Low frequency longitudinal vibrations of an elastic bar made of a dynamic material and excited at one end

The dynamic materials, particularly the spatio-temporal composites, have been investigated in a number of recent publications. In the present paper, we examine a dynamic performance of an elastic bar with material parameters specified as an activated (moving at uniform velocity V) periodic pattern of segments occupied by ordinary materials 1 and 2, with density rho and stiffness k specified as (rho(1), k(1),) and (rho(2), k(2)), respectively. We particularly consider the low frequency wave propagation arising when the period d of the material pattern is much less than the wavelength lambda of a dynamic disturbance. The bar is excited at its left end by a signal g(t). (C) 2000 Academic Press.