To study the vibration transmission character istics of a flexible carbody and its suspended equipment, a vertical mathematical model of highspeed electric multiple unit was established with equipment excitation consi...To study the vibration transmission character istics of a flexible carbody and its suspended equipment, a vertical mathematical model of highspeed electric multiple unit was established with equipment excitation considered. And the dynamic unbalance and impact turbulence excita tion from equipment were taken into account in a single stage and twostage vibration isolation system, respectively. Results show that the excitation transferred to carbody increases with suspension stiffness but decreases with the equipment mass increasing; the vibration transmission can be reduced by increasing the equipment mass or reduce the suspension stiffness. To avoid vibration resonance, the dynamic unbalance frequency of equipment should be out of the possible range of the carbody flexible modes, and a small stiffness should be applied to reduce the impact tur bulence. A small stiffness, however, would result in a large movement of the equipment which is limited by the static deflection requirement, while a great stiffness will transfer high frequency vibration. Therefore, a preferred stiffness should make the suspension frequency of equipment a bit greater than the first bending mode of carbody. Additionally, a 3D rigidflexible coupled dynamics model was built to verify the mathematical analysis, and they show good agreements. Results show that a twostage isolation could reduce the excitation transmission and make the vibration of carbody and equipment acceptable.展开更多
Based on the system of electric power supply for flexible manufacturing systems (FMS), a study has been carried out on the intelligent safety examination, monitoring and maintenance of its running environment. On the ...Based on the system of electric power supply for flexible manufacturing systems (FMS), a study has been carried out on the intelligent safety examination, monitoring and maintenance of its running environment. On the basis of the specific feature of the power supply network of an FMS, real time monitoring system of the power supply network and the fault diagnostic expert system for the power equipment have been designed. This system can diagnose not only definite fault phenomena, but also fuzzy, uncertain fault phenomena as well. Fault diagnostic knowledge base for the power equipment has been founded hierarchy architecture model and the method of fault tree analysis. Feasibility of this system has been proved by computer simulation.展开更多
This paper proposes a novel clamping device for leveling equipment mounted on offshore oil platform jacket,which solves the problem of leveling equipment clamping lifting force of more than 2000 tons.The main features...This paper proposes a novel clamping device for leveling equipment mounted on offshore oil platform jacket,which solves the problem of leveling equipment clamping lifting force of more than 2000 tons.The main features are that lifting force transmits to clamp claw through wedge force amplifier,embed the teeth of claw into the pile,and the embedded depth increases with the lifting force,resulting in a gravitational self-locking function.This theoretical model of clamping device was established,and the force and material characteristic were analyzed,and the feasibility of the theoretical model was verified by thin shell elastic-plastic stability theory and thin-walled structures theory.An experimental prototype of clamping device was produced to test gravity self-locking function and bearable leveling force.Compared with the theoretical model and the experimental results,it proved that the embedded clamping devices have gravitational self-locking function and can meet the need of actual leveling equipment.展开更多
基金supported by the National Science and Technology Support Program of China (No. 2011 BAG10B01)the National Key Basic Research Program of China (No. 2011CB711100)+1 种基金the National Science and Technology Support Program of China (No. U1334206)the New Century Excellent Talents of Ministry of Education funded project (No. NCET-10-0664)
文摘To study the vibration transmission character istics of a flexible carbody and its suspended equipment, a vertical mathematical model of highspeed electric multiple unit was established with equipment excitation considered. And the dynamic unbalance and impact turbulence excita tion from equipment were taken into account in a single stage and twostage vibration isolation system, respectively. Results show that the excitation transferred to carbody increases with suspension stiffness but decreases with the equipment mass increasing; the vibration transmission can be reduced by increasing the equipment mass or reduce the suspension stiffness. To avoid vibration resonance, the dynamic unbalance frequency of equipment should be out of the possible range of the carbody flexible modes, and a small stiffness should be applied to reduce the impact tur bulence. A small stiffness, however, would result in a large movement of the equipment which is limited by the static deflection requirement, while a great stiffness will transfer high frequency vibration. Therefore, a preferred stiffness should make the suspension frequency of equipment a bit greater than the first bending mode of carbody. Additionally, a 3D rigidflexible coupled dynamics model was built to verify the mathematical analysis, and they show good agreements. Results show that a twostage isolation could reduce the excitation transmission and make the vibration of carbody and equipment acceptable.
文摘Based on the system of electric power supply for flexible manufacturing systems (FMS), a study has been carried out on the intelligent safety examination, monitoring and maintenance of its running environment. On the basis of the specific feature of the power supply network of an FMS, real time monitoring system of the power supply network and the fault diagnostic expert system for the power equipment have been designed. This system can diagnose not only definite fault phenomena, but also fuzzy, uncertain fault phenomena as well. Fault diagnostic knowledge base for the power equipment has been founded hierarchy architecture model and the method of fault tree analysis. Feasibility of this system has been proved by computer simulation.
文摘This paper proposes a novel clamping device for leveling equipment mounted on offshore oil platform jacket,which solves the problem of leveling equipment clamping lifting force of more than 2000 tons.The main features are that lifting force transmits to clamp claw through wedge force amplifier,embed the teeth of claw into the pile,and the embedded depth increases with the lifting force,resulting in a gravitational self-locking function.This theoretical model of clamping device was established,and the force and material characteristic were analyzed,and the feasibility of the theoretical model was verified by thin shell elastic-plastic stability theory and thin-walled structures theory.An experimental prototype of clamping device was produced to test gravity self-locking function and bearable leveling force.Compared with the theoretical model and the experimental results,it proved that the embedded clamping devices have gravitational self-locking function and can meet the need of actual leveling equipment.