Measurement of temperature dependent shear modulus using frequency dependent SAWs ToF delay in laser-induced...

Area of Science:

• Materials Science
• Acoustics
• Thermodynamics

Background:

• Surface acoustic waves (SAWs) exhibit frequency-dependent phase velocity in inhomogeneous media.
• Local and dynamic heating creates temperature gradients affecting material elastic properties.

Purpose of the Study:

• To develop a method for measuring temperature-dependent shear modulus using SAW time-of-flight.
• To investigate the dispersion of SAWs in materials with spatially varying temperature fields.

Main Methods:

• Generation of broad-band SAWs using pulsed laser heating.
• Time-frequency analysis and differential techniques to measure frequency-dependent time-of-flight variations.
• Solving an inverse problem using differential evolution to extract material properties.

Main Results:

• Successfully measured frequency-dependent time-of-flight variations of SAWs.
• Evaluated temperature-dependent shear modulus and surface temperature distribution.
• Obtained shear modulus for Ti-6Al-4V alloy consistent with literature values.

Conclusions:

• The proposed method accurately determines temperature-dependent shear modulus.
• SAW dispersion analysis is effective for characterizing materials under dynamic thermal loads.
• This technique offers a non-contact method for evaluating thermomechanical properties.