MgAl2O4 particle-reinforced AC4C based alloy composites were fabricated by the stirring-casting method. The effects of the average sizes and the size distributions of MgAl2O4 particles on the dispersibility were inves...MgAl2O4 particle-reinforced AC4C based alloy composites were fabricated by the stirring-casting method. The effects of the average sizes and the size distributions of MgAl2O4 particles on the dispersibility were investigated, and the microstructures, strength, and fatigue properties of MgAl2O4 particle-reinforced AC4C based alloy composites were evaluated. Tensile strength in the MgAl2O4 particle-reinforced AC4C based alloy composite was increased by using the classified particles. The fatigue limit at 107 cycles in the MgA1204 particle-reinforced AC4C-Cu composite increased by 27% compared to the unreinforced alloy at 250 ~C. Dislocations were observed in the matrix around the MgAl204 particle which resulted from the mismatch of thermal expansion coefficients between MgAl2O4 and Al, and resisted failure and caused fatigue cracks to propagate around the MgAl2O4 particles, resulting in extensive crack deflection and crack bowing which contributed to the improvement of fatigue strength.展开更多
In this paper,we consider the fuel economy optimization problem for a mild hybrid electric vehicle(HEV)using hierarchical model predictive control.In the proposed algorithm,two problems are addressed:eco-driving and t...In this paper,we consider the fuel economy optimization problem for a mild hybrid electric vehicle(HEV)using hierarchical model predictive control.In the proposed algorithm,two problems are addressed:eco-driving and torque distribution.In the eco-driving problem,vehicle speed was controlled.Considering the reduction in fuel consumption and NOx emissions,the torque required to follow the target speed was calculated.Subsequently,in the torque distribution problem,the distribution between the engine and motor torques were calculated.In this phase,engine characteristics were considered.These problems differ in terms of time scales;therefore,a hierarchical model predictive control is proposed.Lastly,the numerical simulation results demonstrated the efficacy of this research.展开更多
ISO 13565-3 provides an evaluation method for plateau structure surfaces used as sliding surfaces in machine tools and automobile engines.The evaluation method for plateau structure surfaces of ISO 13565-3 has problem...ISO 13565-3 provides an evaluation method for plateau structure surfaces used as sliding surfaces in machine tools and automobile engines.The evaluation method for plateau structure surfaces of ISO 13565-3 has problems,such as the processing procedure has an ambiguous basis,and the calculation method is not specified.The existing evaluation method that solves these problems requires the implementation of a difficult algorithm.In subsequent evaluation methods,these problems were resolved,and the implementation of complicated calculation algorithms became unnecessary.However,these methods use algorithms that do not conform to the evaluation method of ISO 13565-3.This lack of adherence to the ISO standard may hinder their application in the industrial world.Therefore,in this study,a new method that conforms to the evaluation method of ISO 13565-3 with a more concise algorithm was developed.We concluded that this proposed method can contribute to the formation of plateau surfaces and production control in the industrial world.展开更多
文摘MgAl2O4 particle-reinforced AC4C based alloy composites were fabricated by the stirring-casting method. The effects of the average sizes and the size distributions of MgAl2O4 particles on the dispersibility were investigated, and the microstructures, strength, and fatigue properties of MgAl2O4 particle-reinforced AC4C based alloy composites were evaluated. Tensile strength in the MgAl2O4 particle-reinforced AC4C based alloy composite was increased by using the classified particles. The fatigue limit at 107 cycles in the MgA1204 particle-reinforced AC4C-Cu composite increased by 27% compared to the unreinforced alloy at 250 ~C. Dislocations were observed in the matrix around the MgAl204 particle which resulted from the mismatch of thermal expansion coefficients between MgAl2O4 and Al, and resisted failure and caused fatigue cracks to propagate around the MgAl2O4 particles, resulting in extensive crack deflection and crack bowing which contributed to the improvement of fatigue strength.
文摘In this paper,we consider the fuel economy optimization problem for a mild hybrid electric vehicle(HEV)using hierarchical model predictive control.In the proposed algorithm,two problems are addressed:eco-driving and torque distribution.In the eco-driving problem,vehicle speed was controlled.Considering the reduction in fuel consumption and NOx emissions,the torque required to follow the target speed was calculated.Subsequently,in the torque distribution problem,the distribution between the engine and motor torques were calculated.In this phase,engine characteristics were considered.These problems differ in terms of time scales;therefore,a hierarchical model predictive control is proposed.Lastly,the numerical simulation results demonstrated the efficacy of this research.
文摘ISO 13565-3 provides an evaluation method for plateau structure surfaces used as sliding surfaces in machine tools and automobile engines.The evaluation method for plateau structure surfaces of ISO 13565-3 has problems,such as the processing procedure has an ambiguous basis,and the calculation method is not specified.The existing evaluation method that solves these problems requires the implementation of a difficult algorithm.In subsequent evaluation methods,these problems were resolved,and the implementation of complicated calculation algorithms became unnecessary.However,these methods use algorithms that do not conform to the evaluation method of ISO 13565-3.This lack of adherence to the ISO standard may hinder their application in the industrial world.Therefore,in this study,a new method that conforms to the evaluation method of ISO 13565-3 with a more concise algorithm was developed.We concluded that this proposed method can contribute to the formation of plateau surfaces and production control in the industrial world.
