This thesis is concerned with developing a two-dimensional (2D) ultrasound speckle tracking technique to quantify 2D axial and lateral strain fields for studying tissue dynamics. Knowledge of tissue displacement to infer strain characteristics is of major clinical importance. In part, this is due to the lack of simple and accurate non-invasive techniques to measure in vivo strain. The establish...

Integral expressions are determined for the elastic displacement and stress fields due to stationary or moving dislocation loops in finite samples. These general expressions are valid for anisotropic media as well. Specifically for the stress fields, a line integral representation is found, thus showing rigorously the independence of the stress fields with respect to the choice of slip planes. ...

Reconstruction and monitoring of displacement and strain fields is an important problem in engineering. We analyze the remote and nonobtrusive methods of strain measurement based on photogrammetry and Digital Image Correlation (DIC). The method is based on covering the photographed surface with a pattern of speckles and comparing the images taken before and after the deformation. In this study,...

Three spatial verification techniques are applied to three datasets. The datasets consist of a mixture of real and artificial forecasts, and corresponding observations, designed to aid in better understanding the effects of global (i.e., across the entire field) displacement and intensity errors. The three verification techniques, each based on well-known statistical methods, have little in com...

This paper examines the process of domain nucleation in ferroelectric perovskites at a free surface due to electrical fields applied through a charged tip above the surface. We use a real-space phase-field model to model the ferroelectric, and apply a boundary element-based numerical method that enables us to accurately account for the stray electric fields outside the ferroelectric and the int...

In this paper, a rectangular sandwich plate with a constrained layer and an electrorheological (ER) fluid core is investigated. The rectangular plate is covered an ER fluid core and a constraining layer to improve the stability of the system. The two outer layers of the sandwich structure are elastic. The viscoelastic materials express the middle layer behavior under electric field and small st...

Laser micro bending process of Ti6Al4V square bar are carried out using a 3D thermo-mechanical finite element analytical model (FEM). The transient temperature fields, displacement fields, stress fields and strain fields are obtained and analyzed. The results show that the bending angel during laser micro bending process is in good agreement with experimental measurements. The effects of proces...

The locomotion of articulated mechanical systems is often complex and unintuitive, even when considered with the aid of reduction principles from geometric mechanics. In this paper, we present two tools for gaining insights into the underlying principles of locomotion: connection vector fields and connection height functions. Connection vector fields illustrate the geometric structure of the re...

Moment tensors are indefinite tensors derived from seismic measurements and encode important information about earthquakes and surface displacement in the earth’s mantle. Appropriate analysis of scattered moment tensor fields requires multi-scale visualization to identify related seismic events. For this matter we provide a visualization of the tensor field at different scales based on multivar...