The effect of geometry on thermoelastic damping in micro-beam resonators is evaluated using an eigenvalue formulation and a customized finite element method. The vented clamped–clamped (CC) and clamped-free (CF) beams with square-shaped vents along their centerlines, are both analyzed by the finite element method. The quality factor and the resonant frequency are obtained as functions of variou...

We investigate the thermoelastic properties of close-packed phases of iron at pressures up to 400 GPa and temperature to 6000 K using a tight-binding total-energy method and the cell model of the vibrational partition function. The calculated properties are in good agreement with available static and shock-wave experimental measurements. The compressional behavior of a number of thermoelastic p...

An idealized model consisting of a thermal conductor and a thermal insulator separated by a thin layer of lubricating fluid is developed to investigate thermoelastic instability with fluid lubrication. The governing equations are solved for the critical speed. A new dimensionless parameter H0 is defined to predict the critical speed. Furthermore, the effects of various materials and the wavelen...

Besides permitting an accurate determination of the ferromagnetic-to-paramagnetic phase transition temperature and the characteristic temperatures for the beginning and end of the growth of martensite (austenite) phase at the expense of austenite (martensite) phase while cooling (heating), the results of an extensive ac susceptibility, sound velocity and internal friction investigation of the t...

In this paper, the basic governing equations for isotropic and homogeneous generalized thermoelastic half-space under hydrostatic initial stress are formulated in the context of the Green and Naghdi theory of types II and III. These governing equations are solved analytically to obtain the dimensional velocities in an xy-plane. It is shown that there exist three plane waves, namely a thermal wa...

We investigate a three-dimensional mathematical thermoelastic scattering problem from an open surface which will be referred to as a screen. Under the assumption of the local "nite energy of the uni"ed thermoelastic scattered "eld, we give a weak model on the appropriate Sobolev spaces and derive equivalent integral equations of the "rst kind for the jump of some trace operators on the open sur...

Hematopoietic stem cell (HSC) therapy can significantly lower instances of infection in chemotherapy patients by accelerating the recovery of white blood cells in the body. However, therapy requires that HSCs be stored at cryogenic temperatures to retain the cells' ability to proliferate. Currently, cells are stored in polymeric blood bags that are subject to fracture at the extremely low stora...

A constitutive model to describe macroscopic elastic and transformation behaviors of polycrystalline shape-memory alloys is formulated using an internal variable thermodynamic framework. In a departure from prior phenomenological models, the proposed model treats initiation, growth kinetics, and saturation of transformation distinctly, consistent with physics revealed by recent multi-scale expe...

The microstructure evolution (crystallite size and microstrain) as well as the residual stress of Cu thin films of various thicknesses (250 nm, 500 nm and 1 ìm) on passivated Si substrates during isochronal annealing was investigated by in-situ X-ray diffraction measurements in the temperature range between 25°C and 250°C. Before annealing, the thermoelastic behaviour was investigated excluding...

The Thermodynamics of linear irreversible processes is presented from a unified viewpoint. This provides a new and synthetic approach to the linear mechanics of deformation of solids, which includes as particular cases the classical theory of Elasticity, Thermoelasticity and Viscoelasticity. The first two sections constitute an introduction to the general concepts and principles of linear Therm...