title: A two-dimensional pseudospectral model for time reversal and nonlinear elastic wave spectroscopy.
abstract: One way to characterize metallic materials in the presence of defects like dislocation networks is to measure their large dynamic nonlinear elastic response. In this numerical study, a new method combining the nonlinear elastic wave spectroscopy (NEWS) method with a time reversal (TR) process is proposed. This method, called NEWS-TR, uses nonlinear analysis as a pretreatment of time reversal and then consists of retrofocusing only nonlinear components on the defect position. A two-dimensional pseudospectral time domain algorithm is developed here to validate the NEWS-TR method as a potential technique for damage location. Hysteretic nonlinear behavior of the materials being studied is introduced using the Preisach-Mayergoyz model. Moreover, in order to extend this solver in two dimensions, the Kelvin notation is used to modify the elastic coefficient tensor. Simulations performed on a metallic sample show the feasibility and value of the NEWS-TR methodology for microdamage imaging. Retrofocusing quality depends on different parameters such as the filtering method used to keep only nonlinear components and the nonlinear effect measured. In harmonic generation, pulse inversion filtering seems to be a more appropriate filtering method than classical harmonic filtering for most defect positions, mainly because of its ability to filter all fundamental components.
authors.affiliation: Université François-Rabelais de Tours, LUSSI/CNRS FRE-2448, ENIVL rue de Chocolaterie, BP 3410, 41034 Blois Cedex, France. thomas.goursolle@univ-tours.fr
authors.forename: Thomas
authors.initials: T
authors.lastname: Goursolle
authors.forename: Samuel
authors.initials: S
authors.lastname: Callé
authors.forename: Serge
authors.initials: S
authors.lastname: Dos Santos
authors.forename: Olivier
authors.initials: O
authors.lastname: Bou Matar
mesh_terms: D000162:Acoustics; D000465:Algorithms; D003198:Computer Simulation; D004548:Elasticity; D005240:Feasibility Studies; D005583:Fourier Analysis; D008422:Materials Testing; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D009038:Motion; D017711:Nonlinear Dynamics; D011312:Pressure; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D008670:Metals