Presented the methods to obtain the cogging force of permanent magnet linear synchronous motors(PMLSMs), analyzed the characteristics of the cogging force, and provided a basis for reducing the effect of the cogging f...Presented the methods to obtain the cogging force of permanent magnet linear synchronous motors(PMLSMs), analyzed the characteristics of the cogging force, and provided a basis for reducing the effect of the cogging force. 2-dimensional finite element method(2D FEM) was used to solve the whole motor when its mover was at dif- ferent position, so that the relation was derived between the cogging force and the mover position. The analysis results show that the cogging force between the two ends of the primary iron-core and the secondary permanent magnets (PMs) is sinusoidal function of the mover position under certain conditions only. Two proposed methods, namely direct and indirect methods, are applied to calculate the cogging force between the primary iron-core teeth and the secondary PMs. The agreement of the two methods is validated.展开更多
Objective: To analyze the stress distribution of calcaneus with posterior articular facet compressed after fracture and talus during gait. Methods: A wedge under the posterior articular was transected from a normal fi...Objective: To analyze the stress distribution of calcaneus with posterior articular facet compressed after fracture and talus during gait. Methods: A wedge under the posterior articular was transected from a normal finite element model of calcaneus and talus to simulate malformation of compression of the posterior facet after fracture of calcaneus. The model was used to simulate for three subphases of the stance during the gait(heel strike, midstance, push off) and calculate the finite element. The results were compared with normal situation. Results: The stress distribution within the bone in situation of malformation was obtained and regions of elevated stresses for three subphases were located. The results were significantly different from that of normal situation. Conclusion: The simulation of calcaneus and talus in malformation has important clinic implication and can provide an insight into the factors contributing to many clinic pathogenic changes after fracture of calcaneus.展开更多
A 3-D modeling of FEA （finite element analysis） design provides for high-speed synchronous with PMs （permanent magnets） applied in aerospace application will be examined under design considerations ofn = 12,000 rp...A 3-D modeling of FEA （finite element analysis） design provides for high-speed synchronous with PMs （permanent magnets） applied in aerospace application will be examined under design considerations ofn = 12,000 rpm, short-duty operation, and etc. for an ARWM （aerospace retraction wheel motor）. First, lumped-elements will be fine-tuned following numerical method results is reported steady-state and transient solutions. Besides, the equations of thermal modeling such as Re, N,,, G,. and Pr numbers in order to calculate heat-transfer coefficient of convection on the rotor and stator surfaces in the air-gap have calculated. This section illustrates the temperature distribution of each point in a clear view. By CFD （fluid dynamic analysis） analysis, the fluid dynamics were modeled, pressure and velocity streamlines of cooling-flow have analyzed. An optimization algorithm was derived in order to have optimized number of water-channels as well. Second, calculation of nodal and tangential forces which deal with mechanical stresses of the ARWM have represented. The paper discusses an accurate magnetic-field analysis that addresses equivalent stress distribution in the magnetic core through using the transient FEA to estimate motor characteristics. The whole model shear and normal mechanical stresses and total deformation oftbe ARWM has been investigated by transient FEA. The end-winding effects were included by the authors.展开更多
In this paper, using axial field finite analysis method, the field of a movable core type linear oscillation motor is analyzed. The program of axial field finite analysis is worked out. Using this program, we analyze ...In this paper, using axial field finite analysis method, the field of a movable core type linear oscillation motor is analyzed. The program of axial field finite analysis is worked out. Using this program, we analyze various fields, including the field excited by permanent magnet materials, the field by two coils respectively, and the fields with the core moving to various positions.展开更多
基金Supported by the National Natural Science Foundation of China (60474043)
文摘Presented the methods to obtain the cogging force of permanent magnet linear synchronous motors(PMLSMs), analyzed the characteristics of the cogging force, and provided a basis for reducing the effect of the cogging force. 2-dimensional finite element method(2D FEM) was used to solve the whole motor when its mover was at dif- ferent position, so that the relation was derived between the cogging force and the mover position. The analysis results show that the cogging force between the two ends of the primary iron-core and the secondary permanent magnets (PMs) is sinusoidal function of the mover position under certain conditions only. Two proposed methods, namely direct and indirect methods, are applied to calculate the cogging force between the primary iron-core teeth and the secondary PMs. The agreement of the two methods is validated.
文摘Objective: To analyze the stress distribution of calcaneus with posterior articular facet compressed after fracture and talus during gait. Methods: A wedge under the posterior articular was transected from a normal finite element model of calcaneus and talus to simulate malformation of compression of the posterior facet after fracture of calcaneus. The model was used to simulate for three subphases of the stance during the gait(heel strike, midstance, push off) and calculate the finite element. The results were compared with normal situation. Results: The stress distribution within the bone in situation of malformation was obtained and regions of elevated stresses for three subphases were located. The results were significantly different from that of normal situation. Conclusion: The simulation of calcaneus and talus in malformation has important clinic implication and can provide an insight into the factors contributing to many clinic pathogenic changes after fracture of calcaneus.
文摘A 3-D modeling of FEA （finite element analysis） design provides for high-speed synchronous with PMs （permanent magnets） applied in aerospace application will be examined under design considerations ofn = 12,000 rpm, short-duty operation, and etc. for an ARWM （aerospace retraction wheel motor）. First, lumped-elements will be fine-tuned following numerical method results is reported steady-state and transient solutions. Besides, the equations of thermal modeling such as Re, N,,, G,. and Pr numbers in order to calculate heat-transfer coefficient of convection on the rotor and stator surfaces in the air-gap have calculated. This section illustrates the temperature distribution of each point in a clear view. By CFD （fluid dynamic analysis） analysis, the fluid dynamics were modeled, pressure and velocity streamlines of cooling-flow have analyzed. An optimization algorithm was derived in order to have optimized number of water-channels as well. Second, calculation of nodal and tangential forces which deal with mechanical stresses of the ARWM have represented. The paper discusses an accurate magnetic-field analysis that addresses equivalent stress distribution in the magnetic core through using the transient FEA to estimate motor characteristics. The whole model shear and normal mechanical stresses and total deformation oftbe ARWM has been investigated by transient FEA. The end-winding effects were included by the authors.
文摘In this paper, using axial field finite analysis method, the field of a movable core type linear oscillation motor is analyzed. The program of axial field finite analysis is worked out. Using this program, we analyze various fields, including the field excited by permanent magnet materials, the field by two coils respectively, and the fields with the core moving to various positions.
