This paper presents a preliminary study of the effects residual plastic strains have on Lamb wave velocities and time of flight measurements. The potential application of this research is non-destructive evaluation and structural health monitoring, particularly reconstructing plastic strain fields. The finite deformation of a semi-infinite plate due to residual plastic strain is used to accommodate the changes in plate thickness and elongation. The results show that the S₀ mode exhibits significant variations in group velocity in the highly dispersive regions, as much as a 2% increase in velocity with a 1% plastic strain. However, for time of flight measurements, the plate elongation had an order of magnitude effect rather than showing velocity changes. By exploiting time delay measurements, it may be possible to use wave speed measurements to determine plastic zones through Lamb-like waves.

Date Published: 3 April 2013
PDF: 9 pages
Proc. SPIE 8689, Behavior and Mechanics of Multifunctional Materials and Composites 2013, 86890A (3 April 2013); doi: 10.1117/12.2012072

Published in SPIE Proceedings Vol. 8689:
Behavior and Mechanics of Multifunctional Materials and Composites 2013
Nakhiah C. Goulbourne; Hani E. Naguib, Editor(s)