Applied Mechanics and Materials Vols. 55-57

Abstract: Ti₅₀Cu₂₃Ni₂₀Sn₇ amorphous alloys powder was prepared by mechanical alloying (MA) in a high-energy planetary ball mill. Milling parameters such as rotational velocity of ball mill, ball to powder weight ratio as well as milling time were throughly investigated. Mechanism of mechanical alloying was throughly discussed.

Abstract: Firstly the schematic diagram and working principle of this power drive transmission system of high-performance four-wheel off-road vehicles are introduced. And then the kinematic characteristic of the device is analyzed based on an off-road vehicle.

Abstract: This paper reported the effects of Al-5Ti-B-2RE on the microstructures and mechanical properties of an Al-10Mg alloys. It has been shown that the addition of 6wt.% Al-5Ti-B-2RE alloy can decrease the average grain sizes and increase the mechanical properties of the Al-10Mg alloy. Grain refinement mechanism is due to TiAl₃ andTiB₂ particles formation nucleation of aluminum，rare earth elements enhancing the kinetics of α-Al nucleation and inducing low growing speed of crystals. And the grain refinement strengthening and dispersion strengthening lead to improve the mechanical properties.

Abstract: A pad conditioner or diamond disk is needed to regenerate the asperity structure of the pad and recover its designated role in the chemical mechanical polishing process. In this paper, the effect of dressing load and speed on removal rate of oxidized wafers were investigated using a polycrystalline diamond disk and brazed diamond disk. It was found that polycrystalline diamond disk enable the manufacturer to tightly control diamond leveling and the cutter’s shape by comparison with a brazed diamond disk that contains discrete diamond grits of random orientation. Experimental results revealed that for polycrystalline diamond disk, the removal rate of oxidized wafer displayed an almost unchanged curve when the load was less than 4kg, but the removal rate of oxidized wafer for brazed diamond disk initially increased with the dressing load, reaching a maximum value at a dressing load of approximately 4 kg. Then, it decreased slowly with further increases of the dressing load. The removal rate of oxidized wafer remains unchanged with dressing speed.

Abstract: In this paper, a new measure method was suggested to examine the reaction time of visual attention of drivers using a new-style mechatronic visual attention measurement system. The system can control the peripheral environment illuminance and the present of stimulus at the start locations, and change the color of stimulus in terms of visual attention shift theory in three-dimensional (3D) space. The measurement system included the setting of observation location, stimuli location, moving speed, environment illuminance. The paper introduced the test method of visual function and the test procedures of the reaction time. The results demonstrated that this measurement system can be used to examine the reaction time and judgment response of drivers in three environmental illuminance conditions, and show that the response training for visual attention can improve the vision judgment ability of drivers.

Abstract: Web service composition is very important in web service technology. Domain Ontology is used for semantic web service match and automatic web service composition. When a web service is registered, it will be related to the concepts in the domain ontology with its output concepts. To start a semantic match or composition starts, only the related web service with the annotated concept will be used. The approach can deal with not only the sequential but also the parallel service composition problems The proposed approach was verified by experiments and case studies.

Abstract: In this paper the model of Copula-based security assessment of power insulators under the impact of the storm is proposed. The model firstly analysis the daily average winds speed, the historical daily rainfall data to get the probability of wind speed and daily rainfall distribution. Then presents the model of security assessment of power insulators under the impact of wind and rainfall by considering not only the probability of relevance between the daily average wind speed and daily rainfall by using Copula join function, but also the combination of meteorological factors on the impact of power insulators security. This work was supported by the Key Scientific and Technological Project of Hunan Province of China (2008FJ1006).

Abstract: This paper presents experimental investigations on influence of important process parameters viz., laser power, scan speed, layer thickness, hatching space along with their interactions on dimensional accuracy of Selective Laser Sintering (SLS) processed pro-coated sand mold. It is observed that dimensional error is dominant along length and width direction of built mold. Optimum parameters setting to minimize percentage change in length and width of standard test specimen have been found out using Taguchi’s parameter design. Optimum process conditions are obtained by analysis of variance (ANOVA) is used to understand the significance of process variables affecting dimension accuracy. Scan speed and hatching space are found to be most significant process variables influencing the dimension accuracy in length and width. And laser power and layer thickness are less influence on the dimension accuracy. The optimum processing parameters are attained in this paper: laser power 11 W; scan speed 1200 mm/s; layer thickness 0.5 mm and hatching space 0.25 mm. It has been shown that, on average, the dimensional accuracy under this processing parameters combination could be improved by approximately up to 25% compared to other processing parameters combinations.

Abstract: This paper studies heterogeneous open vehicle routing problem. Since the standard genetic algorithm is short of convergent speed and partial searching ability as well as easily premature, improved genetic algorithm is then adopted as an optimized solution. Firstly, sequence of real numbers coding is used to simplify the problem; it may construct the initial solution pertinently in order to improve the feasibility. The individual amount control choice strategy can guard the diversity of group. The adopting some arithmetic crossover operator can enhance local search ability of the chromosome. Finally, comparing to standard genetic algorithm, simulation results demonstrate the effectiveness and good quality.

Abstract: Pentadiagonal Toeplitz systems of linear equations arise in many application areas. Because of the structure and many good properties of pentadiagonal Toeplitz matrices, they have been applied in Mechanical Control. Based on [1], in this paper, we present an improved fast algorithm for solving symmetric pentadiagonal Toeplitz systems.