Advanced Materials Research Vols. 150-151

Abstract: Wavelet analysis is a popular subject in science research. The notion of univariate orthog- -onal wavelet packs is generalized. First, the notion of biorthogonal nonseparable trivariate wavelet packs is proposed and a procedure for constructing them is presented. Next, the biorthogonality pro- -perty of trivariate wavelet packs is investigated, and three biorthogonality formulas of wavelet packs are established. Moreover, it is shown how to gain new Riesz bases of space from these wavelet packs.

Abstract: The application of thermoelastic stress analysis in composite materials is particularly complicated because of the anisotropy of the material, which determines the thermoelastic effect to be depended on the material property and mechanical performance. This paper describes a theoretical and experimental analysis on full-filed stress distribution from thermoelastic measurements and its application to determination of stress concentration. The sum of the principal stress can be measured by Thermal Stress Analysis (TSA). Lock-in Thermography has been applied to measure the sum of principal stress distribution of component structure by its high thermal resolving. In this study, Experiments were carried out with GFRP composite ply and foam materials under cyclic load. The thermoelastic constant is obtained for GFRP and foam composite materials. The stress concentration is analyzed for a specimen with a hole. The experimental results show the stress distribution can be measured and analyzed using Lock-in thermography. It is found that the composite material structure stress can be evaluated with good accuracies by lock in thermography.

Abstract: Fly ash can improve the physical and mechanical properties of the magnesium phosphate cement (MPC) paste. The influence of fly ash on the strength, the mortar fluidity, the durability and the setting time of MPC paste were studied in this paper. The results show that: The function of fly ash to the MPC is as followed: physical fill, superplastic and chemical reactions; the optimal content of fly ash is about 30% by weight, and MPC with 30% fly ash has excellent mechanical property and high fluidity; the fineness of magnesia affected the mechanical properties of MPC.

Abstract: A novel conducting copolymer, was successfully achieved by electrochemical oxidation of the monomer mixtures of 3, 4-ethylenedioxythiophene (EDOT) and triphenylene (TP) in the acetonitrile solvent system containing 0.1 mol/L LiClO4. The resulting copolymer possesses the advantages of both polytriphenylene and poly(3, 4-ethylenedioxythiophene), such as good redox activity, considerable fluorescence property and relatively high electrical conductivity. Ultraviolet-visible, FT-IR and scanning electron microscopy were used to characterize and investigate the structure of the copolymers. Fluorescence spectra revealed that the copolymer dissolved in common organic solvents was a good blue light emitter, with a strong emission at 439 nm. All these results indicate that the copolymer films as obtained have many potential applications in various fields, such as organic light-emitting diodes (OLEDs).

Abstract: The purpose of this study is to investigate the effect of turning parameters on the surface integrity of Inconel 718. The turning parameters studied were cutting speed of 90, 120, 150 m/min, feed rate of 0.15, 0.25, 0.25mm/rev and depth of cut of 0.3, 0.4, 0.5 mm under minimum quantity lubricant (MQL) using coated carbide tool. surface response methodology (RSM) design of experiment using Box-Behnken approach has been employed consisting of various combination of turning parameters Surface roughness, surface topography, microstructure and the micro hardness of the machined surface were studied after the machining process. Feed rate was found to be the most significant parameter affecting the surface roughness. The optimum parameter was obtained with Ra equal to 0.243 µm at cutting speed of 150 m/min, feed rate of 0.25 mm/rev and depth of cut of 0.3mm. A mathematical model for surface roughness was developed using Response Surface Methodology. The effect of turning parameters and factor interactions on surface roughness is presented in 3D graphical form, which helps in selecting the optimum process parameters to achieve the desired surface quality.

Abstract: Carbonation of concrete for hydraulic structure containing mineral admixtures is studied. It is observed that the fly ash is not benefit to the carbonation resistance, and the different content of fly ash in concrete may play a different role without activator. However, concrete for hydraulic structure using binary admixture of fly ash and slag will make up the defects and when the fly ash to slag ratio is 1:1, the depth of carbonation decreases comparing to concrete using fly ash.

Abstract: Paper studies on phosphorus slag powder(PSP) processed from phosphorus slag with different open-air storage time, analyses the changes in the performance of PSP and the impact on properties of cementitious materials. The results showed that with the growth of open storage time, vitreous structure of PSP would gradually be decomposed, part of the vitreous would transform into crystal form. Density of powder would diminish and ignition loss increase. Activity of PSP would slowly decreases, and the activity differences main reflected after 90d. Concerning on the point of concrete strength rating, 10 years phosphorus slag can still be used. The above provide a basis for resource utilization of phosphorus slag with long storage time.

Abstract: Interlaminar behavior of paulownia wood sandwich can be enhanced by grooves arranged on the surface of the paulownia wood core. Three kinds of silane coupling agents are used by three different ways in order to improve the interface furtherly. All the specimens are manufactured by VARIM process. DCB method is used to measure the interlaminar energy release ratio(ERR) between the face sheet and paulownia wood core. By comparing the ERRs, the way that core surface pretreated by agent-added resins gets the most effective improvement. By analyzing the component of the ERRs, the improvement mostly comes from the interfaces of glass fibers and vinyl resins left in the grooves. The adhesion of the vinyl resin and paulownia wood gets little benefit from the coupling agents.

Abstract: In this paper, a series of polyurethane elastomers (PUE) were prepared employing casting method using toluene diisocyanate (TDI), hydroxy-terminated butadiene-acrylonitrile copolymer(HTBN) and polytetrahydrofuran glycol (PTMG) as the main raw materials, and using 2,4- and 2,6- dimethylthioaromatic diamine (DMTDA) as a chain extender. The effects of the content of NCO in PUE (NCO%), mass ratio of HTBN/PTMG, molecular weight of PTMG, dosage of chain extender and heat treatment on the mechanical properties of PUE were studied. The results showed that the lower molecular weight of PTMG and the higher heat treatment temperature were both favorable for increasing the mechanical properties of PUE. When the mass ratio of HTBN/PTMG was 35:65, NCO% was 6.0%, molar ratio of NCO/NH2 was 1.20 and heat treatment time was 2h at 115 , the mechanical properties of PUE were best.

Abstract: According to the dissipation energy principles of plastic Three-dimensional finite element analysis of antiseismic capability of Fe/Zn composite by the finite element software ANSYS. It is the very first time to study responds process of earthquake of metal layer composite. Observed in “Time Hist Postpro” that biggest stress of Fe is lower than the yield intensity of Fe, the biggest stress of Zn is bigger than the yield intensity, Fe supports load and Zn absorbs energy are proved. It is provided to the theories for the system of the new material according to.