Nonlinear acoustic scattering by a partially closed surface-breaking crack
2005 (English)In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 117, no 2, 592-600 p.Article in journal (Refereed) Published
A theoretical model describing the nonlinear scattering of acoustic waves by surface-breaking cracks with faces in partial contact is presented. The nonlinear properties of the crack are accounted for by suitable boundary conditions that are derived from micromechanical models of the dynamics of elastic rough surfaces in contact. Both linear and nonlinear responses of the crack are shown to be largest for a shear vertical wave incident on the surface containing the crack at an angle just above the critical angle for longitudinal waves. These findings question the fitness for the purpose of a conventional inspection method, which utilizes shear vertical waves at 45degrees of incidence to search for surface-breaking cracks in many engineering components. For angles of incidence proximal to the critical angle of longitudinal waves, the efficiency of the second harmonic's generation appears to be the highest. Thanks to the increased sensitivity to surface-breaking cracks, this configuration seems to offer a solution to the localization problem, a task that has eluded nonlinear techniques operating under other circumstances. Finally, this model suggests a simple interpretation of the highly localized nonlinear response of delaminations in composite materials.
Place, publisher, year, edition, pages
2005. Vol. 117, no 2, 592-600 p.
Composite materials, Composite micromechanics, Cracks, Elasticity, Mathematical models, Second harmonic generation, Localisation, Longitudnal waves, Surface-breaking cracks
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-7889DOI: 10.1121/1.1850052ISI: 000226986900013ScopusID: 2-s2.0-13544262435OAI: oai:DiVA.org:kth-7889DiVA: diva2:13052
QC 201009062008-01-142008-01-142010-12-17Bibliographically approved