A new contact model of traveling wave ultrasonic motor (TWUSM) with a visco-elastic stator frictional layer was presented. In this model, the initial boundaries were revised, and the rotor revolution speed could he ...A new contact model of traveling wave ultrasonic motor (TWUSM) with a visco-elastic stator frictional layer was presented. In this model, the initial boundaries were revised, and the rotor revolution speed could he calculated iteratively. This model was compared with compliant slider and rigid stator model. The results of motor characteristics simulations showed that the motors based on this model would gain bigger stall torque. Then the friction and wear characteristics of two models were analyzed. The motors based on this model had lower coefficient of friction and better wear resistance.展开更多
Product design plays a decisive role in material resource consumption in manufacturing systems. So it is significant to study optimal utilization of material resources of manufacturing system from the perspective of p...Product design plays a decisive role in material resource consumption in manufacturing systems. So it is significant to study optimal utilization of material resources of manufacturing system from the perspective of product design. This paper firstly defines concept of product design, then after an analysis of design objectives the author proposes a target system of product design with three subsystems: structural system, functional system, and technical system. Finally, a product design system on Architectural Metal Structure Enterprises is developed and used in light of the great consumption of material resources in Metal Structure Enterprises. The system has got an obvious effect on improving comprehensive optimal using rate of material resources of enterprises, reducing design cycle, improving management of enterprises.展开更多
According to the critical size ratio for the characteristic particle size to film thickness between grinding wheel and work, the machining mechanisms in abrasive jet precision finishing with grinding wheel as restrain...According to the critical size ratio for the characteristic particle size to film thickness between grinding wheel and work, the machining mechanisms in abrasive jet precision finishing with grinding wheel as restraint can be categorized into four states, namely, two-body lapping, three-body polishing, abrasive jet machining and fluid hydrodynamic shear stress machining. The critical transition condition of two-body lapping to three-body polishing was analyzed. The single abrasive material removal models of two-body lapping, three-body polishing, abrasive jet finishing and fluid hydrodynamic shear stress machining were proposed. Experiments were performed in the refited plane grinding machine for theoretical modes verification. It was found that experimental results agreed with academic modes and the modes validity was verified.展开更多
This paper introduces an efficient holistic approach to the design optimization of lightweight structures of braided fiber-reinforced plastic material. The approach aims to mitigate the paradox of making design decisi...This paper introduces an efficient holistic approach to the design optimization of lightweight structures of braided fiber-reinforced plastic material. The approach aims to mitigate the paradox of making design decisions at early development phases, when necessary information is incomplete or lacking detail so as to properly make these decisions. However, expert knowledge is available and though it is imprecise in nature, it can compensate to create useful models. Manufacturing effort for the braiding process has been described by information accumulated via interviews with braiding experts. This information is then modelled using the soft-computing approach by fuzzy-rule-based systems. The resulting models can further be efficiently integrated into the structural design optimization process. A multidisciplinary design optimization is facilitated considering several aspects including manufacturing effort and structural mechanics, which can be used in early design phases leading to more holistic designing and, thereby, unlocking lightweight and cost-reducing potentials. Benefits of this method, including viability and ease of implementation, are proven by investigations on two academic test problems before advancing to the challenging automotive engineering design problem of the roadster A-pillar.展开更多
基金Sponsored by the Natural Sciences Foundation of China (Grant No 50575055)the National 973 Key Development Project in Fundamental Science Research (Grant No2007CB607602)
文摘A new contact model of traveling wave ultrasonic motor (TWUSM) with a visco-elastic stator frictional layer was presented. In this model, the initial boundaries were revised, and the rotor revolution speed could he calculated iteratively. This model was compared with compliant slider and rigid stator model. The results of motor characteristics simulations showed that the motors based on this model would gain bigger stall torque. Then the friction and wear characteristics of two models were analyzed. The motors based on this model had lower coefficient of friction and better wear resistance.
基金Foundation item: Funded by China 863 R&D Program(No: 2002AA414080)
文摘Product design plays a decisive role in material resource consumption in manufacturing systems. So it is significant to study optimal utilization of material resources of manufacturing system from the perspective of product design. This paper firstly defines concept of product design, then after an analysis of design objectives the author proposes a target system of product design with three subsystems: structural system, functional system, and technical system. Finally, a product design system on Architectural Metal Structure Enterprises is developed and used in light of the great consumption of material resources in Metal Structure Enterprises. The system has got an obvious effect on improving comprehensive optimal using rate of material resources of enterprises, reducing design cycle, improving management of enterprises.
基金Sponsored by the National Natural Science Foundation of China (Grant No 50475052)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No 20040145001)
文摘According to the critical size ratio for the characteristic particle size to film thickness between grinding wheel and work, the machining mechanisms in abrasive jet precision finishing with grinding wheel as restraint can be categorized into four states, namely, two-body lapping, three-body polishing, abrasive jet machining and fluid hydrodynamic shear stress machining. The critical transition condition of two-body lapping to three-body polishing was analyzed. The single abrasive material removal models of two-body lapping, three-body polishing, abrasive jet finishing and fluid hydrodynamic shear stress machining were proposed. Experiments were performed in the refited plane grinding machine for theoretical modes verification. It was found that experimental results agreed with academic modes and the modes validity was verified.
文摘This paper introduces an efficient holistic approach to the design optimization of lightweight structures of braided fiber-reinforced plastic material. The approach aims to mitigate the paradox of making design decisions at early development phases, when necessary information is incomplete or lacking detail so as to properly make these decisions. However, expert knowledge is available and though it is imprecise in nature, it can compensate to create useful models. Manufacturing effort for the braiding process has been described by information accumulated via interviews with braiding experts. This information is then modelled using the soft-computing approach by fuzzy-rule-based systems. The resulting models can further be efficiently integrated into the structural design optimization process. A multidisciplinary design optimization is facilitated considering several aspects including manufacturing effort and structural mechanics, which can be used in early design phases leading to more holistic designing and, thereby, unlocking lightweight and cost-reducing potentials. Benefits of this method, including viability and ease of implementation, are proven by investigations on two academic test problems before advancing to the challenging automotive engineering design problem of the roadster A-pillar.