Wave propagation in nonlocal microstretch solid

This work investigates the possibility of plane waves propagating through an isotropic non local microstretch solid of infinite extent. Five basic waves consisting of three longitudinal waves and two transverse waves may travel with distinct speeds. All these waves are frequency dependent and hence, dispersive in nature. The nonlocal parameter is present in the analytical expressions of phase speeds of all the existing waves. A comparison is also made to study the variation of phase speeds against nonlocal parameter. It is found that dispersion curves possess five branches: (a) a longitudinal acoustic branch, (b) a transverse acoustic branch, and (c) three optic branches. The reflection phenomenon of plane longitudinal wave incident at a stress free boundary surface of a nonlocal microstretch elastic half-space is studied and the formulae for various reflection coefficients are obtained. The variation of these reflection coefficients with angle of incidence has also been depicted graphically for a specific model. (C) 2016 Elsevier Inc. All rights reserved.