The need for micro-mechanics based understanding leading to meso-scale models for understanding relation between microstructure and ultrasonic higher harmonic generation is emphasized. Three important aspects of material behavior, namely tension-compression asymmetry, shear-normal coupling and deformation induced anisotropy that are relevant to ultrasonic higher harmonic generation are identified. Of these, the role of tension-compression asymmetry in micro-scale material behavior on ultrasonic higher harmonic generation is investigated in detail. It is found that the tension-compression asymmetry is directly related to ultrasonic even harmonic generation and an energy based measure is defined to quantify the asymmetry. Using this energy based measure, a homogenization based approach is employed to quantify the acoustic nonlinearity in material with micro-voids and the findings are discussed.

Date Published: 23 March 2015
PDF: 11 pages
Proc. SPIE 9438, Health Monitoring of Structural and Biological Systems 2015, 94380R (23 March 2015); doi: 10.1117/12.2179894

Published in SPIE Proceedings Vol. 9438:
Health Monitoring of Structural and Biological Systems 2015
Tribikram Kundu, Editor(s)