Goursolle T., Dos Santos S., Vander Meulen F., Haumesser L., Bou Matar O. «Ultrasonic parametric imaging of metallic samples using nonlinear acoustic measurements» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 120-128 (2005)

A calibrated contact phase modulation method [Vila M., Vander Meulen F., Dos Santos S., Haumesser L. and Bou Matar O. Contact phase modulation method for acoustic nonlinear parameter measurement in solid // Ultrasonics 2004, V.42(1-9) P.1061–1065] have been developed in the laboratory. Nonlinear effects coming from parametric interaction of an high and a low frequency waves can be measured as a phase modulation of the HF acoustic beam. According to the NDE needs, the nonlinearity in samples with interfaces, coming from aeronautic industries (two layers of aluminum bonded by an epoxy thin layer), must be measured. In order to meet these needs, our method has been extended. Thanks to additional measurements of reflection coefficient, calibration procedure, based on the selfreciprocity principle applied to the LF transducer, has led us to obtain absolute value of the LF particle velocity at the bonded interface. To know the feasibility of this extension, preliminary results of nonlinear parameter have been obtained in bi-layer samples considering the propagation inside the layer only. An image has been created by slope values of phase modulation obtained from 25 regularly spaced measurements.

Haumesser L., Bou Matar O., Dos Santos S., Vander Meulen F. «Transmission through and reflection from a fluid elastic layer: quasi-linear approximation» High intensity acoustic waves in modern technological and medical applications. Joint Workshop of Russian Acoustical Society (RAS) and French Acoustical Society (SFA). Special Session of the XVI Meeting of Russian Acoustical Society (Moscow. 14–18 November 2005), с. 75-80 (2005)

Second Harmonic Generation (SHG) in a three fluid layer system, is investigated in the quasi-linear approximation. Considering an initially sinusoidal plane wave normally incident upon the central layer, the pressure radiated from the later is evaluated at double frequency. Analytical expressions for the reflected and transmitted pressure fields are derived from series of reflected and refracted waves. Results are discussed as a function of the geometrical and material characteristics of the system.