Wave propagation in imperfectly bonded single walled carbon nanotube-polymer composites

Abstract

In this paper, wave propagation in single walled carbon nanotube(SWNT) embedded polymer composites is studied, taking into account imperfect bonding between the SWNT and the matrix. The imperfect bonding is in terms of SWNT pull-out from the matrix and also partial interfacial shear stress transfer. The nanocomposite is considered as a continuum axisymmetric cylinder and modeled using the wavelet based spectral finite element technique which is especially suited for wave propagation analysis in finite dimension structures. This numerical scheme involves the Daubechies scaling function approximation in time and one spatial (axial) dimension. The effects of the SWNT pull-out and the partial interfacial shear stress transfer are incorporated in the model as constraints which are imposed using the penalty matrix method. Numerical experiments are performed to study the axial wave propagation in SWNT-polymer composites due to a broadband impulse load with frequency content in the terahertz range. The effects of the pull-out and the partial interfacial shear stress transfer on the wave characteristics are studied primarily for the axial wave propagation. These effects are also observed for the radial wave propagation due to axial-radial coupling arising from the finiteness of the nanocompositestructure.