Applied Mechanics and Materials Vols. 727-728

Abstract: The study on CuO/zeolite preparation for COD_r removal from acid bright red GR wastewater was carried out. The optimal process parameters,with zeolite/copper nitrate solution ratio of 1:4 g/mL, copper nitrate solution concentration of 1.0mol/L, calcining temperature of 400°Cand calcining time of 5 h, were determined by single test method .The CuO/zeolite prepared under the optimal conditions obtained high COD_Cr and chroma removal rates with more than 87%and 99,9%,respectively.The process model of CuO/zeolite preparation was established by response surface methodology. The model was proved to be reliable and accurate and its theoretical values were very close to the the actual test values with absolute relative errors ranged from 0.00% to 1.49%, which can be used to predict, adjust and control the process conditions of CuO/zeolite preparation for getting desired COD_Cr removal rate.

Abstract: A statistical constitutivemodel, which takes account the effect of strain rate, was presented to describethe stress-strain relationship of unidirectional fiber reinforced metal matrixcomposites (UFRMMC). To verify its reliability, tensile tests on a unidirectionalSiC/Al composite wire, were carried out at different strain rates, and thestress-strain curves were obtained. The testing results show that both thestrength and ductility of the composite wire all increase with increasingstrain rate. Simulated stress-strain curves, derived from the constitutivemodel, fit the tested results well, which indicates that the model is valid andreliable.

Abstract: this paper develops a kind of nano infrared smoke material with static explosion contrast test with copper powder material. In the condition of reducing charge amount, the smoke property has been improved to a large extent. The loading density of original copper powder material is 2.3 g/cm³ with effective shielding period of no more than 60s for intermediate & far infrared and action area of 100 m². However, nano infrared smoke material, with density of no more than 1.6 g/cm³, can have an effective shielding period of more than 70s for intermediate & far infrared and action area of over 120 m².

Abstract: In this study, the maximum and smallest vertical principle stresses σ₁ and σ₃ as well as maximum shear stress τ_max distributions, obtained from Mohr circle in each quadrant, are used to investigate the applicability of various ductile material failure theories. Based on the yield tensile stress σ_yt equals to yield compressive stress σ_yc (σ_yt=σ_yc=σ_y) and the known practical yield shear stress and yield stress ratio τ_y/σ_y=0.42~0.75 of ductile materials, we prove that the maximum vertical stress failure theory cannot be applied to the first quadrant (σ₁>σ₃≧0) as well as the third quadrant (σ₃<σ₁≦0) while τ_y/σ_y< 0.5, and it does also not applicable to the second or fourth quadrant (σ₁>0 and σ₃<0). In this study, the modified maximum shear stress failure line can be fit all ductile material depending on τ_y/σ_y=0.42~0.75 in all quadrants, thus the more reasonable results can be obtained.

Abstract: In the present paper, the Ti-15Ni-6Al-2Zr alloy is fabricated and heat treated at different temperatures. Its microstructure and morphology of Ti₂Ni phase are investigated by SEM and TEM. The results reveal that the Ti-15Ni-6Al-2Zr alloy is composed of eutectoid and eutectic microstructure, which possesses fine Ti₂Ni fiber in eutectoid region and fine α-Ti phase in eutectic region. With the increase of heat treatment temperature, the amount of α-Ti and Ti₂Ni phases decrease gradually. When the heat treatment temperature is higher than 900°C, almost no α-Ti phase is left. The transformation temperature of α-Ti phase to β-Ti phase is about 850°C, and the transformation of α-Ti phase promotes the decrease of Ti₂Ni phase. During the heat treatment, the Ti₂Ni fiber phase experiences the refining, fragmentation, coarsening and granulating.

Abstract: In order to research the effect of core material on strength and stiffness of hat stiffener, using the finite element method which establishes a series of hat stiffener finite element models with different core materials. This research indicates that foam core material in simple models can be negligible, and pinewood needs to be considered. For large and complex composite material structures, from the security and efficiency aspects to consider, the core material of hat stiffener could be ignored in their models.Using Beam188, Beam189, Shell99 element to simulate rectangular hat stiffeners, the results shows that the beam elements can simulate the hat stiffeners instead of shell elements when setting up a finite model of the whole ship in order to simplify the modeling.This study provides a basis for the simplification of GFRP fishing vessel finite element model and makes great significance to its direct calculations and rapid design. Meanwhile, this study has a certain reference value for the design and calculation of the hat stiffeners in composite ship．

Abstract: In the present paper, the Mg-Zn-Y-Nd alloy is fabricated by as casting and hot extrusion. Microstructure and mechanical properties of the as-cast, heat treated and hot extruded alloys are investigated. The results exhibit that Mg₂₄Y₅ phase with eutectic structure forms in the as-cast alloy, which has an orientation relationship with matrix of _. The precipitating phase separates the matrix semi-continuously. The heat treatment results in most precipitates solid soluted into matrix, but there are still some nanoscale particles and residual phase along grain boundary. The hot extrusion refines the microstructure and leads to the formation of stacking faults in the matrix. Compared with the as-cast and heat treated alloy, the hot extruded alloy obtain great improvement in mechanical properties, which should be attributed to the grain refinement, solid solution and fomation of crystal defects

Abstract: Microstructure analysis and tensile fracture analysis were conducted on the domestic and imported 7050-T7451 aluminum alloy to investigate the material differences between them. Tensile test shows that the yield strength and tensile strength of domestic 7050-T7451 aluminum alloy are both higher than imported 7050-T7451 aluminum alloy, however, the material elongation and the reduction of area are both lower than imported material. Microstructure analysis shows that compared with domestic 7050-T7451 aluminum alloy, in the imported 7050-T7451 aluminum alloy, the degree of recrystallization and anisotropy is less, and the grain size is smaller. In addition, the transition from material surface to center organization of imported 7050-T7451 aluminum alloy is more smooth and uniform than domestic material. From tensile fracture analysis, it concluded that the domestic 7050-T7451 aluminum alloy has large grain size, low structural homogeneity, and little toughness characteristic of fracture, and those characteristics cause low elongation and low reduction of area of domestic 7050-T7451 aluminum alloy.

Abstract: One system of Shrinkage reducing monomer was prepared by esterification reaction, the test method of esterification rate was discussed, to find out the significant factors of the esterification rate by using the orthogonal design. The influence of ether-to-acid mole ratio, reaction temperature, catalyst dosage and reaction time on the esterification was also investigated. The results demonstrate that the suitable esterifying conditions mainly require the suitable proportion of MA to C5H12O3 as 1~1.05 to 1, and under the temperature of 120~125°C, and 3~3.5hours of reaction time.

Abstract: Hospital sewage effluentwater quality similar to that of its integrated waste water, waste watercontent than the more complex chemical composition, the use of this treatmentis a biofilm of bio-contact oxidation process for the management of hospitalWaste water to run effective and save operating costs, facilitatethe management of operations, and achieved satisfactory economic benefits,social benefits and environmental benefits.