Advanced Materials Research Vols. 562-564

Abstract: Tandem GMA welding technology has high deposition rates and good welding quality. But the electromagnetic interference (EMI) between the tandem GMA welding arcs is the most important factor which can influence the welding quality .Via Orthogonal Experiments and variance analysis, this paper did some basic theory research of the mutual arc interference mechanism in the GMA welding. The study was carried out from three mainly aspects ,the welding arc length control mode ,the parameters of the control pulse and the optimal range parameters in high-speed welding .The high-speed camera system was used to observe the metal transfer .In this paper the researchers realized the stability work of high-speed movement of tandem GMAW welding .

Abstract: Aimed at a new mining method of oil shale—Borehole Hydraulic Mining, the experiment platform for Borehole Hydraulic mining of oil shale is designed based on this, in order to evaluation of the effective damage to oil shale in different forms of jet, determine the economic and reasonable high-pressure jet parameters. The finite element analysis is conducted to the key components of the experimental platform. The Results Show that the parts design is reasonable and the experiment platform meets the requirements. The experimental platform provides the reliable equipment guarantee for the effective implementation of the hydraulic mining experiment.

Abstract: This paper presents a generalized simulation algorithm for cutting forces prediction of helical milling. Calculating cutting thickness and the transition of coordinate system are the key points. The average cutting coefficient model is adopted. The simulation algorithm and related software are developed. It can predict cutting forces for inner and outer circle of helical milling. The validation and accuracy of the simulation algorithm has been verified by experiments.

Abstract: LiMn₂O₄ nanofibers were prepared via electrospinning and followed by calcination. The surface morphology of as-spun and pure LiMn₂O₄ nanofibers was characterized by a scanning electron microscope (SEM) with an average diameter of 180 nm. After calcination at 800 °C in air for 5 h, charge/discharge capacity of pure LiMn₂O₄ nanofibers was measured in the potential range of 3.0 to 4.3 V. Battery testing showed that LiMn2O4 have a high discharge capacity of 80 mAh/g and 85% of the initial charge capacity was maintained for 5 cycles.

Abstract: The paper discusses durability test methods for wheel bearings. Through studying on the offset between the center line of a wheel and the center line on which the tire is forced, we get the determination method for the simulating load position on the wheel bearing . Depending on the influence study of inner circle or outer circle rotating method to the life performance of the wheel bearings, we give the test method on the bench. Based on the discussing of the bench monitoring method of wheel bearings, we give the effective and simple method to determine the failure of wheel bearings with Kur tosis.

Abstract: Night vision system has been greatly used on saloon cars, and greatly improved the night vision of them. But it is still blank in night vision system usage in engineering vehicles. Engineering vehicle works often in the night, and exploring for fixing night vision system to engineering vehicles and broaden night vision is significant for active security. Through comparing various technical parameters to explore fixing appropriate night vision system to engineering vehicles is significant.

Abstract: The local mean decomposition (LMD), a new adaptive time-frequency analysis method, is the research focus in the fault diagnosis field in recent years. In this paper, the LMD’s characteristics are obtained by processing multi-component frequency and amplitude modulation signal, which are usually used to describe the gear pitting corrosion fault signals. Base on the simulation analysis, LMD is presented to deal with the vibration signals of gear pitting corrosion fault, comparing with traditional method. The results show that the gear pitting corrosion defect can be diagnosed by LMD effectively, and LMD can eliminate the false composition effect, thus improving the accuracy of gear fault diagnosis.

Abstract: A dynamical model of engine vehicle was built by using ADAMS/Car. Based on that, another dynamical model of four-independent-wheel-drive electric vehicle was built too. Two simulation experiments of steering wheel angle step input and steering wheel angle impulse input were done. Considering the vehicle mathematical model with two linear degrees of freedom, the transient response and frequency response characteristics were evaluated. Simulation results indicated that time-domain and frequency-domain characteristics of four-independent-wheel-drive electric vehicle were influenced because of its heavy unsprung mass, and that leaded to the deteriorative handling stability.

Abstract: Against the problem of roller surface nodular of Baotou sheet steel factory galvanized vertical reduction annealing furnace, products defects of dezincification, leak plating, scratches before galvanized and so on, and from these aspects of analysis including the vertical annealing furnace’s working principle and structural characteristics, it was found that these main reasons causing this fault was that entry seal roller did not turn for high temperature deformation and condensed water of roller surface pollute strip steel, by improving the design and transformation of entry seal structure, the defects which caused by these reasons is solved, greatly improved the quality of the products, and there for provide the safeguard for the continuous and stable operation galvanized units.

Abstract: The frictional resistance of gas-liquid two-phase flow in vertical helically coiled pipe was investigated by means of experiment and numerical simulation. The resistance data in the conditions of different gas-liquid ratio was obtained. A numerical simulation platform was developed based on the heat and mass transfer theory and characteristics of the FLUENT software. Comparing and analyzing the results of experiment and simulation, it indicates that there is good computational accuracy of the numerical simulation platform, and the platform can provide a good support for the design and research of vertical helically coiled pipe.