In cryogenic wind tunnel tests,piezoelectric stacks are adopted to realize the vibration control of the cantilever sting.However,the free stroke and blocking force of the piezoelectric stack would decrease dramaticall...In cryogenic wind tunnel tests,piezoelectric stacks are adopted to realize the vibration control of the cantilever sting.However,the free stroke and blocking force of the piezoelectric stack would decrease dramatically as the temperature decreases.This paper proposes a convenient and effective warming structure for the piezoelectric stack,which could keep it working at operating temperatures when the ambient temperature drops.The piezoelectric stack actuator is wrapped with the heating film,and this resulting assembly is then wrapped with the aerogel material for thermal insulation.Both ends of the piezoelectric stack actuator make direct contact with the payload structure.Both one-dimensional and two-dimensional theoretical analyses of the heating conduction problem of the piezoelectric stack actuator are conducted.These analyses results are compared with those of the finite element simulation analysis.The finite element method results show a good consistency with the two-dimensional theoretical results,and a slight deviation of only 0.91 K is observed,indicating its potential for protecting piezoelectric stacks at low temperatures.展开更多
In order to improve the performance of whole-spacecraft vibration isolation systems,choosing piezoelectric stacks and viscoelastic material as the active and passive vibration isolation components,an innovative whole-...In order to improve the performance of whole-spacecraft vibration isolation systems,choosing piezoelectric stacks and viscoelastic material as the active and passive vibration isolation components,an innovative whole-spacecraft hybrid vibration isolation system (WSHVIS) is designed and studied.The finite element method is used to establish the dynamic model of WSHVIS and analyze its frequency response characteristic.According to the analysis results,eigensystem realization algorithm is applied to obtain the minimum-order state-space model of WSHVIS,which is used to design controller.On this basis,off-line simulation and on-line realization for the WSHVIS is performed.The simulation and experimental results showed that WSHVIS can effectively reduce the vibration loads transmitted from launch vehicle to spacecraft.Compared with passive vibration isolation system,the hybrid vibration isolation system has a significant inhibitory effect on the low-frequency vibration components,and can greatly increase the safety and reliability of spacecraft.展开更多
基金the National Natural Science Foundation of China(No.11872207)Aeronautical Science Foundation of China(No.20180952007)+2 种基金Foundation of National Key Laboratory on Ship Vibration and Noise(No.614220400307)Natural Science Foundation of Jiangsu Province(No.BK20200413)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘In cryogenic wind tunnel tests,piezoelectric stacks are adopted to realize the vibration control of the cantilever sting.However,the free stroke and blocking force of the piezoelectric stack would decrease dramatically as the temperature decreases.This paper proposes a convenient and effective warming structure for the piezoelectric stack,which could keep it working at operating temperatures when the ambient temperature drops.The piezoelectric stack actuator is wrapped with the heating film,and this resulting assembly is then wrapped with the aerogel material for thermal insulation.Both ends of the piezoelectric stack actuator make direct contact with the payload structure.Both one-dimensional and two-dimensional theoretical analyses of the heating conduction problem of the piezoelectric stack actuator are conducted.These analyses results are compared with those of the finite element simulation analysis.The finite element method results show a good consistency with the two-dimensional theoretical results,and a slight deviation of only 0.91 K is observed,indicating its potential for protecting piezoelectric stacks at low temperatures.
基金Sponsored by the Commission of Science Technology and Industry for National Defense (Grant No.C4120062301)
文摘In order to improve the performance of whole-spacecraft vibration isolation systems,choosing piezoelectric stacks and viscoelastic material as the active and passive vibration isolation components,an innovative whole-spacecraft hybrid vibration isolation system (WSHVIS) is designed and studied.The finite element method is used to establish the dynamic model of WSHVIS and analyze its frequency response characteristic.According to the analysis results,eigensystem realization algorithm is applied to obtain the minimum-order state-space model of WSHVIS,which is used to design controller.On this basis,off-line simulation and on-line realization for the WSHVIS is performed.The simulation and experimental results showed that WSHVIS can effectively reduce the vibration loads transmitted from launch vehicle to spacecraft.Compared with passive vibration isolation system,the hybrid vibration isolation system has a significant inhibitory effect on the low-frequency vibration components,and can greatly increase the safety and reliability of spacecraft.
