Polymer composites integrated with carbon nanotubes (CNT) have shown the virtue of exhibiting an improved mechanical response as well as a significant enhancement in damping capacity. This paves the way to the exploitation of CNT nanofillers not only for structural reinforcement purposes but also for advantageously shaping and optimizing the hysteretic response of light-weight polymer materials. In this work, the hysteretic response of CNT/polymer nanocomposites is described through a phenomenological 1D model directly derived from a full 3D nonlinear constitutive model. The 3D constitutive model is able to describe the nanocomposites damping response by accounting for the mean source of energy dissipation, namely, the interfacial CNT/matrix stick-slip phenomenon. The proposed 1D phenomenological model, mimicking the Bouc-Wen model of smooth plasticity, is employed for the identification of experimental force-displacement cycles obtained in bending mode on a set of thermoplastic polymer nanocomposites with increasing weight fractions of nanotubes. Experimental findings show significant enhancements (greater than 50 %) in both elastic and damping properties of the 3 wt% CNT nanocomposite with respect to the pristine polymer material. Such material behavior is fully captured through the 1D phenomenological model. The model parameters are optimized via the differential evolution algorithm over a series of hysteretic force-displacement cycles for increasing displacement amplitudes. The main model parameters are represented by the CNT volume fraction and the interfacial shear strength at the CNT/matrix interfaces. The possibility of modulating the hysteretic response of the nanocomposites through the material parameters enables a multi-scale design of the material properties by exploiting the 1D phenomenological model as a computational tool. Thus, the identified model parameters represent a feasible set of parameters to be introduced in the full 3D nonlinear constitutive model for a more accurate description of the mechanical and damping response of the CNT nanocomposites.
Formica, G., Talò, M., Carboni, B., Lanzara, G., Lacarbonara, W. (2018). Hysteretic dissipation in carbon nanotube nanocomposites. In Proceedings of 10th European Solid Mechanics Conference (ESMC 2018).
Hysteretic dissipation in carbon nanotube nanocomposites
Giovanni Formica;Giulia Lanzara;
2018-01-01
Abstract
Polymer composites integrated with carbon nanotubes (CNT) have shown the virtue of exhibiting an improved mechanical response as well as a significant enhancement in damping capacity. This paves the way to the exploitation of CNT nanofillers not only for structural reinforcement purposes but also for advantageously shaping and optimizing the hysteretic response of light-weight polymer materials. In this work, the hysteretic response of CNT/polymer nanocomposites is described through a phenomenological 1D model directly derived from a full 3D nonlinear constitutive model. The 3D constitutive model is able to describe the nanocomposites damping response by accounting for the mean source of energy dissipation, namely, the interfacial CNT/matrix stick-slip phenomenon. The proposed 1D phenomenological model, mimicking the Bouc-Wen model of smooth plasticity, is employed for the identification of experimental force-displacement cycles obtained in bending mode on a set of thermoplastic polymer nanocomposites with increasing weight fractions of nanotubes. Experimental findings show significant enhancements (greater than 50 %) in both elastic and damping properties of the 3 wt% CNT nanocomposite with respect to the pristine polymer material. Such material behavior is fully captured through the 1D phenomenological model. The model parameters are optimized via the differential evolution algorithm over a series of hysteretic force-displacement cycles for increasing displacement amplitudes. The main model parameters are represented by the CNT volume fraction and the interfacial shear strength at the CNT/matrix interfaces. The possibility of modulating the hysteretic response of the nanocomposites through the material parameters enables a multi-scale design of the material properties by exploiting the 1D phenomenological model as a computational tool. Thus, the identified model parameters represent a feasible set of parameters to be introduced in the full 3D nonlinear constitutive model for a more accurate description of the mechanical and damping response of the CNT nanocomposites.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
