Piezoelectric vibration solutions : Absorbers and Suspensions
Résumé
Most industrial machines present vibrations. These vibrations can lead to premature aging, mechanical failure, local noise pollution or discomfort for people working nearby vibration sources. In particular, in the naval industry, vibrations can lead to several problems such as the deterioration of acoustic stealth for military applications, non-respect of the norms limiting the radiated noises on ships or the deterioration of underwater acoustic measurements on scientific ships. To offer efficient vibration damping solutions, PYTHEAS Technology has developed several devices based on piezoelectricity materials seeking to address the weaknesses of traditional solutions. Currently, the most commonly used solution consists of adding dissipative materials, often viscoelastic ones, which convert vibrations into heat. This solution has the advantage to be simple and cheap. However, its vibration damping performances are limited and its lifetime is often reduced due to creep. Active devices form the second main solution. They present better vibration damping performances, but their cost and complexity are obstacles to their deployment. PYTHEAS Technology has developed and tested several concepts of absorbers and suspensions which allow to reach a damping coefficient (ξ) equivalent to the one of active systems (ξ>10%),while remaining simple and having more than ten years of lifetime. Furthermore, the electromechanical conversion provided by the piezoelectric effect brings additional advantages : Vibration frequency tracking if it varies over time, Damping of several modes simultaneously using only one device (gain in terms of added mass and size), Device?s fine-tuning using the electronic (reduction of manufacturing costs),... This paper is an overview of the concepts developed by PYTHEAS Technology and their potential applications.
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