Applied Mechanics and Materials Vols. 477-478

Abstract: In order to overcome the low precision of analytic formulas for equivalent elastic modulus of honeycomb, the in-plane deformations of honeycomb are simulated numerically through finite element analysis (FEA) software Ansys. The representative volume element (RVE) is firstly selected and modeled in 3D, according to the repetition of honeycomb cell. Then the deformations of RVE under three different boundary conditions are discussed on several premises. And the equivalent elastic modulus of two specifications of honeycomb from experiments, analytic formulas of Gibson and FEAs simulation results are presented and compared, adequately proving the effectiveness of the above method. Finally, the fitting formulas of equivalent elastic modulus that are convenient for engineering application are proposed by analyzing series of different sizes honeycomb.

Abstract: The UV-curable liquid compositions were developed with different oligomers (epoxy diacrylates, EDA; epoxy monoacrylates, EMA; or polyurethane-modified epoxy monoacrylates, PMEMA), reactive diluents and photoinitiators. Thin films were prepared by curing these mixtures using a high pressure mercury lamp. The change of absorption peaks of double bond and epoxy group were identified by Fourier Transform Infrared (FTIR) spectra during UV dual curing process. Gel content, mechanical, volume shrinkage and thermal characterizations of the UV-cured films were investigated. The gel content, youngs modulus and stress at break turned to maximum values as the degree of polymerization achieved the maximum value, except for the strain at break. The flexibility of UV dual cured films using PMEMA as oligomer was improved due to grafting of the soft chain segments (polyurethane). The volume shrinkage test indicated that the UV dual cured films exhibited lower internal stress and higher cohesive force than simple radical UV cured films. The thermogravimetric analysis of UV cured films revealed that UV dual cured films prepared from PMEMA showed excellent thermal stability.

Abstract: 70# and 90# matrix asphalt mixture with MaR were studied through dynamic modulus test, rutting test, freeze-thaw splitting test, bending test to study the applicability of the Modifying agent of rubber plastic compound (MaR) in matrix asphalt mixture.Test results were Compared with SBSI-C modified asphalt mixture.The results indicate that: high-temperature stability of MaR+70# asphalt mixture is as well as SBSI-C modified asphalt mixture,and is bettere than MaR+90# asphalt mixture; water stability of MaR+90# asphalt mixture is bettere than SBSI-C modified asphalt mixture and MaR+70# asphalt mixture; low temperature performance of MaR+90# asphalt mixture is bettere than MaR+70# asphalt mixture, but is worse than modified asphalt mixture SBSI-C ; MaR+70# asphalt mixture can be first used in area of resisting high temperature and rutting, MaR+90# asphalt mixture can be used if the water stability performance and low temperature performance are considered.

Abstract: In-situ Ni-Al Intermetallic compound reinforced aluminum matrix was fabricated by powder metallurgy technology. By the use of Optical Microscopy and Scanning Electron Microscopy (SEM), microstructure, thermodynamics and dynamics was investigated in this paper. The results show that in-situ Ni-Al/Al composite consists of primary α-Al phase and NiAl reinforcement. In addition, Ni-Al/Al system dynamics model was established. From the dynamics model, the main factors affecting the reaction rate of the system are heating temperature, nickel content and the diffusion layer thickness δ. During the temperature of 400~460°C, NiAl intermetallic compound can be obtained.

Abstract: Waterborne polyurethane waterproofing composite has been prepared using polyurethane emulsion, cement, sand, and distilled water as raw materials, respectively. The compression performance of the samples has been determined by tensile testing machine. The microstructure of the samples has been observed by metallographic microscope. At the same time, the water resisting property of samples has been presented. The result shows that the surface of samples becomes the more smoothing with the increase ratio of cement to sand. The best compressive strength and water resisting property have been obtained when the weight of polyurethane emulsion to distilled water was 1:5 and the ratio of sand to cement was 2.1:1.

Abstract: The radical polymerization of optically active methacrylamide derivative, N-[o-(4-isopropyl-4,5-dihydro -1,3-oxazol-2-yl)phenyl] methacrylamide ((S)-MeOPMAM), was carried out under various conditions. The effect of Lewis acid, that is, rare earth metal trifluoromethanesulfonates on the free-radical polymerization were examined under different solvents. The polymerization in the presence of rare earth metal trifluoromethanesulfonates produced isotactic-rich polymers compared with those obtained without the Lewis acid. The polymerization characteristics and the chiroptical behavior of the resultant polymers have been examined by using circular dichroism (CD), UV–Vis, and NMR spectroscopies.

Abstract: When the railway pass through the desert and highlands, it is often corroded and buried by the sand. So it is necessary to spread out nylon material sand-fixation net along with the railway for windbreak and sand-fixation. The using of the refractory nylon net is restricted because it is difficult to be degraded. Nowadays, much attention has been paid to the desertification. To mitigate the effects of desertification, it is imperative to research for a new type of sand-fixation material. Here, we deal fiber-linen with advanced surface treatment technology to make a new kind of material which can be degraded. It is not only environmental-friendly and advanced but also very cheap, Whats more, it has the excellent abilities of ageing resistance, water resistance, and UV resistance.

Abstract: A solvent-free cross-linked alternating copolymer electrolyte is synthesized through photo copolymerization of comb-like poly (ethylene glycol) ester maleate and styrene. Phase transitions, thermal properties, ionic conductivities and electrochemical stabilities are investigated to characterize the alternating copolymer electrolyte. The flexible solid polymer electrolyte (spe) with lithium salt content of 15 wt.% and MA/-OH = 1 has a good ionic conductivity of 1.45×10^-5 S cm^-1 at 35 °C and a superior electrochemical stability to 5.2 V. The maleic anhydride on the main chain increases the rigidity of the copolymer matrix and decreases the ionic conductivity.

Abstract: UV-shaped corrugated cardboard Fusion V-shaped and U-shaped structure the advantages made, to make up for the lack of V-type and two U-shaped corrugated cardboard, the higher the compressive strength, good elasticity, is widely used UV type corrugated manufacturing corrugated board. But no strict standards for UV-shaped concrete structure of corrugated board size parameter corresponding corrugating roll no uniform size of the corrugated shape, in order to achieve the best elasticity and compressive strength. First, by mathematical methods, the corrugated structure is analyzed, and analysis to facilitate research, to select the 1/4 cycle corrugated. Create multiple vertical auxiliary line level is divided into 10 equal parts, to identify key points in shape between the V-shaped and U-shaped curve, connecting into multiple segments curve. Studied the actual thickness of the corrugated board of 3.8mm, a smaller thickness and therefore a straight line can be connected to each group of the resultant key points simplify the corrugated curve, model 1/4 of a cycle of UV-shaped corrugated first determined, using the symmetry of the model to establish a cycle, 300mm side length of the square created by one cycle of replication, about 38 of the corrugated board corrugated cycle. Use of finite element analysis in ANSYS corrugated structure, including a gradual transition to a simplified model of the 11 U-shaped flute-shaped corrugated cardboard from the V-shaped set of material properties, loads are cloth pressure, research corrugated cardboard stress and strain, i.e., the smaller the radius of curvature of the curve can be obtained along corrugated, the closer the U-shaped, corrugated board having a larger strain, i.e. has good flexibility, consistent with the empirical data to prove the feasibility of this analysis method.

Abstract: Copolymer (aniline-co-pyrrole)/TiO₂ composites with different TiO₂ contents were prepared by chemical oxidative polymerization method. The crystal structure and morphology evolution of composites were characterized by XRD and SEM. Using Tafel polarization plots and temporal OCP to study the anti-corrosion properties of Pani/py/TiO₂+EP coatings in 3.5% NaCl solution at the same time. It has been found that the anti-corrosion abilities of the composite are strongest when the TiO₂ content accounts for 30%, which shows better abilities of metal protection than Pani and Pani/py.