This study utilizes ANSYS to establish FEM's model of metamorphic core complex,and used thermal-structure analysis to simulate metamorphic core complex's temperature field and stress field.The metamorphic core...This study utilizes ANSYS to establish FEM's model of metamorphic core complex,and used thermal-structure analysis to simulate metamorphic core complex's temperature field and stress field.The metamorphic core complex formation mechanism is discussed.The simulation results show that the temperature field change appearing as the earth surface's temperature is the lowest,and the temperature of metamorphic core complex's nucleus is the highest.The temperature field is higher along with depth increase,and the stress field change appearing as the biggest stress occurs in the nucleus.The next stress field occurs at the top of the cover.展开更多
The rotary forging of a cartridge bottom is simulated by finite element method with DEFORM TM . The analysis of stress and strain rate results indicates that the deformation conditions and the final geometry of a prod...The rotary forging of a cartridge bottom is simulated by finite element method with DEFORM TM . The analysis of stress and strain rate results indicates that the deformation conditions and the final geometry of a product are not completely axis symmetrical under the partial loading conditions during the rotary forging operations. It is therefore required to have a few more rotary forging cycles at the end of total feeding to eliminate nonuniformity. The results of simulation show that the optimization of rotary forging process conditions can be achieved to avoid the underfill defect resulting from improper process conditions. This technology can be used to manufacture ring components with thin bottoms by properly controlling the working process and the tooling motion.展开更多
Nano-porous ultra-high specific surface ul- trafine fibers are created by the method of “electrospin- ning-phase separation-leaching” (EPL) for the first time. First of all, polymer solutions of polyacrylonitrile (P...Nano-porous ultra-high specific surface ul- trafine fibers are created by the method of “electrospin- ning-phase separation-leaching” (EPL) for the first time. First of all, polymer solutions of polyacrylonitrile (PAN) and polyvinylpyrrolidone (PVP) blends dissolved in co-solvent are electrospun to make ultrafine fibers when charged to high voltages. The incompatibility of PAN and PVP induces phase separation to form microdomains of PVP in the poly- mer blend ultrafine fibers. Then, PVP microdomains in the blend fibers are leached out in water, and porous PAN ul- trafine fibers are obtained. Lastly, the surface and cross-section of the porous ultrafine fibers are observed in detail by field emission scanning electron microscope (FE- SEM), and the specific surface of the ultrafine fibers is measured by means of nitrogen absorption. With increasing the content of PVP, the specific surface area of the ultrafine fibers increases apparently. The specific surface area of the porous ultrafine fibers with the diameter of 2130 nm is more than 70 m2·g?1. The cross-section of the PAN porous ultrafine fibers after leaching of PVP microdomains from polymer blend fibers with the feed ratio of PAN/PVP of 10/20 shows the characteristic of porous structure with pore diameter of ca 30 nm according to FESEM photo.展开更多
文摘This study utilizes ANSYS to establish FEM's model of metamorphic core complex,and used thermal-structure analysis to simulate metamorphic core complex's temperature field and stress field.The metamorphic core complex formation mechanism is discussed.The simulation results show that the temperature field change appearing as the earth surface's temperature is the lowest,and the temperature of metamorphic core complex's nucleus is the highest.The temperature field is higher along with depth increase,and the stress field change appearing as the biggest stress occurs in the nucleus.The next stress field occurs at the top of the cover.
文摘The rotary forging of a cartridge bottom is simulated by finite element method with DEFORM TM . The analysis of stress and strain rate results indicates that the deformation conditions and the final geometry of a product are not completely axis symmetrical under the partial loading conditions during the rotary forging operations. It is therefore required to have a few more rotary forging cycles at the end of total feeding to eliminate nonuniformity. The results of simulation show that the optimization of rotary forging process conditions can be achieved to avoid the underfill defect resulting from improper process conditions. This technology can be used to manufacture ring components with thin bottoms by properly controlling the working process and the tooling motion.
文摘Nano-porous ultra-high specific surface ul- trafine fibers are created by the method of “electrospin- ning-phase separation-leaching” (EPL) for the first time. First of all, polymer solutions of polyacrylonitrile (PAN) and polyvinylpyrrolidone (PVP) blends dissolved in co-solvent are electrospun to make ultrafine fibers when charged to high voltages. The incompatibility of PAN and PVP induces phase separation to form microdomains of PVP in the poly- mer blend ultrafine fibers. Then, PVP microdomains in the blend fibers are leached out in water, and porous PAN ul- trafine fibers are obtained. Lastly, the surface and cross-section of the porous ultrafine fibers are observed in detail by field emission scanning electron microscope (FE- SEM), and the specific surface of the ultrafine fibers is measured by means of nitrogen absorption. With increasing the content of PVP, the specific surface area of the ultrafine fibers increases apparently. The specific surface area of the porous ultrafine fibers with the diameter of 2130 nm is more than 70 m2·g?1. The cross-section of the PAN porous ultrafine fibers after leaching of PVP microdomains from polymer blend fibers with the feed ratio of PAN/PVP of 10/20 shows the characteristic of porous structure with pore diameter of ca 30 nm according to FESEM photo.
