Advanced Materials Research Vols. 314-316

Abstract: The isothermal section at 573 K of the Ni-Cu-La system was experimentally validated as well as the Mg-La-Cu system was thermodynamically evaluated. Four sample alloys in the Ni-Cu-La system were prepared and analyzed by ICP, XRD and BSE/EDS. All the experimental results were compared favorably with the calculated phase relationships. For the Mg-La-Cu ternary system, the isothermal section at 673 K was assessed on the basis of the available results in literatures, which showed a good agreement with the experimental data. Based on the thermodynamic models and parameters of the six binaries and four ternaries, the Mg-Ni-La-Cu system was finally modeled. The non-equilibrium solidification path La0.7Mg0.3Ni2.8-xCux (x=0-0.4) and the vertical section of LaNi5-Mg2Cu were calculated and analyzed from the viewpoint of hydrogen storage alloys design.

Abstract: The constitutive equations, describing the relations between stresses and strains in the single layer graphene, were obtained based on the anisotropic theory. The equations showed that (1) there are 3 nonzero stress components in graphene for it is in the plane stress state; (2) there are 4 elastic constants independent in the constitutive equations describing the material properties of graphene; and (3) the normal stress merely results in normal strains if graphene in simple tension in primary directions but generates the normal strains and shear strains if in non-primary directions. In addition, the Hamilton method determining the 4 elastic constants in constitutive equations of graphene was introduced.

Abstract: The flow of plastic melt in macro and micro parts during the filling phase of injection molding is an interesting area to discover. The visualization technique is a common method used to understand the phenomena of polymer flow in mold cavity. Various shapes and sizes were fabricated on aluminum molds embedded with Polymethyl Methacrylate (PMMA) as observation window. Electrical discharge machining (EDM) and micro mechanical machining method were employed to fabricate plastic parts shape on aluminum mold cavity. This paper focuses and discusses in detail on the Polypropylene (PP) melt flow injected using a custom made vertical injection molding machine. The PP melt flow can be clearly seen through the PMMA window and captured using high speed camera. The captured images are then compared with result from commercially available plastic injection molding software, Autodesk MoldFlow. It was found that there is good agreement for macro plastic parts but not for the micro parts. It can be concluded that, the analysis software has less capability in predicting the flow of melt plastic in micro parts.

Abstract: Using the improved Ant Colony Algorithm to optimize torsion bar diameter, and take the optimization results into practice. Results not only show the Ant Colony Algorithm is feasible and provides a new method choosing torsion bar diameter but also is satisfied.Based on maximum deformation energy and not exceeding the allowable stress values of a torsion-bar spring, the thesis builds the optimization model for the self-balancing torsion bar.

Abstract: In this study, the automotive glove-box-cover was decided as a model, which was assembled on the instrument panel. The material of the cover was Kingfa Sci & Tech Co Ltd, PP+EPDM+20%Talc co-polymer. Firstly, the effects of the process parameters on warpage were examined using FFD. To look for the warpage values, the CAE software Moldflow was used. The significant parameters were found out. Secondly, to determine the distortions of the special points over the top surface of the glove-box-cover, the software Ansys10.0 was used. The structural analyses of the glove-box-cover with different thickness were done in order to determine the performance, and the suggested thickness of the cover was pointed out. At the same time, the strongest and weakest points were found out.

Abstract: In the plastic injection molding process, interaction between design and analysis is very intensive. However, current computer-aided systems (CAD and CAE) are realized as isolated modules. Thus, designers need to transform data models between CAD and CAE systems. Defects of many data errors and duplicated work are inevitable. This paper presents a CAD/CAE integrated system, building on top of existing CAD and CAE systems. The framework of the system is designed. A parametric integration model is established to achieve bidirectional association between the two systems. Details of key technologies in pre- and post- processing are discussed, such as mesh generation, feature recognition, and automatic evaluation of analysis results. A practical engineering case is studied to illustrate that the system can effectively avoid mesh repair and remodeling in pre-processing, reduce the dependency on experience in analysis result evaluation, and greatly improve the efficiency of iterative design-analysis-optimization process.

Abstract: The grafting polymerization reaction of Hemp fibers and acrylonitrile was studied in this paper, discussed hyperchromatic solution of Hemp fibers. The morphology, structure and chemical composition of Hemp fiber after and before grafting polymerization treatment were analyzed through SEM, XRD and FTIR. Results showed that grafting percentage and dyeing percentage were all enhanced because of grafting polymerization treatment on Hemp fiber.

Abstract: Based on Hyperbolic sine relationship proposed by Sellar and Tegart rheology stress model for high-purity high-temperature plastic deformation of polycrystalline aluminum was constructed by Zenner-Hollomon parameters. Parameters influencing rheology stress of aluminum were optimized，through the initial population identification、selection、crossover、mutation、evaluation and screening, concluding the connection between rheology stress、deformation rate and deformation temperature by GA(genetic algorithm). The results show that GA is feasible, through model validation by experimental data and comparing calculated and experimental results under different deformation rates.

Abstract: In order to quantify the design and simulation of various types of composite microstructure, through the Visual C++ programming language developed software 3D-ProDesign, the software for the computer to become real, complex and diverse, "mass" level three-dimensional composite material microstructure structure "samples", in the simulation process of these samples compare actual composite material component objects state , spatial orientation, spatial distribution, crystallographic orientation ,(designed can independent control of the information of the software module), and to be the microstructure of the geometric details of the simulation of an automatic forming, and can be any combination of the basic module is constructed based fiber such as polycrystalline particles enhanced composite material mixed variety of complex models of materials microstructure model, simulation model has been used in material microstructure micromechanical response calculated.

Abstract: With the characteristics of un-touching, high-automatic and high-speed, we measured 3D shape by digital moiré patterns. And it can measure 3D shape without compensator, auxiliary mirror, hologram and other assistant modules. So it is widely used in measurement of 3D shape. But with the negative effect of grating area and CCD resolution of the camera, it has some problems in large aperture, steep aspheric surface, even off-axis aspheric testing. Focus on these problems; this paper established a sub-region splicing measurement of aspheric surface by using the combination of digital moire patterns and digital phase shifting technology. This paper also illustrated the basic theory, and the mathematical implementation procedure. In all, sub-region splicing digital moiré patterns can be considered as another method, which beyond compensation tests to measurement of aspheric surface.