TRANSIENT ELASTIC-WAVES IN FINITE LAYERED MEDIA - ONE-DIMENSIONAL ANALYSIS

Transient wayes induced by a trapezoidal pulse are studied for a class of finite periodic elastic media using a modal method. For weakly coupled systems, approximate relations are derived for peak compressive stress and group velocity. Peak stress behind the wave front is proportional to transmissibility: the product of frequency interval of the first propagating zone and time interval of the equivalent rectangular pulse which conserves impulse. Along the stack, stress is attenuated or magnified exponentially depending on transmissibility. Finally, the effect on peak stress of disorder in the stack is investigated.