This thesis work focuses on the design, fabrication and measurement of Gallium Arsenide (GaAs) nano-optomechanical disk resonators. These disks are both GHz frequency mechanical resonators, and high Q (> 10) optical whispering gallery mode resonators. By confining optical and mechanical energy on a sub-μm volume, they enable extremely large optomechanical coupling strengths (g0 >1 MHz). We pres...

The optical methods of Caustics, Photoelasticity and Isopachics for the evaluation of the stress intensity factors and the distribution of the principal stresses at a bi-material interface crack-tip, were proposed. The caustics, isochromatic and isopachic fringes are developed from the stress field which results from a stress function X(r, ). When the crack-tip, which is perpendicular to interf...

The disk in diametral compression has been investigated frequently on developing experimental techniques, such as photoelasticity and Moiré interferometry, for several decades. Theoretically, the compression as a concentrated force is more conducive to analyze but it is impossible to achieve such loading condition experimentally. The distributed compression on a finite area at rim is important ...

Shape memory alloy (SMA) wires can be embedded in a host material to alter the stiffness or modal response and provide vibration control. The interaction between the embedded SMA and the host material is critical to applications requiring transfer of loads or strain from the wire to the host. Although there has been a significant amount of research dedicated to characterizing and modeling the r...

The generation and the subsequent evolution of dynamic failure events in homogeneous layered materials that occur within microseconds after impact were investigated experimentally. Tested configurations include three-layer and two-layer, bonded Homalite specimens featuring different bonding strengths. High-speed photography and dynamic photoelasticity were utilized to study the nature, sequence...

This work presents a strategy for automatic analysis of photoelastic fringe patterns. The study is focused on the analysis of color type photoelastic fringes. By capturing and analyzing color fringes automatically, the difference between principal stresses of a sample are quantitatively determined. Among many techniques available in literature, the color photoelasticity is chosen as the basis f...

One of the prominent threats in the endeavor to develop next-generation space assets is the risk of space debris impact in earth’s orbit and micrometeoroid impact damage in deep space. To date, there is no study available which concentrates on the analysis of dynamic crack growth from hypervelocity impacts on such structures, resulting in their eventual catastrophic degradation. Experiments con...