Applied Mechanics and Materials Vols. 66-68

Abstract: A practical flexible friction transmission is presented here, which has a stable operation, a high reliability, a low maintenance cost and a high value in use.

Abstract: This paper discusses the basic principle of numerical control interpolation, including the straight line and arc (Agreeable circle or Negative circle) interpolation method of point by point comparison, Digital Differential Analyzer (DDA) and time-slicing method. By using Visual Basic 6.0 software, the implementation of the interpolation process and dynamic simulation results are displayed on the screen, and the implementation process of interpolation is observed directly, such as continuous interpolation, manual interpolation, step interpolation and interpolation of a closed graph.

Abstract: It is based on the monitoring result a motor of 1600KW start of petro-chemical oil refinery in Urumqi , the paper probe and analyze that high-capacity motor’s start exercise bad influence over the power quality of circuit: voltage sag and harmonics current, and take some improving actions based on its features.

Abstract: The small-deflection response of a free–free beam subjected to a local uniformly distributed impulsive load at one free end is examined; the material of the beam is assumed to be rigid and perfectly plastic. Solutions are obtained for various combinations of the magnitude and length of the local uniformly distributed impulsive load. The location of the plastic hinge on the beam depends not only on the magnitude of the load but also on the length of the load applied. As the length of the applied uniformly local distributed load is fixed, the plastic hinge would occur in the region between the limit position of plastic hinge ε_lim and the critical position of plastic hinge ε_c which are determined by the length of the applied load.

Abstract: In the present work, Al-Ni-Ce-C amorphous powders with different compositions have been prepared by a high energy ball milling technique. The amorphization behaviors of the Al-Ni-Ce-C powders have been studied using X-ray diffraction and transmission electron microscopy. The results show that alloy compositions have a great influence on the amorphization behavior of the Al-Ni-Ce-C powders and the optimum composition is Al₈₅Ni₁₀Ce₅+1 wt.% C for the formation of amorphous phase. The thermal stability of the as-milled powders has been investigated by differential scanning calorimetry. It has been found that the compositional effects on thermal stability are similar to those on the amorphization of Al-Ni-Ce-C. In addition, the more addition of carbon decreases both glass forming ability and thermal stability of the Al-Ni-Ce-C system under ball milling conditions. Furthermore, comparison has been carried out between Al₈₅Ni₁₀Ce₅+1 wt.% C amorphous powders and Al₈₅Ni₁₀Ce₅ glassy ribbons with respect to thermal stability.

Abstract: This paper described an industrial scale experience of melting as-cast high-ductility nodular iron. We discussed the rationale of selection of chemical compositions and the practice of speroidising and inoculation processes. The experimental results show that nodular iron castings with consistent quality at cast state can be produced using cupola melting technique. The castings of two heavy truck components–brake shoes and brake plates produced meet the technical requirements set in China standard GB/T1348-2009.

Abstract: High or low voltage electrical contact is a kind of pseudo alloy which is mostly composed of a high melting point material and a low one. Liquid-solid wettability is widely used in the manufacture of contact materials and its subsequent processing. This article focuses on several solutions to the difficulties encountered during the process by liquid-solid wettability.

Abstract: Testing ways and means are introduced to measure oil film thickness of a main bearing in multi-cylinder IC engines with two eddy current sensors. A 4100QB diesel engine is taken as a model to detect the influences of loads and journal speeds on oil film thickness of a main bearing. It can be inferred from the test that the Minimum Oil Film Thickness (MOFT) constantly decreases with the increase of the loads while the journal speed keeps stable, and MOFT constantly increases corresponding to the increase of the journal speeds while loads on the bearing are unchanged.

Abstract: This paper first presented modeling methods and procedures aiming to a truck cab and its occupant under blast loading, followed by numerical simulation analysis of dynamic responses of the cab and blast injuries of the occupant by using Ls_Dyna. According to energy history the response duration can be divided into three phases, corresponding to local effect, whole effect and drop down effect. And two schemes for cab blast-resistant design including an aluminum foam sandwich plate and a V-shape deflector were put forward. Using the proposed numerical models, response characters of the two schemes were analyzed, advantages and shortcomings were compared with the initial design. Simulation results show that dynamic responses of cab structure and occupants decrease obviously by using sandwich structure filled aluminum foam, but for a V-shaped deflector it is very difficult to protection the cab structure and occupants simultaneously. And effect of several key parameters, i.e. relative density of foam core, and core thickness were discussed also.

Abstract: A thermal model for laser-assisted cutting of mullite is developed in this paper. Laser-assisted cutting has been proposed as a promising means for achieving cost-efficient production of high quality ceramic parts. At high temperatures the yield strength of ceramics can decrease below the fracture strength, changing the material deformation behavior from brittle to ductile and enabling the use of a single point cutting tool to remove material at rates approaching those of metal cutting. Assuming the system to be symmetrical and neglecting the heat loss taken away by removal material, the problem is formulated in a cylindrical coordinate system that moves with the laser beam or cutting tool. An analytical solution for this thermal model is obtained. The results calculated by this model agree with the available experimental data. The temperature history is presented during laser-assisted cutting of mullite. The effects of feed rate and laser power on temperature history are also discussed in this study.