Applied Mechanics and Materials Vols. 457-458

Abstract: Polysulfone (PSF) hollow fiber ultrafiltration membranes were successfully prepared by dry-wet spinning technology. Dimethylacetamide (DMAC) was used as a solvent, water was used as bore liquid and coagulation bath, polyvinylpyrrolidone (PVP) was used as polymeric additive. The effects of spinning conditions on membrane structures and properties were investigated in present study. The results indicated that with the increase of PVP concentration, pure water flux increased and developed finger-like pores were formed. High coagulation bath temperature restricted pure water flux, 30°C was the best for the preparation of high-performance ultrafiltration membranes. When the air length was 11cm, the membrane comprehensive performance was the best.

Abstract: This paper summarizes the method of benzoin condensation reaction, and studied the influence of benzoin yield under different ultrasonic frequency and phase transfer catalyst, Experiments prove that benzyltriethylammonium bromide is the best phase transfer catalyst in three catalysts and the benzoin yield increased with the increase of ultrasonic frequency.

Abstract: The influence rules of the mineral admixtures containing fly ash, ground slag and silica fume on the early-age autogenous shrinkage of high-performance concrete have been discussed in this paper. According to the research results, fly ash mixture can substantially decrease the early-age autogenous shrinkage of high-performance concrete, while the silica fume will increase the autogenous shrinkage. Meanwhile the influence of ground slag on autogenous shrinkage is related to its fineness and admixture amount. Generally, it is believed that when the fineness of the fly ash is higher than 4000cm2/g, the autogenous shrinkage will increase with the increasing admixture amount. The double admixture or multi-admixture of fly ash or ground slag is better for reducing the early-age autogenous shrinkage of concrete than the single-admixture. The early-age autogenous shrinkage of concrete occurs in distinctive linear dependence with the three types of mineral admixtures.

Abstract: Due to the practical problems nowadays that the duty cycle is small and the utility rate of solar energy is low of photoelectric sensor light sensitive array, and having analyzed the advantages on solar energy utilization of square aperture spherical micro-lens than traditional circular aperture micro-lens array, we conduct a research on the fabricating of square aperture spherical micro-lens and testing technology. With the help of light spread theory, we analyses the relationship between light amplitude distributing rules, exposure length and exposure energy, establish a mathematical model of light distributing rules and use computer software to emulate the model. The results indicate solar energy distributes regularly in adhesive film. If the energy is fixed, exposure length will gradually become saturated following time. At the same time, we fabricate infrared quartz micro-lens array with array 256×256, single element lens 40×40μm, spherical radius 60μm, single element spacing 1μm.The experiment data are the same as emulation results.

Abstract: Intact Fe₃O₄/polyaniline (PANI) composite hollow microspheres were prepared by using hollow glass microspheres (HGS) as substrate. Fe₃O₄ nanoparticles were synthesized by adding surfactant of sodium dodecyl-benzenesulfonate (SDBS). HGS was pretreated by silane coupling agent, and consequently adsorbed magnetic iron oxide. A successive coating of polyaniline layer on HGS/Fe₃O₄ was involved through polymerization of aniline with HCl as dopant, and finally the multifunctional composite hollow microspheres (HGS/Fe₃O₄/PANI) were obtained.The morphology analysis by SEM revealed that the composite microspheres were formed by a layer of dense Fe₃O₄ nanoparticles and a layer of PANI on HGS. It was found that the conductivity of the prepared HGS/Fe₃O₄/PANI was about 10^-3 S/cm, and the magnetization was of 5.60 emu/g, indicating the composite microspheres were multifunctional with conductive and magnetic properties.

Abstract: The deformation of constant flow and closed type hydrostatic rotary table of heavy duty CNC machine tool has a great influence on the film thickness because of its large diameter, high load-bearing. According to the circular plate deformation theory of elasticity, differential equations of worktable deformation are derived in the simply supported conditions when bearing uniform force of different locations. Displacement curves of worktable are obtained. Force and deformation weaknesses of hydrostatic rotary table are found, which can provide theory basis for supporting location of heavy workpiece machining and whether oil film is failure or not.

Abstract: Calculation of car brake system design, also according to the known automotive related parameters is obtained by calculating the main parameters. The brake and braking torque, braking moment and braking force distribution coefficient and hydraulic brake drive mechanism related parameters. Finally, the braking performances are analyzed in detail.

Abstract: An eddy current detection and automatic separating system is developed to defect the weld defects in HFW pipe and separate the defective pipe. Application of phase sensitive detector, the pure signal of the weld defect is obtained through a low-pass filter. The information of the weld defect signal, the displacement of flying saw and the welding speed of welded pipe are fused together. The mathematical model is established for unfixed length truncation of the defective welded pipe. An automatic separating system is designed to cut and separate the defective welded pipes in the production line. The practice shows that this system can accurately detect the weld defect, cut the welded pipe in the perfect position and maximumly reserve the welded pipe without defect. This detection and separating system can improve the quality of the welded pipes and avoid the waste.

Abstract: In this paper, we propose a three-dimensional analytical model based on Greens Function to investigate the Impact of temperature rising on simple lithium-ion batteries and control the heat generation during charge/discharge of battery operation. The modeling is based on heat-transform mechanism analysis method that gives a closed-form solution for the fundamental problem of heat conduction in battery cores with orthotropic thermal conductivities. The method uses a simple lithium-ion battery examined, considered the ambient temperature and initial temperature as 25°C, subjected to transient heat generation in various convective cooling boundary conditions at its surfaces.

Abstract: The objective of this paper provides a numerical implementation procedure of thermo-metallurgical-mechanical constitute equation based on additively decomposition of strain rate. Together with phase transformation kinetics, the macro material properties are determined by assigning temperature dependent material properties to each phase and by applying mixture rule to combine. Then the constitute equation is implemented into general purpose implicit finite element program via user material subroutine. The effectiveness of developed computational method is confirmed by a Satoh test simulation. Simulation of Satoh test demonstrates that transformation induce plasticity has significant effect of the evolution of residual stress and can not be neglected for alloy steel during hot working process.