Advanced Materials Research Vols. 482-484

Abstract: This paper first to roll bending forming algorithm is-implicit algorithm and genetic algorithm was carried on the detailed comparison demonstrates to the existing literature experiment for object model, based on the implicit algorithm, established for prediction of the residual stress multi-channel times roll bending forming simulation method, solve the problems of the simulation process convergence, and the influence of the cold bending forming the prediction precision steel simulation parameters were analyzed. Sure the implicit algorithm based on the roll bending forming lane simulation method, and emphasizes to discuss how to solve the resulting convergence problem.

Abstract: The effects of different electromagnetic field and technological parameters on the microstructure and composition segregation of Pb-80%Sn alloy were studied. The results show that, both rotating and spiral magnetic field can improve the composition segregation ,refine grains of alloy. Moreover,the spiral magnetic field is more effective on improving composition homogenization and grain refining. The electromagnetic force distribution of spiral magnetic field is more helpful to form a well stirring in a larger zone and promote the formation of equiaxed grains, and the direction of the grain arrangement is much smaller. The technical parameters of spiral magnetic field have been optimized. It is found that, under the spiral magnetic field condition, when stirring time and exciting current exceeded a critical value, the size of the primary phase became larger. Therefore, there existed an optimum value of magnetic stirring parameters for the homogenization of component and refinement of grains.

Abstract: The characterizations of hot working behavior of a near-α titanium alloy using the approach of processing maps are described. Processing map in the α+β region exhibit a domain of the globularization process of lamellar structure and α dynamic recrystallization with a power dissipation efficiency of 0.6-0.9. In the β region the map exhibited a domain centered around 1060°C and 0.1 s^-1 with a power dissipation efficiency of 0.76 where the β phase undergoes dynamic recrystallization. At higher strain rate flow instability occurs in the α+β region due to adiabatic shear bands formation as well as in the β region due to flow inhomogeneity of β phase.

Abstract: The glass transition temperaure Tg of amorphous polymer thin film was investigated. The opposite experimental results, the increase or decrease in Tg of thin film with decreasing film thickness, were found. It was believed that the free surface near the polymer-air interface has a smaller chain ends density, leading to the decrease in Tg; while the polymer-substrate interface has a larger chain ends density, resulting in the increase in Tg. However, there are a competition between the both, and the interaction of polymer and substrate is a dominant factor to affect Tg of thin film. In addition, the multilayer model of thin film was proposed to explain the effect of the free surface and the interface on the Tg of thin film.

Abstract: To obtain high-quality dried banana, by means of solid-phase micro-extraction, GC-MS, the total ion chromatogram (TIC) changes with time of banana aroma in different drying stages were analyzed. With searching in NISI Willy Database, the aromatic components of above samples were obtained. By classifying the types of the aroma components, the changes of its total number and the classification of substances were compared. A result was drawn that types of total aroma and its main ingredient changed slightly in its normal drying, and substances of esters had high content and the most species. But while drying to the anhydrous state, the main component material isoamyl butyrate transferred to furfural, and Aldehydes, ketones, furans substances increased significantly. These changes were associated with the physical diffusion of material components, biochemical synthesis and chemical decomposition. The results provide a basis for high-quality and high-efficiency banana dryer design.

Abstract: In this paper, spectrum analysis is conducted on wear elements in lubricating oil of a heavy vehicle to study the wear conditions. The wear elements in lubrication oil of the heavy vehicle’s transmission system were analyzed, and the evaluation value of wearied vehicle is calculated by processing spectrum data using fuzzy set theory. The two-dimensional concentration gradient model of the vehicle’s wear and tear state is obtained. The method provides the basis for understanding and judging wear action and fault diagnosis of the vehicle intelligently.

Abstract: The main purpose of this paper is to research the mechanical properties of polyurethane filled steel tube PFST members with different hoop coefficients and slenderness ratios under axial compression by experimental studies. The influencing laws on stability, ductility and properties of axial compression of the PFST members are got, and the simplified calculating formula for ultimate loading capacity is presented by the regressive analysis.

Abstract: Fibrous membranes with a fiber diameter between 320 and 460 nm were electrospun from poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-graft-poly(N-vinylpyrrolidone) (PHBV-g-PVP) and their specific water absorption behaviors were investigated for biomaterial purposes. Water swelling experiments indicate that all samples have a great capacity for water uptake, while a remarkable overshoot occurs for the membranes electrospun from PHBV-g-PVP other than those from PHBV. DSC characterization indicates that only non-freezable bound water and free water can be distinguished in all electrospun membranes.

Abstract: The weight loss rate, FTIR characteristic, static mechanical properties and dynamic mechanical properties of neat epoxy resin and glass fiber/ epoxy resin laminates (GF/EP) after thermal-cold cycling were studied in this paper. The rule of static tensile and flexural strength of neat epoxy resin and GF/EP after ageing was investigated through the static mechanical properties analysis. The ageing mechanism of GF/EP was studied by analyzing the storage modulus (E′), loss modulus (E"), loss factor of GF/EP and FITR of epoxy resin. The results show that the weight loss rate increases with the ageing time，which is up to 9% after 400 times ageing cycle. The strength and flexural strength of GF/EP decreased by 6% and 21% after ageing, while the tensile strength of neat epoxy resin increases by 8% and its flexural strength increases slightly after ageing. The mechanism analysis reveals that internal defects of GF/EP would be induced by thermal-cold cycling stress, which results in the interface bonding strength dropping and the performance reducing.

Abstract: With practical small coal roadway coal winning machine for reference to the tunneling of the prototype, the mining of coal industry robot is analyzed. The coal set up 3 d model of the robot, and analyzed the main part. Coal institutions became a hybrid driven simplified controllable seven poles structure model, the use of robots COSM OSM otion coal mining mechanism model of the simulation and analysis, and the results show that: through a mixture of drive controllable institutions can make the smaller of input enough amplifier, which can save energy, reflected the superiority of the composite driving controllable institutions. And on a movement cycle repeated impact there, this characteristic is suitable for the coal mining robots work characteristics, can reduce the reaction, which is beneficial to the whole of the equipment operation.