Labyrinth seal can cause steam-exciting, the structural and operating parameters of labyrinth seal have effect on stability of rotor-system. For investigating the coupling influences of the structure and operating par...Labyrinth seal can cause steam-exciting, the structural and operating parameters of labyrinth seal have effect on stability of rotor-system. For investigating the coupling influences of the structure and operating parameters of labyrinth seals on dynamic coefficients, a model of calculating dynamic coefficients of labyrinth seals is presented using a two control volume model. The coupling influences of parameters on cross-coupled stiffness and direct damping of labyrinth seal are discussed. In the conclusion, a reference of preventing steam-exciting vibration and optimum determination of design parameters of labyrinth seals are provided.展开更多
The impact buckling of a laminated composite bar is investigated in case of one of its ends moving due to axial impact compression. The governing equations considering the first- order shear deformation effect are der...The impact buckling of a laminated composite bar is investigated in case of one of its ends moving due to axial impact compression. The governing equations considering the first- order shear deformation effect are derived by the Hamilton principle and solved by the finite difference method. The critical axial shortness is determined by the B - R cirterion. The given example is used to highlight the influences of initial imperfection, impact velocity, stress wave and coupled stiffness. It is found that the unsymmetrically laminated bar has a quite different dynamic buckling behaviour from that of the symmetrically laminated bar.展开更多
The arc curved beams have been widely applied in the construction industry in recent years. The calculation methods for arc curved beams provided by the industry have been varied. This paper mainly researches on the m...The arc curved beams have been widely applied in the construction industry in recent years. The calculation methods for arc curved beams provided by the industry have been varied. This paper mainly researches on the method of reckoning the force state of a curved beam with multiple straight beams. By comparing the three-dimensional stiffness matrix of the straight beam element and the curved beam element, the coupling stiffness of a curved beam is discovered. By using multiple finite element analysis software, this paper undertakes a case analysis of multiple models and subsequently provides some referential parameter for engineering design by approximating a curve by straight beams.展开更多
基金This project is supported by National Natural Science Foundation of China(59990472). Manuscript received on November 30, 1999 r
文摘Labyrinth seal can cause steam-exciting, the structural and operating parameters of labyrinth seal have effect on stability of rotor-system. For investigating the coupling influences of the structure and operating parameters of labyrinth seals on dynamic coefficients, a model of calculating dynamic coefficients of labyrinth seals is presented using a two control volume model. The coupling influences of parameters on cross-coupled stiffness and direct damping of labyrinth seal are discussed. In the conclusion, a reference of preventing steam-exciting vibration and optimum determination of design parameters of labyrinth seals are provided.
基金The present research work was financially supported by the National Natural Science Foundation of China.(No.19472042)
文摘The impact buckling of a laminated composite bar is investigated in case of one of its ends moving due to axial impact compression. The governing equations considering the first- order shear deformation effect are derived by the Hamilton principle and solved by the finite difference method. The critical axial shortness is determined by the B - R cirterion. The given example is used to highlight the influences of initial imperfection, impact velocity, stress wave and coupled stiffness. It is found that the unsymmetrically laminated bar has a quite different dynamic buckling behaviour from that of the symmetrically laminated bar.
文摘The arc curved beams have been widely applied in the construction industry in recent years. The calculation methods for arc curved beams provided by the industry have been varied. This paper mainly researches on the method of reckoning the force state of a curved beam with multiple straight beams. By comparing the three-dimensional stiffness matrix of the straight beam element and the curved beam element, the coupling stiffness of a curved beam is discovered. By using multiple finite element analysis software, this paper undertakes a case analysis of multiple models and subsequently provides some referential parameter for engineering design by approximating a curve by straight beams.
