Experimental study of the acoustic radiation strain in solids

This letter demonstrates that an eigenstrain is induced when a wave propagates through an elastic solid with quadratic nonlinearity. It is shown that this eigenstrain is intrinsic to the material, but the mean stress and the total mean strain are not. Instead, the mean stress and total means strain also depend on the boundary conditions, so care must be taken when using the static deformation to measure the acoustic nonlinearity parameter of a solid.

Section: Introductionmentioning

confidence: 99%

On the acoustic-radiation-induced strain and stress in elastic solids with quadratic nonlinearity (L)

Jacobs²,

Nagy³

2011

“…These results are similar to those recently published in the case of a solid. 16 A discussion about the pressure associated to the quasi-static part of the LF displacement is presented in Sec. III.…”

Section: B Experimental Resultsmentioning

confidence: 99%

Optical measurements of the self-demodulated displacement and its interpretation in terms of radiation pressure

Rénier

Barrière

Royer

2007

Self Cite

Using a sensitive optical interferometer, the low frequency displacement nonlinearly generated by an ultrasonic tone burst propagating in a liquid is studied. Close to the source, the low frequency displacement contains a quasi-static component, which is affected by diffraction effects farther from the transducer. The experimental setup provides quantitative results, which allow the determination of the nonlinearity parameter of the liquid with a good accuracy. Such measurements are carried out in water and ethanol. Finally, the pressure associated with the low frequency displacement is discussed. Introducing the temporal mean value of the displacement, as already done in lossless solids, the noncumulative part of this second order pressure is associated with the static part of the low frequency displacement. This interpretation leads to extend the definition of the Rayleigh radiation pressure usually introduced for a continuous plane wave radiated in a confined fluid.

“…Narasimha et al 7 conducted similar experiments in Al7175-T7351 alloy using a piezoelectric receiver and confirmed that the detected quasistatic pulse exhibited a flat-top shape and its amplitude was independent of the duration of the tone burst. In response, Cantrell 8 argued that the experimental results of Jacob et al 5 were the spurious consequence of uncorrected diffraction and attenuation effects in their measurements and suggested that the results of Narasimha et al 7 were a consequence of the characteristics of their receiving transducer.…”

Section: Introductionmentioning

confidence: 97%

“…Later on, additional experimental, computational, and analytical evidence emerged which shows that Yost and Cantrell's prediction of a right-triangular shape for the quasistatic displacement pulse cannot be independently verified. Jacob et al 5 conducted displacement measurements with an optical interferometer in fused silica and aluminum alloy samples and found that the quasistatic displacement pulse produced by a longitudinal acoustic wave exhibited a flat-top shape with amplitude independent of the duration of the tone burst, but proportional to the propagation distance. R enier et al 6 also found that the amplitude of the quasistatic displacement generated by an ultrasonic tone burst propagating through water was linearly proportional to the propagation distance.…”

Section: Introductionmentioning

confidence: 98%

Finite-size effects on the quasistatic displacement pulse in a solid specimen with quadratic nonlinearity

Nagy

Jacobs

2013

There is an unresolved debate in the scientific community about the shape of the quasistatic displacement pulse produced by nonlinear acoustic wave propagation in an elastic solid with quadratic nonlinearity. Early analytical and experimental studies suggested that the quasistatic pulse exhibits a right-triangular shape with the peak displacement of the leading edge being proportional to the length of the tone burst. In contrast, more recent theoretical, analytical, numerical, and experimental studies suggested that the quasistatic displacement pulse has a flat-top shape where the peak displacement is proportional to the propagation distance. This study presents rigorous mathematical analyses and numerical simulations of the quasistatic displacement pulse. In the case of semi-infinite solids, it is confirmed that the time-domain shape of the quasistatic pulse generated by a longitudinal plane wave is not a right-angle triangle. In the case of finite-size solids, the finite axial dimension of the specimen cannot simply be modeled with a linear reflection coefficient that neglects the nonlinear interaction between the combined incident and reflected fields. More profoundly, the quasistatic pulse generated by a transducer of finite aperture suffers more severe divergence than both the fundamental and second order harmonic pulses generated by the same transducer.