Thoughts on Thermomechanics

Admitting Spontaneous Violations of the Second Law in Continuum Thermomechanics

We survey new extensions of continuum mechanics incorporating spontaneous violations of the Second Law (SL), which involve the viscous flow and heat conduction. First, following an account of the Fluctuation Theorem (FT) of statistical mechanics that generalizes the SL, the irreversible entropy is shown to evolve as a submartingale. Next, a stochastic thermomechanics is formulated consistent wi...

Analysis of Structures and Thermomechanics for Surveys and Research

Frame-Free Continuum Thermomechanics

The principle of material frame-indifference is a fundamental concept in classical physics. In 1972 Walter Noll showed that one can formulate constitutive laws without using any external frames of reference. Constitutive laws formulated in this way vacuously satisfy the principle of material frame-indifference. This thesis describes the basic concepts involved in formulating frame-free continuu...

A Thermomechanical Theory of Solid-Fluid Mixtures

Motivated by Rivlin's ideas on the thermomechanics of continuous media, we state the second law of thermodynamics in two parts and apply it to study the behavior of a mixture of an elastic solid and a viscous fluid.

Probing Thermomechanics at the Nanoscale: Impulsively Excited Pseudosurface Acoustic Waves in Hypersonic Phononic Crystals

High-frequency surface acoustic waves can be generated by ultrafast laser excitation of nanoscale patterned surfaces. Here we study this phenomenon in the hypersonic frequency limit. By modeling the thermomechanics from first-principles, we calculate the system's initial heat-driven impulsive response and follow its time evolution. A scheme is introduced to quantitatively access frequencies and...