Advanced Materials Research Vols. 433-440

Abstract: Rolling contact fatigue (RCF) is the name given to crack growth and material damage generated as a result of high loads transmitted between two surfaces which are rolling with relative to each other. An understanding of rolling contact fatigue failure mechanism and a prediction of lifetimes are of interest to both manufacturer and researcher. Subsurface originated cracks have been recognized as one of the main modes of failure for rolling contact fatigue (RCF) of bearings. Numbers of investigators have attempted to determine the physical mechanism involved in rolling contact fatigue of bearings and proposed models to predict their fatigue lives. This paper attempts to cover the most widely used probabilistic life models used in RCF.

Abstract: Imaging logging is a new technique which has been developing in recent years, its’ silo facilities could collect large information with high resolution, and the measurement result is usually presented in graphics after processed. This paper presents a new imaging logging technique based on magnetic-acoustic Tomography with Magnetic Induction(MAT-MI), introduces its’ logging principle, gives detailed experimental system, makes a simple copper coil experiment and verifies the feasibility of the technique. These studies will lay a foundation for practical application of new imaging logging technology.

Abstract: It is of importance to identify the subway train random vibration load correctly. On the basis of the in-situ dynamic response measurement, the deterministic data for vertical acceleration of rail were obtained. The problem of identifying the random vibration load of subway train was solved in Matlab, according to the simplified vibration model of vehicle system, and in Newmark-β method. Then the time curve and the amplitude spectrum curve of the vertical random vibration train load were obtained. Compared with Fast Fourier Transform method, Newmark-β method is more simple and practical to simulate the train vertical random vibration load directly in the time domain.

Abstract: In this paper, the multi-input linear and nonlinear mathematical differential equations of inverted pendulum system were established based on the traditional single-input linear inverted pendulum. Aiming at multi-input nonlinear model, nonlinear state transformation are carried through on the basis of the test of distribution involution and the calculation of integral manifold, then, the multi-input nonlinear inverted pendulum system was transformed into two single-input nonlinear inverted pendulum system to study. In the end, make use of related nonlinear system control theory of the sliding mode variable structure, designed the controller structure.

Abstract: Scholars, in order to find out the reason of the unknown reason flashover of insulators for high voltage over-head line, have made a lot of research on it. There have been two theories put forward, both of which infer the impetus after appearance of the partial arc, neither of them expound how is the partial arc formed. Based on the two theories, this paper puts forward a new theory - the theory of plasmoid shortens the valid insulation distance by which leads to the breakdown, of whose main viewpoint is whether the breakdown occurs depends on the comparation between the valid insulation distance on insulator’s surface and the shortened valid insulation distance on insulator’s space around by the plasmoid. Furthermore, we put forward the plasmoid mathematical model by kinetics equations of fluid system. Particularly, except for the fluid motion features, the influence by the self-generating electric field and magnetic field must be considered

Abstract: A good chair cushion not only provides comfort but also control the posture and to reduce the risk of pressure sore occurred. The purpose of this study was to evaluate the mechanical interaction between the cushion and user of wheelchair. The buttock model geometric, individual data’s of healthy male subject were acquired by 3D reconstruction form laser scanner, while the custom made cushion design based on the Tekscan Clinseat pressure assessment system data. A standard clinical experiment protocol for the collection of interface pressure distribution was developed. The pressure distribution data of buttocks-cushion interface was collected when the subject sat on an initial cushion. According to the pressure distribution data and parameters of cushion material that was acquired in the material test; an individual mathematics model was built and then transferred into CAD software to create the CAD model of the cushion deflection geometry.

Abstract: Experimental study on the physico-chemical properties of bio-oil and diesel emulsification has been carried out in this paper, which was based on the preliminary experiment. The effect of surface tension and viscosity on the stability of emulsions were particular concerned. It was found that the longest stable time, the lowest viscosity and lowest surface tension can be obtained simultaneously when the hydrophile and lipophile balance (HLB) value was of the optimal value, i.e. 6.5. Experimental results indicated that the stable time of emulsion decreased rapidly with the increase of bio-oil content, while the value of surface tension and viscosity increased. Meantime, it was shown that the most stable emulsions had the lowest value of viscosity and surface tension.

Abstract: The stainless steels is more and more applications to the medical field, the most is the austenitic stainless steel. In this paper, 00Cr18Ni14Mo3 mechanical properties of austenitic stainless steel screw, compared to the solution of the former and the sample microstructure after solution treatment, energy spectrum and the torque angle reverse faults, compared to solution treatment found that mechanical properties of the samples after meet the standard can be applied to practice

Abstract: This paper presents a novel Multi-Degree-of-Freedom spherical reluctance motor with magnetic levitation, it analyses mechanism of magnetic force and electromagnetic torque that spherical motor generates. Conducted a comprehensive control of the spherical motor and analysis and simulate the results of the suspension control system. The simulation experiments show that the state synchronization suspension control owns high precision and immunity to interference

Abstract: Through the orthogonal experiment, research on the process parameters of the qualiity coating with the new auxiliary ,such as different pickled time, parched time, hot-dip time , and analyzed by scanning electron microscopy, X-ray diffraction. The results show that BiOCl is a new fluxing agent and the optimal parameters for pickled time, the parch time , hot-dip time, respectively,10s,120s,9s,through this we can get bright, smooth, corrosion resistant coatings