The Fusion-Driven Subcritical System(FDS)is a subcritical nuclear energy systemdrived by fusion neutron source.In this paper,an advanced plasma configuration for FDS systemhas been proposed,which aims at high beta,hig...The Fusion-Driven Subcritical System(FDS)is a subcritical nuclear energy systemdrived by fusion neutron source.In this paper,an advanced plasma configuration for FDS systemhas been proposed,which aims at high beta,high bootstrap current and good confinement.Afixed-boundary equilibrium code has been used to obtain ideal equilibrium configuration.In order展开更多
The distribution and configuration of surfactants at interface in surfactant-water-oil systems have been investigated using discontinuous molecular dynamic simulations. There exists a certain equilibrium concentration...The distribution and configuration of surfactants at interface in surfactant-water-oil systems have been investigated using discontinuous molecular dynamic simulations. There exists a certain equilibrium concentration of surfactants at interface for the systems with certain interactions among surfactant, water and oil. The interface length and equilibrium morphology of the systems are dependent on the equilibrium concentration of surfactants at interface and the total amount of surfactants. The interaction strengths among surfactant, water and oil determine the equilibrium concentration of surfactants at interface. Three typical configurations of surfactants at interface have been observed: ailene1 surfactant 0 molecules are perpendicular to the interface and arranged closely; ailene2 perpendicular to the interface and arranged at interval 0 of two particles; ailene3 lie down in the interface partly. 0 Key words surfactant - phase separation - equilibrium configuration CLC number O 469 - O 64 Foundation item: Supported by the National Natural Science Foundation of China (10274056) and the Foundation of the Education Ministry of Hubei ProvinceBiography: YUAN Yin-quan (1964-), male, Ph. D., research direction: soft matter.展开更多
The influence of weights is usually ignored in the study of nonlinear vibrations of plates.In this paper,the effect of structure weights on the nonlinear vibration of a composite circular plate with a rigid body is pr...The influence of weights is usually ignored in the study of nonlinear vibrations of plates.In this paper,the effect of structure weights on the nonlinear vibration of a composite circular plate with a rigid body is presented.The nonlinear governing equations are derived from the generalized Hamilton's principle and the von Kármán plate theory.The equilibrium configurations due to weights are determined and validated by the finite element method(FEM).A nonlinear model for the vibration around the equilibrium configuration is established.Moreover,the natural frequencies and amplitude-frequency responses of harmonically forced vibrations are calculated.The study shows that the structure weights introduce additional linear and quadratic nonlinear terms into the dynamical model.This leads to interesting phenomena.For example,considering weights increases the natural frequency.Furthermore,when the influence of weights is considered,the vibration response of the plate becomes asymmetrical.展开更多
In several previous studies,it was reported that a supported pipe with small geometric imperfections would lose stability when the internal flow velocity became sufficiently high.Recently,however,it has become clear t...In several previous studies,it was reported that a supported pipe with small geometric imperfections would lose stability when the internal flow velocity became sufficiently high.Recently,however,it has become clear that this conclusion may be at best incomplete.A reevaluation of the problem is undertaken here by essentially considering the flow-induced static deformation of a pipe.With the aid of the absolute nodal coordinate formulation(ANCF)and the extended Lagrange equations for dynamical systems containing non-material volumes,the nonlinear governing equations of a pipe with three different geometric imperfections are introduced and formulated.Based on extensive numerical calculations,the static equilibrium configuration,the stability,and the nonlinear dynamics of the considered pipe system are determined and analyzed.The results show that for a supported pipe with the geometric imperfection of a half sinusoidal wave,the dynamical system could not lose stability even if the flow velocity reaches an extremely high value of 40.However,for a supported pipe with the geometric imperfection of one or one and a half sinusoidal waves,the first-mode buckling instability would take place at high flow velocity.Moreover,based on a further parametric analysis,the effects of the amplitude of the geometric imperfection and the aspect ratio of the pipe on the static deformation,the critical flow velocity for buckling instability,and the nonlinear responses of the supported pipes with geometric imperfections are analyzed.展开更多
Nine kinds of structure systems were proposed for the flexible airship according to the inherent structural characteristics. On the basis of equilibrium configuration of the oating airship subjected to the ascent heli...Nine kinds of structure systems were proposed for the flexible airship according to the inherent structural characteristics. On the basis of equilibrium configuration of the oating airship subjected to the ascent helium buoyancy and gravity,the structural analysis procedure was developed and the computation models were presented for the airship. Then the systematic numerical analysis was carried out for a 25 m long airship,the comparison of principal stress of envelope was performed between the nonlinear numerical analysis result and the engineering elastic theory result. The structural performances were evaluated thoroughly. Finally,the reasonable structural systems were proposed. Accordingly,the results herein were valuable to structural design for flexible airship especially for large flexible airship.展开更多
基金National Sciences Foundation of China(No.10175068)
文摘The Fusion-Driven Subcritical System(FDS)is a subcritical nuclear energy systemdrived by fusion neutron source.In this paper,an advanced plasma configuration for FDS systemhas been proposed,which aims at high beta,high bootstrap current and good confinement.Afixed-boundary equilibrium code has been used to obtain ideal equilibrium configuration.In order
文摘The distribution and configuration of surfactants at interface in surfactant-water-oil systems have been investigated using discontinuous molecular dynamic simulations. There exists a certain equilibrium concentration of surfactants at interface for the systems with certain interactions among surfactant, water and oil. The interface length and equilibrium morphology of the systems are dependent on the equilibrium concentration of surfactants at interface and the total amount of surfactants. The interaction strengths among surfactant, water and oil determine the equilibrium concentration of surfactants at interface. Three typical configurations of surfactants at interface have been observed: ailene1 surfactant 0 molecules are perpendicular to the interface and arranged closely; ailene2 perpendicular to the interface and arranged at interval 0 of two particles; ailene3 lie down in the interface partly. 0 Key words surfactant - phase separation - equilibrium configuration CLC number O 469 - O 64 Foundation item: Supported by the National Natural Science Foundation of China (10274056) and the Foundation of the Education Ministry of Hubei ProvinceBiography: YUAN Yin-quan (1964-), male, Ph. D., research direction: soft matter.
基金Project supported by the National Natural Science Foundation of China(No.12002195)the National Science Fund for Distinguished Young Scholars of China(No.12025204)the Program of Shanghai Municipal Education Commission of China(No.2019-01-07-00-09-E00018)。
文摘The influence of weights is usually ignored in the study of nonlinear vibrations of plates.In this paper,the effect of structure weights on the nonlinear vibration of a composite circular plate with a rigid body is presented.The nonlinear governing equations are derived from the generalized Hamilton's principle and the von Kármán plate theory.The equilibrium configurations due to weights are determined and validated by the finite element method(FEM).A nonlinear model for the vibration around the equilibrium configuration is established.Moreover,the natural frequencies and amplitude-frequency responses of harmonically forced vibrations are calculated.The study shows that the structure weights introduce additional linear and quadratic nonlinear terms into the dynamical model.This leads to interesting phenomena.For example,considering weights increases the natural frequency.Furthermore,when the influence of weights is considered,the vibration response of the plate becomes asymmetrical.
基金supported by the National Natural Science Foundation of China(Nos.11972167,12072119)the Alexander von Humboldt Foundation。
文摘In several previous studies,it was reported that a supported pipe with small geometric imperfections would lose stability when the internal flow velocity became sufficiently high.Recently,however,it has become clear that this conclusion may be at best incomplete.A reevaluation of the problem is undertaken here by essentially considering the flow-induced static deformation of a pipe.With the aid of the absolute nodal coordinate formulation(ANCF)and the extended Lagrange equations for dynamical systems containing non-material volumes,the nonlinear governing equations of a pipe with three different geometric imperfections are introduced and formulated.Based on extensive numerical calculations,the static equilibrium configuration,the stability,and the nonlinear dynamics of the considered pipe system are determined and analyzed.The results show that for a supported pipe with the geometric imperfection of a half sinusoidal wave,the dynamical system could not lose stability even if the flow velocity reaches an extremely high value of 40.However,for a supported pipe with the geometric imperfection of one or one and a half sinusoidal waves,the first-mode buckling instability would take place at high flow velocity.Moreover,based on a further parametric analysis,the effects of the amplitude of the geometric imperfection and the aspect ratio of the pipe on the static deformation,the critical flow velocity for buckling instability,and the nonlinear responses of the supported pipes with geometric imperfections are analyzed.
文摘Nine kinds of structure systems were proposed for the flexible airship according to the inherent structural characteristics. On the basis of equilibrium configuration of the oating airship subjected to the ascent helium buoyancy and gravity,the structural analysis procedure was developed and the computation models were presented for the airship. Then the systematic numerical analysis was carried out for a 25 m long airship,the comparison of principal stress of envelope was performed between the nonlinear numerical analysis result and the engineering elastic theory result. The structural performances were evaluated thoroughly. Finally,the reasonable structural systems were proposed. Accordingly,the results herein were valuable to structural design for flexible airship especially for large flexible airship.
