Advanced Materials Research Vols. 139-141

Abstract: A new method of rolling-plowing-extrusion is proposed for fabricating outside 3D integral fins on the stainless steel tube. The fabricated process of fins is divided into two stages, rolling and plowing-extrusion, at first ribs are obtained on the stainless steel tube by the rolling process, and then 3D integral fins are obtained by the plowing-extrusion process. In this study, the principle of the rolling-plowing-extrusion is briefed; rolling process and plowing-extrusion process are analyzed, respectively. Through the experiments, the effect of technical parameters on fins forming and structures is investigated; experimental results are shown that accurate matching technical parameters and plowing tool angles is the key to the fins forming and structures; further analytical results indicate that when rolling speed and plowing speed is 50r/min, rolling feed rate is 0.16 mm/r, rolling depth is approximately 0.80-1.00mm, plowing feed rate is above 2.16mm/r, plowing depth is approximately 0.25-0.45mm, the optimal fins are obtained

Abstract: In this paper, the multidisciplinary design optimization based on Approximation Model for supercharge turbo is studied. Temperature and pressure loads are transferred to the solid model by distance-weighted function, and structure deformation is transferred to aerodynamic model by mesh regenerated method in order to avoid mesh aberration. The Multidisciplinary analysis (MDA) model of supercharge turbo considering aerodynamic, heat transfer, strength and vibration is obtained on the basis of information transferring, which is solved by iterated three times. The Kriging Approximation Model which fits the sample space accurately is employed in the MDO process to reduce computational cost. Results show that performance of supercharge turbo is improvement on the MDO system based on Approximation Model, meanwhile the computational time of the optimization system is saved. Also, this method is suitable for other Multidisciplinary Design Optimization problems.

Abstract: The bend-twist coupling design method of spar cap of 1.5MW wind turbine blade made by biased hybrid fibers is discussed, and the coupling parameter is established. It is found that flap-twist coupling effect is only related to the laminated materials, not sensitive to the geometry shape. When varying the angle of off-axis carbon fibers from 7.5° to 30° and the volume fraction from 10% to 90%, different bend-twist coupling effect can be obtained. The results show that the optimal angle of spar cap is closer to 18°, and of skins are about 13°. When constraints, such as fibers strain, the in-plane shear stress and Von Mises stress of static index, are added on the blade, the spar cap is optimized with about 45% carbon fiber volume fraction and 18° off-axis angle. Finally, the impact of natural frequencies of dynamic performance on the blade design is proved to be inessential.

Abstract: . For a medium or large-sized gear drive, in order to achieve the optimum weight reduction effect, an approach of weight reduction design is proposed that multi-objective optimization of gear parameters is carried out firstly, and then structural optimization is adopted to design the gear former. The rational design parameters of a gear drive are determined by the multi-objective optimization with minimizing the sum of gear volumes and the equivalent moment of inertia of input shaft (EMI) synchronously. Conceptual design of the former is given by structural topology optimization of the gear, and the reasonability of topology optimization can be demonstrated by static and dynamic analysis. The results indicate that for a double-reduction gearbox of 500KW co-rotating twin screw pulping extruder, the EMI of the gear drive reduces by 20.88% through the multi-objective optimization of gear parameters, and the moment of inertia of a bull gear reduces by 38.86% through structural topology optimization.

Abstract: In order to enhance design reliability of a co-rotating twin screw pulping extruder (TSPE), optimum design on screw parameters of the TSPE was studied based on the extrusion model. The maximum shear flux or the minimum power consumption, or the two synchronous optimizations were taken as objective functions, and constraint conditions, such as thread lead, depth of thread, screw rotational speed, number of reverse thread lead, actual top width of the flight, torsional strength and stiffness of the screw mandrel, and so on were confirmed base on actual requirements of the TSPE manufacture and application. The optimizing results show that two-objective optimum design results split the difference of the two single-objective optimum design, and it is the most economical in reducing manufacture cost of the equipment and pulping expenses.

Abstract: Production scheduling is the key for the enterprise efficiency improvement, and is hot research topic for the advanced manufacturing all the time. Green manufacturing has become the inevitable trend, but environmental protection is ignored in scheduling research and in fact it’s very important. The concept of green scheduling is put forward and the definition of green scheduling is present. The difference between green scheduling and traditional scheduling is contrasted. The environmental effect and the resource consumption are synthetically taken into account, accordingly the index system of green scheduling is constructed and the model of green scheduling is set up. The resolution strategy with two steps is put forward for green scheduling. Pareto optimal solution set is firstly obtained, and then Pareto optimal solutions are evaluated and determined with the standardization and the entropy weight, and the satisfying solution is finally searched out.

Abstract: A novel Wood-Polymer Composite, Wood-PSt composite combining both advantages of wood and polystyrene was fabricated by determining the polymerization craft of monomer in wood porous structure through impregnating monomer into wood pores and followed by in-situ polymerization through a thermal-catalyst treatment. The performance was examined, and its structure was also characterized by SEM and FTIR. The results indicate that the optimum polymerizing craft is: 80oC, 8h and 3% AIBN. Under the optimum craft, the mechanical properties involving modulus of elasticity and compression strength were linearly increased with content of polystyrene. SEM and FTIR show that styrene polymerized under the employed polymerization craft, and the resultant polystyrene relatively full generated in wood cellular structure, in accordance with the results of the optimum polymerizing craft. Such composite having good mechanical properties and biomass features can be widely used in fields of construction, traffic and furniture.

Abstract: At present there are a lot of waste of energy in the mechanical processing, which causes increasingly serious pollution of environment. Resource conservation and environmental protection are achieved through the application of green manufacturing technology in mechanical processing. Remanufacturing project, which is a green project according with national sustainable development, is a method to resolve the waste of resources. Laser remanufacturing is a new concept of advanced repair technology that integrates advanced processing technology of laser cladding, laser cladding materials technology and many other technologies. Laser remanufacturing technology is based on laser cladding which is a new surface modification technology. This article describes the technical characteristics and principles of laser cladding. And this paper introduces laser remanufacturing technology by the examples of rotors, gears, shafts and other large wearing parts. the laser remanufacturing technology with the fast development, high efficiency and precision, will not only have a broad market demand, but also have significant economic and social benefits.

Abstract: The electronic products continue to upgrade at present, how to recycle the discarded electronic products is one of the key research of green design. The method of active disassembly using smart material (ADSM) has acquired widespread concerns. For some products, there is a long distance between the internal active disassembly structure and shell, it needs a long time to reach to the stimulation temperature of internal active disassembly structure, and therefore, it is difficult to completely disassemble these discarded electric products by one step. Moreover, it is not conducive to recycling the material if the components and parts of the disassembly products are mixed together, and the efficiency of disassembly is very low. This paper puts forward multi-step active disassembly method of products, it gives specific procedures of classifying steps according to the principle of division, and it proves the feasibility and superiority of the multi-step active disassembly method of products by referring to mobile model.

Abstract: Heat dissipation and cost are the key issues for light-emitting diode (LED) packaging. In this paper, based on the thermal resistance network model of LED packaging, three-dimensional heat dissipation model of high power multi-chip LED packaging is developed and analyzed with the application of finite element method. Temperature distributions of the current multi-chip LED packaging model are investigated systematically under the different materials of the chip substrate, die attach, and/or different structures of the heat sink and fin. The results show that the junction temperature can be decreased effectively by increasing the height of the heat sink, the width of the fin, and the thermal conductivity of the chip substrate and die attach materials. The lower cost and higher reliability for LED source can be obtained through reasonable selection of materials and structure parameters of the LED lighting system.