High-Order Harmonic-Wave Generation of Ultrasonic Shear Waves

ABSTRACT

The high-order harmonic-wave generation of ultrasonic shear waves has not yet been studied. We generated high-order shear harmonic waves and studied them in terms of the nonlinear wave mechanism associated with strain waves. When the shear waves propagated through highly dissipative MnCu20Ni5Fe2, TiNi, and Sn-3Al specimens and were reflected from the far side of the specimen, we observed high-order harmonic waves up to the fifth- order of the fundamental frequency. The frequency f increases linearly with the harmonic-frequency order number n, f= α (n-1) + c. The order number coefficient α increases as Poisson' s ratio increases, suggesting that the generation of high-order harmonic waves can be attributed to anharmonic solids with large elastic deformability and high transparency for shear waves.