A new method which is a combination of sensitivity analysis and modal synthesis technique was applied to the simple calculation of design sensitivities of the dynamic characteristics of substructurally combined rotati...A new method which is a combination of sensitivity analysis and modal synthesis technique was applied to the simple calculation of design sensitivities of the dynamic characteristics of substructurally combined rotating systems. In this paper the free interface mode method was introduced as a basic tool for the modal synthesis technique. As an example, the sensitivities of the critical speeds of a high-specd winding mechanism on textile machine with respect to design modifications were obtained by the new method introduced in this paper and compared with the values obtained by using another method.展开更多
The dynamic analysis of a 1150 MW turbine generator system using the transfer matrix method (TMM) and the finite element method (FEM) for computation is presented.Excellent agreement was obtained between critical spe...The dynamic analysis of a 1150 MW turbine generator system using the transfer matrix method (TMM) and the finite element method (FEM) for computation is presented.Excellent agreement was obtained between critical speeds computed by TMM and FEM,respectively.The entire system modes are considerably different from the individual component modes.Using the mode shapes as a baseline,modal analysis of field balance can be implemented for this rotor system.A comparison of the experimental and theoretical predictions are presented,too.The forced responses of the system including foundation or pedestal mass,stiffness and damping effects were computed by means of FEM.It is approved that an appropriately formed and placed force couple,as a dynamic balance couple,may suppress strong forced vibrations in the vicinity of critical speeds close to the operating speed.Also,the bearings of low pressure turbines need to be well damped to avoid exciting lower and median critical speed modes.展开更多
文摘A new method which is a combination of sensitivity analysis and modal synthesis technique was applied to the simple calculation of design sensitivities of the dynamic characteristics of substructurally combined rotating systems. In this paper the free interface mode method was introduced as a basic tool for the modal synthesis technique. As an example, the sensitivities of the critical speeds of a high-specd winding mechanism on textile machine with respect to design modifications were obtained by the new method introduced in this paper and compared with the values obtained by using another method.
文摘The dynamic analysis of a 1150 MW turbine generator system using the transfer matrix method (TMM) and the finite element method (FEM) for computation is presented.Excellent agreement was obtained between critical speeds computed by TMM and FEM,respectively.The entire system modes are considerably different from the individual component modes.Using the mode shapes as a baseline,modal analysis of field balance can be implemented for this rotor system.A comparison of the experimental and theoretical predictions are presented,too.The forced responses of the system including foundation or pedestal mass,stiffness and damping effects were computed by means of FEM.It is approved that an appropriately formed and placed force couple,as a dynamic balance couple,may suppress strong forced vibrations in the vicinity of critical speeds close to the operating speed.Also,the bearings of low pressure turbines need to be well damped to avoid exciting lower and median critical speed modes.
