Issue 29

C. Maruccio et alii, Frattura ed Integrità Strutturale, 29 (2014) 49-60; DOI: 10.3221/IGF-ESIS.29.06 49 Focussed on: Computational Mechanics and Mechanics of Materials in Italy Numerical homogenization of piezoelectric textiles with electrospun fibers for energy harvesting C. Maruccio Università del Salento claudio.maruccio@unisalento.it L. De Lorenzis Technische Universität Braunschweig l.delorenzis@tu-braunschweig.de A BSTRACT . Piezoelectric effects are exploited in an increasing number of micro- and nano-electro-mechanical systems. In particular, energy harvesting devices convert ambient energy (i.e. mechanical pressure) into electrical energy and their study is nowadays a very important and challenging field of research. In this paper, the attention is focused on piezoelectric textiles. Due to the importance of computational modeling to understand the influence that micro-scale geometry and constitutive variables have on the macroscopic behavior, a homogenization strategy is developed. The macroscopic structure behaviour is obtained defining a reference volume element (RVE) at the micro-scale. The geometry of the RVE is based on the microstructural properties of the material under consideration and consists in piezoelectric polymeric nano-fibers subjected to electromechanical contact constraints. This paper outlines theory and numerical implementation issues for the homogenization procedure. Moreover, within this approach the average response resulting from the analysis of different fiber configurations at the microscale is determined providing a multiphysics constitutive model for the macro-scale. K EYWORDS . Electromechanical Coupling; Multiphysics Modeling; Multiscale Modeling; Shell elements; Energy harvesting. I NTRODUCTION lectrospinning is a simple and versatile method for generating ultrathin fibers from a rich variety of materials that include polymers, composites and ceramics [1]. This non-mechanical, electrostatic technique involves the use of a high voltage electrostatic field to charge the surface of a polymer solution droplet and thus to induce the ejection of a liquid jet through a spinneret. Nowadays, nanofiber technology is opening up new scenarios in several industrial fields. Applications range from energy harvesting technologies [2, 3] to tissue and biomedical engineering, aerospace materials, and device integration with architectural or design components. Nanofibers can increase the performance of traditional materials and allow engineering optimization of existing textiles and fabrics and even development of new E