Evaluation of Effective Elastic Properties of Nitride NWs/Polymer Composite Materials Using Laser-Generated Surface Acoustic Waves

Abstract

In this paper we demonstrate a high potential of transient grating method to study the behavior of surface acoustic waves in nanowires-based composite structures. The investigation of dispersion curves is done by adjusting the calculated dispersion curves to the experimental results. The wave propagation is simulated using the explicit integral and asymptotic representations for laser-generated surface acoustic waves in layered anisotropic waveguides. The analysis of the behavior permits to determine all elastic constants and effective elastic moduli of constituent materials, which is important both for technological applications of these materials and for basic scientific studies of their physical properties.

Simulation of multiwavelength conditions in laser picosecond ultrasonics

“…The detection process 7,8,[11][12][13][14] corresponds therefore to a time domain spectroscopy, permitting a direct temporal monitoring of the propagation of phonons. [5][6][7][8][15][16][17] This picosecond ultrasonic approach has been found relevant for nano-materials and materials analysis, [18][19][20][21][22] for thin films and nanomultilayers characterization, 13,23,24 as well as detecting defects. [23][24][25][26][27] Key fundamental quantities can be extracted from ultrasonic measurements, such as thickness, sound velocity, attenuation coefficient, refractive index, elastic stiffness values, 28 and residual stress present in the material.…”

Special Issue on Laser Ultrasonics

“…Li et al [6] report the first application of nonlinear longitudinal acoustic pulses generated and detected by lasers for nondestructive diagnostics of material thermal aging. Glushkov et al [7] applied the transient grating method to study the behavior of surface acoustic waves in nanowire-based composite structures.…”

Study of Ultrasonic Guided Wave Propagation in Bone Composite Structures for Revealing Osteoporosis Diagnostic Indicators

“…The developed algorithms of the Green’s matrix allow simulating the wave propagation in arbitrarily anisotropic [ 27 , 28 ], functionally graded [ 29 ], or fluid-filled porous [ 30 ] layered structures. Therefore, this approach has already proved its effectiveness in solving various NDT and SHM problems, such as crack detection [ 31 ] and time-reversed defect location [ 32 ], the restoration of effective elastic moduli of fiber-reinforced composite plates [ 33 ], nitride nanowire-based composite materials [ 34 ], trapped mode resonance identification [ 35 , 36 ], and others. The main objective of the current studies is to leverage the benefits of the Green’s matrix-based approach in identifying concealed diagnostic indicators of developing osteoporosis from recorded surface signals.…”

“…The objective function of the inverse problem is expressed in terms of the Green’s matrix elements calculated at the points of GW dispersion curves selected from the recorded signals. Such an objective function, proposed in [ 34 , 42 ], reduces computational costs by 2–3 orders of magnitude compared to the conventional fitting of theoretically calculated and experimentally obtained dispersion curves.…”