This paper investigates the vibration characteristics of a double-overhung rub rotor considering gyroscopic couples and slanting contact between rotors and stators. This paper deduces a new contact model according to ...This paper investigates the vibration characteristics of a double-overhung rub rotor considering gyroscopic couples and slanting contact between rotors and stators. This paper deduces a new contact model according to slant contact between rotor and stator, which close to real rub condition, and compared with simple contact model.With rotating speed and support span changing, the dynamic behaviors of rotors are simulated by the fourth Runge-Kutta method. The results illustrate that gyroscopic couples and slant contact model can lead to rub occurrence at a lower speed compared with no gyroscopic couples or slant contact. Resonance has a huge effect on radial displacement and frequency spectrum of disk, and in resonance interval the frequency components are complex. At the same rotating speed, support span has a monotonous effect on amplitude of radial displacement. These results might provide some reference to estimate whether rubbing occurs and help to control rubbing force.展开更多
Volterra series is a powerful mathematical tool for nonlinear system analysis,and there is a wide range of nonlinear engineering systems and structures that can be represented by a Volterra series model.In the present...Volterra series is a powerful mathematical tool for nonlinear system analysis,and there is a wide range of nonlinear engineering systems and structures that can be represented by a Volterra series model.In the present study,the random vibration of nonlinear systems is investigated using Volterra series.Analytical expressions were derived for the calculation of the output power spectral density（PSD） and input-output cross-PSD for nonlinear systems subjected to Gaussian excitation.Based on these expressions,it was revealed that both the output PSD and the input-output crossPSD can be expressed as polynomial functions of the nonlinear characteristic parameters or the input intensity.Numerical studies were carried out to verify the theoretical analysis result and to demonstrate the effectiveness of the derived relationship.The results reached in this study are of significance to the analysis and design of the nonlinear engineering systems and structures which can be represented by a Volterra series model.展开更多
基金National Natural Science Foundation of China C Grant No.51335006
文摘This paper investigates the vibration characteristics of a double-overhung rub rotor considering gyroscopic couples and slanting contact between rotors and stators. This paper deduces a new contact model according to slant contact between rotor and stator, which close to real rub condition, and compared with simple contact model.With rotating speed and support span changing, the dynamic behaviors of rotors are simulated by the fourth Runge-Kutta method. The results illustrate that gyroscopic couples and slant contact model can lead to rub occurrence at a lower speed compared with no gyroscopic couples or slant contact. Resonance has a huge effect on radial displacement and frequency spectrum of disk, and in resonance interval the frequency components are complex. At the same rotating speed, support span has a monotonous effect on amplitude of radial displacement. These results might provide some reference to estimate whether rubbing occurs and help to control rubbing force.
基金supported by the National Science Fund for Distinguished Young Scholars (11125209)the National Natural Science Foundation of China (10902068,51121063 and 10702039)+1 种基金the Shanghai Pujiang Program (10PJ1406000)the Opening Project of State Key Laboratory of Mechanical System and Vibration (MSV201103)
文摘Volterra series is a powerful mathematical tool for nonlinear system analysis,and there is a wide range of nonlinear engineering systems and structures that can be represented by a Volterra series model.In the present study,the random vibration of nonlinear systems is investigated using Volterra series.Analytical expressions were derived for the calculation of the output power spectral density（PSD） and input-output cross-PSD for nonlinear systems subjected to Gaussian excitation.Based on these expressions,it was revealed that both the output PSD and the input-output crossPSD can be expressed as polynomial functions of the nonlinear characteristic parameters or the input intensity.Numerical studies were carried out to verify the theoretical analysis result and to demonstrate the effectiveness of the derived relationship.The results reached in this study are of significance to the analysis and design of the nonlinear engineering systems and structures which can be represented by a Volterra series model.
