The objective of this research was to analytically and experimentally study the capabilities of piezoelectric plate actuators for suppressing utter. Piezoelectric materials are characterized by their ability to produce voltage when subjected to a mechanical strain. The converse piezoelectric e ect can be utilized to actuate a structure by applying a voltage. For this investigation, a two-degree...

In this paper a new approach is presented to reduce vibrations for oneand two-dimensional mechanical structures, as beam or thin plates, by means of several piezoelectric transducers shunted with a proper electric network system. The governing equations of the whole system are coupled to each other through the direct and converse piezoelectric effect. More in detail, the mechanical equations ar...

Piezoelectric materials are widely used in the design of smart structures. It is thus of major technological interest to provide efficient modelings of such structures. In the case of thin piezoelectric plates, classical studies generally lead to two different models. These two models can be linked to the distinction between sensors and actuators. Here, we extend these results to the second ord...

Limpet teeth are striking examples of a biological fibrous nanocomposite consisting of goethite mineral within a polymeric chitin matrix. The mechanical function of limpet teeth is critically dependent on the efficient composite behaviour of goethite, formed as distinct discontinuous nanofibres, reinforcing the matrix. The mechanical properties of discrete volumes from a limpet tooth measured u...

The propagation of both surface and flexural acoustic plate modes along y-rotated x-propagation GaPO4 piezoelectric substrates was studied for several y-cut angles: the phase velocity and coupling coefficient dispersion curves were theoretically calculated for two different electroacoustic coupling configurations. The investigation of the acoustic field profile across the plate thickness reveal...

We investigate the possibility of designing phononic crystal-based devices for telecommunication applications using materials commonly employed in microfabrication. We focus our attention on a phononic crystal made of a square array of cylindrical holes drilled in an active piezoelectric PZT5A matrix. Two different structures are considered, namely, a freestanding phononic crystal plate and a p...

We extend our modeling of smart structures to second order piezoelectricity. We show that three different models have to be taken into account, which broadens the scope of the sensors and actuators field. Second order piezoelectricity being compatible with isotropy, we also propose a systematic study of the impact of crystalline symmetries on our models. To cite this article: T. Weller, C. Lich...

Nanocomposite membranes composed of polymer and inorganic nanoparticles are a novel method to enhance gas separation performance. In this study, membranes were fabricated from polysulfone (PSf) containing magnesium oxide (MgO) nanoparticles and gas permeation properties of the resulting membranes were investigated. Membranes were prepared by solution blending and phase inversion methods. Morpho...