Nonlinear vibrations and viscoelasticity of a self-healing composite cantilever beam: Theory and experiments

Abstract

A self-healing beam was fabricated by using a microencapsulated healing agent (5E2N) with dispersed multi-walled carbon nanotubes (MWCNT). Grubbs’ catalyst was dispersed in the epoxy matrix reinforced with MWCNT. The self-healing material was specifically realized for this study modifying a formulation developed for satellites. Experiments were conducted on the self-healing beam in order to identify the viscoelastic material properties by vibration measurements. In addition, large-amplitude vibration experiments were carried out on the self-healing cantilever beam. A refined third-order shear deformation theory was developed to model the nonlinear vibrations of the cantilever beam. The model retains rotary inertia and in-plane and rotational nonlinearities in addition to traditional von Kármán nonlinear terms; it uses the mechanical properties experimentally identified. A satisfactory comparison of experimental and numerical results for nonlinear vibrations of the self-healing cantilever beam is presented for five different excitation levels.