Dynamic stability of a composite beam with piezoelectric actuators and sensors

• Main Authors: J.-Y. Lin, 林忠義
• Other Authors: L.-W. Chen
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/14780935236189025606

碩士 === 國立成功大學 === 機械工程學系 === 88 === The objective of this dissertation is to study the dynamic stability problems of a composite beam with piezoelectric materials. The mathematical model based on a layerwise theory is developed for laminated composite beams with piezoelectric actuators. A finite element model is employed to solve vibration and dynamic stability problems. An ideal linear strain-displacement is assumed for the piezoelectric actuation. The influence of boundary conditions on the change in shapes of laminated beams with piezoelectric actuators is studied. If the beam is longitudinally restrained at both ends the piezoelectric actuators induce in-plane stresses that significantly affect the dynamic behaviors of the beam. The stiffness of the beam can be piezoelectrically tuned to significantly change the natural frequencies. The buckling of the beam can be postponed beyond the first critical load. The dynamic stability behaviors of slender isotropic and composite beams with piezoelectric layers subjected to axial periodic compressive loads are investigated. The top piezoelectric layer acts as an actuator, and the bottom later can be as a sensor or actuator. The effects of the in-plane stresses on the dynamic stability of the beam with piezoelectric layers are examined. A simple negative velocity feedback control algorithm that coupling the direct and converse piezoelectric effects is used to actively control the dynamic response of a beam through a closed control loop. The influence of the feedback control gain on the response of the beam is evaluated.