Mechanical Engineering Commons^™

Novel Patterning Techniques To Improve Digital Image Correlation In Challenging Environments, Weston Craig

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A camera-based measurement technique called digital image correlation (DIC) is beneficial to measure displacement and strain in challenging environments (such as post-irradiation evaluation and high temperature environments) due to its non-contacting nature and ability to obtain measurements over multiple length scales. This technique requires a surface pattern which influences the measurement resolution and accuracy of the measurements. This thesis explores two novel patterning techniques to allow the use of DIC in more challenging environments:

The first is to determine if a pattern created from printed text can be used as a pattern in DIC. Native patterns are patterns already present …

High-Magnification Digital Image Correlation Techniques For Aged Nuclear Fuel Cladding Testing, Robert Scott Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nuclear fuel cladding in light water reactors, often made of zirconium alloys, is naturally made more brittle by exposure to the water coolant during normal reactor operation. However, this embrittlement by zirconium hydrides changes the mechanical behavior of the cladding material, affecting how it will deform and what may cause it to fail. Because the cladding already has different properties in different material directions, mechanical testing also needs to be direction specific. In addition, to understand the effects that these microscale hydride features have, measurements of deforming cladding need to be at a microscale. This dissertation describes several high-magnification innovations …

A High-Magnification Uv Lens For High-Temperature Optical Strain Measurements, Robert S. Hansen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Digital Image Correlation (DIC) is an experimental method used to produce full-field strain maps of specimens undergoing deformation. In this measurement, images of a specimen are taken before and after mechanical and thermal loading, then software is used to track deformation and compute strains. DIC has been recently adapted for high-temperature tests by using ultraviolet (UV) range cameras, lenses, and filters to produce the images.

Application of DIC to small length scales and at high temperatures can be performed with proper equipment. However, for these measurements, there is no commercially available high-magnification lens that will allow images to be taken …

Thermo-Mechanical Reliability Of Micro-Interconnects In Three-Dimensional Integrated Circuits: Modeling And Simulation, Omar Rodriguez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three-dimensional integrated circuits (3D ICs) have been designed with the purpose of achieving higher communication speed by reducing the interconnect length between integrated circuits, and integrating heterogeneous functions into one single package, among other advantages. As a growing, new technology, researchers are still studying the different parameters that impact the overall lifetime of such packages in order to ensure the customer receives reliable end products. This study focused on the effect of four design parameters on the lifetime of the interconnects and, in particular, solder balls and through-silicon vias (TSVs). These parameters included TSV pitch, TSV diameter, underfill stiffness and …