d.o.f. vibration platform is introduced, which may be used in active vibration control, presion manufacturing, and other precision positioning fields. The platform is mainly comprised of four parts: the top board of the platform, flexure hinges, amplification mechanisms and gaint magnetostrictive actuators (GMAs). Among them, finite element analysis is taken on flexure hinges; the constitutive model of GMA is described. Eventually, the dynamic model of the system is established. According to the model, a simulation system based on SIMULINK is carried out. The simulation results verify the model, and may serve for the active control analysis of the platform system.

Abstract: Finite element models of an eddy current sensor array are built up by electromagnetic-circuit couple method, and the influences of conformable substrate on sensor’s output characteristics are analyzed by those models. It is shown that the model contains the conformable substrate has almost the same output characteristics as the model without it, but the output amplitudes and phases of the former model are higher than the latter. Therefore we can simply the sensor as a single surface to facilitate the analysis, and then revise it to fit to the real sensor.

Abstract: This paper proposed the design and experimental evaluation of a radiometric instrumentation system which was developed for measuring the volume concentration and phase distribution of pulverized coal in a pneumatic conveying pipeline.The system employed point γ-ray source with 180° plane angle of emergence source collimator, γ-ray detector multi-element independent each other annular arrayed out of the sensor conduct wall,every detector element was standardized singly,in order accommodate the inhomogeneity of the pulverized coal distribution in the pipeline.the instrument system would be able to determine the volume concentrition independently of the flow pattern while obtain the distribution information of pulverized coal in the conveying pipeline cross section. The static experment improved that the solution was correct in principle.

Abstract: The study of storage layer paleo-pressure in hydrocarbon accumulation period reveals the oil migration direction in Dongying depression. By using of stratum back-stripping method and porosity evolutionary function, the paleo-depth and paleo-porosity of storage layer during Ed, Ng and Nm periods are restored firstly, then the paleo-formation pressure is further recovered by the help of Fillippone formula and time-average equation. The study shows that pressure coefficient is increasing gradually over the 3 periods and overpressure distribution is due to the opening faults. Relations between paleo-pressure and hydrocarbon migration have been analyzed to deduce oil migration direction in storage layer.

Abstract: Using constant temperature hot-wire anemometer IFA300, we measured the wall turbulence on different normal location of the boundary layer in the wind tunnel experiment section. The wind tunnel is of low turbulence intensity. We have applied Fourier transform, Wavelet transform and Hilbert-Huang transform to analyze the turbulent fluctuating velocity obtained by measurement and have compared turbulent energy transfer law in different wall distance. This article quantitatively analyzed on the eddy motion process for different wall distance in wall turbulence from the energy point of view. It also discussed the energy transfer law based on eddy combination theory and the inertial sub-range.

Abstract: . The tracing precision is greatly influenced because of the friction when high-precise linear motor moved in a low speed.Explore the ways of nonlinear friction compensation in a practical angle. A tribology mathematical model has been found based on the viscoplasticity theory and Stribeck friction mathematical model.This paper aims at applying the Stribeck friction mathematical model to linear motor slider system and designing the controller.The controller can be designed by the feed-forward Integral to conduct identification and compensation online, according to the characters of tribology model.the stability of systems has also been analyzed by using Liapunov functions and LaSalle Invariance Principle.As has been demonstrated by the experimental results, the friction compensation of this model has improved the tracing performance of linear motor slider system.