Applied Mechanics and Materials Vol. 274

Abstract: To reduce the cost of HDPE optical cable sheath, we selected HDPE as matrix materials, inorganic nanometer particles (CaCO₃, SiO₂) as modifier, prepared the modified HDPE optical cable sheath by mechanical blending method. The combination of CaCO₃ particles with HDPE matrix was improved by titanate doped, which was able to facilitate the homogeneous dispersion of CaCO₃ particles inside HDPE. To modify the optical cable sheath and reduce the product cost, the disparity of the inorganic nano-particle was analyzed, and the ratio of raw material and mixing technology were also improved. The experimental results indicated that: the sheathing compound with insulating characteristic as well as all technical indexes that reached its national standard, especially the toughening effect of the CaCO₃, could be produced when CaCO₃ content reached 7.5% and the volume resistivity was 10⁴ times higher than the national standard. The mechanical modification of CaCO₃ was better than SiO₂.

Abstract: The interval element-free Galerkin method (IEFGM) is proposed to analyze a bi-material cantilever beam, which is an interfacial mechanics problem including uncertain parameters. Interval method could be applied to study the influences of the uncertain parameters on structural responses. The IEFGM could be used to approximate the displacement fields without depending on meshes. Combining these two methods, the interval equilibrium equations are derived, and a method of dealing with the discontinuities on the interface is introduced.

Abstract: The deformation behavior and damage mechanism of 3-D carbon/epoxy braided composites with different braiding angles under the monotonic compressive loading are investigated by the acoustic emission (AE) technique. The damage process is divided into several different regions based on the change of the accumulative AE event counts. Correlations between the damage mechanisms and the AE results are established in terms of the events energy and amplitude. These correlations can be used to monitor the fracture growth process in the braided composites. Experimental results reveal that the AE technique is an effective tool for identifying damage mechanisms.

Abstract: Aluminum nitride (AlN) nano-wire was synthesized by double decomposition with AlCl3 and NaN3 in stainless steel cauldron without solvent and using Mg as promoter. The effect of reaction temperature, holding time and promoter to the structure, surface morphology and particle size are analyzed. The synthesized AlN was characterized using X-ray diffraction (XRD) and scanning electronic microscopy (SEM). A series of electron microscopy characterization results show that the optimum reaction conditions are as follows: reaction temperature is 450°C and holding time is 8h. The average diameter of AlN nano-wire is 100nm.

Abstract: The seawater corrosion resistance performances of 00Cr13Ni7Co5Mo4W maraging stainless steel were contrastively investigated by using electrochemical measurements and chemical immersion tests. The results show that breakdown potential of specimen in aging-state is reduced due to R phase precipices during aging. The difference between breakdown potential and protection potential of maraging stainless steel is little, and the restorability of the passive film is strong with small-scale shallow pits. After solution treated at 1100°C for 1h followed by aged 490°C for 8h,the breakdown potential and the annual corrosion rate of 00Cr13Ni7Co5Mo4W maraging stainless steel were 230 mV and 1.5091µm/a , respectively, showing a good resistance to seawater corrosion.

Abstract: Nanocrystalline M-type Co2+ substituted barium hexaferrites samples having generic formula barium Ba0.5Sr0.5Fe12-xCoxO19 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by chemical co-precipitation method. The sintered samples were characterized by XRD, SEM and VSM techniques. All the XRD patterns showed the single phase of the magnetoplumbite barium ferrite without other intermediate phase. The lattice parameters (a and c) obtained from XRD data decreases with increase in cobalt content x. The magnetic behavior of the samples was studied using vibrating sample magnetometer technique. The saturation magnetization (Ms) first increases reaching a maximum of 63.684 emu/g at x=0.4, and then decreases. The coercivity (Hc) decreases with increase in cobalt content x.

Abstract: In this article, hexagonal boron nitride nanosheets have been successfully synthesized by the method of solid-phase sintering using boron oxide (B2O3) and sodium azides (NaN3) as the reactants and magnesium powder as catalyst at 450 °C. Results from XRD suggest that the synthesized products be indexed as pure h-BN. The surface morphology of the products was observed by the scanning electron microscope, that the products are constituted of a large number of the structure of nanosheets. And the SEM images show the sheetlike materials with a diameter of about 500-900 nm, and the thickness is about 100 nm. The far-infrared absorption spectrum showed that the typical sp2 hybrid structure of hexagonal boron nitride. The optical properties of the product are observed in the PL spectra, which shows that the prepared BN emits strong visible luminescence at 445 nm (λex = 325 nm).

Abstract: Chemical precipitation method was used to prepare phosphors ZnO: Eu²⁺ and Mn²⁺ (urea as a precipitating agent, ZnO as a substrate and Eu, Mn as doping elements). A series of preparations with different composition and sintering temperature were characterized by scanning electron microscope (SEM), thermal gravimetric analysis (TG-DTA), x-ray powder diffraction (XRD) and fluorescence spectrophotometer respectively, and the nano-particle characteristics and luminescence properties of the product were studied in detail. The results showed that the size of the nano-particle was uniform (with a narrow distribution), and the fluorescence mechanism would not change when Eu and Mn were doped in the ZnO matrix to prepare luminescence material, it was a feasible way to reduce the damage to the environment and further to explore the ZnO phosphor technology and the application of light-emitting.change when Eu and Mn were doped in the ZnO matrix to prepare luminescence material, it was a feasible way to reduce the damage to the environment and further to explore the ZnO phosphor technology and the application of light-emitting.

Abstract: The seawater corrosion resistance of 00Cr13Ni7Co5Mo4W maraging stainless steel by different temperature aging treatment have been studied by using potentiodynamic polarization curves and uniform corrosion immersion test, the corrosion morphology and microstructure of maraging stainless steel were analyzed by scanning electron microscopy and metallographic microscope. The results showed that 00Cr13Ni7Co5Mo4W maraging stainless steel of different aging temperature processing had occurred the obvious self-passivation, the breakdown potential of maraging stainless steel after different temperature aging treatment are E _470°C >E _490°C >E _510°C >E _450°C, and the corrosion rate relationship are R _470°C 490°C 510°C450°C .The breakdown potential and the annual average corrosion rate of 00Cr13Ni7Co5Mo4W maraging stainless steel are 300 mV and 1.2590µm/a respectively, with the best resistance to seawater corrosion.

Abstract: Human skin is a highly scattering translucent material and is difficult to be scaled. In this paper, we combine approximation of specular reflection with subsurface scattering in the texture space and introduce the dynamic environment lighting to render the human skin to obtain a much more realistic expression. Considering lower computation and requirement for real-time, we use few spherical harmonics coefficients to represent the environment lighting approximated by the environment map. Further, by rotating the environment map, we obtain dynamic rendering effect of human skin appearance, which has a great practical value for creation of virtual character in real scene.