دانلود رایگان مقاله انگلیسی کنترل لرزش و تحلیل یک پرتو FGM منعطف چرخشی با یک توده بزرگ در زمینه دما - الزویر 2019

Abstract

Based on the high-order coupling (HOC) modelling theory, vibration control of a rotating rigid-flexible coupled smart composite structure in temperature field is investigated. A flexible beam made of functionally graded materials (FGM) with a lumped mass and two piezoelectric films perfectly bonded to it is attached to a horizontal rotating hub. By using the method of assumed modes to describe the deformations of the FGM beam and piezoelectric films, the rigid-flexible coupling dynamic equations of the system with the high order geometric nonlinear terms are derived via employing Lagrange’s equations. A PD controller is used in the vibration control of the system. Simulation results indicate that the intense thermally induced vibrations of the FGM beam along the longitudinal and transverse direction are efficiently suppressed after the piezoelectric active control effect works. The HOC model is more accurate than the previous low order coupled (LOC) model when the temperature gradient increases. The influence of high-order nonlinearity in the present HOC model on the characteristics of dynamics and control of flexible structures should not be ignored. The effect of temperature variation on the free vibration characteristics of the rotating smart structure is gentle despite non-negligibility.

Conclusion

Vibration control and analysis of a rotating FGM beam with a lumped mass and bonded piezoelectric films in temperature field were investigated. The thermo-electro-mechanical dynamic model of the smart system was developed based on the HOC modeling theory. Equations of motion of the system were derived by employing Lagrange’s equations. The characteristics of the active control of the thermally induced vibration of the rotating FGM beam were investigated. According to the numerical results, the cost of the vibration control can be reduced by selecting the control gain properly. The influence of high-order nonlinearity in the present HOC model on the behaviors of dynamics and control of flexible structures in thermal environment should be included. The effect of temperature variation on the free vibration characteristics of the rotating smart structure is quite gentle despite non-negligibility. Besides, parameters such as the volume fraction exponent of the FGM beam, the location of the lumped mass and the angular velocity of the hub have significant impacts on the dynamic behaviors of the system. The results of this paper can be used to provide theoretical basis for vibration and control analysis for blades, robot arms, and other rotary flexible structures operating in high temperature field.