Applied Mechanics and Materials Vols. 66-68

Abstract: Production scheduling problem is the one of the most basic, important and difficult theoretical research in a manufacturing system. In the past decades of research, the classical scheduling theory has made signficant progress, but the actual scheduling problems are much more complicated than the classical theory. In order to study, the actual scheduling problems are often made much simpler. Therefore, it is difficult for the results of the classical scheduling theory to been put into practice. The considerable gap also exists between the classical scheduling theory and the actual scheduling problem. But with the increasingly fierce market competition, customers have become increasingly demanding product diversification, product life cycle is shorter and more sophisticated structure of the product makes the actual scheduling a large number of uncertainties, the traditional model has become difficult to obtain satisfactory results. This paper makes a analysis on the uncertainties of production scheduling,and tries to solve re-entrant production scheduling problem based on QPSO. It introduces the mathematical model and the solving process based on QPSO algorithm. Then it makes construction strategies to solve it. The paper simulates with Visual C. The results show that this algorithm is feasibility.

Abstract: Aramid fiber (AF) was treated by NaOH solution of various concentrations with supersonic vibration at room temperature. The density of NaOH solution was the main parameter. Elongation at break and break strength were tested. The chemical composition of AF was characterized by elemental analysis. The surface of AF was examined by scanning electronic microscopy (SEM). It was shown that elongation at break of treated AF was not decreased, and break strength was a little increased, first increases and then decreases as the concentration of NaOH solution raising. It was also found that the surface of AF after modified was a little rougher. Low concentration of NaOH solution was fit to modify AF.

Abstract: The comparison between carbon fiber reinforced different matrixes composites was studied in this work. Carbon fiber reinforced phenolic resin composite and carbon fiber reinforced benzoxazine resin composite were made by pultrusion processing. Bending strength test and charpy impact strength test were taken to characterize the toughness of different composites, and scanning electronic micro-scopy(SEM) was applied to evaluate the interfacial properties between carbon fiber and different matrixes. It was shown that compared with carbon fiber reinforced phenolic composite, carbon fiber reinforced benzoxazine composite had better performance in toughness and interfacial property. Bending strength and toughness were mainly depending on the property of matrixes, interfacial property was determined by carbon fiber and matrixes.

Abstract: The Ni-P-SiC composite coatings with homogeneous distribution were prepared through adding nano-SiC grains into the Ni-P chemical plating liquid. The morphology of the composite coatings was analyzed by SEM. The coatings microhardnesses at the SiC composite content for different concentration were measured using the microhardness tester. The wear property of coatings was evaluated by the friction-wear tester and the abrasion mechanism of coatings was also analyzed. The results show that the microstructures of the composite coatings are superior to the common coatings because the nano-SiC particles refine the crystal grains of the composite coatings. The hardness and wear resistance of the composite plating coatings were well improved under the strengthening effect of nano-SiC grains.The wear resistance was the best when the SiC concentration was 4g/L.

Abstract: In order to improve its comprehensive properties and speed up its development period, a measuring-controlling platform was designed and tested for MR damper based on virtual instrument in this paper. Parameters and its comprehensive properties of the manufactured MR damper with embedded controller are firstly introduced and show. Then, its design principle of a measuring-controlling unit for MR damper with embedded controller is analyzed. Finally, a virtual integral developing platform based on virtual instrument and Labview environment is designed and developed. And a lot of properties test are finished for the designed and manufactured MR damper. Testing results show that the developed integral platform could meet its engineering application requirements of MR damper with embedded controller.

Abstract: In this paper, aimed at wheel-axle with axle load of 30 ton, the three dimensional finite element model was established, and the interference fit between wheel and axle was considered. According to Standard EN13103, the vertical load and the lateral load were determined, and then the stress distribution of axle was computed under two cases: only vertical load and both vertical and lateral load. The result shows that: the increase of axle load causes the increase of slip between axle and hub, which leads to an increase of fretting damage and a reduction in fatigue life. In addition, Dang Van criterion was employed to evaluate the fatigue of the whole axle. It is found that the transition zone next to wheel seat and the interface of hub and axle are dangerous points, which is in accordance with the practice.

Abstract: ZnO/SiO₂ composite films were deposited on Si substrate by RF magnetron sputtering technique and annealed in air .The influence of sputtering and annealing treatment conditions on the composition,the surface morphology and the wettability of the composite films was investigated by XRD, EDS, SEM and contact angle measurement. The results show that ZnO, SiO₂ and Zn₂SiO4 are main phases in the composite films existing by hexagonal wurtzite structure ,amorphous structure and willemite structure respectively. In this experimental conditions we get superior crystallization property of ZnO nanometer tissue with hexagonal wurtzite structure. The tissue shows bamboo leaf-like shape.The composite films has super hydrophobic,the contact angle is 146°.

Abstract: In this article, separation of touching grain kernels and measurement of geometric features in an image are presented. The objective of this work is to discriminate single corn kernel and some broken kernels, which are difficult to achieve on the existing machinery and equipment, especially for the counted number and quality inspection process. The digital image was obtained from flatted conveyor belt; the geometrical features were analyzed using Matlab R2009a software. It was used for recognizing multiple kernels for once. Intact and broken kernels were characterized by the changed geometrical features and combining SVM for the classification of them with accuracy 95%.Which meet the requirement of corn quality inspection comparable to subjective human inspection.

Abstract: The tensile properties and fracture mechanisms of fully lamellar TiAl based alloy was studied by room and high temperature (400°C) tensile test. The results indicated that: the crack initiated between weak lamellar interfaces．With tension increased, the cracks extended along lamellar direction. Crack propagation resistance was enhanced at colony boundary. Ligaments broke while load increased, and then the main crack and microcrack linked. The fracture process was that the main crack occurred firstly, microcrack appeared and then propagated, the main crack and microcrack were linked，and the alloy fractured finally; The ductility of the alloy at 400°C was superior to that at room temperature; The fracture mechanism of the fully lamellar TiAl based alloy is brittle cleavage fracture.

Abstract: This paper introduces the plan and the process of dynamical and statical load test study which is made on the road bridge. It can validate the quality of the bridge by comparing measured stress&deflection and theoretical calculation.Experimental results show that the computational methods and analytical methods are reliable, The stiffness and bearing capacity of the bridge meet the design requirements. The technology of load test and method of data analysis have high reference value to similar engineering.