Contrôle de Vibrations Large Bande À L'aide D'éléments Piézoélectriques Utilisant Une Technique Non-linéaire

Download or read book Contrôle de Vibrations Large Bande À L'aide D'éléments Piézoélectriques Utilisant Une Technique Non-linéaire written by Linjuan Yan and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to protect structures, extend their lifespan and decrease the incomfort resulting from undesired vibrations, many works have been reported for reducing vibrations. Along with the development of smart materials such as piezoelectric materials which are extensively used for vibration control and noise reduction due to their unique features (high integrability, compactness, light weight and high bandwidth), control systems can be designed in a more compact and simple form. Additionally, due to the conversion between mechanical energy and electrical energy, vibrations can be effectively attenuated by electromechanical approaches. Synchronized Switch Damping on Inductor (SSDI) technique attracted lot of attentions as an effective semi-passive technique which can artificially increase the converted energy by nonlinear voltage inversion process, thus allowing superior control performance compared to passive technique with low power requirement and simple control algorithm. Based on this semi-passive control technique, the objectives of this work are threefold. The first aim is improving the multimodal/broadband control performance of SSDI. An enhanced strategy based on spatial filtering according to the mode shapes of the vibrating structure is proposed. In order to separate the uninterested modes and effectively damp the targeted modes, sum and different switches respectively based on the sum of the piezovoltages of two anti-symmetrically bonded patches and the voltage difference of the two symmetrically bonded piezoelectric elements are introduced. Since the vibration modes can be spatially filtered by these connections, multimodal vibrations can be damped significantly and simultaneously as the sum and difference switches are employed, with an increase of total inversion coefficient. Then, electromechanical TMD (tuned mass damper) featuring piezoelectric materials combined with the semi-passive nonlinear technique SSDI is presented. Using this electromechanical semi-passive nonlinear TMD, the mechanical energy is not only transferred between host structure and TMD device but also converted as electrical energy stored in the piezoelectric patches and/or dissipated in the connected circuit, which allows excellent damping performance for limiting the vibrations. The last investigated method consists in electromechanical periodic structures featuring the nonlinear switching interface. Such a structure can effectively attenuate the elastic waves and damp the vibration in a wider frequency band since it has the capability of filtering propagative waves within stop bands attributed to the structural periodicity and the superior damping ability which is attributed to the nonlinear voltage inversion process that increases the voltage amplitude and decreases the phase between voltage and speed. Finally, a conclusion proposes a summary of the main results obtained in this thesis, as well as new extensions and ways of the proposed techniques.