Executive Summary : | Non-destructive evaluation (NDE) techniques are crucial in detecting cracks, characterizing materials, and preventing failures. Ultrasonic and thermal techniques are widely used, as they can be applied to various mediums, including conducting, insulating, magnetic, fluid, or solid. The thermomechanical phenomenon refers to the change in a material's thermal response due to applied mechanical loads, while vibrothermography involves the temperature changes due to induced vibrations. Developing a technique to predict the extent of damage in a material and its service life based on mechanical loading history and measured surface temperature would be valuable. This requires precise measurements in experiments, a thorough mathematical understanding of physics, and correlation between experiments and theory. This project focuses on mathematical modeling, with two objectives: providing a fully coupled parameterized thermomechanical model that explains the decreasing and increasing trends in temperatures in monotonic tensile or compressive loads, and quantifying the viscoelastic heat source in solids. The aim is to accurately identify the viscoelastic material properties in terms of frequency-dependent wave propagation parameters. |