کنترل لرزش و تحلیل یک پرتو FGM منعطف چرخشی در زمینه دما
Abstract
1- Introduction
2- Physical model and equations
3- Vibration control and analysis
4- Conclusion
References
Abstract
Based on the high-order coupling (HOC) modeling 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.
Introduction
Functionally graded materials (FGMs) are one type of advanced composites which has remarkable properties and promising applications in the field of spacecraft, nuclear industries, and other engineering applications. The FGMs, formed by continuous graduation of two or more constituent phases over a specified volume, were mainly designed and developed to resist high temperature gradients. Gupta and Talha [1] made a comprehensive literature review on structural characteristics of FGM structures under thermo-electro-mechanical loadings, and provided an overview of the future research directions in the design and analysis of FGMs. He et al. [2] introduced the finite element formulation based on thin plate theory to control the shape and vibration of FGM plate with integrated piezoelectric sensors and actuators under mechanical load. Liew et al. [3] investigated postbuckling and thermal postbuckling behavior of FGM plates with two opposite edges fixed and with surface-bonded piezoelectric actuators. Huang and Shen [4] studied the effects of temperature change, voltage and volume fraction distribution on the nonlinear vibration and dynamic response of FGM plate under thermo-electro loading. Shen [5] studied the nonlinear thermal bending response and postbuckling of FGMs plates with piezoelectric actuators under thermal and electrical loads. Fakhari et al. [6] studied nonlinear natural frequencies and dynamic responses of FGM plates with surface bonded piezoelectric layers based on HSDT. Jia et al. [7] made thermal-mechanical-electrical buckling analysis of microFGM beams by using the modified couple stress theory. Wang and Shen [8] studied the nonlinear vibration of functionally graded graphene reinforced composite (FG-GRC) face sheets in thermal environments.