Electrorheologica (ER) technique is a developing technology. In a wide range of engineering applications of ER fluid, shock absorbers employing ER fluids, whose damping force can be controlled continuously and promptl...Electrorheologica (ER) technique is a developing technology. In a wide range of engineering applications of ER fluid, shock absorbers employing ER fluids, whose damping force can be controlled continuously and promptly through electric signals, is one of the most prospective applications of ER fluid. In this paper, the theoretical midel and method to predict the damping force of ERF shock absorbers are established.展开更多
The electrorheological fluid(ERF)is a kind of intelligent material withbright prospects for industry applications, which has viscoelastic characteristic under the appliedelectric field. The dynamic model of a milling ...The electrorheological fluid(ERF)is a kind of intelligent material withbright prospects for industry applications, which has viscoelastic characteristic under the appliedelectric field. The dynamic model of a milling system with an ERF damper is established, and thechaffer suppression mechanism of the ER effect is discussed theoretically. Both the theoreticalstudy and the experimental investigation show that the additional damping and additional stiffnessproduced by the ERF increase with the rise in the strength of electric field E, but their influenceon the cuffing stability is different. Only when both additional damping and additional stiffnesscooperate, the milling chatter can be suppressed quickly and effectively. In additional, an ERFdamper used on the arbor of horizontal spindle milling machine is developed, and a series of millingchatter control experiments are performed. The experimental results show that the milling chaffercan be suppressed effectively by using the ER damper.展开更多
The passive suspension system of tracked vehicle is designed to get its suspension parameters based on a certain common velocity and a certain road surface roughness. Its performance optimization only exists in a cert...The passive suspension system of tracked vehicle is designed to get its suspension parameters based on a certain common velocity and a certain road surface roughness. Its performance optimization only exists in a certain operating mode without far-ranging adaptability. Holding the damper basic frame form and applying semi-active suspension system based on MR (magnetorheological) damper, the vehicle can keep its optimum efficiency between energy dissipation and vibration reduction in all kinds of operating modes. Theoretical analysis and experiments show that the damping performances provided by this MRF(magnetorheological fluids) vane damper are same as those provided by traditional damper, and the new damper has the better controllability and adaptability.展开更多
With many features,the magnetorheological fluid( MRF) damper is widely applied in the semiactive vibration control system. And sensitivity analysis is an important method to study the influence weight of various param...With many features,the magnetorheological fluid( MRF) damper is widely applied in the semiactive vibration control system. And sensitivity analysis is an important method to study the influence weight of various parameters on damping force characteristics. A mathematical model of the output damping force on the MRF damper is established by the mechanism modeling method,a first order output sensitivity equation is deduced and the expression of the first order output sensitivity function is obtained. The first-order sensitivity functions of ten design parameters are solved,and the influence degree of system parameters change on the output force of MRF damper is analyzed by comparing the sensitivity index of the parameters. Two sensitivities of vibration velocity and control current are obtained through experiment to prove the other parameters sensitivity analysis conclusion by analogy verification,which provides guidance for the structure optimization design of MRF damper.展开更多
This paper presents an experimental study of the seismic response of a 0.6-scale three-story seismicresistant building structure consisting of a moment resisting frame （MRF） with reduced beam sections （RBS）, and a...This paper presents an experimental study of the seismic response of a 0.6-scale three-story seismicresistant building structure consisting of a moment resisting frame （MRF） with reduced beam sections （RBS）, and a frame with nonlinear viscous dampers and associated bracing （called the DBF）. The emphasis is on assessing the seismic performance for the design basis earthquake （DBE） and maximum considered earthquake （MCE）. Three MRF designs were studied, with the MRF designed for 100%, 75%, and 60%, respectively, of the required base shear design strength determined according to ASCE 7-10. The DBF with nonlinear viscous dampers was designed to control the lateral drift demands. Earthquake simulations using ensembles of DBE and MCE ground motions were conducted using the real-time hybrid simulation method. The results show the drift demand and damage that occurs in the MRF under seismic loading. Overall, the results show that a high level of seismic performance can be achieved under DBE and MCE ground motions, even for a building structure designed for as little as 60% of the base shear design strength required by ASCE 7-10 for a structure without dampers.展开更多
文摘Electrorheologica (ER) technique is a developing technology. In a wide range of engineering applications of ER fluid, shock absorbers employing ER fluids, whose damping force can be controlled continuously and promptly through electric signals, is one of the most prospective applications of ER fluid. In this paper, the theoretical midel and method to predict the damping force of ERF shock absorbers are established.
基金This project is supported by Provincial Science and Technology Foundation of Jilin, China(No.963532) Received October 11, 2001
文摘The electrorheological fluid(ERF)is a kind of intelligent material withbright prospects for industry applications, which has viscoelastic characteristic under the appliedelectric field. The dynamic model of a milling system with an ERF damper is established, and thechaffer suppression mechanism of the ER effect is discussed theoretically. Both the theoreticalstudy and the experimental investigation show that the additional damping and additional stiffnessproduced by the ERF increase with the rise in the strength of electric field E, but their influenceon the cuffing stability is different. Only when both additional damping and additional stiffnesscooperate, the milling chatter can be suppressed quickly and effectively. In additional, an ERFdamper used on the arbor of horizontal spindle milling machine is developed, and a series of millingchatter control experiments are performed. The experimental results show that the milling chaffercan be suppressed effectively by using the ER damper.
文摘The passive suspension system of tracked vehicle is designed to get its suspension parameters based on a certain common velocity and a certain road surface roughness. Its performance optimization only exists in a certain operating mode without far-ranging adaptability. Holding the damper basic frame form and applying semi-active suspension system based on MR (magnetorheological) damper, the vehicle can keep its optimum efficiency between energy dissipation and vibration reduction in all kinds of operating modes. Theoretical analysis and experiments show that the damping performances provided by this MRF(magnetorheological fluids) vane damper are same as those provided by traditional damper, and the new damper has the better controllability and adaptability.
基金Supported by the National Natural Science Foundation of China(No.51375423,51505410)the National Key Basic Research Program(No.2014CB046400)
文摘With many features,the magnetorheological fluid( MRF) damper is widely applied in the semiactive vibration control system. And sensitivity analysis is an important method to study the influence weight of various parameters on damping force characteristics. A mathematical model of the output damping force on the MRF damper is established by the mechanism modeling method,a first order output sensitivity equation is deduced and the expression of the first order output sensitivity function is obtained. The first-order sensitivity functions of ten design parameters are solved,and the influence degree of system parameters change on the output force of MRF damper is analyzed by comparing the sensitivity index of the parameters. Two sensitivities of vibration velocity and control current are obtained through experiment to prove the other parameters sensitivity analysis conclusion by analogy verification,which provides guidance for the structure optimization design of MRF damper.
文摘This paper presents an experimental study of the seismic response of a 0.6-scale three-story seismicresistant building structure consisting of a moment resisting frame （MRF） with reduced beam sections （RBS）, and a frame with nonlinear viscous dampers and associated bracing （called the DBF）. The emphasis is on assessing the seismic performance for the design basis earthquake （DBE） and maximum considered earthquake （MCE）. Three MRF designs were studied, with the MRF designed for 100%, 75%, and 60%, respectively, of the required base shear design strength determined according to ASCE 7-10. The DBF with nonlinear viscous dampers was designed to control the lateral drift demands. Earthquake simulations using ensembles of DBE and MCE ground motions were conducted using the real-time hybrid simulation method. The results show the drift demand and damage that occurs in the MRF under seismic loading. Overall, the results show that a high level of seismic performance can be achieved under DBE and MCE ground motions, even for a building structure designed for as little as 60% of the base shear design strength required by ASCE 7-10 for a structure without dampers.
