Influence of a strong low-frequency wave on the propagation of weak ultrasonic pulses in a rod resonator made of annealed polycrystalline copper

An experimental study of an influence a strong low-frequency wave on the propagation weak ultrasonic pulses in acoustic resonator made annealed polycrystalline copper has been carried out. The measurements were out with harmonic excitation at its first four longitudinal modes range from 2 to 15 kHz, frequency varied 65 400 kHz. analysis observed nonlinear effects was within framework polycrystal equation state obtained basis modified string model Granato-Lucke dislocation. values parameters dissipative and reactive nonlinearity dislocations are determined. Keywords: dislocation nonlinearity, copper, elastic waves.