Applied Mechanics and Materials Vols. 490-491

Abstract: With a logical reasoning-realistic analysis binding methodology and the theories of internet of things and supply chain management, probes into the development trend of productive materials terminal distribution. From three perspectives, value process, technical platform and node selection, the research indicates the operation mechanism of terminal distribution, providing a theoretical support for dual promotion of efficiency and effectiveness in terminal logistics of productive materials.

Abstract: We present the study based on extended Maxwell-Garnett effective medium theory for the effective dielectric function of the diamond like carbon film with embedded silver nanoparticles (DLC-Ag) and rigorous coupled-wave analysis to evaluate resonance characteristics in a visible range of periodic 1-D grating structure on their base. The relief sub-wavelength grating structures on base DLC-Ag nanocomposite have been investigated for sensing applications.

Abstract: filter get peoples attention increasingly as it has become the core of dust bag. In this paper, cleaning process residual resistance and peel rate of dust cleaning cycle were studied. Experimental results show that the initial resistance of the filter were close to the filters, polyester dust filter has a high cleaning strip ratio and a larger interval.

Abstract: The friction-resistant sisal fiber/nanoSiO₂ phenol formaldehyde resin composites were prepared through compression molding. In order to enhance the bonding between the sisal fiber (SF) and polymer matrix, sisal fibers were treated with different surface modifiers (alkali, coupling agent and borax). The friction and wear properties of the composite materials were investigated with a constant speed (D-SM) tester. The worn surfaces of composites were observed by scanning electron microscope (SEM). The results showed that the adoption of nanoSiO₂ phenol formaldehyde resin as matrix resin can solve the heat fade of the friction material. The friction and wear parameters of the treated sisal fiber composites can meet the requirement of standards GB5763-1998. The fiber treatment methods had great influence on the friction and wear properties of the fiber composites. Specifically, the borax treated fiber composites showed low wear rates at different temperatures. The highest friction and wear resistances of sisal fiber composites were reached when the fiber content was 15%. Our data demonstrated that the sisal fiber is an ideal substitute of asbestos for brake pads.

Abstract: Steel with low yield ratio (YR0.75) and high heat input welding was made by combining Zr, Ti microalloying. Its microstructure investigated by optical and electron microscopes (SEM, TEM), consists of ferrite with the fine pearlite which not only ensures the high strength and toughness but also decreases the yield ratio. The steel was simulated in 100 kJ/cm heat input welding. The microstructures for heat affected zone (HAZ) of weldments mainly consisted of acicular ferrites which nucleate on fine Zr and Ti contained inclusions. The acicular ferrites decrease detrimental influence of grain coursing in the HAZ and make the steel good toughness in low temperature.

Abstract: Effect of different aging treatments(namely AT1, AT2, AT3 and AT4) on the tensile strength(TS) and stress corrosion cracking(SCC) resistance of 7A04 aluminum alloy in 3.5% NaCl+0.5% H₂O₂ solution was investigated using constant load tensile stress corrosion test. Electrochemical behavior of the alloy after different aging treatments was analyzed in 3.5% NaCl solution. The results show that AT1 (i.e. 135°C/16h) increases the TS but decreases the SCC resistance of 7A04. AT2 (i.e. 120°C/7h+165°C/10h) provides the highest SCC resistance and simultaneously retains the TS. AT3 (i.e. 115°C/5h+165°C/10h) decreases both the TS and SCC resistance. The electrochemical analysis indicates that the corrosion resistance of AT2 is the highest, which helps enhance the SCC resistance. The scanning electron micrographs reveal that intergranular corrosion occurs from the corrosion pits on the surface of the specimens when tested under stress, resulting in the ultimate fracture.

Abstract: As a low permeability, high thermal conductivity and mechanical strength soil, bentonite has been widely used as buffer/backfill material for nuclear waste disposal. Underground water flow behavior in bentonite was studied in this paper. A numerical simulation was conducted to predict the water absorption test of MX-80 bentonite, which is worldwide known commercial material. ABAQUS was used for simulating the water flow in the soil column in which hydro-mechanical coupled model is taken into consideration. Darcys law and van Genuchten soil water retention curve model were used for water flow. Ideal elastic model, Drucker-Prager plastic model and wetting expansive model were taken to describe the stress-strain relations of the soil. Comparison between experimental and simulation results shows that the proposed numerical method is reasonable to predict the water flow in MX-80 bentonite.

Abstract: The effects of the primary Si phase and applied load on the dry sliding wear behaviors of hypereutectic Al-20Si alloy were investigated. The results show that coarse polygonal and star-like primary Si was refined into fine blocky shape by increasing superheat treatment temperature. The friction coefficient and wear rate significantly decrease after decreasing the size and changing the morphology of primary Si. Moreover, the friction coefficient and wear rate increase with the increase of applied load. Therefore, the wear properties are greatly influenced by the parameters like morphology and size of primary Si as well as applied load.

Abstract: Thin film deposition (TFD) is used to coat materials including metals, glasses and textiles with film thicknesses varying from angstrom to millimeter values. TFD methods find usage in many industries such as coating parts for engineering industries, nuclear industries and decorative industries. TFD methods are applied on textile substrates to obtain anti-static, UV-absorbing, antimicrobial, superhydrophobic and fire-resistant properties. In this study, thermal evaporation which is a TFD technique was used to coat para-aramid fabrics with Fullerene C60 nanoparticles. Samples having 0.1 μm, 0.2 μm and 0.3 μm Fullerene C60 film thicknesses were produced. Morphology and tensile properties of the samples were analysed by AFM (atomic force microscopy) analysis. An uncoated fabric was used as the control sample to compare the tensile properties of the samples. Compared to the uncoated fabric, the coated fabrics showed an increase in tensile strength. As the fullerene film thickness increased, a decrease in tensile properties was also observed. The decrease observed in the tensile properties for the C60 coated fabric samples might be caused by the coarser particles accumulating on the fabric surface as the thickness increased.

Abstract: The electrothermal effect of the carbon fiber concrete provides a new way to eliminate the snow and ice on an airfield runway. But the electrothermal effect of concrete reinforced with hybrid carbon and steel fiber and the appropriate fiber content are still unknown. The research aims at the questions above and investigates the electrothermal effect of concrete slabs with different hybrid fiber contents. It shows that the addition of steel fiber can increase the electrothermal effect of hybrid fiber concrete when the carbon fiber content is about 0.6% ~ 0.8% of cement by weight, which means that steel fiber can help to form conductive network. But the electrothermal effect of hybrid fiber concrete is reduced when carbon fiber content reaches 1.0% of cement by weight, because the addition of steel fiber will block uniform dispersal and effective overlap of the carbon fiber and the conductive network gets worse. Air bubbles generate inside the concrete can also increase the electrical resistivity of the hybrid fiber concrete and the electrothermal effect gets worse.