Advanced Materials Research Vols. 308-310

Abstract: Gyro-Free Inertial Navigation System(GFINS) is constructed mainly with accelerometers. A nine-accelerometer GFINS scheme is designed and the prototype is manufactured. Then quaternion based attitude resolution algorithm is developed, the algorithm is also applied to the GFINS prototype, the results show that the algorithm can effectively offspring the cone-effect, and the attitude is resolute validly, the maximum attitude error is up to 0.37°, the maximum azimuth error is 0.47°.

Abstract: Weight reduction is a priority across the automotive industry for improved fuel efficiency and CO2 reduction, and crash safety is the first design criterion considered during vehicle development. This paper is concerned with lightweight design of front rail on a vehicle chassis frame structure through material substitution, i.e., replacing the original mild steel with advanced high strength steel (AHSS), without deteriorating the vehicle’s crashworthiness performance. Magic Cube approach (MQ), a systematic design approach, is conducted to analyze the design problem: by applying space decomposition, a system-to-subsystem-to-component model is developed, which simplifies the design problem. Numerical simulation is carried out with LS-DYNA to evaluate the crashworthiness performances of the original and the new-designed front rail. The result shows that up to 30% weight can be reduced in the new design through material substitution while the crash performance remains the same as in the original design.

Abstract: This paper presents results on mechanical behavior of multilayer piezoelectric stack actuators for use in active member under combined electro-mechanical Loadings. The objective of this study is to investigate the behavior of piezoelectric materials and to determine the properties necessary for design of such actuator systems. Two types of experiments are performed: influences of the preload on characteristics of the stack and dynamic test. The measurements indicate strong dependence of the actuator piezoelectric properties on the electro-mechanical loading conditions. The displacement output is initially enhanced with an increase of the mechanical preload, and the maximum value is obtained at the preload of about 0.4 KN. But much higher preload will cause the decrease of the displacement output. Within low frequency band of about 400 Hz, the displacement magnitude of the stack is nearly constant, and the phase lag increases with the increase of the driving frequency at the applied sine sweep voltage with the amplitude of 150V.

Abstract: Support vector machine(SVM) is a new learning machine based on the statistical learning theory. For it not only has solid theory, but also can solve many practical problems in optimizing area, such as small samples, over learning, high dimension and local minima. And has shown attractive potential and promising performance in a wide range of fields and applications. In this paper, the least square support vector machine(LS-SVM), which developed from normal SVM, has been used for predicting and modeling the underwater acoustic performance of sandwich composite plates, which were composed of fiber-reinforced plastics/acoustic rubber/fiber-reinforced plastics. Effective result indicate that LS-SVM is of potential application in sandwich structural composite design and acoustic material research.

Abstract: Nanocrystalline CoFe₂O₄ ferrite have been synthesized by a spraying-coprecipitation method. X-ray diffraction (XRD) and Transmission electron microscope (TEM) confirmed the formation of single-phase CoFe₂O₄ ferrite nanoparticles in the range 10 nm ~ 100 nm depending on the calcining temperature. The magnetic measurements show that specific saturation magnetization of nanocrystalline CoFe₂O₄ ferrite increases from 36.1 A•m2•kg-1 to 88.6 A•m2•kg-1 as grain size increases from 12 nm to 98 nm. The coercivity shows a peak with grain size, peaking at around 43 nm. The magnetic behaviour of nanocrystalline CoFe₂O₄ ferrite might be attributed to the effects of surface and random anisotropy.

Abstract: A new optically active amphiphilic graft copolymer bearing quinine pendants poly[3,3-bis(triazolyl-L-quinine) methyl oxetane]-g-poly(ethylene oxide) (PBTQMO-g-MPEO) was synthesized by ‘‘click’’ reaction of azido-modified PBAMO-g-MPEO diblock copolymer and 10,11-didehydro quinine. The fourier transform infrared spectrum(FTIR) and 1H nuclear magnetic resonance spectroscopy (1HNMR) were used to confirm its structure and composition.

Abstract: For new copper online cooling equipment, the heat transfer coefficients of impinging jet and flow cooling on the surface of copper plate are obtained through the finite element method. The results provide boundary conditions for temperature field computation. Three-dimensional temperature field compute model is built. Different nozzle horizontal distributions are designed. After calculation, the nozzle arrangement of cooling uniformity is obtained. The jet distribution density curve is used to get the transverse cooling intensity curve. The study provides theoretical basis for obtaining straight plate.

Abstract: The unperturbed dimensions of symmetric polymers are investigated by an improved conformational statistic method considering effect of side groups. Following the deduced formulas, the characteristic ratios of mean-square radius of gyration for poly(dimethylsilmethylene) (PDMSM), poly(vinylidene fluoride)(PVDF), polyphosphate(PP), polyoxymethylene(POM) and poyisobutylene (PIB) are calculated 0.69, 0.84, 1.23, 0.85 and 1.18, respectively. The ratios of mean-square dipole moment are 0.35, 0.48, 0.59 and 0.79 for PP, PDMSM, POM and PVDF long chains, respectively. From comparing the ratios of five polymers, it is found that the consideration of side groups for short chains is exceedingly important in calculation of characteristic quantity, especially for the inorganic polymers with heteroatom. PVDF are excellent in flexibility and electric dipole properties. The temperature characters of PIB are concerned closely with its conformational energy.

Abstract: The effect of the Ce on the mechanical property and corrosion resistant of the 2Cr13 stainless steel are studied in this research. The conclusions show that the hardness and tensile property of the 2Cr13 steel will decrease with the increasing of the amount of Ce. Although the corrosion resistance of 2Cr13Ce steel is better than 2Cr13 steel, the corrosion resistance of 2Cr13Ce contained 0.28%Ce is better than the steel contained 1.39%Ce. In this experiment, when the Ce content is 0.28%, 2Cr13 stainless steel can have good mechanical property and corrosion resistant.

Abstract: High-property carbon refractories for blast furnaces should have high thermal conductivity and excellent porosity characteristics. The relationship between porosity characteristics and thermal conductivity of different graphite size (100mesh, 200mesh, 325mesh, 600mesh and 100mesh respectively) containing carbon refractories was investigated by using mercury porosimeter and laser thermal conductivity instrument. The results indicate that the thermal conductivity was reduced with the increase of porosity and <0.1μm pore volume as well as the decrease of mean pore diameter under the same condition, which was related to the short of thermal conductive route.