As the power transmission system of an aircraft,a hydraulic pipeline system is equivalent to the " blood vessel" of the aircraft. With the development of aircraft hydraulic system to high pressure,high speed...As the power transmission system of an aircraft,a hydraulic pipeline system is equivalent to the " blood vessel" of the aircraft. With the development of aircraft hydraulic system to high pressure,high speed and high power ratio,the fluid-structure interaction vibration mechanism of hydraulic pipeline is more complex and the influence of friction coupling on vibration cannot be ignored. The fluid-structure interaction of hydraulic pipeline will lead to system vibration,lower reliability of system operation and even pipeline rupture. Taking a hydraulic pipeline of C919 aircraft wingtip as the research object,a 14-equation model of fluid-structure interaction vibration considering friction coupling effect is established in this paper. The effects of friction and fluid parameters on the pipeline fluid-structure interaction vibration characteristics are studied and verified by experiments. The research results will provide theoretical guidance for the analysis of the pipeline fluid-structure interaction vibration and have important theoretical significance and great engineering value for promoting the localization process of large aircraft.展开更多
As a novel coupling beam for coupled shear wall structures,the bending-type frictional steel truss coupling beam(BFTCB)concentrates the deformation and energy dissipation in friction dampers at the bottom chord,allowi...As a novel coupling beam for coupled shear wall structures,the bending-type frictional steel truss coupling beam(BFTCB)concentrates the deformation and energy dissipation in friction dampers at the bottom chord,allowing the main body to remain elastic during earthquakes.As the preparatory work for resilient structure design based on the BFTCB,this work concentrates on developing the hysteretic model for BFTCB.Firstly,the BFTCB stiffness-strength decoupling mechanism was introduced,i.e.,the shear strength is provided by friction dampers while webs control its initial stiffness.Secondly,a hysteretic model that reflects the BFTCB two-stage sliding characteristic was proposed.The model consists of a trilinear backbone curve and the unloading and reverse loading rules.The model has eight control parameters,of which two core parameters(initial stiffness and limiting shear strength)are derived from the BFTCB stiffness-strength decoupling mechanism,whereas the remaining parameters are obtained by theoretical analysis and empirical calibration.The hysteretic model was then compared with the test curves and demonstrated good accuracy.Finally,a series of FE prototypes of BFTCB with different design stiffnesses and strengths was adopted to verify the hysteretic model.The results showed that the proposed model fitted well with the FE prototypes,indicating its applicability to BFTCB with varying core design parameters.Therefore,the hysteretic model can be adopted for BFTCB to support the resilient shear wall structure design.展开更多
基金Supported by the National Key Basic Research Program of China(No.2014CB046405)
文摘As the power transmission system of an aircraft,a hydraulic pipeline system is equivalent to the " blood vessel" of the aircraft. With the development of aircraft hydraulic system to high pressure,high speed and high power ratio,the fluid-structure interaction vibration mechanism of hydraulic pipeline is more complex and the influence of friction coupling on vibration cannot be ignored. The fluid-structure interaction of hydraulic pipeline will lead to system vibration,lower reliability of system operation and even pipeline rupture. Taking a hydraulic pipeline of C919 aircraft wingtip as the research object,a 14-equation model of fluid-structure interaction vibration considering friction coupling effect is established in this paper. The effects of friction and fluid parameters on the pipeline fluid-structure interaction vibration characteristics are studied and verified by experiments. The research results will provide theoretical guidance for the analysis of the pipeline fluid-structure interaction vibration and have important theoretical significance and great engineering value for promoting the localization process of large aircraft.
基金supported by the Scientific Research Fund of MultiFunctional Shaking Tables Laboratory of Beijing University of Civil Engineering and Architecture(2022MFSTL06)Science&Technology Foundation of Liaoning Province,China:General Program(2021-MS131).
文摘As a novel coupling beam for coupled shear wall structures,the bending-type frictional steel truss coupling beam(BFTCB)concentrates the deformation and energy dissipation in friction dampers at the bottom chord,allowing the main body to remain elastic during earthquakes.As the preparatory work for resilient structure design based on the BFTCB,this work concentrates on developing the hysteretic model for BFTCB.Firstly,the BFTCB stiffness-strength decoupling mechanism was introduced,i.e.,the shear strength is provided by friction dampers while webs control its initial stiffness.Secondly,a hysteretic model that reflects the BFTCB two-stage sliding characteristic was proposed.The model consists of a trilinear backbone curve and the unloading and reverse loading rules.The model has eight control parameters,of which two core parameters(initial stiffness and limiting shear strength)are derived from the BFTCB stiffness-strength decoupling mechanism,whereas the remaining parameters are obtained by theoretical analysis and empirical calibration.The hysteretic model was then compared with the test curves and demonstrated good accuracy.Finally,a series of FE prototypes of BFTCB with different design stiffnesses and strengths was adopted to verify the hysteretic model.The results showed that the proposed model fitted well with the FE prototypes,indicating its applicability to BFTCB with varying core design parameters.Therefore,the hysteretic model can be adopted for BFTCB to support the resilient shear wall structure design.
